docs: add comprehensive developer guide (mdBook)

Add a browsable mdBook developer guide under docs/dev-guide/ covering the full PiCloud v1.1.9 surface for developers building on the platform: - Guide: introduction, 10-minute quickstart, core concepts, writing scripts - Tutorials: 5 end-to-end example apps (URL shortener, webhook receiver, TODO API with auth, scheduled report, file-upload service) + feature matrix - SDK reference: kv/docs/files, pubsub/queue, http, email, users, secrets, invoke/retry/dead_letters, stdlib, ctx & events - HTTP API reference: every /api/v1 endpoint, auth, and capability - CLI reference: the `pic` client + the server admin recovery command - Config: every PICLOUD_* env var, capabilities & roles - Deployment: Docker Compose, bare binary, Caddy/TLS, production checklist - Operations: security, best practices, troubleshooting Every example was built and run against a live instance; SDK signatures, endpoint paths, and env vars were verified against source. Build the site with `mdbook serve docs/dev-guide`. A pointer is added to README. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-20 13:54:23 +02:00
44 changed files with 3989 additions and 0 deletions
--- a/README.md
+++ b/README.md
@@ -28,6 +28,20 @@ cargo check --workspace
 cargo run -p picloud
 ```

+## Documentation
+
+The **Developer Guide** in [`docs/dev-guide/`](docs/dev-guide/) is the place to start using PiCloud —
+quickstart, core concepts, full SDK / HTTP-API / CLI reference, five end-to-end example apps, and
+deployment + security guides. Build and read it locally with [mdBook](https://rust-lang.github.io/mdBook/):
+
+```sh
+cargo install mdbook          # once
+mdbook serve docs/dev-guide   # then open http://localhost:3000
+```
+
+Architecture and contributor notes live alongside it in [`docs/`](docs/) (`sdk-shape.md`,
+`stdlib-reference.md`, `versioning.md`, …) and in [`serverless_cloud_blueprint.md`](serverless_cloud_blueprint.md).
+
 ## Repository Layout

 ```
--- a/docs/dev-guide/.gitignore
+++ b/docs/dev-guide/.gitignore
@@ -0,0 +1,2 @@
+# mdBook build output — generated by `mdbook build`, not source.
+book/
--- a/docs/dev-guide/book.toml
+++ b/docs/dev-guide/book.toml
@@ -0,0 +1,23 @@
+[book]
+title = "PiCloud Developer Guide"
+description = "How to build and run serverless apps on PiCloud — write Rhai scripts, get HTTP endpoints."
+authors = ["PiCloud"]
+language = "en"
+src = "src"
+
+[output.html]
+default-theme = "navy"
+preferred-dark-theme = "navy"
+smart-punctuation = true
+git-repository-url = ""
+edit-url-template = ""
+
+[output.html.fold]
+enable = true
+level = 1
+
+[output.html.search]
+enable = true
+limit-results = 30
+use-boolean-and = true
+boost-title = 2
--- a/docs/dev-guide/src/SUMMARY.md
+++ b/docs/dev-guide/src/SUMMARY.md
@@ -0,0 +1,66 @@
+# Summary
+
+[Introduction](introduction.md)
+
+# Guide
+
+- [Quickstart](guide/quickstart.md)
+- [Core concepts](guide/concepts.md)
+- [Writing scripts](guide/writing-scripts.md)
+
+# Tutorials
+
+- [Overview & feature matrix](examples/index.md)
+- [URL shortener](examples/url-shortener.md)
+- [Webhook receiver](examples/webhook-receiver.md)
+- [TODO API with auth](examples/todo-api.md)
+- [Scheduled report](examples/scheduled-report.md)
+- [File-upload service](examples/file-upload.md)
+
+# SDK reference
+
+- [Overview](reference/sdk/overview.md)
+- [The execution context & events](reference/sdk/ctx-and-events.md)
+- [Storage: kv, docs, files](reference/sdk/storage.md)
+- [Messaging: pubsub, queue](reference/sdk/messaging.md)
+- [Outbound HTTP](reference/sdk/http.md)
+- [Email](reference/sdk/email.md)
+- [Users & auth](reference/sdk/users.md)
+- [Secrets](reference/sdk/secrets.md)
+- [Composition: invoke, retry, dead_letters](reference/sdk/composition.md)
+- [Standard library](reference/sdk/stdlib.md)
+
+# HTTP API reference
+
+- [Overview & authentication](reference/rest-api/overview.md)
+- [Apps & domains](reference/rest-api/apps.md)
+- [Scripts, routes & logs](reference/rest-api/scripts.md)
+- [Triggers](reference/rest-api/triggers.md)
+- [Topics & realtime](reference/rest-api/topics.md)
+- [Secrets, KV & files](reference/rest-api/data-admin.md)
+- [Queues & dead-letters](reference/rest-api/queues.md)
+- [App users](reference/rest-api/app-users.md)
+- [Members, admins & API keys](reference/rest-api/access.md)
+
+# CLI reference
+
+- [The `pic` CLI](reference/cli/pic.md)
+- [Server admin commands](reference/cli/server-admin.md)
+
+# Configuration
+
+- [Environment variables](reference/config/env-vars.md)
+- [Capabilities & roles](reference/config/capabilities.md)
+
+# Deployment
+
+- [Docker Compose](deploy/docker-compose.md)
+- [Running the bare binary](deploy/bare-binary.md)
+- [Caddy & TLS](deploy/caddy-tls.md)
+- [Production checklist](deploy/production-checklist.md)
+
+# Operations
+
+- [Security](operations/security.md)
+- [Best practices](operations/best-practices.md)
+- [Troubleshooting](operations/troubleshooting.md)
--- a/docs/dev-guide/src/deploy/bare-binary.md
+++ b/docs/dev-guide/src/deploy/bare-binary.md
@@ -0,0 +1,82 @@
+# Running the bare binary
+
+You can run `picloud` directly against a Postgres you provide — handy for development against the
+source, debugging, or a setup where you manage the database and proxy yourself.
+
+## Prerequisites
+
+- **Rust 1.92+** (pinned in `rust-toolchain.toml`).
+- **PostgreSQL 15+** reachable via `DATABASE_URL`. The easiest Postgres is the compose one:
+  `docker compose up -d postgres` (publishes `127.0.0.1:15432`).
+
+## Build and run
+
+```sh
+cargo build -p picloud            # or --release
+
+export DATABASE_URL="postgres://picloud:picloud@localhost:15432/picloud"
+export PICLOUD_BIND="0.0.0.0:18080"        # 8080 is a common conflict — pick a free port
+export PICLOUD_PUBLIC_BASE_URL="http://localhost:18080"
+# Dev master key (local only):
+export PICLOUD_DEV_MODE=true
+export PICLOUD_DEV_INSECURE_KEY="i-understand-this-is-insecure"
+# Bootstrap admin (only needed on a fresh DB):
+export PICLOUD_ADMIN_USERNAME="admin"
+export PICLOUD_ADMIN_PASSWORD="change-me"
+
+cargo run -p picloud
+```
+
+It applies migrations, seeds the bootstrap admin + `hello` example on a fresh DB, and listens on
+`PICLOUD_BIND`. Verify:
+
+```sh
+curl localhost:18080/healthz   # ok
+curl localhost:18080/version
+```
+
+**Minimal requirements:** just `DATABASE_URL` and a master key — either `PICLOUD_SECRET_KEY` (base64 of
+32 bytes) *or* the dev-mode pair above. `PICLOUD_DEV_MODE=true` **alone** aborts at startup; you must
+also set `PICLOUD_DEV_INSECURE_KEY`. The bootstrap admin vars are only consulted when `admin_users` is
+empty. Full list: [Environment variables](../reference/config/env-vars.md).
+
+## A real master key
+
+For anything beyond throwaway local use, generate a proper key instead of dev mode:
+
+```sh
+export PICLOUD_SECRET_KEY="$(head -c 32 /dev/urandom | base64)"
+# (then DON'T set PICLOUD_DEV_MODE / PICLOUD_DEV_INSECURE_KEY)
+```
+
+Keep this stable — see the [rotation caveat](../operations/security.md#secrets-and-the-master-key).
+
+## Running the dashboard in dev
+
+The SvelteKit dashboard has its own Vite dev server with hot reload:
+
+```sh
+cd dashboard
+npm install
+npm run dev        # serves on http://localhost:5173
+```
+
+> **Port footgun.** Vite proxies `/api` and `/healthz` to **`http://127.0.0.1:18080`** by default — not
+> 8080. So either run `picloud` on `18080` (as above), or point Vite elsewhere:
+> `PICLOUD_API=http://localhost:9000 npm run dev`. The dashboard dev port is `5173`
+> (`PICLOUD_DASHBOARD_PORT` to change).
+
+For a production-style static build, `npm run build` emits a static SPA (served by Caddy in the
+compose stack). You usually don't need the Vite dev server unless you're hacking on the dashboard
+itself — the [compose stack](docker-compose.md) already serves a built dashboard at `/admin`.
+
+## The `pic` CLI
+
+Build it alongside: `cargo build -p picloud-cli` → `target/debug/pic`. Point it at your instance:
+
+```sh
+printf "$PICLOUD_ADMIN_PASSWORD" | pic login --url http://localhost:18080 --username admin --password-stdin
+pic whoami
+```
+
+See the [CLI reference](../reference/cli/pic.md).
--- a/docs/dev-guide/src/deploy/caddy-tls.md
+++ b/docs/dev-guide/src/deploy/caddy-tls.md
@@ -0,0 +1,71 @@
+# Caddy & TLS
+
+Caddy is the single entry point in front of PiCloud. The same topology serves dev and production — only
+the upstream targets and TLS settings change.
+
+## Routing topology
+
+Caddy routes by path prefix (from `caddy/Caddyfile`):
+
+| Path | Goes to |
+|---|---|
+| `/healthz`, `/version` | picloud (liveness + version) |
+| `/api/v1/admin/*` | picloud (control plane) |
+| `/api/v1/execute/*` | picloud (execute-by-id) |
+| `/api/*` (anything else) | **404** — reserved for future API versions |
+| `/admin/*` | the dashboard SPA |
+| **everything else** | picloud's **user-route matcher** — your scripts' routes |
+
+That final catch-all is what makes arbitrary user paths like `/hello` or `/r/abc123` work: Caddy
+forwards them to picloud, which matches them against the [route table](../guide/concepts.md#routes-and-domains)
+(or returns a JSON `404`). This is why your routes can't use the reserved prefixes `/api/`, `/admin/`,
+`/healthz`, `/version` — Caddy would never forward them to the matcher.
+
+## Security headers & body limit
+
+The Caddyfile adds defense-in-depth headers and a hard body cap:
+
+- `X-Content-Type-Options: nosniff` and `Referrer-Policy: no-referrer` on **every** response.
+- A strict CSP, `X-Frame-Options: DENY`, `Cache-Control: no-store`, and a locked-down
+  `Permissions-Policy` on the **dashboard** and **admin API**.
+- A **12 MB request-body ceiling** at the proxy (just above the orchestrator's 10 MiB user-route read).
+- **User-route responses get no CSP on purpose** — your scripts own their own response headers. The
+  `?` (set-if-missing) operator means a script's own header wins over the default.
+
+## Production: HTTPS with Let's Encrypt
+
+Layer the production overlay, which swaps in `caddy/Caddyfile.prod` and exposes 80/443:
+
+```sh
+export PICLOUD_DOMAIN="picloud.example.com"
+export PICLOUD_ADMIN_EMAIL="you@example.com"
+export POSTGRES_PASSWORD="$(head -c 24 /dev/urandom | base64)"
+export PICLOUD_SECRET_KEY="$(head -c 32 /dev/urandom | base64)"
+export PICLOUD_ADMIN_USERNAME="admin"
+export PICLOUD_ADMIN_PASSWORD="…"
+export PICLOUD_PUBLIC_BASE_URL="https://picloud.example.com"
+
+docker compose -f docker-compose.yml -f docker-compose.prod.yml up -d --build
+```
+
+Caddy obtains and renews a certificate for `PICLOUD_DOMAIN` automatically (HTTP/TLS-ALPN challenge — the
+host must be reachable on 80/443 from the internet). The prod overlay also:
+
+- **removes the published Postgres port** (DB reachable only inside the compose network);
+- adds **HSTS** to every response (on top of the dev headers);
+- sets `restart: unless-stopped` on all services.
+
+The prod Caddyfile reads `PICLOUD_DOMAIN` and `PICLOUD_ADMIN_EMAIL` from the environment, so set them
+before `up`.
+
+## Custom domains for your apps
+
+PiCloud's app [domains](../reference/rest-api/apps.md#domains) are matched by picloud *after* Caddy
+forwards the request — they're independent of Caddy's own host config. For multi-tenant setups
+(`{tenant}.example.com`), point a wildcard DNS record + Caddy cert at the box, then let each app claim
+its host pattern. The most-specific app claim wins; unclaimed hosts get a `404 no app claims host`.
+
+## Adding a future API version
+
+When `/api/v2/...` ships, add a `handle /api/v2/admin/* { … }` block before the catch-all `/api/*`
+404, mirroring the v1 block. The v1 routes stay live through the deprecation window.
--- a/docs/dev-guide/src/deploy/docker-compose.md
+++ b/docs/dev-guide/src/deploy/docker-compose.md
@@ -0,0 +1,88 @@
+# Deploy with Docker Compose
+
+The default stack runs the whole system — Postgres, the `picloud` binary, the dashboard, and a Caddy
+reverse proxy — behind one port. It's the recommended way to run PiCloud for local dev and single-node
+production.
+
+## The stack
+
+`docker-compose.yml` defines four services:
+
+| Service | Role | Exposed |
+|---|---|---|
+| `postgres` | the database | host `127.0.0.1:15432` (dev convenience; removed in prod) |
+| `picloud` | the all-in-one binary | internal `:8080` only |
+| `dashboard` | the SvelteKit SPA | internal `:80` only |
+| `caddy` | reverse proxy / entry point | host `:${PICLOUD_HOST_PORT:-8000}` → `:80` |
+
+Only Caddy is published. It routes by path: `/healthz`, `/version`, `/api/v1/admin/*`,
+`/api/v1/execute/*` → picloud; `/admin/*` → dashboard; everything else → picloud's user-route matcher.
+See [Caddy & TLS](caddy-tls.md).
+
+## First run
+
+```sh
+cp .env.example .env
+# edit .env — at minimum set PICLOUD_ADMIN_USERNAME and PICLOUD_ADMIN_PASSWORD
+docker compose up -d --build
+```
+
+On first boot picloud runs migrations, seeds the bootstrap admin from `PICLOUD_ADMIN_USERNAME` /
+`PICLOUD_ADMIN_PASSWORD` (as instance `owner`), and seeds a `hello` example into the `default` app.
+Then:
+
+```sh
+curl localhost:8000/healthz      # ok
+curl localhost:8000/version      # {"product":"1.1.9","sdk":"1.10",...}
+curl localhost:8000/hello        # {"message":"Hello, world!"}
+open  http://localhost:8000/admin
+```
+
+> **The compose file makes `PICLOUD_ADMIN_USERNAME`/`PICLOUD_ADMIN_PASSWORD` mandatory** (it uses
+> `${VAR:?…}`), so `docker compose up` errors out if they're unset — even though the binary itself only
+> needs them on a fresh DB. This is intentional: it stops you from shipping with no admin.
+
+## The dev `.env`
+
+The shipped `.env.example` runs in **dev mode**: it sets `PICLOUD_DEV_MODE=true`, and
+`docker-compose.override.yml` (gitignored, applied automatically) supplies
+`PICLOUD_DEV_INSECURE_KEY=i-understand-this-is-insecure` so the stack boots with a deterministic,
+world-known master key. **This is for local dev only** — at-rest encryption is meaningless with a public
+key. For anything real, set a true `PICLOUD_SECRET_KEY` and don't use dev mode (see
+[Production checklist](production-checklist.md)).
+
+Key `.env` settings:
+
+| Variable | Purpose |
+|---|---|
+| `PICLOUD_HOST_PORT` | host port Caddy listens on (default 8000) |
+| `POSTGRES_PASSWORD` | DB password — **change for prod** |
+| `PICLOUD_POSTGRES_HOST_PORT` | host port for Postgres (dev only; default 15432) |
+| `PICLOUD_PUBLIC_BASE_URL` | the URL users actually reach (rendered in the dashboard, `/version`) |
+| `PICLOUD_ADMIN_USERNAME` / `PICLOUD_ADMIN_PASSWORD` | bootstrap admin |
+| `RUST_LOG` | log verbosity |
+
+The full variable list is in [Environment variables](../reference/config/env-vars.md).
+
+## Everyday operations
+
+```sh
+docker compose ps                      # service health
+docker compose logs -f picloud         # tail the server
+docker compose exec postgres psql -U picloud picloud   # poke the DB (dev)
+docker compose down                    # stop (keeps data)
+docker compose down -v                 # stop and WIPE Postgres + Caddy volumes
+docker compose up -d --build           # rebuild after a code change
+```
+
+Data lives in the `postgres_data` volume (and, for `files`, inside the picloud container's
+`PICLOUD_FILES_ROOT` — mount a volume there if you use `files` in production). Recover a locked-out
+admin with [`picloud admin reset-password`](../reference/cli/server-admin.md):
+
+```sh
+docker compose exec picloud picloud admin reset-password admin
+```
+
+For production (real domain, HTTPS, no published DB port), layer the prod overlay — see
+[Caddy & TLS](caddy-tls.md) and the [Production checklist](production-checklist.md). To run the binary
+without Docker, see [Running the bare binary](bare-binary.md).
--- a/docs/dev-guide/src/deploy/production-checklist.md
+++ b/docs/dev-guide/src/deploy/production-checklist.md
@@ -0,0 +1,77 @@
+# Production checklist
+
+Before exposing PiCloud to real traffic, walk this list. Items marked **critical** can compromise the
+whole instance if skipped.
+
+## Secrets & keys
+
+- [ ] **Critical: set a real `PICLOUD_SECRET_KEY`** (base64 of 32 random bytes) and **do not** use
+      `PICLOUD_DEV_MODE` / `PICLOUD_DEV_INSECURE_KEY`. The dev key is world-known — every `secrets`
+      value and realtime key would be "encrypted" with a public value.
+      ```sh
+      export PICLOUD_SECRET_KEY="$(head -c 32 /dev/urandom | base64)"
+      ```
+- [ ] **Store the key in a secret manager**, not in a committed `.env`. If you lose it, every encrypted
+      secret becomes undecryptable. **Rotating it orphans existing ciphertext** — there's no auto
+      re-encryption; rotate deliberately and re-`set` your secrets. See
+      [Security → master key](../operations/security.md#secrets-and-the-master-key).
+- [ ] **Critical: change `POSTGRES_PASSWORD`** from the dev default.
+- [ ] Prefer `PICLOUD_ADMIN_PASSWORD_HASH` (a pre-computed Argon2id PHC string) over a raw
+      `PICLOUD_ADMIN_PASSWORD`, so the plaintext never lands in env/compose.
+
+## Network & TLS
+
+- [ ] Deploy with the **prod overlay** for automatic HTTPS:
+      `docker compose -f docker-compose.yml -f docker-compose.prod.yml up -d`. See
+      [Caddy & TLS](caddy-tls.md).
+- [ ] Set `PICLOUD_DOMAIN`, `PICLOUD_ADMIN_EMAIL`, and `PICLOUD_PUBLIC_BASE_URL` (to your `https://`
+      origin).
+- [ ] Confirm **Postgres is not publicly exposed** (the prod overlay removes the host port mapping).
+- [ ] **Critical: do not set `PICLOUD_HTTP_ALLOW_PRIVATE`** — leaving the SSRF guard on stops scripts
+      probing your internal network via `http::*`.
+
+## Data & durability
+
+- [ ] Back up the **Postgres volume** *and* the **`files` blob storage** (`PICLOUD_FILES_ROOT`)
+      together — file metadata and bytes live in different places.
+- [ ] Mount a persistent volume for `PICLOUD_FILES_ROOT` if you use the `files` SDK (otherwise blobs
+      live inside the container and vanish on `down`).
+- [ ] Set retention to taste: `PICLOUD_DEAD_LETTER_RETENTION_DAYS`,
+      `PICLOUD_ABANDONED_EXECUTIONS_RETENTION_DAYS`.
+
+## Capacity & limits
+
+- [ ] Tune `PICLOUD_MAX_CONCURRENT_EXECUTIONS` and `PICLOUD_DB_MAX_CONNECTIONS` together to your
+      hardware. Past the concurrency cap, data-plane requests get `503 Retry-After: 1` — make sure
+      clients handle it.
+- [ ] Review the [sandbox ceilings](../reference/config/env-vars.md#sandbox-ceilings)
+      (`PICLOUD_SANDBOX_MAX_*`) — the defaults are conservative; raise only deliberately.
+- [ ] Review the [size caps](../reference/config/env-vars.md#data-plane-size-caps) for `kv`, `docs`,
+      `queue`, `pubsub`, `files`.
+
+## Email
+
+- [ ] Configure `PICLOUD_SMTP_*` if any script (or the `users` flows) sends mail — otherwise
+      `email::send` throws `NotConfigured` (the dev sink does **not** exist outside dev mode).
+
+## Application hygiene
+
+- [ ] Remember the [data plane is public](../operations/security.md#the-data-plane-is-public): every
+      route runs with full app authority. Audit each public route — does it expose data it shouldn't?
+- [ ] Put auth (`users::verify`, a shared secret, etc.) on every route that needs it; the platform
+      won't.
+- [ ] Scope **API keys** narrowly (least-privilege scopes, bind to one app, set `expires_at`).
+- [ ] Use **per-app members** with the lowest role that works (`viewer`/`editor`/`app_admin`) rather
+      than handing out instance `admin`.
+- [ ] Prefer **`async` dispatch** for slow or fire-and-forget work so the request path stays fast.
+
+## Observability
+
+- [ ] Set `RUST_LOG` sensibly (`info,picloud=info` in prod).
+- [ ] Alert on the unresolved **dead-letter** count (`pic dead-letters count --app …` /
+      `GET …/dead_letters/count`).
+- [ ] Remember that `log::` output is captured for **async/triggered** runs, not synchronous HTTP runs
+      ([why](../guide/writing-scripts.md#logging)).
+
+When all boxes are checked, you're running on a real key, behind HTTPS, with a private database,
+backed up, and with auth on the routes that need it.
--- a/docs/dev-guide/src/examples/file-upload.md
+++ b/docs/dev-guide/src/examples/file-upload.md
@@ -0,0 +1,126 @@
+# Tutorial: File-upload service
+
+Accept file uploads, store them as blobs, announce each upload on a [pubsub](../reference/sdk/messaging.md#pubsub)
+topic, and stream those announcements to a browser over [SSE](../reference/rest-api/topics.md). This
+exercises [`files`](../reference/sdk/storage.md#files), [`base64`](../reference/sdk/stdlib.md#base64),
+`pubsub::publish_durable`, and a realtime topic — and surfaces two real platform constraints about
+binary I/O.
+
+> **Two things to know up front (both verified below):**
+> 1. **There are no raw request bytes** — `ctx.request.body` is JSON. So uploads arrive as
+>    **base64 inside a JSON field**, which the script decodes.
+> 2. **Script responses are always JSON** — a script *cannot* stream raw bytes back through its
+>    response (a blob body serializes to a hex JSON string). So downloads either return **base64 in
+>    JSON** (shown here) or use the **admin files endpoint**, which serves true raw bytes.
+
+## 1. App, host, topic
+
+```sh
+pic apps create vault --name "File Vault"
+pic apps domains add vault vault.localhost
+# register a public, externally-subscribable topic (note: --app is a flag, name is positional)
+pic topics create --app vault file.uploaded --external --auth-mode public
+```
+
+## 2. Upload
+
+`upload.rhai` — decode the base64 body, store the blob, publish:
+
+```rhai
+let b = ctx.request.body;
+if type_of(b) != "map" || !b.contains("b64") {
+    return #{ statusCode: 400, body: #{ error: "expected JSON { name, content_type, b64 }" } };
+}
+let bytes = base64::decode(b.b64);                              // Blob
+let id = files::collection("uploads").create(#{
+    name: b.name, content_type: b.content_type, data: bytes
+});
+pubsub::publish_durable("file.uploaded", #{ id: id, name: b.name, size: bytes.len() });
+return #{ statusCode: 201, body: #{ id: id, size: bytes.len() } };
+```
+
+## 3. Download (base64 in JSON)
+
+`download.rhai`:
+
+```rhai
+let id = ctx.request.params.id;
+let meta = files::collection("uploads").head(id);              // metadata, () if missing
+if meta == () { return #{ statusCode: 404, body: #{ error: "not found" } }; }
+let bytes = files::collection("uploads").get(id);              // the Blob
+return #{ statusCode: 200, body: #{
+    name: meta.name, content_type: meta.content_type, b64: base64::encode(bytes)
+} };
+```
+
+## 4. Deploy and route
+
+```sh
+pic scripts deploy upload.rhai   --app vault --name upload
+pic scripts deploy download.rhai --app vault --name download
+UP=$(pic --output json scripts ls --app vault | jq -r '.[]|select(.name=="upload").id')
+DL=$(pic --output json scripts ls --app vault | jq -r '.[]|select(.name=="download").id')
+pic routes create --script $UP --path /files               --method POST
+pic routes create --script $DL --path '/files/:id/data' --path-kind param --method GET
+```
+
+## 5. Upload and download
+
+```sh
+H='Host: vault.localhost'
+B64=$(printf 'hello pics' | base64)               # aGVsbG8gcGljcw==
+
+curl -s -X POST http://localhost:18080/files -H "$H" -H 'Content-Type: application/json' \
+  -d "{\"name\":\"greeting.txt\",\"content_type\":\"text/plain\",\"b64\":\"$B64\"}"
+# {"id":"98698d33-…","size":10}
+
+curl -s http://localhost:18080/files/<id>/data -H "$H"
+# {"b64":"aGVsbG8gcGljcw==","content_type":"text/plain","name":"greeting.txt"}
+# → base64-decode "b64" on the client to recover the bytes
+```
+
+Need true raw bytes (e.g. to `<img src>` an upload)? Use the authenticated admin endpoint, which sets
+`Content-Type`/`Content-Disposition` and streams the bytes:
+
+```sh
+curl http://localhost:18080/api/v1/admin/apps/$(pic --output json apps show vault | jq -r .id)/files/uploads/<id> \
+  -H "Authorization: Bearer $TOKEN" -o greeting.txt
+```
+
+…or the CLI: `pic files get --app vault --collection uploads --id <id> --out greeting.txt`.
+
+## 6. Watch uploads live (SSE)
+
+Subscribe to the topic; every upload pushes an event:
+
+```sh
+curl -N http://localhost:18080/realtime/topics/file.uploaded -H 'Host: vault.localhost'
+```
+
+Upload another file from a second terminal and the subscriber prints:
+
+```text
+data: {"message":{"id":"1313221c-…","name":"c.txt","size":10},
+       "published_at":"2026-…Z","topic":"file.uploaded"}
+```
+
+The published payload is under `message`. In a browser that's
+`new EventSource('https://your-host/realtime/topics/file.uploaded')`. For non-public topics, mint a
+subscriber token (`pubsub::subscriber_token`) or use an app-user session — see
+[Topics & realtime](../reference/rest-api/topics.md).
+
+## Notes, constraints & next steps
+
+- **Size caps.** Per-file blobs cap at `PICLOUD_FILES_MAX_FILE_SIZE_BYTES` (100 MiB), but the upload
+  also passes through the request-body limit (~10 MiB) **and** base64 inflates by ~33%. For large
+  files you'll want chunking or a different ingest path; this base64-in-JSON pattern suits modest
+  files (avatars, attachments, docs).
+- **Blobs in / metadata out.** `files::...head(id)` returns metadata only (name, content_type, size,
+  checksum) — cheap; `...get(id)` returns the bytes.
+- **Storage location.** Bytes live on disk under `PICLOUD_FILES_ROOT`; metadata in Postgres. Back both
+  up together.
+- **`files` triggers.** A blob create/update/delete can fire a [`files` trigger](../reference/rest-api/triggers.md)
+  (`ctx.event.files`, metadata only) — e.g. to generate a thumbnail or scan an upload.
+
+Next: validate `content_type` and reject disallowed types; generate thumbnails in a `files`-trigger
+consumer; or gate uploads behind the [auth pattern from the TODO tutorial](todo-api.md).
--- a/docs/dev-guide/src/examples/index.md
+++ b/docs/dev-guide/src/examples/index.md
@@ -0,0 +1,59 @@
+# Tutorials — overview & feature matrix
+
+Five complete, copy-pasteable example apps. Each was built and run against a real instance while
+writing this guide — the commands and outputs are what actually happened. Work through them in any
+order; together they touch most of the platform.
+
+Every tutorial assumes the [Quickstart](../guide/quickstart.md) stack is running and you're logged in
+with `pic`. Each creates its own [app](../guide/concepts.md#apps) and claims a `*.localhost` host, so
+you address it with a `Host:` header (`curl -H 'Host: links.localhost' …`).
+
+> **A note on ports.** These tutorials use `http://localhost:18080` (a bare binary — see
+> [Running the bare binary](../deploy/bare-binary.md)). If you followed the Quickstart's **Docker
+> Compose** stack, substitute **`8000`** for `18080` everywhere (including the `short_url` the URL
+> shortener builds). Same behavior, different port.
+
+## Which tutorial shows which feature
+
+| | [URL shortener](url-shortener.md) | [Webhook receiver](webhook-receiver.md) | [TODO API](todo-api.md) | [Scheduled report](scheduled-report.md) | [File upload](file-upload.md) |
+|---|:--:|:--:|:--:|:--:|:--:|
+| `kv` | ● | ● | | ● | |
+| `docs` | | | ● | | |
+| `files` | | | | | ● |
+| `secrets` | | ● | | | |
+| `http` (outbound) | | ● | | | |
+| `email` | | | | ● | |
+| `users` (auth) | | | ● | | |
+| `pubsub` + SSE | | | | | ● |
+| `queue` | | ● | | | |
+| `invoke`/`retry` | | ● | | | |
+| dead-letters | | ● | | | |
+| stdlib (`random`/`base64`/`time`) | ● | | | ● | ● |
+| route params (`:id`) | ● | | ● | | ● |
+| async dispatch (`202`) | | ● | | | |
+| cron trigger | | | | ● | |
+| queue trigger | | ● | | | |
+| modules (`import`) | | | | ● | |
+
+## The five apps
+
+1. **[URL shortener](url-shortener.md)** — `POST /shorten` + `GET /r/:code`. The gentlest start: KV,
+   a param route, a random code, a `302` redirect. *(~10 min.)*
+2. **[Webhook receiver](webhook-receiver.md)** — authenticate with a shared secret, accept with `202`,
+   process on a durable queue with retries, forward over HTTP, handle failures as dead-letters. The
+   most feature-dense tutorial. *(~25 min.)*
+3. **[TODO API with auth](todo-api.md)** — real multi-user signup/login built from the `users` SDK,
+   per-user data in `docs`. Shows that PiCloud has no built-in auth endpoints — you compose them.
+   *(~20 min.)*
+4. **[Scheduled report](scheduled-report.md)** — a cron trigger that aggregates data, formats it via an
+   imported module, and emails a summary (verified against the dev mail sink). *(~15 min.)*
+5. **[File-upload service](file-upload.md)** — store blobs, announce uploads on a pubsub topic, stream
+   them to a browser via SSE. Clears up how binary I/O works (base64-in/JSON-out). *(~20 min.)*
+
+## Patterns they share
+
+- **One app per project**, each claiming its own host — that's the isolation boundary.
+- **Deploy from a file** with `pic scripts deploy file.rhai --app <slug>`, then bind routes.
+- **Inspect with the admin side** — `pic kv get`, `pic logs`, `pic dead-letters ls`, the dashboard.
+- **Read the "Notes, constraints & next steps"** box at the end of each — that's where the real-world
+  caveats and security gotchas live.
--- a/docs/dev-guide/src/examples/scheduled-report.md
+++ b/docs/dev-guide/src/examples/scheduled-report.md
@@ -0,0 +1,124 @@
+# Tutorial: Scheduled report
+
+Run a job on a schedule that aggregates data and emails a summary. This exercises a
+[`cron` trigger](../reference/rest-api/triggers.md), a reusable [`module`](../guide/writing-scripts.md#modules-and-imports)
+script imported with `import`, [`kv`](../reference/sdk/storage.md#kv) reads, and
+[`email::send_html`](../reference/sdk/email.md) — verified here against the **dev email sink** so you
+need no real SMTP server.
+
+## 1. App
+
+```sh
+pic apps create reports --name "Scheduled Reports"
+```
+
+(No domain needed — a cron-triggered script isn't reached over HTTP.)
+
+## 2. A shared formatting module
+
+`report_fmt.rhai` (`kind: module` — only `fn`/`const`, no top-level statements):
+
+```rhai
+fn summary(n) {
+    `Signups so far: ${n}`
+}
+```
+
+## 3. The report worker
+
+`reporter.rhai` reads a metric, formats it via the module, and emails it. It handles both a real cron
+firing (`ctx.event.cron`) and a manual test run (no event):
+
+```rhai
+import "report_fmt" as fmt;
+
+let hits = kv::collection("metrics").get("signups");
+if hits == () { hits = 0; }
+
+let when = if "event" in ctx && ctx.event.source == "cron" {
+    ctx.event.cron.scheduled_at          // RFC 3339 string of the scheduled tick
+} else {
+    time::now()
+};
+
+let line = fmt::summary(hits);
+email::send_html(#{
+    to: "ops@example.com",
+    from: "reports@reports.app",
+    subject: `Report @ ${when}`,
+    text: line,                          // plain-text fallback
+    html: `<p>${line}</p>`
+});
+log::info("report sent", #{ when: when, line: line });
+return #{ statusCode: 200, body: #{ sent: true, line: line } };
+```
+
+## 4. Deploy
+
+```sh
+pic scripts deploy report_fmt.rhai --app reports --kind module --name report_fmt
+pic scripts deploy reporter.rhai   --app reports --name reporter
+RP=$(pic --output json scripts ls --app reports | jq -r '.[]|select(.name=="reporter").id')
+```
+
+## 5. Test it once, by hand
+
+You can run any script directly by id (no route needed) with `execute`. There's no cron event this way,
+so the worker falls back to `time::now()`:
+
+```sh
+curl -s -X POST http://localhost:18080/api/v1/execute/$RP -H 'Content-Type: application/json' -d '{}'
+# {"line":"Signups so far: 0","sent":true}
+```
+
+Because the dev stack has no SMTP relay, the mail went to the **in-memory dev sink**. Read it back
+(instance owner/admin only; this route exists only in dev mode):
+
+```sh
+curl -s http://localhost:18080/api/v1/admin/dev/emails -H "Authorization: Bearer $TOKEN"
+```
+```json
+[{"captured_at":"2026-…Z","from":"reports@reports.app","to":["ops@example.com"],
+  "raw":"From: reports@reports.app\r\nSubject: Report @ 2026-…Z\r\n…multipart/alternative…"}]
+```
+
+## 6. Put it on a schedule
+
+Cron expressions are **6 fields (with seconds)**. This fires every 10 seconds — handy for a demo:
+
+```sh
+pic triggers create-cron --app reports --script $RP --schedule '*/10 * * * * *'
+```
+
+Within ~10 seconds it fires; confirm via the execution log (source `cron`), where — because cron runs
+are asynchronous — the `log::` output is captured:
+
+```sh
+pic logs $RP --source cron --limit 3
+# … status=success source=cron … (the "report sent" log entry is recorded)
+```
+
+Then replace it with a real schedule and timezone, e.g. 8 AM daily in Berlin, and remove the demo one:
+
+```sh
+pic triggers create-cron --app reports --script $RP --schedule '0 0 8 * * *' --timezone Europe/Berlin
+pic triggers ls --app reports
+pic triggers rm --app reports <demo_trigger_id>
+```
+
+## Notes, constraints & next steps
+
+- **Module fns don't see `ctx`.** An imported module gets no access to the caller's scope — pass what
+  it needs as arguments (here, `fmt::summary(hits)`). Module fns *can* call SDK namespaces.
+- **Cron resolution is seconds, 6 fields.** `*/10 * * * * *` = every 10s; `0 0 8 * * *` = 08:00:00
+  daily. Set `--timezone` (IANA name) or it runs in UTC.
+- **Real SMTP.** Configure `PICLOUD_SMTP_*` ([env vars](../reference/config/env-vars.md)) for actual
+  delivery; without it (outside dev mode) `email::send_html` throws `NotConfigured`.
+- **Where does the metric come from?** Here it's a `kv` key you'd increment elsewhere in your app (the
+  [quickstart counter](../guide/quickstart.md#step-5-write-your-first-script) pattern). A report often
+  aggregates [`docs`](../reference/sdk/storage.md#docs) instead — `docs.find(...)` then fold.
+- **Don't over-fire.** Each tick is a full execution counted against your concurrency budget; a
+  10-second cron in production is rarely what you want.
+
+Next: have the report run per user (loop `users::list`, email each), or push results to a dashboard
+over [pubsub + SSE](file-upload.md) instead of email.
--- a/docs/dev-guide/src/examples/todo-api.md
+++ b/docs/dev-guide/src/examples/todo-api.md
@@ -0,0 +1,158 @@
+# Tutorial: TODO API with auth
+
+Build a multi-user TODO API where each user signs up, logs in, and sees only their own items. This is
+the tutorial that shows how **app-user authentication** actually works in PiCloud: there is no built-in
+`/signup` or `/login` — you compose them from the [`users`](../reference/sdk/users.md) SDK and bind
+them to your own routes. Data lives in [`docs`](../reference/sdk/storage.md#docs).
+
+> **The key idea:** PiCloud gives you `users::create`, `users::login`, `users::verify` — the
+> *primitives*. The endpoints (`/auth/signup`, the bearer-token check on protected routes) are yours to
+> write. This is more work than a turnkey auth box, but it means auth is *your* code with no hidden
+> behavior. See [Concepts → authentication](../guide/concepts.md#authentication-three-kinds-of-identity).
+
+## 1. App and host
+
+```sh
+pic apps create todo --name "TODO API"
+pic apps domains add todo todo.localhost
+```
+
+## 2. Signup
+
+`signup.rhai` — create the user, then log them straight in:
+
+```rhai
+let b = ctx.request.body;
+if type_of(b) != "map" || !b.contains("email") || !b.contains("password") {
+    return #{ statusCode: 400, body: #{ error: "email and password required" } };
+}
+if !users::email_available(b.email) {            // anonymous-safe pre-check
+    return #{ statusCode: 409, body: #{ error: "email already registered" } };
+}
+let display = if b.contains("display_name") { b.display_name } else { () };
+users::create(#{ email: b.email, password: b.password, display_name: display });
+let token = users::login(b.email, b.password);   // mint a session token
+return #{ statusCode: 201, body: #{ token: token } };
+```
+
+## 3. Login
+
+`login.rhai`:
+
+```rhai
+let b = ctx.request.body;
+let token = users::login(b.email, b.password);   // () on bad credentials
+if token == () { return #{ statusCode: 401, body: #{ error: "invalid credentials" } }; }
+return #{ statusCode: 200, body: #{ token: token } };
+```
+
+## 4. The TODO endpoints (one script, branches on method)
+
+A single `todos.rhai` handles `POST /todos`, `GET /todos`, and `DELETE /todos/:id`. Each begins by
+turning the `Authorization: Bearer …` header into a user with `users::verify`:
+
+```rhai
+// --- authenticate ---
+let hdr = if "authorization" in ctx.request.headers { ctx.request.headers["authorization"] } else { "" };
+let token = if hdr.starts_with("Bearer ") { hdr.sub_string(7) } else { hdr };
+let me = users::verify(token);                    // () if invalid/expired
+if me == () { return #{ statusCode: 401, body: #{ error: "unauthorized" } }; }
+
+// --- handle the request ---
+let todos = docs::collection("todos");
+let method = ctx.request.method;
+
+if method == "POST" {
+    let id = todos.create(#{ owner: me.id, text: ctx.request.body.text, done: false });
+    return #{ statusCode: 201, body: #{ id: id } };
+}
+if method == "GET" {
+    let mine = todos.find(#{ owner: me.id });     // only this user's docs
+    return #{ statusCode: 200, body: #{ todos: mine } };
+}
+if method == "DELETE" {
+    let id = ctx.request.params.id;
+    let row = todos.get(id);
+    // 404 if missing OR not owned by the caller — never reveal another user's item
+    if row == () || row.data.owner != me.id { return #{ statusCode: 404, body: #{ error: "not found" } }; }
+    todos.delete(id);
+    return #{ statusCode: 204, body: () };
+}
+return #{ statusCode: 405, body: #{ error: "method not allowed" } };
+```
+
+## 5. Deploy and bind
+
+```sh
+pic scripts deploy signup.rhai --app todo --name signup
+pic scripts deploy login.rhai  --app todo --name login
+pic scripts deploy todos.rhai  --app todo --name todos
+
+SU=$(pic --output json scripts ls --app todo | jq -r '.[]|select(.name=="signup").id')
+LI=$(pic --output json scripts ls --app todo | jq -r '.[]|select(.name=="login").id')
+TD=$(pic --output json scripts ls --app todo | jq -r '.[]|select(.name=="todos").id')
+
+pic routes create --script $SU --path /auth/signup --method POST
+pic routes create --script $LI --path /auth/login  --method POST
+pic routes create --script $TD --path /todos             --method POST
+pic routes create --script $TD --path /todos             --method GET
+pic routes create --script $TD --path '/todos/:id' --path-kind param --method DELETE
+```
+
+(Binding several routes to one script is normal — the script branches on `ctx.request.method`.)
+
+## 6. Use it
+
+```sh
+H='Host: todo.localhost'
+# sign up → get a token
+curl -s -X POST http://localhost:18080/auth/signup -H "$H" -H 'Content-Type: application/json' \
+  -d '{"email":"ada@example.com","password":"lovelace99","display_name":"Ada"}'
+# {"token":"JCMgEH6i_DLtNggsEE9KspGNaUHIYvBcV0p4jG9fKZ8"}
+
+TOK=…   # paste the token
+
+# unauthenticated request is rejected
+curl -s -o /dev/null -w '%{http_code}\n' http://localhost:18080/todos -H "$H"        # 401
+
+# create a couple of todos
+curl -s -X POST http://localhost:18080/todos -H "$H" -H "Authorization: Bearer $TOK" \
+  -H 'Content-Type: application/json' -d '{"text":"write docs"}'
+# {"id":"391bc9df-…"}
+
+# list them — each is a docs envelope (your fields under `data`)
+curl -s http://localhost:18080/todos -H "$H" -H "Authorization: Bearer $TOK"
+```
+```json
+{"todos":[
+  {"id":"0816b607-…","data":{"done":false,"owner":"8c7716bc-…","text":"ship it"},
+   "created_at":"2026-…Z","updated_at":"2026-…Z"},
+  {"id":"391bc9df-…","data":{"done":false,"owner":"8c7716bc-…","text":"write docs"},
+   "created_at":"2026-…Z","updated_at":"2026-…Z"}
+]}
+```
+
+Operators can see registered users (but never their passwords) from the admin side:
+
+```sh
+pic users ls --app todo
+# id … email ada@example.com … display_name Ada … last_login_at … created_at …
+```
+
+## Notes, constraints & next steps
+
+- **`find_by_email` is privileged.** Anonymous (public) scripts can't call it — it's an
+  anti-enumeration guard. `email_available` *is* anonymous-safe (a signup form needs it) but isn't
+  throttled, so rate-limit it if abuse matters. [Security →](../operations/security.md#user-enumeration)
+- **Ownership checks are yours.** The platform scopes data to the *app*, not to a *user*. "Only my
+  todos" is enforced by the `owner` field + the `row.data.owner != me.id` check — there's no automatic
+  per-user row security. Get this right on every protected handler.
+- **`docs.update` replaces `data` wholesale.** To toggle `done`, read the doc, set the field, and
+  `update` with the full map.
+- **Sessions slide.** `users::verify` extends the session TTL on each call
+  (`PICLOUD_APP_USER_SESSION_TTL_HOURS`). Use `users::logout(token)` to end one.
+- **Add roles** with `users::add_role(me.id, "pro")` and gate features on `users::has_role(...)`.
+
+Next: add email verification (`users::send_verification_email` + a `/auth/verify` route) and password
+reset — the [users SDK reference](../reference/sdk/users.md#email-tied-flows) lists the flow. The
+[scheduled-report tutorial](scheduled-report.md) shows how to email users on a cron.
--- a/docs/dev-guide/src/examples/url-shortener.md
+++ b/docs/dev-guide/src/examples/url-shortener.md
@@ -0,0 +1,118 @@
+# Tutorial: URL shortener
+
+Build a classic link shortener: `POST /shorten` stores a long URL under a random code; `GET /r/:code`
+redirects to it. You'll use [`kv`](../reference/sdk/storage.md#kv) storage, a
+[`:param` route](../guide/concepts.md#routes-and-domains), the [`random`](../reference/sdk/stdlib.md#random)
+stdlib, and a `302` [response envelope](../guide/writing-scripts.md#the-response-envelope-in-detail).
+
+**Prereqs:** the [Quickstart](../guide/quickstart.md) stack running, and you're logged in with `pic`.
+We use `http://localhost:18080`; adjust the port to yours.
+
+## 1. Create the app and claim a host
+
+Each tutorial gets its own [app](../guide/concepts.md#apps) for isolation. Locally we claim a
+`*.localhost` host and pass it with a `Host:` header.
+
+```sh
+pic apps create links --name "Link Shortener"
+pic apps domains add links links.localhost
+```
+
+## 2. The "shorten" script
+
+`shorten.rhai`:
+
+```rhai
+// POST /shorten   body: { "url": "https://..." }   ->  { code, short_url }
+let body = ctx.request.body;
+if type_of(body) != "map" || !body.contains("url") {
+    return #{ statusCode: 400, body: #{ error: "json body with a 'url' field required" } };
+}
+let links = kv::collection("links");
+let code = random::string(6);          // 6 alphanumeric chars
+links.set(code, body.url);
+return #{
+    statusCode: 201,
+    body: #{ code: code, short_url: `http://links.localhost:18080/r/${code}` }
+};
+```
+
+## 3. The "redirect" script
+
+`redirect.rhai`:
+
+```rhai
+// GET /r/:code   ->  302 to the stored URL, or 404
+let code = ctx.request.params.code;
+let target = kv::collection("links").get(code);   // () when absent
+if target == () {
+    return #{ statusCode: 404, body: #{ error: "unknown code" } };
+}
+return #{ statusCode: 302, headers: #{ "Location": target }, body: () };
+```
+
+## 4. Deploy and bind routes
+
+```sh
+pic scripts deploy shorten.rhai  --app links --name shorten
+pic scripts deploy redirect.rhai --app links --name redirect
+
+SH=$(pic --output json scripts ls --app links | jq -r '.[]|select(.name=="shorten").id')
+RD=$(pic --output json scripts ls --app links | jq -r '.[]|select(.name=="redirect").id')
+
+pic routes create --script $SH --path /shorten --method POST
+pic routes create --script $RD --path '/r/:code' --path-kind param --method GET
+```
+
+## 5. Try it
+
+```sh
+curl -X POST http://localhost:18080/shorten -H 'Host: links.localhost' \
+  -H 'Content-Type: application/json' -d '{"url":"https://example.com/some/long/path"}'
+```
+```json
+{"code":"pE4wVV","short_url":"http://links.localhost:18080/r/pE4wVV"}
+```
+
+```sh
+curl -i http://localhost:18080/r/pE4wVV -H 'Host: links.localhost'
+```
+```text
+HTTP/1.1 302 Found
+location: https://example.com/some/long/path
+```
+
+```sh
+curl -i http://localhost:18080/r/nope -H 'Host: links.localhost'
+# HTTP/1.1 404 Not Found
+```
+
+## 6. Look inside
+
+Every stored link is just a KV entry — inspect them straight from the admin side:
+
+```sh
+pic kv ls  --app links --collection links
+pic kv get --app links --collection links pE4wVV
+# "https://example.com/some/long/path"
+```
+
+(`pic kv get` prints the stored value as JSON — a string value comes back quoted.)
+
+## Notes, constraints & next steps
+
+- **Collisions.** `random::string(6)` over 62 symbols is only ~36 bits (6 × log₂62) — fine for a
+  demo, but at scale two codes will eventually collide and the second `set` would silently overwrite
+  the first. For production, check `links.has(code)` and regenerate on collision, use more characters,
+  or use `random::uuid()`.
+- **Size cap.** A stored value can't exceed `PICLOUD_KV_MAX_VALUE_BYTES` (256 KiB) — irrelevant for
+  URLs, but good to know ([overview](../reference/sdk/overview.md#size-caps)).
+- **Validate input.** We checked the body is a map with a `url`. A real version should also validate
+  the URL scheme to avoid storing `javascript:` links you later redirect to.
+- **Open redirect.** Redirecting to arbitrary user-supplied URLs is an
+  [open-redirect](../operations/security.md) vector if codes are guessable and the links are
+  attacker-controlled — fine here, but think about it for auth flows.
+
+Next: add per-link click counts (another `kv` collection, like the quickstart counter), or move to
+[`docs`](../reference/sdk/storage.md#docs) if you want to store metadata (owner, created-at, hits) per
+link and query it — which is exactly what the [TODO API tutorial](todo-api.md) does.
--- a/docs/dev-guide/src/examples/webhook-receiver.md
+++ b/docs/dev-guide/src/examples/webhook-receiver.md
@@ -0,0 +1,148 @@
+# Tutorial: Webhook receiver
+
+Receive webhooks reliably: authenticate the caller with a shared secret, accept fast with `202`, do the
+slow work on a durable [queue](../reference/sdk/messaging.md#queue), forward downstream over
+[`http`](../reference/sdk/http.md) with [`retry`](../reference/sdk/composition.md#retry), and let
+failures land in the [dead-letter](../reference/sdk/composition.md#dead-letters) queue for replay.
+
+This exercises [`secrets`](../reference/sdk/secrets.md), [async dispatch](../guide/concepts.md#dispatch-modes-sync-vs-async),
+`queue::enqueue`, a `queue` trigger, `http` + `retry`, and dead-letters.
+
+> **Why a shared secret, not HMAC?** The 1.1.9 script SDK has **no hashing/HMAC primitive** — `base64`
+> and `hex` exist, but not `sha256`/`hmac`. So a script can't verify a provider's HMAC signature
+> itself. (The platform *does* HMAC-verify built-in [inbound-email triggers](../reference/rest-api/triggers.md)
+> server-side.) For script-level webhooks, use a shared-secret header, which is what we do here.
+
+## 1. App, host, and the secret
+
+```sh
+pic apps create hooks --name "Webhook Receiver"
+pic apps domains add hooks hooks.localhost
+printf 'shhh-secret-token' | pic secrets set --app hooks webhook_token
+```
+
+## 2. The receiver (sync, returns 202)
+
+`receiver.rhai` — verify the secret, enqueue, accept:
+
+```rhai
+// POST /ingest   header: x-webhook-token: <secret>   body: the event JSON
+let expected = secrets::get("webhook_token");
+let got = if "x-webhook-token" in ctx.request.headers { ctx.request.headers["x-webhook-token"] } else { "" };
+if got != expected {
+    return #{ statusCode: 401, body: #{ error: "bad or missing webhook token" } };
+}
+queue::enqueue("deliveries", ctx.request.body, #{ max_attempts: 2 });
+return #{ statusCode: 202, body: #{ accepted: true } };
+```
+
+We verify and enqueue synchronously (so a bad token gets a real `401`), then return `202` — the heavy
+lifting happens off the request path.
+
+## 3. The consumer (runs per queued message)
+
+`consumer.rhai` — note the event shape: the payload is `ctx.event.queue.message`, and the retry count
+is `ctx.event.queue.attempt`:
+
+```rhai
+let msg = ctx.event.queue.message;
+log::info("processing delivery", #{ id: msg.id, attempt: ctx.event.queue.attempt });
+
+if msg.fail == true {
+    throw "simulated downstream failure";   // forces retries → dead-letter (for the demo)
+}
+
+// Forward downstream, retrying transient failures.
+let policy = retry::policy(#{ max_attempts: 3, backoff: "exponential", base_ms: 200 });
+let resp = retry::run(policy, || http::get("https://example.com"));
+
+kv::collection("delivered").set(msg.id, `${resp.status}`);
+```
+
+## 4. Deploy, route, and register the queue trigger
+
+```sh
+pic scripts deploy receiver.rhai --app hooks --name receiver
+pic scripts deploy consumer.rhai --app hooks --name consumer
+
+RCV=$(pic --output json scripts ls --app hooks | jq -r '.[]|select(.name=="receiver").id')
+CON=$(pic --output json scripts ls --app hooks | jq -r '.[]|select(.name=="consumer").id')
+
+pic routes create --script $RCV --path /ingest --method POST
+
+# Register the consumer on the "deliveries" queue. The per-kind wrapper `pic triggers create-queue`
+# works too; we use the JSON form here only to set a short retry backoff so the dead-letter demo is
+# quick (the wrapper doesn't expose retry knobs):
+pic triggers create-from-json --app hooks --kind queue \
+  --body "{\"script_id\":\"$CON\",\"queue_name\":\"deliveries\",\"retry_max_attempts\":1,\"retry_base_ms\":300}"
+```
+
+## 5. Send some webhooks
+
+```sh
+B=http://localhost:18080/ingest
+# bad token → 401
+curl -s -o /dev/null -w '%{http_code}\n' -X POST $B -H 'Host: hooks.localhost' \
+  -H 'Content-Type: application/json' -d '{"id":"d1"}'                              # 401
+
+# good token, succeeds → 202, processed in the background
+curl -s -o /dev/null -w '%{http_code}\n' -X POST $B -H 'Host: hooks.localhost' \
+  -H 'x-webhook-token: shhh-secret-token' -H 'Content-Type: application/json' \
+  -d '{"id":"d3","event":"order.created","fail":false}'                            # 202
+
+# good token, fails downstream → 202 now, dead-letter after retries
+curl -s -o /dev/null -w '%{http_code}\n' -X POST $B -H 'Host: hooks.localhost' \
+  -H 'x-webhook-token: shhh-secret-token' -H 'Content-Type: application/json' \
+  -d '{"id":"d4","fail":true}'                                                      # 202
+```
+
+After a moment, the happy delivery is recorded and its background run's `log::` output is captured
+(async/triggered runs persist logs — sync HTTP runs don't):
+
+```sh
+pic kv get --app hooks --collection delivered d3      # "200"
+pic logs $CON --source queue --limit 5                # shows the "processing delivery" entries
+```
+
+## 6. Dead-letters {#dead-letters}
+
+The `fail` delivery used up its delivery attempts and became a dead-letter. We enqueued it with
+`max_attempts: 2`, so the dead-letter row shows `attempts 2`:
+
+```sh
+pic dead-letters count --app hooks                    # 1
+pic dead-letters ls --app hooks --unresolved
+# id … attempts 2 … last_error "script runtime error: Runtime error: simulated downstream failure …"
+```
+
+Re-enqueue it (e.g. after fixing the downstream), or close it out:
+
+```sh
+pic dead-letters replay  --app hooks <dl_id>                       # Replayed dead-letter <id>
+pic dead-letters resolve --app hooks <dl_id> --reason ignored      # close without replay
+```
+
+`replay` marks the row `replayed` and puts the original message back on the queue. `resolve` takes one
+of a **fixed set** of reasons — `replayed`, `ignored`, `handled_by_script`, `handler_failed` — not
+free text. You can also automate this: register a [`dead_letter` trigger](../reference/rest-api/triggers.md)
+that runs a script (with `ctx.event.dead_letter`) to alert or call
+[`dead_letters::replay`/`resolve`](../reference/sdk/composition.md#dead-letters).
+
+## Notes, constraints & next steps
+
+- **Idempotency.** A queued message can run more than once (a retry after a partial success, or a
+  visibility-timeout expiry). Use `ctx.event.queue.attempt` and a dedup key (`if
+  kv::collection("done").has(msg.id) { return; }`). See
+  [Best practices](../operations/best-practices.md#idempotent-consumers).
+- **SSRF.** `http::*` blocks private/loopback targets — `http::get("http://localhost…")` throws
+  `http: blocked by SSRF policy: loopback`. Forwarding to your own internal services from a script
+  requires a routable address (or, in dev only, `PICLOUD_HTTP_ALLOW_PRIVATE=true`).
+  [Security →](../operations/security.md#ssrf)
+- **Size cap.** A queued message can't exceed `PICLOUD_QUEUE_MAX_PAYLOAD_BYTES` (256 KiB).
+- **Two retry layers.** The in-script `retry::run` retries *within one execution*; the trigger's
+  `retry_max_attempts` retries the *whole execution*. Pick one as your primary strategy to avoid
+  multiplicative delays.
+
+Next: swap the shared-secret check for the platform's [inbound-email trigger](../reference/rest-api/triggers.md)
+if you're ingesting mail, or fan a single event out to several consumers with
+[`pubsub`](../reference/sdk/messaging.md#pubsub).
--- a/docs/dev-guide/src/guide/concepts.md
+++ b/docs/dev-guide/src/guide/concepts.md
@@ -0,0 +1,177 @@
+# Core concepts
+
+This chapter is the mental model. Read it once and the rest of the guide clicks into place.
+
+## The request lifecycle
+
+```text
+            ┌─────────────────────────────────────────────────────────────┐
+ request ──▶│ 1. Caddy proxy   2. resolve Host → app   3. match the route  │
+            │                     (most-specific           (method+path     │
+            │                      domain claim wins)        in that app)    │
+            └─────────────────────────────────────────────────────────────┘
+                                          │ found a script
+                                          ▼
+            ┌─────────────────────────────────────────────────────────────┐
+            │ 4. run the script in a sandbox, with `ctx` populated          │
+            │ 5. script calls the SDK (kv, http, …) — all scoped to the app │
+            │ 6. script returns a response envelope → HTTP response         │
+            └─────────────────────────────────────────────────────────────┘
+```
+
+Two phases matter most: **Host → app**, then **route within that app**. A request whose `Host` no app
+claims gets `404 {"error":"no app claims host …"}`. A request that hits a claimed host but matches no
+route gets `404 {"error":"no route matches …"}`. (The built-in `default` app claims `localhost`, which
+is why the quickstart's `curl localhost:8000/...` just works.)
+
+## Apps
+
+An **app** is a tenant: an isolated namespace that owns scripts, routes, domain claims, and *all* data
+(KV, docs, files, secrets, users, queues, topics). Isolation is the headline guarantee:
+
+> **A script can only ever touch its own app's data.** Every SDK call derives the app from the
+> execution context on the server — never from anything the script passes. There is no API for a
+> script to name another app. This is enforced in the platform, not by convention.
+
+You create apps from the dashboard (Apps → New), the CLI (`pic apps create <slug>`), or HTTP
+(`POST /api/v1/admin/apps`). An app has a URL-safe **slug** (`^[a-z0-9][a-z0-9-]{0,62}$`) and a
+display name. The `default` app exists on every install and is where the seeded example lives.
+
+Cross-app data sharing does not exist in 1.1.9 — isolation is strict by design. (It is on the roadmap
+for a later release.)
+
+## Scripts
+
+A **script** is a Rhai program belonging to one app. There are two **kinds**:
+
+| Kind | Runs on | Can bind routes/triggers? | Top-level statements? |
+|---|---|---|---|
+| `endpoint` (default) | HTTP requests, events, `invoke()`, `/execute/{id}` | yes | yes |
+| `module` | never directly — only `import`ed by other scripts | no | no — only `fn` and `const` |
+
+A **module** is a library. Another script in the *same app* pulls it in with
+`import "modulename" as alias;` and calls `alias::some_fn(...)`. Cross-app imports are impossible (the
+import name carries no app). Modules are how you share helpers without copy-paste. See
+[Writing scripts](writing-scripts.md#modules-and-imports).
+
+Each script carries sandbox settings — a wall-clock `timeout_seconds`, a `memory_limit_mb`, and
+optional fine-grained [sandbox overrides](writing-scripts.md#sandbox-limits). New scripts default to a
+30-second timeout and 256 MB.
+
+## Routes and domains
+
+A **route** binds an incoming HTTP request to a script. A route has:
+
+- a **host** match: `any` (the default, matches whatever host the app claims), `strict` (one exact
+  host), or `wildcard` (`*.example.com`, optionally capturing the subdomain into a param);
+- a **path** match of one of three **path kinds**:
+  - `exact` — `/webhook` matches only `/webhook`;
+  - `param` — `/users/:id` matches `/users/42` and exposes `ctx.request.params.id == "42"`;
+  - `prefix` — `/files/*` matches `/files/a/b/c` and exposes the tail as `ctx.request.rest`;
+- an optional **method** (`GET`, `POST`, …); omit it to match any method;
+- a **dispatch mode** (below).
+
+> **Param syntax is deliberately split.** Route paths use `:name` (`/users/:id`). Domain patterns use
+> `{name}` (`{tenant}.example.com`). Never mix them. [More →](writing-scripts.md).
+
+**Domains.** Beyond the `default` app, an app's routes only match once the app **claims** the request's
+`Host`. Claim patterns are exact (`api.example.com`), wildcard (`*.example.com`), or parameterized
+(`{tenant}.example.com`). The most specific claim wins. Locally you can claim something like
+`myapp.localhost` and test with `curl -H 'Host: myapp.localhost' localhost:8000/...` — that's the
+pattern the [tutorials](../examples/index.md) use. The port is stripped before matching.
+
+**Reserved prefixes.** PiCloud refuses to create routes under `/api/`, `/admin/`, `/healthz`, or
+`/version` — those belong to the platform. Pick any other path.
+
+## The response envelope
+
+An `endpoint` script's return value becomes the HTTP response. The rule
+([`engine.rs`](../reference/sdk/ctx-and-events.md)):
+
+- **Return a map containing a `statusCode` key** → that's the structured envelope:
+  ```rhai
+  return #{
+      statusCode: 201,
+      headers: #{ "Content-Type": "application/json", "Location": "/things/7" },
+      body: #{ id: 7 }
+  };
+  ```
+  `statusCode` is a required integer; `headers` (string→string) and `body` are optional. A `body` that
+  is a map/array is serialized to JSON.
+- **Return anything else** (a map without `statusCode`, a string, a number, an array) → PiCloud wraps
+  it in a **`200 OK`** with that value as the body.
+
+So `return #{ ok: true };` and `return #{ statusCode: 200, body: #{ ok: true } };` both produce
+`200 {"ok":true}`. Use the full envelope when you need a non-200 status, custom headers, or redirects.
+
+## Dispatch modes: sync vs async
+
+Every route (and trigger) has a **dispatch mode**:
+
+- **`sync`** (default for routes) — the caller waits; the script's envelope is the HTTP response.
+- **`async`** — PiCloud immediately returns **`202 Accepted`** with an `execution_id`, and runs the
+  script in the background via the dispatcher. The caller never sees the script's return value.
+
+Use `async` for fire-and-forget work (webhooks you don't need to answer in detail, fan-out, slow jobs)
+so the client isn't blocked. Triggers default to `async`. [More on choosing →](../operations/best-practices.md#sync-vs-async).
+
+## Triggers and events
+
+A **trigger** fires a script on an *event* rather than an HTTP request. PiCloud has eight trigger
+kinds:
+
+| Kind | Fires when… | `ctx.event` carries |
+|---|---|---|
+| `kv` | a key is set/deleted in matching collections | `op`, `kv.{collection,key,value}` |
+| `docs` | a document is created/updated/deleted | `op`, `docs.{collection,id,data,prev_data}` |
+| `files` | a blob is created/updated/deleted | `op`, file metadata (never the bytes) |
+| `pubsub` | a message is published to a matching topic | `pubsub.{topic,payload}` |
+| `queue` | a message is claimed off a named queue | `queue.{…}`, attempt count |
+| `cron` | a schedule ticks | `cron.{schedule,timezone,scheduled_at,fired_at}` |
+| `email` | mail arrives at the inbound webhook | the parsed message |
+| `dead_letter` | another trigger exhausts its retries | the failed event + error |
+
+The triggered script reads `ctx.event` (absent on plain HTTP invocations, so you can test
+`if "event" in ctx`). Triggers are created per-kind — see [Triggers](../reference/rest-api/triggers.md)
+and the [`ctx.event` reference](../reference/sdk/ctx-and-events.md#events).
+
+## Authentication: three kinds of identity
+
+Keep these straight — they are easy to confuse:
+
+| Identity | Who | Used for | Managed by |
+|---|---|---|---|
+| **Admin user** | you / your team | the control plane (dashboard, CLI, admin API) | `pic admins`, bootstrap env vars |
+| **API key** | you / a CI job | the control plane, non-interactively | `pic api-keys`, dashboard profile |
+| **App user** | *your app's* end-users | whatever *your* scripts decide | the `users` SDK, in your scripts |
+
+An **admin user** or **API key** is a *principal* on the control plane, with an **instance role**
+(`owner` > `admin` > `member`) and, for members, per-app **app roles** (`app_admin` > `editor` >
+`viewer`). See [Capabilities & roles](../reference/config/capabilities.md).
+
+> **There is no built-in end-user signup/login HTTP endpoint.** App-user authentication is the
+> [`users` SDK](../reference/sdk/users.md) — you compose `users::create`, `users::login`,
+> `users::verify` into *your own* routes. This trips people up; the
+> [TODO API tutorial](../examples/todo-api.md) shows the full pattern.
+
+## The data plane is unauthenticated by default
+
+Routes you create are **public**. A request to your route runs the script with **full app authority** —
+it can read every secret, every KV key, every user in the app. PiCloud does *not* put auth in front of
+your routes for you. If a route must be restricted, your script enforces it (check a token, call
+`users::verify`, compare an HMAC). This is the single most important security point —
+see [Security](../operations/security.md).
+
+## The five version surfaces
+
+`GET /version` returns five independent numbers. They move independently on purpose:
+
+| Surface | Example | What it tracks | Notes |
+|---|---|---|---|
+| `product` | `1.1.9` | the release build | semver of the whole platform |
+| `sdk` | `1.10` | the script-visible API | **`major.minor`** — `1.10` is the *tenth minor*, not `1.1.0`. Read it at runtime as `ctx.sdk_version`. A minor bump only *adds*; existing scripts keep working. |
+| `api` | `1` | the HTTP API major | appears in URLs as `/api/v1/...` |
+| `schema` | `44` | the DB migration number | monotonic, forward-only |
+| `wire` | `1` | inter-node protocol | reserved; cluster mode is a future release |
+
+The recurring mistake is reading `sdk: "1.10"` as "version 1.1.0". It isn't. It's SDK 1, minor 10.
--- a/docs/dev-guide/src/guide/quickstart.md
+++ b/docs/dev-guide/src/guide/quickstart.md
@@ -0,0 +1,170 @@
+# Quickstart
+
+This gets you from nothing to a live, custom HTTP endpoint — backed by persistent storage — in about
+ten minutes. We'll use the built-in **default app** so there's zero setup friction; later you'll learn
+to create your own [apps](concepts.md#apps) with their own [domains](concepts.md#routes-and-domains).
+
+> Every command and response below was produced by running it. If yours differ, check
+> [Troubleshooting](../operations/troubleshooting.md).
+
+## Step 1 — Boot the stack
+
+The fastest path is Docker Compose, which brings up Postgres, PiCloud, the dashboard, and a Caddy
+reverse proxy behind one port.
+
+```sh
+git clone <your-picloud-checkout> picloud && cd picloud
+cp .env.example .env          # then edit: set PICLOUD_ADMIN_USERNAME / PICLOUD_ADMIN_PASSWORD
+docker compose up -d --build
+```
+
+The default `.env` runs in **dev mode** (a deterministic, insecure master key — fine for local, never
+for production) and publishes Caddy on host port **8000**. The dashboard is at
+`http://localhost:8000/admin`.
+
+> **Prefer running the binary directly?** See [Running the bare binary](../deploy/bare-binary.md).
+> The only difference is the port. This guide uses `http://localhost:8000`; export it once so you can
+> paste the rest verbatim:
+>
+> ```sh
+> export PICLOUD=http://localhost:8000
+> ```
+
+## Step 2 — Confirm it's alive
+
+```sh
+curl $PICLOUD/healthz
+# ok
+
+curl $PICLOUD/version
+```
+```json
+{"api":1,"product":"1.1.9","public_base_url":"http://localhost:8000","schema":44,"sdk":"1.10","wire":1}
+```
+
+That `sdk` field — `"1.10"` — is the SDK version your scripts target. It is a `major.minor` string (the
+tenth minor of SDK v1), **not** the product release `1.1.9`. See
+[the five version surfaces](concepts.md#the-five-version-surfaces).
+
+## Step 3 — Log in
+
+You authenticate once and use a **bearer token** for every control-plane call. Three equivalent ways:
+
+**Dashboard:** open `http://localhost:8000/admin`, enter your admin username/password.
+
+**CLI** (recommended for the rest of this guide):
+```sh
+printf 'YOUR_PASSWORD' | pic login --url $PICLOUD --username admin --password-stdin
+# Logged in as admin (owner) at http://localhost:8000
+pic whoami
+```
+
+**Raw HTTP:**
+```sh
+TOKEN=$(curl -s -X POST $PICLOUD/api/v1/admin/auth/login \
+  -H 'Content-Type: application/json' \
+  -d '{"username":"admin","password":"YOUR_PASSWORD"}' | jq -r .token)
+```
+The login response is:
+```json
+{"user":{"id":"…","username":"admin","instance_role":"owner","email":null},
+ "token":"V-f-0ey3eEcFKBWH5_6GLCqBkih08bhWtY-5GHCxZ04",
+ "expires_at":"2026-06-18T19:49:39Z"}
+```
+Pass it as `Authorization: Bearer $TOKEN` on admin requests. (The `pic` CLI stores it for you in
+`~/.config/picloud/credentials`.)
+
+## Step 4 — Meet the seeded "hello" script
+
+A fresh install seeds one example script into the default app, bound to `GET /hello`:
+
+```sh
+curl $PICLOUD/hello
+# {"message":"Hello, world!"}
+
+curl $PICLOUD/hello -H 'Content-Type: application/json' -d '{"name":"Fabi"}'
+# {"message":"Hello, Fabi!"}
+```
+
+Open it in the dashboard (Apps → Default → Scripts → hello) to see its source. It's a good template:
+it reads `ctx.request.body` and returns a [response envelope](concepts.md#the-response-envelope).
+
+## Step 5 — Write your first script
+
+Create a file `counter.rhai`:
+
+```rhai
+// Count visits, persisted in KV across requests and restarts.
+let hits = kv::collection("counters");
+let n = hits.get("home");      // () if the key has never been set
+if n == () { n = 0; }
+n += 1;
+hits.set("home", n);
+return #{ statusCode: 200, body: #{ count: n } };
+```
+
+Deploy it to the default app:
+
+```sh
+pic scripts deploy counter.rhai --app default --name counter
+```
+```json
+{"action":"created","id":"3502852c-030b-4e39-82f6-121220095da7","name":"counter","version":"1"}
+```
+
+Grab that `id` — call it `$SID`.
+
+> Doing it in the dashboard instead? Apps → Default → Scripts → **New script**, paste the source,
+> save. Doing it over raw HTTP? `POST /api/v1/admin/scripts` with
+> `{"app_id":"…","name":"counter","source":"…"}` — see [Scripts](../reference/rest-api/scripts.md).
+
+## Step 6 — Bind a route
+
+A script does nothing until a [route](concepts.md#routes-and-domains) points at it.
+
+```sh
+pic routes create --script $SID --path /count --method GET
+# Created route 9df71836-… (GET * /count)
+```
+
+Now hit it — the count persists between calls:
+
+```sh
+curl $PICLOUD/count    # {"count":1}
+curl $PICLOUD/count    # {"count":2}
+curl $PICLOUD/count    # {"count":3}
+```
+
+You just wrote a stateful endpoint with no database wiring, no migrations, no deploy pipeline.
+
+## Step 7 — Look behind the curtain
+
+Read what your script stored, straight from KV:
+
+```sh
+pic kv get --app default --collection counters home
+# 3
+```
+
+And see every execution, with timing and status:
+
+```sh
+pic logs $SID --limit 3
+```
+```text
+created_at                        source  status   summary
+2026-06-17T19:54:01.265901+00:00  http    success  -
+2026-06-17T19:54:01.161625+00:00  http    success  -
+```
+
+The dashboard shows the same under the script's **Executions** tab, including each run's `log::` output.
+
+## Where to next
+
+You now understand the core loop: **write a script → bind a route → call it → inspect**. From here:
+
+- **Understand the model** → [Core concepts](concepts.md): apps, isolation, dispatch, events, versions.
+- **Write better scripts** → [Writing scripts](writing-scripts.md): the `ctx` object, the envelope,
+  error handling, logging, sandbox limits.
+- **Build something real** → the [tutorials](../examples/index.md): a URL shortener, a webhook
+  receiver, an authenticated TODO API, a scheduled report, and a file-upload service.
--- a/docs/dev-guide/src/guide/writing-scripts.md
+++ b/docs/dev-guide/src/guide/writing-scripts.md
@@ -0,0 +1,206 @@
+# Writing scripts
+
+Scripts are written in [Rhai](https://rhai.rs/book/) — a small, embeddable language with Rust-flavored
+syntax, dynamic typing, maps (`#{ ... }`), arrays, and closures (`|x| ...`). This chapter covers what's
+specific to writing scripts *for PiCloud*: the `ctx` object, the response envelope, errors, logging,
+modules, and the sandbox. For the SDK calls themselves (`kv`, `http`, …) see the
+[SDK reference](../reference/sdk/overview.md).
+
+## The shape of a script
+
+An `endpoint` script runs top to bottom; whatever it `return`s (or the value of its last expression)
+becomes the [response envelope](concepts.md#the-response-envelope).
+
+```rhai
+// Read input from ctx, do work, return a response.
+let body = ctx.request.body;
+let name = if type_of(body) == "map" && body.contains("name") { body.name } else { "world" };
+return #{ statusCode: 200, body: #{ message: `Hello, ${name}!` } };
+```
+
+There's no `main`, no handler signature, no framework. The whole file *is* the handler.
+
+## `ctx` — the execution context
+
+Every run gets a global `ctx` map. The fields:
+
+| Field | Type | Notes |
+|---|---|---|
+| `ctx.sdk_version` | string | e.g. `"1.10"` — for feature detection |
+| `ctx.execution_id` | string (UUID) | unique per run |
+| `ctx.script_id` | string (UUID) | the running script |
+| `ctx.script_name` | string | |
+| `ctx.request_id` | string (UUID) | correlation id, also in logs |
+| `ctx.invocation_type` | string | `"http"`, `"function"` (via `invoke()`), or `"scheduled"` |
+| `ctx.request` | map | the request, see below |
+| `ctx.event` | map | **present only for triggered runs** — see [events](../reference/sdk/ctx-and-events.md#events) |
+
+`ctx.request`:
+
+| Field | Type | Notes |
+|---|---|---|
+| `ctx.request.path` | string | e.g. `"/users/42"` |
+| `ctx.request.method` | string | uppercased, e.g. `"GET"` |
+| `ctx.request.headers` | map | **lowercased** keys → values: `ctx.request.headers["authorization"]` |
+| `ctx.request.body` | dynamic | **already JSON-parsed** when the body is JSON; a string otherwise; `()` if empty |
+| `ctx.request.params` | map | captures from `:name` path segments; empty if none |
+| `ctx.request.query` | map | query-string params; empty if none |
+| `ctx.request.rest` | string | the tail captured by a `prefix` (`/*`) route; empty otherwise |
+
+> **`ctx.request.body` is parsed for you.** If the client sends `Content-Type: application/json`, the
+> body arrives as a Rhai map/array/scalar — you do **not** call `json::parse` on it. Only parse raw
+> strings you get from elsewhere. Header keys are always lowercase. Test for presence before indexing:
+> `if "x-api-key" in ctx.request.headers { ... }`.
+
+> **There are no raw request bytes in `ctx`.** The body is JSON (or a string). To accept a binary
+> upload, have the client base64-encode it inside a JSON field and `base64::decode` it in the script —
+> see the [file-upload tutorial](../examples/file-upload.md).
+
+## The response envelope, in detail
+
+```rhai
+// Full control: status, headers, body.
+return #{
+    statusCode: 302,
+    headers: #{ "Location": "https://example.com/target" },
+    body: ()
+};
+```
+
+- `statusCode` — required integer if the map is to be treated as an envelope. Omit it and the *whole
+  map* becomes a `200` JSON body instead.
+- `headers` — a `string → string` map. Values are stringified.
+- `body` — **always serialized as JSON.** A map/array becomes a JSON object/array; a string becomes a
+  JSON *string* (so `body: "pong"` is sent as `"pong"`, with quotes); `()` becomes `null`.
+
+Shortcut: returning any non-envelope value yields `200 OK` with that value as the JSON body. `return #{
+ok: true };` ⇒ `200 {"ok":true}`; `return "pong";` ⇒ `200 "pong"`.
+
+> **Responses are always JSON.** The response body is JSON-encoded regardless of any `Content-Type`
+> header you set (the default content type is `application/json`; you can override the *header*, but
+> the *bytes* stay JSON). In 1.1.9 a script route therefore **cannot serve raw HTML, plain text, or
+> binary** — to return a file's bytes, send base64 in JSON or use the
+> [admin files endpoint](../reference/rest-api/data-admin.md#files). See the
+> [file-upload tutorial](../examples/file-upload.md).
+
+## Errors
+
+A script that **`throw`**s aborts and produces an HTTP **502**:
+
+```rhai
+if ctx.request.body == () { throw "body required"; }
+```
+```text
+HTTP/1.1 502 Bad Gateway
+{"error":"Runtime error: body required (line 1, position 30)"}
+```
+
+To return a *clean* client error instead of a 502, return an envelope with the status you want:
+
+```rhai
+if ctx.request.body == () {
+    return #{ statusCode: 400, body: #{ error: "body required" } };
+}
+```
+
+SDK calls follow a consistent convention so you can decide whether to guard or let it bubble:
+
+- **They throw** on real failures (DB down, payload over a size cap, authorization denied).
+- **They return `()`** for "not found" (`kv::...get` of a missing key, `users::login` with bad
+  credentials, etc.). Test with `== ()`.
+- **They return a `bool`** for predicates (`...has(k)`, `...delete(k)` → was-it-present).
+
+Wrap risky calls in `try { ... } catch (e) { ... }` when you want to handle failure yourself.
+
+## Logging
+
+`log::<level>(message)` or `log::<level>(message, #{ structured: "data" })`, at four levels:
+
+```rhai
+log::info("charge succeeded", #{ order: id, cents: amount });
+log::warn("retrying upstream");
+log::error("gave up", #{ attempts: 3 });
+log::trace("entered branch A");
+```
+
+There is **no `log::debug`** (`debug` is a reserved word in Rhai) — use `log::trace`.
+
+> **Where do these show up?** Log entries are buffered during the run and persisted to the execution
+> log **for asynchronous and triggered executions** (async routes, cron/queue/kv/… triggers) — view
+> them with `pic logs <script_id>` or the dashboard's **Executions** tab. **Synchronous HTTP
+> executions do not persist the buffered `log::` output** (the row records timing, status, and code
+> only). So `log::` is most useful for background work; for sync endpoints, fold diagnostics into the
+> response during development. This is a deliberate hot-path optimization, not a bug.
+
+## Modules and imports
+
+Factor shared logic into a **module** script (`kind: "module"`) — it may contain only `fn` and `const`
+declarations, no top-level statements:
+
+```rhai
+// module script named "money"
+const CURRENCY = "EUR";
+fn format(cents) {
+    `${CURRENCY} ${cents / 100}.${cents % 100}`
+}
+```
+
+Another script *in the same app* imports it by name:
+
+```rhai
+import "money" as money;
+return #{ statusCode: 200, body: #{ price: money::format(4999) } };
+```
+
+Deploy a module with `pic scripts deploy money.rhai --app myapp --kind module`. Cross-app imports are
+impossible — the import name carries no app, and resolution is scoped to the caller's app. Module names
+can't shadow SDK namespaces (`kv`, `http`, `log`, …). The [scheduled-report
+tutorial](../examples/scheduled-report.md) uses a module.
+
+## Sandbox limits
+
+Every run is bounded. If a script exceeds a limit it's terminated and the request fails (a timeout is
+`504`; an operation-budget overrun is `507`).
+
+| Limit | Default (what scripts get) | What it bounds |
+|---|---|---|
+| `timeout_seconds` | 30 (max 300) | wall-clock time |
+| `memory_limit_mb` | 256 (max 2048) | memory |
+| `max_operations` | 1,000,000 | total Rhai operations (a CPU proxy) |
+| `max_string_size` | 64 KiB | longest string built |
+| `max_array_size` | 10,000 | longest array |
+| `max_map_size` | 10,000 | largest map |
+| `max_call_levels` | 64 | call-stack depth |
+| `max_expr_depth` | 64 | expression nesting |
+
+You can *lower* (or raise, within ceilings) these per script. Via the CLI:
+
+```sh
+pic scripts deploy heavy.rhai --app myapp --timeout 60 --sandbox max_operations=5000000
+```
+
+Per-knob overrides are clamped to admin-configured **ceilings** (defaults: 10M operations, 1 MiB
+strings, 100k array/map, 128 call/expr levels; tunable with `PICLOUD_SANDBOX_MAX_*` — see
+[env vars](../reference/config/env-vars.md)). An override above the ceiling is rejected at deploy time,
+so a typo can't silently create an unrestricted script.
+
+Separately, the whole instance caps **concurrent** executions (`PICLOUD_MAX_CONCURRENT_EXECUTIONS`,
+default 32); past that, new data-plane requests get `503` with `Retry-After: 1` immediately — there's
+no queue. Plan for it; see [Best practices](../operations/best-practices.md).
+
+## Quick reference: idioms
+
+```rhai
+// Default a missing body field
+let n = if "count" in ctx.request.body { ctx.request.body.count } else { 0 };
+
+// Read a header (always lowercase key)
+let auth = if "authorization" in ctx.request.headers { ctx.request.headers["authorization"] } else { "" };
+
+// 404 cleanly
+let row = kv::collection("things").get(id);
+if row == () { return #{ statusCode: 404, body: #{ error: "not found" } }; }
+
+// Redirect
+return #{ statusCode: 302, headers: #{ "Location": target }, body: () };
+```
--- a/docs/dev-guide/src/introduction.md
+++ b/docs/dev-guide/src/introduction.md
@@ -0,0 +1,124 @@
+# PiCloud Developer Guide
+
+**PiCloud is a self-hosted, event-driven serverless platform.** You write small scripts in
+[Rhai](https://rhai.rs) (an embedded scripting language with Rust-like syntax), upload them, and bind
+them to URLs. PiCloud runs each script in a sandbox when a request arrives — no servers to manage, no
+containers to build, no cold-start orchestration to think about. It is built to run comfortably on a
+single box (a home server, a VPS, a Raspberry Pi) and scales to a cluster later without a rewrite.
+
+If you have ever used a "functions" product in a public cloud, the mental model is the same — but the
+whole thing is one binary plus a Postgres database that *you* own.
+
+```text
+   HTTP request                                  ┌──────────────────────────┐
+        │                                        │  your Rhai script        │
+        ▼                                        │                          │
+  ┌───────────┐   resolve Host → app,    ┌──────▶│  let body = ctx.request  │
+  │   Caddy   │──▶ then match the route  ─┘       │  kv::collection("x")...  │
+  │  (proxy)  │      (orchestrator)               │  return #{ statusCode }  │
+  └───────────┘                                   └──────────────────────────┘
+        │                                                      │
+        │                       sandboxed run (executor) ◀─────┘
+        ▼
+   HTTP response  ◀── the response envelope your script returned
+```
+
+## What you can build
+
+A script can do a lot more than return JSON. Through the **SDK** it can store data, send mail, call
+other services, react to events, and run on a schedule:
+
+| Capability | SDK namespace | Backed by |
+|---|---|---|
+| Key/value storage | `kv` | Postgres (JSONB) |
+| Document storage with queries | `docs` | Postgres (JSONB) |
+| Blob / file storage | `files` | Filesystem + Postgres metadata |
+| Outbound HTTP requests | `http` | reqwest, with an SSRF guard |
+| Send & receive email | `email` | SMTP relay / inbound webhook |
+| End-user accounts & login | `users` | Postgres + Argon2id |
+| Pub/sub & realtime (SSE) | `pubsub` | Postgres `LISTEN/NOTIFY` |
+| Durable job queues | `queue` | Postgres |
+| Encrypted secrets | `secrets` | Postgres (AES-256-GCM) |
+| Call other scripts | `invoke` | in-process re-entry |
+| Retry with backoff | `retry` | — |
+| Scheduled / event triggers | (triggers, not an SDK call) | dispatcher |
+
+Plus a **standard library** for the everyday glue: `json`, `base64`, `hex`, `url`, `regex`, `random`,
+`time`. See the [SDK reference](reference/sdk/overview.md) for the full surface.
+
+## Three ways to drive PiCloud
+
+Everything below is just a client of the same HTTP control plane — pick whichever fits:
+
+1. **The dashboard** — a web UI at `/admin` with a code editor, route binder, log viewer, and
+   management screens for every resource. Best for exploring and for editing scripts.
+2. **The `pic` CLI** — a developer command-line client. Best for scripting deploys, CI, and quick
+   inspection. See the [CLI reference](reference/cli/pic.md).
+3. **Plain HTTP** (`curl`, any language) — the underlying REST API. Best when you want no extra
+   tooling, or to integrate from your own code. See the [HTTP API reference](reference/rest-api/overview.md).
+
+This guide shows all three side by side throughout.
+
+## Where to start
+
+> **New here?** → [Quickstart](guide/quickstart.md) (zero to a live endpoint in ~10 minutes) →
+> [Core concepts](guide/concepts.md) → pick a [tutorial](examples/index.md).
+>
+> **Want to build something concrete?** → the [tutorials](examples/index.md) are five complete,
+> copy-pasteable example apps, each exercising a different slice of the platform.
+>
+> **Looking something up?** → the [SDK](reference/sdk/overview.md),
+> [HTTP API](reference/rest-api/overview.md), and [CLI](reference/cli/pic.md) references are
+> organized for lookup. Use the search box (top-left) for anything specific.
+>
+> **Running it in production?** → [Deployment](deploy/docker-compose.md) and the
+> [security chapter](operations/security.md).
+
+## A note on versions
+
+This guide documents **PiCloud product `1.1.9`**. PiCloud tracks five independent version numbers, all
+returned by [`GET /version`](reference/rest-api/overview.md#get-version):
+
+| Surface | Value | Means |
+|---|---|---|
+| `product` | `1.1.9` | the release you're running |
+| `sdk` | `1.10` | the script-visible SDK, in **`major.minor`** form — this is the *tenth minor* of SDK v1, **not** "1.1.0" |
+| `api` | `1` | the HTTP API major version, in the URL as `/api/v1/...` |
+| `schema` | `44` | the database migration number |
+| `wire` | `1` | the inter-node protocol (reserved; cluster mode is a future release) |
+
+Your scripts can read the SDK version at runtime as `ctx.sdk_version` (the string `"1.10"`). Do not
+confuse `sdk` with `product`. [More on versioning →](guide/concepts.md#the-five-version-surfaces)
+
+## Glossary
+
+These terms recur throughout the guide:
+
+- **App** — a tenant/namespace. Owns scripts, routes, domains, and all data. Apps are isolated from
+  each other; a script can only ever touch its own app's data. See [Core concepts](guide/concepts.md#apps).
+- **Script** — a Rhai program. Two kinds: an **endpoint** (runs on requests/events) or a **module**
+  (a library of `fn`/`const` that other scripts `import`).
+- **Route** — a binding from an HTTP method + host + path to a script. One script can have many routes.
+- **Trigger** — a binding that fires a script on an *event* instead of an HTTP request: a KV/docs/files
+  mutation, a published message, a queue message, a cron tick, or inbound email.
+- **Event** — the thing that fired a triggered script; surfaced to the script as `ctx.event`.
+- **Dispatch mode** — `sync` (the caller waits for the script's response) or `async` (the platform
+  returns `202 Accepted` immediately and runs the script in the background).
+- **Collection** — a named bucket inside a storage service. The identity of a stored item is the tuple
+  `(app, collection, key)`. Collections are mandatory.
+- **Response envelope** — the value an endpoint script returns to shape the HTTP response: a map with
+  `statusCode`, optional `headers`, and `body`.
+- **Principal** — the authenticated identity behind a control-plane request: an **admin user** or an
+  **API key**. Distinct from an **app user** (an end-user of *your* app, managed by the `users` SDK).
+- **Instance role** — an admin's platform-wide role: `owner`, `admin`, or `member`.
+- **App role** — a member's per-app role: `app_admin`, `editor`, or `viewer`.
+- **Dead letter** — a record of a triggered execution that exhausted its retries; you can inspect and
+  replay it.
+
+## How to read the code examples
+
+- Rhai snippets are shown as ```rhai``` blocks; they are the *body* of a script.
+- HTTP examples use `curl` against a local dev instance on port `18080` (the dashboard-fronted stack
+  uses `8000` — adjust to your setup; see [Deployment](deploy/docker-compose.md)).
+- CLI examples use the `pic` binary.
+- Wherever a guide says a request "returns X", that output was produced by actually running it.
--- a/docs/dev-guide/src/operations/best-practices.md
+++ b/docs/dev-guide/src/operations/best-practices.md
@@ -0,0 +1,99 @@
+# Best practices
+
+Patterns that hold up as your scripts move from demo to production.
+
+## Sync vs async dispatch {#sync-vs-async}
+
+- Use **`sync`** when the caller needs the result *now* and the work is fast (a lookup, a small
+  computation, a redirect).
+- Use **`async`** (route or trigger) for anything slow or fire-and-forget — webhooks you don't need to
+  answer in detail, fan-out, outbound calls, report generation. The client gets `202` immediately and
+  isn't blocked by your processing.
+- Don't do slow work (a chain of `http` calls, big aggregations) on a `sync` route — you'll hold the
+  connection and burn a concurrency permit. Enqueue it and return `202`.
+
+## Idempotent consumers {#idempotent-consumers}
+
+Queue messages and triggers can fire **more than once** (a retry after a partial success, a
+visibility-timeout expiry). Make consumers idempotent:
+
+```rhai
+let msg = ctx.event.queue.message;
+let done = kv::collection("processed");
+if done.has(msg.id) { return; }        // already handled — skip
+// ... do the work ...
+done.set(msg.id, time::now_ms());
+```
+
+`ctx.event.queue.attempt` (and `ctx.event.dead_letter.attempts`) tell you when you're on a retry.
+
+## Retries & dead-letters
+
+- Wrap genuinely transient calls (`http`, `invoke`) in [`retry::run`](../reference/sdk/composition.md#retry)
+  with a bounded `max_attempts` and exponential backoff. Use `retry::on_codes` so you only retry the
+  failures worth retrying (e.g. `502/503/504`), not deterministic ones (`400`).
+- Don't stack retries blindly: the trigger's own `retry_max_attempts` *and* an in-script `retry::run`
+  multiply. Pick one layer as primary.
+- Let exhausted work become a **dead-letter**, then alert on the count and replay after a fix — rather
+  than retrying forever. A [`dead_letter` trigger](../reference/rest-api/triggers.md) can automate the
+  alert/replay.
+
+## Data modeling
+
+- **`kv`** for simple keyed values, counters, flags, caches. **`docs`** when you need to *find by
+  field*. **`files`** for blobs. **`secrets`** for credentials.
+- Pick **collection names** deliberately — `(app, collection, key)` is the identity; one collection per
+  logical entity (`users`, `orders`) keeps listing and triggers clean.
+- `docs.update` **replaces** the whole `data` map — read-modify-write to change one field.
+- Respect the [size caps](../reference/config/env-vars.md#data-plane-size-caps) (256 KiB for
+  kv/docs/queue/pubsub). If a value is growing toward the cap, you're probably modeling it wrong (split
+  it, or use `files`).
+
+## Pagination
+
+List endpoints (`kv.list`, `docs.list`, admin lists) are **keyset/cursor** paginated. Loop until
+`next_cursor` is `()`:
+
+```rhai
+let c = docs::collection("orders");
+let cursor = ();
+loop {
+    let page = c.list(#{ cursor: cursor, limit: 100 });
+    for doc in page.docs { /* ... */ }
+    cursor = page.next_cursor;
+    if cursor == () { break; }
+}
+```
+
+Don't assume one `list()` returns everything.
+
+## Script organization
+
+- Factor shared logic into a **`module`** and `import` it — don't copy-paste across endpoints.
+- One script can serve **several routes** and branch on `ctx.request.method` / `params` (see the
+  [TODO API](../examples/todo-api.md)); or split per concern. Either is fine — optimize for readability.
+- Validate `ctx.request.body` shape early and return a clean `400`, rather than letting a missing field
+  throw a `502`.
+
+## Logging & debugging
+
+- `log::` output is persisted for **async/triggered** runs — use it freely there and read it with
+  `pic logs <id> --source <kind>`.
+- For **synchronous HTTP** runs, `log::` is **not** persisted (a hot-path optimization). During
+  development, fold diagnostics into the response, or test the logic via an async path / `execute`.
+- Filter logs by `--source` (`http`, `queue`, `cron`, …) to separate request handling from background
+  work.
+
+## Concurrency & limits
+
+- The instance caps concurrent executions (`PICLOUD_MAX_CONCURRENT_EXECUTIONS`); past it, callers get
+  `503 Retry-After: 1`. Build clients that honor `Retry-After`, and keep sync handlers quick so permits
+  free up fast.
+- Lower a script's `timeout_seconds`/sandbox limits if it should be cheap — it fails fast instead of
+  hogging a permit.
+
+## Versioning
+
+- Read `ctx.sdk_version` if you want to feature-detect, but remember it's `major.minor` (`"1.10"`).
+  Minor bumps only *add*; your scripts keep working across them.
+- Don't hardcode assumptions about the `product` version into scripts.
--- a/docs/dev-guide/src/operations/security.md
+++ b/docs/dev-guide/src/operations/security.md
@@ -0,0 +1,105 @@
+# Security
+
+PiCloud gives you isolation and sandboxing by default, but several things are *your* responsibility.
+Read this once before you put a public route online.
+
+## The data plane is public {#the-data-plane-is-public}
+
+**This is the most important point in the whole guide.** The routes you create are public, and a
+request to one runs your script with **full authority over its app's data** — it can read every secret,
+every KV key, every document, every user. PiCloud puts **no authentication in front of your routes**.
+
+The [capability/role model](../reference/config/capabilities.md) governs the *control plane* (the admin
+API) — not your routes. So:
+
+- If a route must be restricted, **the script enforces it** — check a bearer token with
+  `users::verify`, compare a shared secret, etc. (see the [TODO API](../examples/todo-api.md) and
+  [webhook](../examples/webhook-receiver.md) tutorials).
+- Treat anything a public script can read as reachable by anyone who can hit the route. Don't put a
+  secret in a collection a public script reads unless you mean to expose it.
+- A script that calls `users::find_by_email` from an *unauthenticated* context is refused — but that's
+  one specific guard, not a general one.
+
+## Cross-app isolation
+
+Apps are hard-isolated: every SDK call derives the app from the server-side execution context, and
+there is **no `app_id` argument anywhere in the SDK**. A script cannot name or reach another app's
+data, period. This is enforced in the platform, not by convention — you can rely on it. Cross-app
+sharing does not exist in 1.1.9.
+
+## Secrets and the master key {#secrets-and-the-master-key}
+
+- Store credentials in [`secrets`](../reference/sdk/secrets.md), not `kv` — secret values are encrypted
+  at rest (AES-256-GCM) and never returned by the admin API/dashboard/CLI (names only).
+- Set them out-of-band (`pic secrets set` reads the value from stdin) rather than hardcoding in source.
+- **Critical: the master key.** Secrets are encrypted under `PICLOUD_SECRET_KEY`. **Rotating it makes
+  existing secrets undecryptable** (`secrets::get` returns `()`); there's no automatic re-encryption in
+  1.1.9. Treat the key as durable, store it in a secret manager, and if you must rotate, re-`set` every
+  secret afterward.
+- **Never** run production with `PICLOUD_DEV_MODE` + `PICLOUD_DEV_INSECURE_KEY` — that "key" is
+  world-known, so at-rest encryption is worthless.
+
+## SSRF — outbound HTTP {#ssrf}
+
+`http::*` resolves the target and **blocks private, loopback, and link-local addresses** by default, so
+a script taking a user-supplied URL can't be tricked into scanning your internal network. A blocked
+call throws, e.g.:
+
+```text
+http: blocked by SSRF policy: loopback
+```
+
+The escape hatch `PICLOUD_HTTP_ALLOW_PRIVATE=true` disables this — **dev/test only, never production**.
+If you need a script to reach an internal service in prod, give it a routable address, not a private
+one.
+
+## User enumeration {#user-enumeration}
+
+The [`users`](../reference/sdk/users.md) SDK is built to resist account enumeration:
+
+- `users::find_by_email` **requires an authenticated principal** — anonymous/public scripts can't use
+  it to probe who's registered.
+- `users::email_available` *is* anonymous-safe (a signup form legitimately needs it), but it is **not
+  throttled**. If enumeration via the signup form is a concern, rate-limit it yourself (e.g. a `kv`
+  counter keyed by IP).
+
+## Input validation & injection
+
+- `ctx.request.body` is parsed JSON — validate its **shape** before use (`type_of`, `contains`) so a
+  missing field throws a clean `400`, not a confusing `502`.
+- There's no SQL to inject (you don't write SQL), but be careful with **open redirects** (validate URLs
+  before issuing a `302`) and with reflecting user input into emails or downstream HTTP.
+- Storing user-supplied HTML and serving it later is *not* a vector here, because
+  [script responses are always JSON](../guide/writing-scripts.md#the-response-envelope-in-detail) — but
+  if you base64-ship content for a client to render, the usual XSS rules apply on the client.
+
+## Webhook authenticity
+
+The 1.1.9 script SDK has **no HMAC/hashing primitive**, so a script cannot verify a provider's HMAC
+signature itself. Options:
+
+- Use a **shared-secret header** compared against a stored secret (the
+  [webhook tutorial](../examples/webhook-receiver.md) approach).
+- For **inbound email**, use the built-in [email trigger](../reference/rest-api/triggers.md) with an
+  `inbound_secret` — the platform does the HMAC verification server-side.
+
+## API keys & least privilege
+
+- Mint [API keys](../reference/rest-api/access.md#api-keys) with the **narrowest scopes** that work,
+  **bind them to one app** (`--app`), and set `expires_at`. A bound key can't hold `instance:admin`.
+- The raw token is shown once — store it in your secret manager.
+- Revoking a key (or deactivating an admin) takes effect immediately.
+- Prefer **per-app members** with `viewer`/`editor` over handing out instance `admin`.
+
+## Platform hardening (already done for you)
+
+- Caddy adds CSP, `X-Frame-Options`, `nosniff`, `Referrer-Policy`, and (in prod) HSTS to the dashboard
+  and admin API, plus a 12 MB request-body ceiling. User-route responses deliberately get no CSP — your
+  scripts own their headers.
+- Login is rate-limited per IP and per username; passwords use Argon2id; sessions and API keys are
+  stored as hashes.
+- Scripts run in a [sandbox](../guide/writing-scripts.md#sandbox-limits) with operation, memory, and
+  wall-clock limits, and the whole instance caps concurrency.
+
+See the [Production checklist](../deploy/production-checklist.md) for the deployment-time version of
+this page.
--- a/docs/dev-guide/src/operations/troubleshooting.md
+++ b/docs/dev-guide/src/operations/troubleshooting.md
@@ -0,0 +1,106 @@
+# Troubleshooting
+
+Symptoms you'll actually hit, and what they mean. All error strings below are real responses from a
+running instance.
+
+## Routing
+
+**`404 {"error":"no app claims host \"…\""}`**
+No app claims the request's `Host`. The `default` app claims only `localhost`. For another app, claim
+the host first (`pic apps domains add <app> <host>`) and send a matching `Host:` header. Locally:
+`pic apps domains add myapp myapp.localhost` then `curl -H 'Host: myapp.localhost' …`.
+
+**`404 {"error":"no route matches GET /…"}`**
+The host resolved to an app, but no route matches that method+path in *that app*. Check
+`pic routes ls <script_id>`, and that the method matches (a route with `method: null` matches any). Use
+`pic routes match --app <app> <url>` to see what would match.
+
+**My route returns 404 but I just created it.**
+Are you hitting the right app's host? Routes are app-scoped. Also: routes under `/api/`, `/admin/`,
+`/healthz`, `/version` are rejected at creation — Caddy never forwards those to the matcher.
+
+## Script errors
+
+**`502 {"error":"Runtime error: … (line N, position M)"}`**
+Your script `throw`ew (or hit a runtime error). To return a clean client error instead, return an
+envelope: `return #{ statusCode: 400, body: #{ error: "…" } };`.
+
+**`422 invalid script: … 'public' is a reserved keyword`** (or `loop`, `fn`, …)
+Rhai reserves more words than you'd expect (`public`, `loop`, `debug`, …). Rename the variable. Note
+there's no `log::debug` — use `log::trace`.
+
+**`Unknown property 'x' - a getter is not registered …`**
+You accessed `.x` on a value that isn't a map (or whose field is named differently). Most often a
+wrong [`ctx.event`](../reference/sdk/ctx-and-events.md#events) path — e.g. the queue payload is
+`ctx.event.queue.message`, **not** `.payload`; the attempt count is `.attempt`, not `.attempts`.
+
+**`504 Gateway Timeout`** — the script exceeded `timeout_seconds`.
+**`507`** — it blew the operation budget (`max_operations`). Both mean: do less, or raise the limit
+(within [ceilings](../reference/config/env-vars.md#sandbox-ceilings)) at deploy time.
+
+**My `log::info` output isn't in the logs.**
+Synchronous HTTP runs don't persist `log::` output — only async/triggered runs do. Not a bug; see
+[Writing scripts → Logging](../guide/writing-scripts.md#logging).
+
+## SDK calls
+
+**`http: blocked by SSRF policy: loopback`** (or `private`)
+`http::*` blocks private/loopback targets by default. You're trying to reach `localhost`/a private IP.
+Use a public address, or (dev only) `PICLOUD_HTTP_ALLOW_PRIVATE=true`. [More →](security.md#ssrf).
+
+**`email::send` throws `NotConfigured`.**
+No SMTP relay configured. Set `PICLOUD_SMTP_*`, or in dev mode use the sink at
+`GET /api/v1/admin/dev/emails`.
+
+**A `get` returns `()` unexpectedly.**
+`()` means "absent". For `secrets::get` it can also mean decryption failed — did the
+`PICLOUD_SECRET_KEY` change? ([master-key caveat](security.md#secrets-and-the-master-key)).
+
+**A `set`/`enqueue`/`create` throws about size.**
+You exceeded a [size cap](../reference/config/env-vars.md#data-plane-size-caps) (256 KiB for
+kv/docs/queue/pubsub; 100 MiB for files). Remember base64 inflates ~33%.
+
+## API & auth
+
+**`401 Unauthorized` on an admin call.** Missing/invalid/expired bearer token. Re-`pic login`, or check
+the `Authorization: Bearer …` header. **`403 Forbidden`** means you're authenticated but lack the
+[capability](../reference/config/capabilities.md) — wrong role for that action.
+
+**`422 unknown scope: app:read`** (minting an API key)
+That's not a real scope. The seven valid ones: `script:read`, `script:write`, `route:write`,
+`domain:manage`, `log:read`, `app:admin`, `instance:admin`.
+
+**`422 invalid resolution: …`** (resolving a dead-letter)
+Reasons are a fixed set: `ignored`, `handled_by_script`, `handler_failed` (and `replayed`, set by
+`replay`). Not free text.
+
+**`Failed to parse the request body as JSON …`**
+Malformed JSON, or (a classic) unescaped quotes when hand-building a body in the shell. Deploy scripts
+from a `.rhai` file with `pic scripts deploy` instead of inlining source in a JSON string.
+
+## Platform
+
+**`503` with `Retry-After: 1` on a route.**
+The instance hit its concurrency cap (`PICLOUD_MAX_CONCURRENT_EXECUTIONS`, default 32). There's no
+queue — back off and retry. Long-term: raise the cap (and `PICLOUD_DB_MAX_CONNECTIONS` with it), or
+move slow work to `async`.
+
+**Dashboard dev server can't reach the API.**
+Vite proxies `/api` to `http://127.0.0.1:18080` by default — run `picloud` on `18080` or set
+`PICLOUD_API`. [More →](../deploy/bare-binary.md#running-the-dashboard-in-dev).
+
+**Server won't start.**
+- Missing `DATABASE_URL` → it aborts. Set it.
+- `PICLOUD_DEV_MODE=true` *alone* aborts — also set `PICLOUD_DEV_INSECURE_KEY=i-understand-this-is-insecure`,
+  or provide a real `PICLOUD_SECRET_KEY`.
+- `docker compose up` errors on unset `PICLOUD_ADMIN_USERNAME`/`PICLOUD_ADMIN_PASSWORD` (compose makes
+  them mandatory).
+
+**Locked out — forgot the admin password.**
+`docker compose exec picloud picloud admin reset-password <username>` (or run the binary's subcommand
+directly). [More →](../reference/cli/server-admin.md).
+
+## Still stuck?
+
+Check the server logs (`docker compose logs -f picloud` or stdout), bump `RUST_LOG=debug,picloud=debug`,
+and read the execution log for the script (`pic logs <id>` / the dashboard **Executions** tab).
--- a/docs/dev-guide/src/reference/cli/pic.md
+++ b/docs/dev-guide/src/reference/cli/pic.md
@@ -0,0 +1,97 @@
+# The `pic` CLI
+
+`pic` is the PiCloud command-line client — a thin, scriptable wrapper over the same
+[HTTP API](../rest-api/overview.md) the dashboard uses. It's the most ergonomic way to deploy scripts,
+inspect logs, and automate from CI.
+
+## Install & authenticate
+
+`pic` is the `picloud-cli` crate. Build it from the workspace:
+
+```sh
+cargo build -p picloud-cli --release      # binary at target/release/pic
+```
+
+Authenticate once; the token is saved to `~/.config/picloud/credentials`:
+
+```sh
+# interactive (prompts for password)
+pic login --url http://localhost:8000 --username admin
+
+# non-interactive (CI): password from stdin
+printf "$ADMIN_PASSWORD" | pic login --url http://localhost:8000 --username admin --password-stdin
+
+# or authenticate with a long-lived API key instead of a session
+printf 'pic_…' | pic login --url http://localhost:8000 --token -
+```
+
+`PICLOUD_URL` and `PICLOUD_TOKEN` environment variables work too (handy in CI).
+
+## Output format
+
+Global `--output` flag: `tsv` (default — pipe-friendly, columnar) or `json` (`jq`-ready).
+
+```sh
+pic whoami                  # tsv table
+pic --output json apps ls   # JSON array
+```
+
+## Command map
+
+| Group | Commands |
+|---|---|
+| Auth | `login`, `logout`, `whoami` |
+| Apps | `apps ls`, `apps create <slug>`, `apps show <id>`, `apps delete <id> [--force]`, `apps domains {ls,add,rm}` |
+| Scripts | `scripts ls [--app]`, `scripts deploy <file> --app <slug>`, `scripts invoke <id>`, `scripts delete <id>` (also top-level `deploy`, `invoke`) |
+| Routes | `routes ls <script_id>`, `routes create --script … --path …`, `routes rm <id>`, `routes check`, `routes match` |
+| Logs | `logs <script_id> [--limit] [--source]` |
+| Triggers | `triggers ls`, `triggers create-{kv,cron,docs,files,pubsub,queue,email,dead-letter}`, `triggers create-from-json`, `triggers rm` |
+| Topics | `topics {ls,create,update,rm}` |
+| Secrets | `secrets {ls,set,rm}` (value via stdin) |
+| Queues | `queues {ls,show}` |
+| KV | `kv {ls,get}` |
+| Files | `files {ls,get,rm}` |
+| Dead-letters | `dead-letters {count,ls,show,replay,resolve}` |
+| App users | `users {ls,show,reset-password,revoke-sessions}` |
+| Members | `members {ls,add,set,rm}` |
+| Admins (instance) | `admins {ls,create,show,set,rm}` |
+| API keys | `api-keys {mint,ls,rm}` |
+
+Each resource page in the [HTTP API reference](../rest-api/overview.md) lists the matching `pic`
+commands. Run `pic <group> --help` for full flags.
+
+## Worked examples
+
+```sh
+# Deploy a script and bind a route
+pic scripts deploy ./shorten.rhai --app links --name shorten
+SID=$(pic --output json scripts ls --app links | jq -r '.[]|select(.name=="shorten").id')
+pic routes create --script $SID --path /shorten --method POST
+
+# A parameterized route, async dispatch
+pic routes create --script $SID --path '/r/:code' --path-kind param --method GET
+pic routes create --script $SID --path /ingest --method POST --dispatch async
+
+# Module script, sandbox override, custom timeout
+pic scripts deploy ./fmt.rhai --app links --kind module
+pic scripts deploy ./heavy.rhai --app links --timeout 60 --sandbox max_operations=5000000
+
+# Secrets (value never hits shell history)
+printf 'sk_live_…' | pic secrets set --app links stripe_key
+
+# Mint a scoped, app-bound, expiring API key
+pic api-keys mint deploy-bot --scope script:write --scope route:write --app links --expires 30d
+
+# Tail background-execution logs
+pic logs $SID --source queue --limit 20
+```
+
+## Notes & gotchas
+
+- Passwords and API-key values are **never** accepted inline (they'd leak into shell history / `ps`) —
+  always stdin or interactive prompt.
+- `routes create` defaults: host `*` (any), path-kind `exact`, dispatch `sync`. Trigger `create-*`
+  wrappers default dispatch to `async`.
+- `--app` accepts a slug or a UUID anywhere.
+- `pic` only ever talks to the HTTP API — it has no special powers the API doesn't. If something works
+  in `pic` it works in `curl`, and vice versa.
--- a/docs/dev-guide/src/reference/cli/server-admin.md
+++ b/docs/dev-guide/src/reference/cli/server-admin.md
@@ -0,0 +1,42 @@
+# Server admin commands
+
+Separate from the `pic` developer CLI, the **`picloud` server binary** carries a tiny set of
+operator/recovery subcommands you run directly on the host (no auth — they touch the database through
+`DATABASE_URL`). These are for out-of-band situations where you can't log in.
+
+## Bootstrap the first admin (env vars)
+
+On a **fresh install** (empty `admin_users` table), the server seeds the first admin — always as
+`owner` — from environment variables:
+
+| Variable | Notes |
+|---|---|
+| `PICLOUD_ADMIN_USERNAME` | required |
+| `PICLOUD_ADMIN_PASSWORD_HASH` | preferred — a pre-computed Argon2id PHC string, so the raw password never lands in env/compose |
+| `PICLOUD_ADMIN_PASSWORD` | fallback — raw password, hashed on first boot |
+
+If both the hash and the raw password are set, the hash wins (and a warning is logged). **These are
+read only when no admin exists yet** — on a database that already has an admin, they're ignored (with a
+warning). After that, manage admins via [`pic admins`](../rest-api/access.md#admin-users-instance) or
+the recovery command below.
+
+## `picloud admin reset-password`
+
+Reset (and reactivate) an admin's password without logging in — the escape hatch when you've locked
+yourself out:
+
+```sh
+# interactive: prompts for a new password on stdin
+picloud admin reset-password admin
+
+# non-interactive: supply a pre-computed Argon2id PHC hash
+picloud admin reset-password admin --password-hash '$argon2id$v=19$m=…'
+```
+
+It re-activates a deactivated admin and **drops all of that admin's sessions** (forcing re-login). It
+needs the same `DATABASE_URL` (and master key) the server normally runs with. Run it on the host, e.g.
+inside the container: `docker compose exec picloud picloud admin reset-password admin`.
+
+> This is the *only* subcommand on the server binary besides running the server itself. Everything
+> else — creating more admins, changing roles, minting keys — goes through the authenticated API
+> (`pic` or `curl`).
--- a/docs/dev-guide/src/reference/config/capabilities.md
+++ b/docs/dev-guide/src/reference/config/capabilities.md
@@ -0,0 +1,73 @@
+# Capabilities & roles
+
+Every control-plane action requires a **capability**. A request's principal is granted capabilities by
+its **instance role** and (for members) its per-app **app roles**. This page is the authoritative
+mapping.
+
+## Instance roles
+
+| Role | Grants |
+|---|---|
+| `owner` | **everything** — every capability on every app, plus instance settings |
+| `admin` | every capability on every app (implicit `app_admin` everywhere) + instance user management; **not** owner-only instance settings |
+| `member` | **no** instance authority; only the capabilities its app roles grant, on apps it's a member of |
+
+So owners and admins never need an explicit app membership. Members start with nothing until granted an
+app role.
+
+## App roles
+
+App roles form a strict chain — each includes the one before it: **viewer ⊂ editor ⊂ app_admin**.
+
+| App role | Adds |
+|---|---|
+| `viewer` | read scripts, routes, logs, KV, docs, files, secrets (names), app-users |
+| `editor` | + write scripts & routes; write KV/docs/files; publish pubsub; enqueue; write secrets; send email; manage app-users; `invoke` |
+| `app_admin` | + manage domains, triggers, topics, dead-letters; admin app-user actions; app settings & delete |
+
+## Capability reference
+
+Instance-level:
+
+| Capability | Required role |
+|---|---|
+| `InstanceCreateApp` | owner / admin |
+| `InstanceManageUsers` | owner / admin |
+| `InstanceManageSettings` | owner only |
+
+App-level (each is parameterized by the target app; a member needs the listed app role *on that app*):
+
+| Capability | viewer | editor | app_admin | Used by |
+|---|:--:|:--:|:--:|---|
+| `AppRead` | ✓ | ✓ | ✓ | read app/scripts/routes |
+| `AppLogRead` | ✓ | ✓ | ✓ | read execution logs |
+| `AppKvRead` / `AppDocsRead` / `AppFilesRead` / `AppSecretsRead` / `AppUsersRead` | ✓ | ✓ | ✓ | admin data views |
+| `AppWriteScript` | | ✓ | ✓ | create/update scripts |
+| `AppWriteRoute` | | ✓ | ✓ | manage routes |
+| `AppKvWrite` / `AppDocsWrite` / `AppFilesWrite` | | ✓ | ✓ | (data-plane writes) |
+| `AppHttpRequest` | | ✓ | ✓ | outbound `http` |
+| `AppPubsubPublish` | | ✓ | ✓ | `pubsub::publish_durable` |
+| `AppQueueEnqueue` | | ✓ | ✓ | `queue::enqueue` |
+| `AppSecretsWrite` | | ✓ | ✓ | set/delete secrets |
+| `AppEmailSend` | | ✓ | ✓ | `email::send` |
+| `AppUsersWrite` | | ✓ | ✓ | manage app-users |
+| `AppInvoke` | | ✓ | ✓ | `invoke()` |
+| `AppManageDomains` | | | ✓ | domain claims |
+| `AppManageTriggers` | | | ✓ | triggers |
+| `AppTopicManage` | | | ✓ | topics |
+| `AppDeadLetterManage` | | | ✓ | dead-letters |
+| `AppUsersAdmin` | | | ✓ | invitations, resets |
+| `AppAdmin` | | | ✓ | app settings, delete, members |
+
+## API-key scopes
+
+An [API key](../rest-api/access.md#api-keys) carries a subset of capabilities as **scopes**. The seven
+valid scopes: `script:read`, `script:write`, `route:write`, `domain:manage`, `log:read`, `app:admin`,
+`instance:admin`. A key bound to one app cannot hold `instance:admin`.
+
+## A crucial caveat: the data plane runs with full app authority
+
+The capability model above governs the **control plane** (the admin API). It does **not** gate your
+scripts' routes. A public route runs its script with **full authority over its own app's data** — it
+can read every secret and every record. PiCloud puts no auth in front of your routes. If a route must
+be restricted, the script enforces it. See [Security](../../operations/security.md#the-data-plane-is-public).
--- a/docs/dev-guide/src/reference/config/env-vars.md
+++ b/docs/dev-guide/src/reference/config/env-vars.md
@@ -0,0 +1,151 @@
+# Environment variables
+
+The `picloud` server is configured entirely through environment variables. This is the complete list,
+grouped by area. Only `DATABASE_URL` and a master key are strictly required to boot.
+
+## Required to boot
+
+| Variable | Default | Purpose |
+|---|---|---|
+| `DATABASE_URL` | — | **Required.** Postgres connection string. |
+| `PICLOUD_SECRET_KEY` | — | Master encryption key, base64 of 32 bytes. Required **unless** dev mode is acknowledged (below). Encrypts secrets and realtime keys at rest. |
+
+On a **fresh** database you also need the [bootstrap admin](#bootstrap-admin) vars. After that, only
+the two above are required.
+
+## Dev mode
+
+| Variable | Default | Purpose |
+|---|---|---|
+| `PICLOUD_DEV_MODE` | `false` | Enables local-dev conveniences (in-memory email sink). **Never in production.** |
+| `PICLOUD_DEV_INSECURE_KEY` | — | Set to the literal `i-understand-this-is-insecure` to boot without `PICLOUD_SECRET_KEY`, using a deterministic, world-known dev key. `PICLOUD_DEV_MODE=true` **alone aborts** — you must also set this. Never in production. |
+
+## Network & process
+
+| Variable | Default | Purpose |
+|---|---|---|
+| `PICLOUD_BIND` | `0.0.0.0:8080` | HTTP listen address. (In Compose, picloud binds 8080 *inside* the network; Caddy publishes 8000.) |
+| `PICLOUD_PUBLIC_BASE_URL` | `http://localhost:8000` | Public origin reported by `/version` and used to render URLs. |
+| `PICLOUD_DB_MAX_CONNECTIONS` | `32` | Postgres pool size (matched to the execution cap). |
+| `PICLOUD_MAX_CONCURRENT_EXECUTIONS` | `32` | Global cap on simultaneous script runs. Overflow → `503` + `Retry-After: 1`, no queue. |
+| `PICLOUD_SESSION_TTL_HOURS` | `24` | Admin session sliding-window lifetime. |
+| `RUST_LOG` | `info` | `tracing` filter, e.g. `info,picloud=debug`. |
+| `PICLOUD_CONFIG_DIR` | platform default | Where the `pic` CLI stores credentials. |
+
+## Bootstrap admin {#bootstrap-admin}
+
+Read only on a fresh install (empty `admin_users`); ignored afterward. See
+[Server admin commands](../cli/server-admin.md).
+
+| Variable | Purpose |
+|---|---|
+| `PICLOUD_ADMIN_USERNAME` | first admin's username (seeded as `owner`) |
+| `PICLOUD_ADMIN_PASSWORD_HASH` | preferred: Argon2id PHC string |
+| `PICLOUD_ADMIN_PASSWORD` | fallback: raw password |
+
+## Data-plane size caps
+
+Exceeding any cap throws in the script. All in bytes.
+
+| Variable | Default | Caps |
+|---|---|---|
+| `PICLOUD_KV_MAX_VALUE_BYTES` | `262144` (256 KiB) | `kv::...set` value |
+| `PICLOUD_DOCS_MAX_VALUE_BYTES` | `262144` | `docs` document |
+| `PICLOUD_PUBSUB_MAX_MESSAGE_BYTES` | `262144` | `pubsub::publish_durable` message |
+| `PICLOUD_QUEUE_MAX_PAYLOAD_BYTES` | `262144` | `queue::enqueue` message |
+| `PICLOUD_SECRET_MAX_VALUE_BYTES` | `262144` | `secrets::set` value |
+| `PICLOUD_FILES_MAX_FILE_SIZE_BYTES` | `104857600` (100 MiB) | `files::...create/update` blob |
+| `PICLOUD_EMAIL_MAX_MESSAGE_BYTES` | — | inbound/outbound email size |
+| `PICLOUD_EMAIL_MAX_RECIPIENTS` | — | recipients per send |
+| `PICLOUD_HTTP_MAX_REQUEST_BODY_BYTES` | — | outbound `http` request body |
+| `PICLOUD_HTTP_MAX_RESPONSE_BODY_BYTES` | — | outbound `http` response body read |
+
+## Sandbox ceilings
+
+Upper bounds on per-script [sandbox overrides](../../guide/writing-scripts.md#sandbox-limits). An
+override above the ceiling is rejected at deploy time. Defaults are the conservative built-ins.
+
+| Variable | Default ceiling |
+|---|---|
+| `PICLOUD_SANDBOX_MAX_OPERATIONS` | 10,000,000 |
+| `PICLOUD_SANDBOX_MAX_STRING_SIZE` | 1 MiB |
+| `PICLOUD_SANDBOX_MAX_ARRAY_SIZE` | 100,000 |
+| `PICLOUD_SANDBOX_MAX_MAP_SIZE` | 100,000 |
+| `PICLOUD_SANDBOX_MAX_CALL_LEVELS` | 128 |
+| `PICLOUD_SANDBOX_MAX_EXPR_DEPTH` | 128 |
+
+Two related platform-level depth bounds (not per-script overridable):
+
+| Variable | Default | Purpose |
+|---|---|---|
+| `PICLOUD_MAX_TRIGGER_DEPTH` | `8` | max trigger fan-out / `invoke` re-entry depth |
+| `PICLOUD_MODULE_IMPORT_DEPTH_MAX` | `8` | max `import` chain depth |
+
+## Outbound HTTP (`http` SDK)
+
+| Variable | Default | Purpose |
+|---|---|---|
+| `PICLOUD_HTTP_ALLOW_PRIVATE` | `false` | **Dev/test only.** `true` disables the SSRF deny-list (allows requests to private/loopback IPs). Never production. |
+
+## Email / SMTP
+
+Configure a relay to make `email::send` work; without it, sends throw `NotConfigured` (or hit the dev
+sink in dev mode).
+
+| Variable | Purpose |
+|---|---|
+| `PICLOUD_SMTP_HOST` / `PICLOUD_SMTP_PORT` | relay address |
+| `PICLOUD_SMTP_USER` / `PICLOUD_SMTP_PASSWORD` | relay auth |
+| `PICLOUD_SMTP_TLS` | TLS mode |
+| `PICLOUD_SMTP_TIMEOUT_SECS` | send timeout |
+
+## Triggers, dispatcher & background workers
+
+| Variable | Default | Purpose |
+|---|---|---|
+| `PICLOUD_DISPATCHER_ASYNC_EXEC_TIMEOUT_SEC` | `120` | per-message executor budget for async/triggered runs |
+| `PICLOUD_DISPATCHER_TICK_INTERVAL_MS` | — | dispatcher poll interval |
+| `PICLOUD_CRON_TICK_INTERVAL_MS` | — | cron scheduler resolution |
+| `PICLOUD_QUEUE_RECLAIM_INTERVAL_MS` | — | how often expired claims are reclaimed |
+| `PICLOUD_QUEUE_DEFAULT_VISIBILITY_TIMEOUT_SECS` | — | default queue claim lease |
+| `PICLOUD_TRIGGER_RETRY_MAX_ATTEMPTS` | `3` | default trigger retry attempts |
+| `PICLOUD_TRIGGER_RETRY_BACKOFF` | `exponential` | default backoff shape |
+| `PICLOUD_TRIGGER_RETRY_BASE_MS` | `1000` | default backoff base |
+| `PICLOUD_TRIGGER_RETRY_JITTER_PCT` | — | retry jitter |
+| `PICLOUD_DEAD_LETTER_RETENTION_DAYS` | `30` | how long dead-letters are kept |
+| `PICLOUD_ABANDONED_EXECUTIONS_RETENTION_DAYS` | — | sweep window for stale in-flight executions |
+
+## Realtime, subscriber tokens & caches
+
+| Variable | Default | Purpose |
+|---|---|---|
+| `PICLOUD_REALTIME_HEARTBEAT_SEC` | `30` | SSE heartbeat interval |
+| `PICLOUD_REALTIME_BROADCAST_CAPACITY` | — | per-topic broadcast buffer |
+| `PICLOUD_SUBSCRIBER_TOKEN_TTL_DEFAULT_SEC` / `_MIN_SEC` / `_MAX_SEC` | — | bounds for `pubsub::subscriber_token` TTLs |
+| `PICLOUD_SCRIPT_CACHE_SIZE` / `PICLOUD_MODULE_CACHE_SIZE` | — | in-memory cache sizes |
+
+## Files storage
+
+| Variable | Default | Purpose |
+|---|---|---|
+| `PICLOUD_FILES_ROOT` | `./data` | filesystem root for `files` blobs |
+| `PICLOUD_FILES_ORPHAN_SWEEP_INTERVAL_SEC` / `PICLOUD_FILES_ORPHAN_TMP_TTL_SEC` | — | cleanup of stale temp blobs |
+
+## App-user token lifetimes (`users` SDK)
+
+| Variable | Purpose |
+|---|---|
+| `PICLOUD_APP_USER_SESSION_TTL_HOURS` / `_ABSOLUTE_HOURS` | sliding & absolute session lifetime |
+| `PICLOUD_APP_USER_VERIFICATION_TTL_HOURS` | email-verification token TTL |
+| `PICLOUD_APP_USER_PASSWORD_RESET_TTL_HOURS` | password-reset token TTL |
+| `PICLOUD_APP_USER_INVITATION_TTL_DAYS` | invitation TTL |
+
+## `pic` CLI
+
+| Variable | Purpose |
+|---|---|
+| `PICLOUD_URL` | default server URL for `pic` |
+| `PICLOUD_TOKEN` | bearer token for `pic` (CI) |
+
+> Values shown as "—" have an internal default that's safe to leave unset; consult the running
+> instance or release notes if you need the exact number for capacity planning.
--- a/docs/dev-guide/src/reference/rest-api/access.md
+++ b/docs/dev-guide/src/reference/rest-api/access.md
@@ -0,0 +1,84 @@
+# Members, admins & API keys
+
+Three ways identity attaches to the control plane. See
+[Capabilities & roles](../config/capabilities.md) for the full permission model.
+
+## App members
+
+Grant other admin users a per-app role. Under `/api/v1/admin/apps/{id_or_slug}/members`, capability
+**`AppAdmin`**.
+
+| Method & path | Notes |
+|---|---|
+| `GET …/members` | list members + roles |
+| `POST …/members` | grant `{user_id, role}` (`409` if already a member) |
+| `PATCH …/members/{user_id}` | change `{role}` |
+| `DELETE …/members/{user_id}` | remove |
+
+Roles: `viewer` (read scripts/logs/routes/data), `editor` (+ write scripts/routes/KV/docs/files/…),
+`app_admin` (+ members, domains, triggers, topics, dead-letters). Instance `owner`/`admin` implicitly
+have full access to every app, so removing the last explicit member can't orphan an app. **CLI:**
+`pic members ls --app demo`, `pic members add --app demo --user <id> --role editor`,
+`pic members set --app demo --user <id> --role app_admin`, `pic members rm --app demo --user <id>`.
+
+## Admin users (instance)
+
+The platform accounts. Under `/api/v1/admin/admins`, capability **`InstanceManageUsers`** (owner/admin).
+
+| Method & path | Notes |
+|---|---|
+| `GET /api/v1/admin/admins` | list |
+| `POST /api/v1/admin/admins` | create `{username, password, email?, instance_role?}` (default role `admin`) |
+| `GET /api/v1/admin/admins/{id}` | one |
+| `PATCH /api/v1/admin/admins/{id}` | update `{username?, email?, password?, is_active?, instance_role?}` |
+| `DELETE /api/v1/admin/admins/{id}` | delete |
+
+Instance roles: `owner` (everything, including instance settings), `admin` (everything except
+owner-only settings), `member` (no instance powers; only the apps they're a member of). Deactivating an
+admin also expires their API keys and sessions; you can't deactivate the last active admin. The first
+admin is seeded from env vars on a fresh install (see
+[Server admin commands](../cli/server-admin.md)). **CLI:** `pic admins ls`,
+`pic admins create alice --password - --instance-role admin`, `pic admins set <id> --active false`.
+
+## API keys
+
+Long-lived bearer tokens for non-interactive use (CI, scripts). Under `/api/v1/admin/api-keys`; any
+authenticated principal manages **their own** keys.
+
+| Method & path | Notes |
+|---|---|
+| `GET /api/v1/admin/api-keys` | list the caller's keys (no token shown) |
+| `POST /api/v1/admin/api-keys` | mint `{name, scopes, app_id?, expires_at?}` |
+| `DELETE /api/v1/admin/api-keys/{id}` | revoke (takes effect immediately) |
+
+```sh
+curl -X POST $PICLOUD/api/v1/admin/api-keys -H "Authorization: Bearer $TOKEN" \
+  -H 'Content-Type: application/json' -d '{"name":"ci","scopes":["script:read","log:read"]}'
+```
+```json
+{"id":"…","prefix":"D3ZBPTRT","name":"ci","scopes":["script:read","log:read"],
+ "app_id":null,"expires_at":null,"last_used_at":null,"created_at":"…Z",
+ "raw_token":"pic_D3ZBPTRT4AKU3VUCJM5PR2WWEJWV35C6YBLBPJJTYLURD6OW4HUQ"}
+```
+
+The full `raw_token` is shown **exactly once**, on mint. Store it then; afterward only the `prefix` is
+visible.
+
+**Valid scopes** (exactly these seven):
+
+| Scope | Grants |
+|---|---|
+| `script:read` | read scripts |
+| `script:write` | create/update scripts |
+| `route:write` | manage routes |
+| `domain:manage` | manage domains |
+| `log:read` | read execution logs |
+| `app:admin` | full app administration |
+| `instance:admin` | instance-wide administration |
+
+> Common mistake: `app:read`, `app:write`, `instance:write` are **not** scopes and are rejected (`422`).
+
+Bind a key to one app with `"app_id"`; a bound key then can't carry `instance:admin` (rejected). Use
+`"expires_at"` (RFC 3339) for short-lived keys. Present a key just like a session token:
+`Authorization: Bearer pic_…`. **CLI:** `pic api-keys mint ci --scope script:read --scope log:read`
+(optionally `--app demo`, `--expires 30d`), `pic api-keys ls`, `pic api-keys rm <id>`.
--- a/docs/dev-guide/src/reference/rest-api/app-users.md
+++ b/docs/dev-guide/src/reference/rest-api/app-users.md
@@ -0,0 +1,43 @@
+# App users
+
+These are the **administrative** endpoints over your app's end-users — the people who register through
+your scripts' [`users::*`](../sdk/users.md) calls. Operators use them to inspect users, reset
+passwords, revoke sessions, and manage invitations.
+
+> **These are not signup/login endpoints.** End-users never call these. Registration and login happen
+> in *your* scripts via the `users` SDK, on routes you define. There is no built-in `/signup` or
+> `/login`. See the [TODO API tutorial](../../examples/todo-api.md).
+
+Under `/api/v1/admin/apps/{id_or_slug}`, capabilities `AppUsersRead` (reads), `AppUsersWrite`
+(create/update), `AppUsersAdmin` (delete, reset-password, revoke-sessions).
+
+| Method & path | Notes |
+|---|---|
+| `GET …/users` | list end-users |
+| `POST …/users` | create `{email, password, display_name?}` (`password` is **required**) |
+| `GET …/users/{user_id}` | one user |
+| `PATCH …/users/{user_id}` | update `{display_name?}` (only `display_name` is patchable here) |
+| `DELETE …/users/{user_id}` | delete |
+| `POST …/users/{user_id}/reset-password` | mint/apply a reset (returns a one-shot token) |
+| `POST …/users/{user_id}/revoke-sessions` | invalidate all of the user's sessions |
+| `GET …/invitations` | list invitations |
+| `POST …/invitations` | create `{email, display_name?, roles?, template?}` |
+| `DELETE …/invitations/{invite_id}` | revoke an invitation |
+
+(There is no per-user `…/users/{user_id}/invitations` endpoint — invitations are managed at the app
+level via `…/invitations`. Roles aren't set through the create/patch body here; manage them from a
+script with [`users::add_role`](../sdk/users.md#roles).)
+
+```sh
+curl -X POST $PICLOUD/api/v1/admin/apps/$APP/users -H "Authorization: Bearer $TOKEN" \
+  -H 'Content-Type: application/json' -d '{"email":"u1@example.com","password":"hunter2pass"}'
+```
+```json
+{"id":"4fd7df09-…","app_id":"…","email":"u1@example.com","display_name":null,
+ "email_verified_at":null,"last_login_at":null,"created_at":"…Z","updated_at":"…Z","roles":[]}
+```
+
+Passwords are hashed with Argon2id; only hashes are stored — operators cannot read them. **CLI:**
+`pic users ls --app demo`, `pic users show --app demo <id>`,
+`pic users reset-password --app demo <id>` (prints a one-shot token),
+`pic users revoke-sessions --app demo <id>`.
--- a/docs/dev-guide/src/reference/rest-api/apps.md
+++ b/docs/dev-guide/src/reference/rest-api/apps.md
@@ -0,0 +1,62 @@
+# Apps & domains
+
+Apps are tenants; domains route hosts to apps. See [Core concepts](../../guide/concepts.md#apps).
+
+## Apps
+
+| Method & path | Capability | Notes |
+|---|---|---|
+| `GET /api/v1/admin/apps` | authenticated | lists apps the caller can see (members: only theirs) |
+| `POST /api/v1/admin/apps` | `InstanceCreateApp` (owner/admin) | create |
+| `GET /api/v1/admin/apps/{id_or_slug}` | `AppRead` | one app |
+| `PATCH /api/v1/admin/apps/{id_or_slug}` | `AppAdmin` | update name/description/slug |
+| `DELETE /api/v1/admin/apps/{id_or_slug}` | `AppAdmin` | delete (cascades scripts, routes, data) |
+| `POST /api/v1/admin/apps/{id_or_slug}/slug:check` | `AppAdmin` | `{"new_slug":"…"}` → `{ok, conflict_kind?, current_app?, reason?}` |
+
+Create:
+
+```sh
+curl -X POST $PICLOUD/api/v1/admin/apps -H "Authorization: Bearer $TOKEN" \
+  -H 'Content-Type: application/json' \
+  -d '{"slug":"demo","name":"Demo App","description":"…"}'
+```
+```json
+{"id":"41f42060-…","slug":"demo","name":"Demo App","description":null,
+ "created_at":"2026-…Z","updated_at":"2026-…Z"}
+```
+
+**Slug rules:** `^[a-z0-9][a-z0-9-]{0,62}$`, and not one of the reserved words (`new`, `api`, `admin`,
+`apps`, `login`, `healthz`, `version`, …). Renaming a slug records the old one for redirects; reclaim a
+released slug with `"force_takeover": true` in the create/patch body.
+
+## Domains
+
+A non-`default` app's routes only match once the app **claims** the request `Host`.
+
+| Method & path | Capability |
+|---|---|
+| `GET /api/v1/admin/apps/{id_or_slug}/domains` | `AppRead` |
+| `POST /api/v1/admin/apps/{id_or_slug}/domains` | `AppManageDomains` |
+| `DELETE /api/v1/admin/apps/{id_or_slug}/domains/{domain_id}` | `AppManageDomains` |
+
+```sh
+curl -X POST $PICLOUD/api/v1/admin/apps/demo/domains -H "Authorization: Bearer $TOKEN" \
+  -H 'Content-Type: application/json' -d '{"pattern":"demo.localhost"}'
+```
+```json
+{"id":"6ff04d56-…","app_id":"41f42060-…","pattern":"demo.localhost",
+ "shape":"exact","shape_key":"exact:demo.localhost","created_at":"2026-…Z"}
+```
+
+**Pattern shapes** (use `{name}`, never `:name`, in domains):
+
+- exact — `app.example.com`
+- wildcard — `*.example.com`
+- parameterized — `{tenant}.example.com` (the segment is captured into a route param)
+
+The most specific claim wins. Claiming a host another app already holds (in the same shape) returns
+`409`. The `default` app ships claiming `localhost`. Locally, claim `something.localhost` and test with
+`curl -H 'Host: something.localhost' $PICLOUD/...`.
+
+**CLI:** `pic apps create demo --name "Demo App"`, `pic apps domains add demo demo.localhost`,
+`pic apps ls`, `pic apps show demo`.
--- a/docs/dev-guide/src/reference/rest-api/data-admin.md
+++ b/docs/dev-guide/src/reference/rest-api/data-admin.md
@@ -0,0 +1,61 @@
+# Secrets, KV & files (admin views)
+
+These are the operator-facing views over data your scripts write through the
+[`secrets`](../sdk/secrets.md), [`kv`](../sdk/storage.md#kv), and [`files`](../sdk/storage.md#files)
+SDKs. They are read-mostly: you *write* through scripts, and inspect (and prune) here.
+
+## Secrets {#secrets}
+
+Under `/api/v1/admin/apps/{app_id}/secrets`. Values are **never** returned — only names.
+
+| Method & path | Capability | Notes |
+|---|---|---|
+| `GET …/secrets?cursor=&limit=` | `AppSecretsRead` | list names |
+| `POST …/secrets` | `AppSecretsWrite` | set/upsert `{name, value}` |
+| `DELETE …/secrets/{name}` | `AppSecretsWrite` | delete |
+
+```sh
+curl -X POST $PICLOUD/api/v1/admin/apps/$APP/secrets -H "Authorization: Bearer $TOKEN" \
+  -H 'Content-Type: application/json' -d '{"name":"demo_key","value":"s3cr3t"}'
+
+curl $PICLOUD/api/v1/admin/apps/$APP/secrets -H "Authorization: Bearer $TOKEN"
+# {"secrets":[{"name":"demo_key","updated_at":"2026-…Z"}],"next_cursor":null}
+```
+
+There is no update verb — `POST` upserts. **CLI:** `printf 's3cr3t' | pic secrets set --app demo
+demo_key`, `pic secrets ls --app demo`, `pic secrets rm --app demo demo_key` (value read from stdin so
+it never hits shell history).
+
+## KV {#kv}
+
+Under `/api/v1/admin/apps/{app_id}/kv`. Read-only (writes go through `kv::...set`).
+
+| Method & path | Capability | Notes |
+|---|---|---|
+| `GET …/kv?collection=<name>&cursor=&limit=` | `AppKvRead` | list keys in a collection |
+| `GET …/kv/{collection}/{key}` | `AppKvRead` | one value |
+
+```sh
+curl "$PICLOUD/api/v1/admin/apps/$APP/kv?collection=counters" -H "Authorization: Bearer $TOKEN"
+# {"keys":[…],"next_cursor":null}
+curl $PICLOUD/api/v1/admin/apps/$APP/kv/counters/home -H "Authorization: Bearer $TOKEN"
+# {"value":3}
+```
+
+**CLI:** `pic kv ls --app demo --collection counters`, `pic kv get --app demo --collection counters home`.
+
+## Files {#files}
+
+Under `/api/v1/admin/apps/{app_id}/files`.
+
+| Method & path | Capability | Notes |
+|---|---|---|
+| `GET …/files?collection=<name>&cursor=&limit=` | `AppFilesRead` | list metadata |
+| `GET …/files/{collection}/{file_id}` | `AppFilesRead` | download the bytes (sets `Content-Type`, `Content-Disposition`, `Content-Length`) |
+| `DELETE …/files/{collection}/{file_id}` | `AppFilesWrite` | delete |
+
+**CLI:** `pic files ls --app demo --collection avatars`, `pic files get --app demo --collection avatars
+--id <id> --out a.png`, `pic files rm --app demo --collection avatars --id <id>`.
+
+Files live on disk under `PICLOUD_FILES_ROOT` (default `./data`) at
+`<root>/files/<app_id>/<collection>/<id[0:2]>/<id>`; metadata is in Postgres.
--- a/docs/dev-guide/src/reference/rest-api/overview.md
+++ b/docs/dev-guide/src/reference/rest-api/overview.md
@@ -0,0 +1,106 @@
+# HTTP API — overview & authentication
+
+The control plane is a REST API under `/api/v1/`. The dashboard and the `pic` CLI are both just clients
+of it; anything they do, you can do with `curl`. The **data plane** (your scripts' routes,
+`/execute/{id}`, `/healthz`, `/version`) is separate and covered where relevant.
+
+Base URL in this reference: `$PICLOUD` (e.g. `http://localhost:8000` for the Compose stack, or
+`http://localhost:18080` for a bare binary).
+
+## Authentication
+
+Every `/api/v1/admin/*` endpoint (except `auth/login`) requires a **bearer token**:
+
+```
+Authorization: Bearer <token>
+```
+
+A token is either a **session token** (from `auth/login`) or an **API key** (`pic_…`, minted via
+[api-keys](access.md#api-keys)). There is no cookie auth.
+
+### Log in
+
+```sh
+curl -X POST $PICLOUD/api/v1/admin/auth/login \
+  -H 'Content-Type: application/json' \
+  -d '{"username":"admin","password":"…"}'
+```
+```json
+{"user":{"id":"…","username":"admin","instance_role":"owner","email":null},
+ "token":"V-f-0ey3eEcF…","expires_at":"2026-06-18T19:49:39Z"}
+```
+
+| Endpoint | Auth | Purpose |
+|---|---|---|
+| `POST /api/v1/admin/auth/login` | none | exchange username+password for a session token |
+| `POST /api/v1/admin/auth/logout` | optional | revoke the current session (idempotent → `204`) |
+| `GET  /api/v1/admin/auth/me` | bearer | the principal the token resolves to |
+
+Sessions slide: each authenticated request extends the TTL (`PICLOUD_SESSION_TTL_HOURS`, default 24).
+Login is rate-limited per IP and per username.
+
+## Principals, roles & capabilities
+
+The token resolves to a **principal** with an **instance role** (`owner` > `admin` > `member`).
+Members additionally hold per-app roles. Each endpoint requires a **capability**; the full mapping is
+in [Capabilities & roles](../config/capabilities.md). A request that authenticates but lacks the
+capability gets `403`.
+
+## Conventions
+
+- **Content type:** request and response bodies are JSON (`Content-Type: application/json`).
+- **IDs** are UUID strings. Apps also accept their **slug** wherever an id is taken (`{id_or_slug}`).
+- **Update verb is `PATCH`** everywhere — send only the fields you want to change — **except scripts,
+  which use `PUT`** (full update).
+- **Two endpoints use a `:verb` suffix** (not a sub-path): `POST /routes:check`, `POST /routes:match`,
+  `POST /apps/{id_or_slug}/slug:check`.
+- **Pagination** is keyset/cursor based: list endpoints return a `next_cursor` (`null` when exhausted);
+  pass it back as `?cursor=…`. Some accept `?limit=`.
+
+## Errors
+
+Errors are JSON with an `error` string and an appropriate status:
+
+```json
+{"error":"no route matches GET /nope"}
+```
+
+| Status | Meaning |
+|---|---|
+| `400` | malformed request / bad JSON |
+| `401` | missing or invalid token |
+| `403` | authenticated but missing the capability |
+| `404` | resource not found (or, on the data plane, no app/route matched) |
+| `409` | conflict (duplicate, state violation) |
+| `422` | validation error (bad Rhai, route conflict, invalid scope, …) |
+| `429` | rate-limited (login) |
+| `503` | overloaded — execution gate full, `Retry-After: 1` (data plane) |
+
+## `GET /version` and `GET /healthz`
+
+Public, unauthenticated:
+
+```sh
+curl $PICLOUD/healthz     # ok
+curl $PICLOUD/version
+```
+```json
+{"api":1,"product":"1.1.9","public_base_url":"http://localhost:8000","schema":44,"sdk":"1.10","wire":1}
+```
+
+`/healthz` is a liveness probe (the literal string `ok`). `/version` reports the
+[five version surfaces](../../guide/concepts.md#the-five-version-surfaces) plus the configured public
+base URL.
+
+## Map of the API
+
+| Area | Page |
+|---|---|
+| Apps, domains | [Apps & domains](apps.md) |
+| Scripts, routes, logs | [Scripts, routes & logs](scripts.md) |
+| Triggers | [Triggers](triggers.md) |
+| Topics, realtime SSE | [Topics & realtime](topics.md) |
+| Secrets, KV, files (admin views) | [Secrets, KV & files](data-admin.md) |
+| Queues, dead-letters | [Queues & dead-letters](queues.md) |
+| App end-users | [App users](app-users.md) |
+| Members, admin users, API keys | [Members, admins & API keys](access.md) |
--- a/docs/dev-guide/src/reference/rest-api/queues.md
+++ b/docs/dev-guide/src/reference/rest-api/queues.md
@@ -0,0 +1,46 @@
+# Queues & dead-letters
+
+Operator views over the durable [`queue`](../sdk/messaging.md#queue) system and the
+[dead-letters](../sdk/composition.md#dead-letters) that failed executions produce.
+
+## Queues
+
+Under `/api/v1/admin/apps/{app_id}/queues`, capability **`AppLogRead`** (read-only inspection of
+operational state). Enqueue from scripts; consume via a `queue` trigger.
+
+| Method & path | Notes |
+|---|---|
+| `GET …/queues` | list queues with depth counts |
+| `GET …/queues/{queue_name}` | one queue's stats + its registered consumer |
+
+A summary carries `queue_name`, `total`, `pending`, `claimed`. **CLI:** `pic queues ls --app demo`,
+`pic queues show --app demo emails.send`.
+
+## Dead-letters
+
+Under `/api/v1/admin/apps/{app_id}/dead_letters`, capability **`AppDeadLetterManage`** (app_admin+).
+A dead-letter is written when a triggered execution exhausts its retries.
+
+| Method & path | Notes |
+|---|---|
+| `GET …/dead_letters?unresolved=true&limit=&offset=` | list |
+| `GET …/dead_letters/count?unresolved=true` | bare count (cheap; for alerting) |
+| `GET …/dead_letters/{dl_id}` | one row, full payload + error |
+| `POST …/dead_letters/{dl_id}/replay` | re-enqueue the original event; marks the row resolved `replayed` → `204 No Content` |
+| `POST …/dead_letters/{dl_id}/resolve` | close without replaying (reason: one of `ignored`, `handled_by_script`, `handler_failed`) → `204 No Content` |
+
+```sh
+curl "$PICLOUD/api/v1/admin/apps/$APP/dead_letters?unresolved=true" -H "Authorization: Bearer $TOKEN"
+curl -X POST $PICLOUD/api/v1/admin/apps/$APP/dead_letters/$DL/replay -H "Authorization: Bearer $TOKEN"
+```
+
+A `dead_letter` [trigger](triggers.md) can run a script automatically when a dead-letter appears (to
+alert, or to `dead_letters::replay`/`resolve` programmatically). Retention defaults to 30 days
+(`PICLOUD_DEAD_LETTER_RETENTION_DAYS`), swept periodically.
+
+**CLI:** `pic dead-letters count --app demo`, `pic dead-letters ls --app demo --unresolved`,
+`pic dead-letters show --app demo <id>`, `pic dead-letters replay --app demo <id>`,
+`pic dead-letters resolve --app demo <id> --reason "handled manually"`.
+
+The [webhook tutorial](../../examples/webhook-receiver.md#dead-letters) walks the full failure → replay
+loop.
--- a/docs/dev-guide/src/reference/rest-api/scripts.md
+++ b/docs/dev-guide/src/reference/rest-api/scripts.md
@@ -0,0 +1,101 @@
+# Scripts, routes & logs
+
+## Scripts
+
+| Method & path | Capability | Notes |
+|---|---|---|
+| `GET /api/v1/admin/scripts?app=<id\|slug>` | `AppRead` | list (filter by app); returns a plain array, not paginated |
+| `POST /api/v1/admin/scripts` | `AppWriteScript` | create |
+| `GET /api/v1/admin/scripts/{id}` | `AppRead` | one script (with `source`) |
+| `PUT /api/v1/admin/scripts/{id}` | `AppWriteScript` | **full update** (note: PUT, not PATCH) |
+| `DELETE /api/v1/admin/scripts/{id}` | `AppAdmin` | delete |
+| `GET /api/v1/admin/scripts/{id}/logs?limit=&cursor=&source=` | `AppLogRead` | execution logs (below) |
+
+Create:
+
+```sh
+curl -X POST $PICLOUD/api/v1/admin/scripts -H "Authorization: Bearer $TOKEN" \
+  -H 'Content-Type: application/json' -d '{
+    "app_id":"41f42060-…",
+    "name":"greet",
+    "source":"return #{ statusCode: 200, body: #{ ok: true } };",
+    "kind":"endpoint"
+  }'
+```
+
+Fields: `app_id` (required), `name` (required, unique within the app), `source` (required), optional
+`description`, `kind` (`"endpoint"` default | `"module"`), `timeout_seconds`, `memory_limit_mb`, and a
+`sandbox` object of [overrides](../../guide/writing-scripts.md#sandbox-limits). New scripts default to
+`timeout_seconds: 30`, `memory_limit_mb: 256`.
+
+The response is the stored script (with `id`, `version`, timestamps). The source is validated at create
+time: it must parse as Rhai, and a `module` may contain only `fn`/`const`. Invalid source → `422`.
+
+## Routes
+
+| Method & path | Capability | Notes |
+|---|---|---|
+| `GET /api/v1/admin/scripts/{id}/routes` | `AppRead` | routes bound to a script |
+| `POST /api/v1/admin/scripts/{id}/routes` | `AppWriteRoute` | bind a route |
+| `DELETE /api/v1/admin/routes/{route_id}` | `AppWriteRoute` | unbind |
+| `POST /api/v1/admin/routes:check` | `AppRead` | conflict pre-check (note the `:` suffix) |
+| `POST /api/v1/admin/routes:match` | `AppRead` | what would a URL match? |
+
+Bind:
+
+```sh
+curl -X POST $PICLOUD/api/v1/admin/scripts/$SID/routes -H "Authorization: Bearer $TOKEN" \
+  -H 'Content-Type: application/json' -d '{
+    "host_kind":"any", "host":"",
+    "path_kind":"param", "path":"/users/:id",
+    "method":"GET", "dispatch_mode":"sync"
+  }'
+```
+```json
+{"id":"…","app_id":"…","script_id":"…","host_kind":"any","host":"","host_param_name":null,
+ "path_kind":"param","path":"/users/:id","method":null,"dispatch_mode":"sync","created_at":"…Z"}
+```
+
+Fields:
+
+- `host_kind`: `any` (default) | `strict` (exact `host`) | `wildcard` (`*.host`, with optional
+  `host_param_name` to capture the subdomain into a param);
+- `path_kind`: `exact` | `param` (`/users/:id`) | `prefix` (`/files/*`, tail → `ctx.request.rest`);
+- `method`: `GET`/`POST`/… or omit (`null`) to match any;
+- `dispatch_mode`: `sync` (default) | `async` (→ `202 Accepted`, background run).
+
+Routes under `/api/`, `/admin/`, `/healthz`, `/version` are rejected. Conflicts are detected within the
+app only:
+
+```sh
+curl -X POST $PICLOUD/api/v1/admin/routes:check -H "Authorization: Bearer $TOKEN" \
+  -H 'Content-Type: application/json' \
+  -d '{"app_id":"…","host_kind":"any","host":"","path_kind":"exact","path":"/hello"}'
+# {"ok":false,"conflicting_route":{…},"conflict_reason":"IdenticalExact"}
+```
+
+## Execution logs
+
+```sh
+curl "$PICLOUD/api/v1/admin/scripts/$SID/logs?limit=20&source=http" -H "Authorization: Bearer $TOKEN"
+```
+
+Each entry:
+
+```json
+{"id":"…","app_id":"…","script_id":"…","request_id":"…",
+ "request_path":"/count","request_headers":{…},"request_body":null,
+ "response_code":200,"response_body":null,
+ "script_logs":[],"duration_ms":5,"status":"success","source":"http","created_at":"…Z"}
+```
+
+- `?source=` filters by origin: `http`, `kv`, `docs`, `files`, `cron`, `queue`, `pubsub`, `email`,
+  `invoke`, `dead_letter`. Omit for all.
+- `?cursor=` is the keyset cursor (`<rfc3339>_<uuid>`) from the previous page; `?limit=` defaults to 50
+  (max 200).
+- **`script_logs` and `response_body` are populated for async/triggered runs, but empty/null for
+  synchronous HTTP runs** — see [Writing scripts → Logging](../../guide/writing-scripts.md#logging).
+
+**CLI:** `pic scripts deploy file.rhai --app demo`, `pic scripts ls --app demo`,
+`pic routes create --script $SID --path /users/:id --path-kind param --method GET`,
+`pic routes check --app demo --path /hello`, `pic logs $SID --source http`.
--- a/docs/dev-guide/src/reference/rest-api/topics.md
+++ b/docs/dev-guide/src/reference/rest-api/topics.md
@@ -0,0 +1,57 @@
+# Topics & realtime
+
+Scripts publish to topics with [`pubsub::publish_durable`](../sdk/messaging.md#pubsub) — that needs no
+registration. **Registering a topic** is only needed to let *external* clients subscribe over
+Server-Sent Events (SSE) at `/realtime/topics/{topic}`.
+
+## Topic registry
+
+Under `/api/v1/admin/apps/{app_id}/topics`, capability **`AppTopicManage`** (app_admin+).
+
+| Method & path | Notes |
+|---|---|
+| `GET …/topics` | list |
+| `POST …/topics` | register `{name, external_subscribable?, auth_mode?}` |
+| `PATCH …/topics/{name}` | update external/auth settings |
+| `DELETE …/topics/{name}` | unregister (disconnects live subscribers) |
+
+`name` is a concrete topic (no wildcards). `auth_mode` controls what an external subscriber must
+present:
+
+| `auth_mode` | Subscriber must… |
+|---|---|
+| `public` | nothing — anyone can subscribe |
+| `token` | present an HMAC subscriber token from [`pubsub::subscriber_token`](../sdk/messaging.md#pubsub) |
+| `session` | present an app-user session token from [`users::login`](../sdk/users.md) |
+
+## Subscribing (SSE)
+
+```sh
+# public topic
+curl -N $PICLOUD/realtime/topics/orders.created
+
+# token / session topic — pass the token as a query param or bearer header
+curl -N "$PICLOUD/realtime/topics/orders.created?token=$SUBTOKEN"
+curl -N $PICLOUD/realtime/topics/orders.created -H "Authorization: Bearer $SUBTOKEN"
+```
+
+The stream emits each published message as an SSE `data:` event, plus periodic heartbeats
+(`PICLOUD_REALTIME_HEARTBEAT_SEC`, default 30). The browser equivalent is `new EventSource(url)`.
+
+Minting a subscriber token inside a script (for a `token`-mode topic):
+
+```rhai
+let t = pubsub::subscriber_token(["orders.created"], 3600);  // valid 1h
+return #{ statusCode: 200, body: #{ token: t } };
+```
+
+## CLI
+
+```sh
+pic topics create --app demo orders.created --external --auth-mode token   # --app is a flag; name is positional
+pic topics ls --app demo
+pic topics update --app demo orders.created --auth-mode session
+pic topics rm --app demo orders.created
+```
+
+The [file-upload tutorial](../../examples/file-upload.md) wires a publish → SSE subscriber end to end.
--- a/docs/dev-guide/src/reference/rest-api/triggers.md
+++ b/docs/dev-guide/src/reference/rest-api/triggers.md
@@ -0,0 +1,75 @@
+# Triggers
+
+Triggers fire a script on an event instead of an HTTP request. See
+[Core concepts](../../guide/concepts.md#triggers-and-events) for the model and
+[`ctx.event`](../sdk/ctx-and-events.md#events) for what each kind delivers.
+
+All endpoints are under `/api/v1/admin/apps/{app_id}/triggers` and require **`AppManageTriggers`**
+(app_admin+).
+
+| Method & path | Notes |
+|---|---|
+| `GET …/triggers` | list (`{ "triggers": [ … ] }`) |
+| `POST …/triggers/{kind}` | create — **one sub-path per kind** (below) |
+| `DELETE …/triggers/{trigger_id}` | delete |
+
+There is **no update verb** — to change a trigger, delete and recreate. The eight kinds (each its own
+`POST` sub-path): `kv`, `docs`, `files`, `pubsub`, `cron`, `queue`, `email`, `dead_letter`.
+
+## Common fields
+
+Every create body takes `script_id` plus optional dispatch/retry settings:
+
+- `dispatch_mode`: `sync` | `async` (default `async`);
+- `retry_max_attempts`, `retry_backoff` (`exponential` | `linear` | `fixed`), `retry_base_ms` — all
+  optional, defaulting from instance config (`3` / `exponential` / `1000ms`).
+
+A created trigger looks like:
+
+```json
+{"id":"f3214f88-…","app_id":"…","script_id":"…","kind":"cron","enabled":true,
+ "dispatch_mode":"async","retry_max_attempts":3,"retry_backoff":"exponential",
+ "retry_base_ms":1000,"registered_by_principal":"…","created_at":"…Z","updated_at":"…Z"}
+```
+
+## Per-kind bodies
+
+| Kind | `POST …/triggers/<kind>` body (besides `script_id`) |
+|---|---|
+| `kv` | `collection_glob`, optional `ops` (`["insert","update","delete"]`; empty = any) |
+| `docs` | `collection_glob`, optional `ops` |
+| `files` | `collection_glob`, optional `ops` |
+| `pubsub` | `topic_glob` |
+| `cron` | `schedule` (6-field cron, with seconds), optional `timezone` (IANA, default UTC) |
+| `queue` | `queue_name`, optional `visibility_timeout_secs` (≥ 30) |
+| `email` | optional `from_glob`; an `inbound_secret` for HMAC verification |
+| `dead_letter` | optional `source`/`trigger_id`/`script_id` filters (omit = every DL in the app) |
+
+Example — a cron trigger every hour on the hour:
+
+```sh
+curl -X POST $PICLOUD/api/v1/admin/apps/$APP/triggers/cron -H "Authorization: Bearer $TOKEN" \
+  -H 'Content-Type: application/json' \
+  -d '{"script_id":"'$SID'","schedule":"0 0 * * * *","timezone":"Europe/Berlin"}'
+```
+
+Globs match collection/topic names: `*` (all), `users`, `events_*`, `orders.*`.
+
+## CLI
+
+The CLI has per-kind wrappers and a JSON escape hatch:
+
+```sh
+pic triggers create-cron   --app demo --script $SID --schedule "0 0 * * * *"
+pic triggers create-kv     --app demo --script $SID --collection 'users' --op insert
+pic triggers create-queue  --app demo --script $SID --queue emails.send
+pic triggers create-pubsub --app demo --script $SID --topic 'orders.*'
+pic triggers create-email  --app demo --script $SID --inbound-secret <hmac>
+pic triggers ls   --app demo
+pic triggers rm   --app demo <trigger_id>
+# advanced retry/dispatch tuning beyond the wrappers:
+pic triggers create-from-json --app demo --kind docs --body @trigger.json
+```
+
+(CLI wrappers default `dispatch` to `async`.) Inbound email also requires the platform's inbound
+webhook to be reachable; see [Email](../sdk/email.md).
--- a/docs/dev-guide/src/reference/sdk/composition.md
+++ b/docs/dev-guide/src/reference/sdk/composition.md
@@ -0,0 +1,91 @@
+# Composition: invoke, retry, dead_letters
+
+Three small namespaces for composing scripts and handling failure.
+
+---
+
+## `invoke` — call another script {#invoke}
+
+*Since SDK 1.10.* Synchronously call another script **in the same app** and get its return value, or
+fire it off asynchronously. Like a function call across script boundaries.
+
+```rhai
+// Synchronous: runs the target now, returns its value.
+let result = invoke("/internal/price", #{ sku: "abc" });   // by route path
+let result = invoke("price_worker", #{ sku: "abc" });      // by script name
+let result = invoke("01HX…uuid…", #{ sku: "abc" });        // by script id (a UUID string)
+
+// Asynchronous: enqueue it, get an execution id back immediately.
+let exec_id = invoke_async("/internal/price", #{ sku: "abc" });
+```
+
+| Function | Signature | Returns |
+|---|---|---|
+| `invoke(target, args)` | `(string, dynamic)` | the callee's return value |
+| `invoke_async(target, args)` | `(string, dynamic)` | the new execution id (string) |
+
+- **Target is a string**, resolved by a simple heuristic: starts with `/` → a **route path** (matched
+  through the app's route trie); a 36-character UUID → a **script id**; anything else → a **script
+  name**. (There is no `script_id(...)` constructor in 1.1.9 — just pass the string.)
+- **Same-app only** — a cross-app target throws. The callee inherits the caller's principal and runs
+  in the same engine. `ctx.invocation_type` is `"function"` in the callee.
+- **Args** become the callee's `ctx.request.body`. Closures can't be passed.
+- **Depth-limited** — re-entrant `invoke` chains are capped (default 8) to prevent runaway recursion;
+  exceeding it throws.
+
+---
+
+## `retry` — retry with backoff {#retry}
+
+*Since SDK 1.10.* Wrap a fallible closure in a retry loop. Useful around `http`, `invoke`, or any call
+that can fail transiently.
+
+```rhai
+let policy = retry::policy(#{
+    max_attempts: 3,          // 1–20, default 3
+    backoff: "exponential",   // "exponential" | "linear" | "constant", default exponential
+    base_ms: 500,             // 1–60000, default 500
+    jitter_pct: 20            // 0–100, default 20
+});
+
+// Optionally only retry on certain error substrings:
+let policy = retry::on_codes(policy, ["http: 503", "http: 504"]);
+
+let value = retry::run(policy, || http::post(url, payload));
+```
+
+| Function | Signature | Returns |
+|---|---|---|
+| `retry::policy(opts)` | `(map)` | a `Policy` (all fields clamped to their ranges) |
+| `retry::on_codes(policy, codes)` | `(Policy, array of string)` | a `Policy` that retries only when the error string contains one of `codes` (empty = retry on any throw) |
+| `retry::run(policy, closure)` | `(Policy, Fn)` | the closure's value on success; re-throws the last error after the final attempt |
+
+Backoff between attempts: `constant` = `base_ms`; `linear` = `base_ms × attempt`; `exponential` =
+`base_ms × 2^(attempt-1)`. Jitter is applied deterministically as a ± fraction. The sleep is safe to
+perform inside a script (it runs on the blocking worker, not an async reactor).
+
+> The shipped name is **`retry::run`** (not `with`/`call`, which are Rhai reserved words).
+
+---
+
+## `dead_letters` — handle exhausted retries {#dead-letters}
+
+*Since SDK 1.2.* When a triggered execution exhausts its retries, the platform writes a **dead-letter**
+row. From a script (typically a `dead_letter`-trigger handler — see
+[`ctx.event`](ctx-and-events.md#events)) you can act on it:
+
+```rhai
+dead_letters::replay(id);              // re-enqueue the original event; marks the row resolved "replayed"
+dead_letters::resolve(id, "ignored");  // close the row without replaying, with a reason
+```
+
+| Function | Signature | Returns |
+|---|---|---|
+| `dead_letters::replay(id)` | `(string)` | `()` |
+| `dead_letters::resolve(id, reason)` | `(string, string)` | `()` |
+
+IDs are UUID strings. `reason` must be one of the fixed set — `ignored`, `handled_by_script`,
+`handler_failed` (or `replayed`, which `replay` sets for you) — not free text. Operators do the same from the dashboard, `pic dead-letters`, or
+[the dead-letters API](../rest-api/queues.md#dead-letters). (Listing dead letters from a script is not
+in 1.1.9 — use the admin surface.) The
+[webhook tutorial](../../examples/webhook-receiver.md#dead-letters) demonstrates the failure→replay loop.
--- a/docs/dev-guide/src/reference/sdk/ctx-and-events.md
+++ b/docs/dev-guide/src/reference/sdk/ctx-and-events.md
@@ -0,0 +1,106 @@
+# The execution context & events
+
+Every script runs with a global `ctx` map. For HTTP invocations it describes the request; for triggered
+invocations it *also* carries `ctx.event` describing what fired the script.
+
+## `ctx` fields
+
+| Field | Type | Present |
+|---|---|---|
+| `ctx.sdk_version` | string (`"1.10"`) | always |
+| `ctx.execution_id` | string (UUID) | always |
+| `ctx.script_id` | string (UUID) | always |
+| `ctx.script_name` | string | always |
+| `ctx.request_id` | string (UUID) | always |
+| `ctx.invocation_type` | string | always — `"http"`, `"function"` (an `invoke()` call), or `"scheduled"` |
+| `ctx.request` | map | always (synthetic for non-HTTP invocations) |
+| `ctx.event` | map | **only when triggered** |
+
+## `ctx.request`
+
+| Field | Type | Notes |
+|---|---|---|
+| `path` | string | request path |
+| `method` | string | uppercased verb |
+| `headers` | map | **lowercased** keys |
+| `body` | dynamic | JSON-parsed when JSON; string otherwise; `()` if empty |
+| `params` | map | `:name` route captures |
+| `query` | map | query-string params |
+| `rest` | string | tail captured by a `prefix` route |
+
+```rhai
+let id    = ctx.request.params.id;            // from /users/:id
+let page  = ctx.request.query.page;           // from ?page=2
+let token = ctx.request.headers["authorization"];
+let rest  = ctx.request.rest;                 // from a /files/* route
+```
+
+> When a script is reached through `POST /api/v1/execute/{id}` (execute-by-id) or `invoke()`, there is
+> no route match, so `params` and `rest` are empty. Pass everything you need in the body.
+
+## Events
+
+A triggered script reads `ctx.event`. The map always has a `source` discriminant; the rest depends on
+the trigger kind. Guard with `if "event" in ctx { ... }` if a script serves both HTTP and triggers.
+
+### `source: "kv"` — KV mutation
+```rhai
+// ctx.event = #{ source:"kv", op:"insert"|"update"|"delete",
+//                kv: #{ collection, key, value } }   // value is () on delete
+let key = ctx.event.kv.key;
+```
+
+### `source: "docs"` — document mutation
+```rhai
+// ctx.event = #{ source:"docs", op:"insert"|"update"|"delete",
+//                docs: #{ collection, id, data, prev_data } }
+// `prev_data` is the pre-change document on update/delete (change-data-capture); () on insert.
+```
+
+### `source: "files"` — blob mutation
+```rhai
+// ctx.event = #{ source:"files", op:"insert"|"update"|"delete",
+//                files: #{ collection, id, name, content_type, size, checksum, prev } }
+// Metadata only — never the bytes. Fetch them with files::collection(c).get(id) if needed.
+```
+
+### `source: "pubsub"` — message published
+```rhai
+// ctx.event = #{ source:"pubsub", op:"publish",
+//                pubsub: #{ topic, message, published_at } }
+let payload = ctx.event.pubsub.message;   // the published value (note: `message`, not `payload`)
+```
+
+### `source: "queue"` — message claimed
+```rhai
+// ctx.event = #{ source:"queue", op:"receive",
+//                queue: #{ queue_name, message, enqueued_at, attempt, message_id } }
+let payload = ctx.event.queue.message;    // the enqueued value (note: `message`, not `payload`)
+let n       = ctx.event.queue.attempt;    // 1 on first delivery; >1 on a retry — use it to be idempotent
+```
+
+### `source: "cron"` — schedule tick
+```rhai
+// ctx.event = #{ source:"cron", op:"tick",
+//                cron: #{ schedule, timezone, scheduled_at, fired_at } }
+// scheduled_at / fired_at are RFC 3339 strings.
+```
+
+### `source: "email"` — inbound mail
+```rhai
+// ctx.event = #{ source:"email", op:"receive",
+//                email: #{ from, to:[...], cc:[...], subject, text, html, received_at, message_id } }
+// text / html are () when absent.
+```
+
+### `source: "dead_letter"` — another trigger gave up
+```rhai
+// ctx.event = #{ source:"dead_letter",
+//                dead_letter: #{ id, original, attempts, last_error,
+//                                trigger_id, script_id, first_attempt_at, last_attempt_at } }
+// `original` is the event that failed. Use it to alert, or call dead_letters::replay / resolve.
+```
+
+See [Triggers](../rest-api/triggers.md) to register a trigger, and the
+[webhook](../../examples/webhook-receiver.md) and [scheduled-report](../../examples/scheduled-report.md)
+tutorials for working consumers.
--- a/docs/dev-guide/src/reference/sdk/email.md
+++ b/docs/dev-guide/src/reference/sdk/email.md
@@ -0,0 +1,50 @@
+# Email
+
+*Since SDK 1.8.* Send outbound email through a configured SMTP relay. Receiving email is a
+[trigger](../rest-api/triggers.md) (`email` kind), surfaced as `ctx.event` with `source: "email"`.
+
+```rhai
+email::send(#{
+    to: "alice@example.com",
+    from: "alerts@myapp.com",
+    subject: "Build finished",
+    text: "Your deploy completed successfully."
+});
+
+email::send_html(#{
+    to: ["alice@x.com", "bob@y.com"],
+    cc: ["ops@x.com"],
+    bcc: ["audit@x.com"],
+    from: "alerts@myapp.com",
+    reply_to: "support@myapp.com",       // optional; defaults to `from`
+    subject: "Weekly report",
+    text: "Plain-text fallback for non-HTML clients.",
+    html: "<h1>Weekly report</h1><p>…</p>"
+});
+```
+
+| Function | Required fields | Optional fields |
+|---|---|---|
+| `email::send(opts)` | `to`, `from`, `subject`, `text` | `cc`, `bcc`, `reply_to` |
+| `email::send_html(opts)` | `to`, `from`, `subject`, `text`, `html` | `cc`, `bcc`, `reply_to` |
+
+- `to` / `cc` / `bcc` accept a single string or an array of strings.
+- `email::send` is plain-text only; any `html` key is ignored. `email::send_html` requires a non-empty
+  `html` and sends multipart (HTML + the `text` fallback).
+- Both **throw** on failure.
+
+## Configuration & dev mode
+
+- Sending requires an SMTP relay configured via `PICLOUD_SMTP_*` env vars. With no relay configured,
+  `email::send` throws `NotConfigured`.
+- **Except in dev mode:** when `PICLOUD_DEV_MODE=true` and no relay is set, sends succeed into an
+  **in-memory dev sink** — the last 100 messages are readable at `GET /api/v1/admin/dev/emails`
+  (instance owner/admin only). This route exists *only* in that mode. Great for testing the
+  [scheduled-report tutorial](../../examples/scheduled-report.md) without a real mail server.
+
+## Rate limiting
+
+There is **no built-in rate limiting** on `email::send`. If a public route can trigger a send, throttle
+it yourself (e.g. a `kv` counter keyed by sender/IP) — see
+[Security](../../operations/security.md). The `users` SDK's verification/reset/invite helpers send
+mail too; see [Users & auth](users.md).
--- a/docs/dev-guide/src/reference/sdk/http.md
+++ b/docs/dev-guide/src/reference/sdk/http.md
@@ -0,0 +1,77 @@
+# Outbound HTTP
+
+*Since SDK 1.5.* The `http` namespace makes outbound requests from a script — call third-party APIs,
+post to webhooks, fetch data. It is `fetch`-style: non-2xx responses are returned, not thrown; only
+transport-level failures (DNS, TLS, timeout, SSRF block, size) throw.
+
+```rhai
+let r = http::get("https://api.example.com/users/42");
+if r.status == 200 {
+    let user = r.body;          // parsed JSON (because the response was application/json)
+}
+
+let r = http::post("https://api.example.com/orders", #{ item: "sku-1", qty: 2 });
+let r = http::post(url, #{ item: 1 }, #{ headers: #{ "Authorization": "Bearer …" }, timeout_ms: 5000 });
+```
+
+## Functions
+
+| Function | Arities |
+|---|---|
+| `http::get(url)` / `http::get(url, opts)` | bodyless |
+| `http::head(url)` / `http::head(url, opts)` | bodyless |
+| `http::post(url)` / `(url, body)` / `(url, body, opts)` | body |
+| `http::put` / `http::patch` / `http::delete` | same as `post` |
+| `http::post_form(url, form)` / `(url, form, opts)` | form-encoded body from a map |
+| `http::request(method, url)` / `(…, body)` / `(…, body, opts)` | any verb |
+
+## Body dispatch (positional `body` arg)
+
+| Rhai value | Sent as |
+|---|---|
+| map / array | JSON, `Content-Type: application/json` |
+| string | raw bytes, `Content-Type: text/plain` |
+| `()` | no body |
+
+`GET`/`HEAD` ignore any body. `post_form` always sends `application/x-www-form-urlencoded`.
+
+## Options map
+
+| Key | Type | Default | Notes |
+|---|---|---|---|
+| `headers` | map (string→string) | — | header names lowercased internally |
+| `timeout_ms` | int | 30000 | max 60000 |
+| `follow_redirects` | bool | true | |
+| `max_redirects` | int | 5 | max 10 |
+
+Any other key throws ("unknown option key") — so a typo fails loudly.
+
+## Response map
+
+```rhai
+#{
+  status: 200,          // int
+  headers: #{ ... },    // lowercased keys
+  body: ...,            // parsed JSON if the response is application/json and parses; () if empty; else the raw string
+  body_raw: "..."       // always the raw response text
+}
+```
+
+## Security: the SSRF guard
+
+`http::*` resolves the target and **blocks requests to private/loopback/link-local addresses** by
+default, so a script (especially a public one taking a user-supplied URL) can't be tricked into probing
+your internal network. This is on unless an operator sets `PICLOUD_HTTP_ALLOW_PRIVATE=true` (dev/test
+only — see [Security](../../operations/security.md#ssrf)).
+
+```rhai
+// Robust outbound call: bounded timeout, retried on transient upstream errors.
+let policy = retry::on_codes(
+    retry::policy(#{ max_attempts: 3, backoff: "exponential", base_ms: 300 }),
+    ["http: 502", "http: 503", "http: 504"]
+);
+let r = retry::run(policy, || http::post(url, payload, #{ timeout_ms: 5000 }));
+```
+
+See [Composition](composition.md) for `retry`. The
+[webhook tutorial](../../examples/webhook-receiver.md) uses `http` + `retry` against a downstream.
--- a/docs/dev-guide/src/reference/sdk/messaging.md
+++ b/docs/dev-guide/src/reference/sdk/messaging.md
@@ -0,0 +1,73 @@
+# Messaging: pubsub, queue
+
+Two ways for parts of your app (and outside clients) to communicate asynchronously.
+
+- **`pubsub`** — fan-out. A published message is delivered to *every* matching subscriber (triggers,
+  and external SSE clients). Fire-and-forget; no per-consumer durability guarantee beyond delivery.
+- **`queue`** — work distribution. An enqueued message is delivered to *one* consumer, with retries,
+  attempt tracking, and dead-lettering. Use it for jobs that must complete.
+
+---
+
+## `pubsub` — publish/subscribe {#pubsub}
+
+*Since SDK 1.6 (`publish_durable`), 1.7 (`subscriber_token`).*
+
+```rhai
+pubsub::publish_durable("order.created", #{ id: 42, total: 1999 });
+pubsub::publish_durable("metrics.tick", 1);
+```
+
+| Function | Signature | Returns |
+|---|---|---|
+| `pubsub::publish_durable(topic, message)` | `(string, dynamic)` | `()` — throws over `PICLOUD_PUBSUB_MAX_MESSAGE_BYTES` (256 KiB) |
+| `pubsub::subscriber_token(topics)` | `(array of string)` | an HMAC-signed token (string) |
+| `pubsub::subscriber_token(topics, ttl_secs)` | `(array, int\|())` | same, custom TTL |
+
+- **Who receives a message:** any `pubsub` [trigger](../rest-api/triggers.md) whose topic glob matches
+  (runs a script), and any external SSE client subscribed to the topic (if it's a registered,
+  externally-subscribable [topic](../rest-api/topics.md)).
+- **`subscriber_token`** mints a token an outside browser/client presents to subscribe over SSE at
+  `/realtime/topics/{topic}`. Only needed for `secret`/`token`-mode topics. See
+  [Topics & realtime](../rest-api/topics.md).
+- Message encoding follows the [standard rules](overview.md#value-encoding) — blobs become base64,
+  `()` becomes null, closures are rejected.
+
+Publishing needs no topic registration; *external subscription* does.
+
+---
+
+## `queue` — durable job queue {#queue}
+
+*Since SDK 1.10.* A producer + inspection API. Consumption is wired by registering a **`queue`
+trigger** that runs a script per claimed message (`ctx.event.queue`).
+
+```rhai
+queue::enqueue("emails.send", #{ to: "a@b.com", template: "welcome" });
+queue::enqueue("emails.send", msg, #{ delay_ms: 60000, max_attempts: 5 });
+
+let total   = queue::depth("emails.send");          // all rows
+let waiting = queue::depth_pending("emails.send");  // currently claimable
+```
+
+| Function | Signature | Returns |
+|---|---|---|
+| `queue::enqueue(name, message)` | `(string, dynamic)` | `()` — throws over `PICLOUD_QUEUE_MAX_PAYLOAD_BYTES` (256 KiB); closures rejected |
+| `queue::enqueue(name, message, opts)` | `(string, dynamic, map)` | `()` — `opts.delay_ms` (int), `opts.max_attempts` (int) |
+| `queue::depth(name)` | `(string)` | `int` (total) |
+| `queue::depth_pending(name)` | `(string)` | `int` (claimable now) |
+
+The consumer side:
+
+1. Deploy a consumer script that reads `ctx.event.queue.message` (the enqueued value).
+2. Register a queue trigger: `pic triggers create-queue --app <a> --script <id> --queue emails.send`.
+3. On failure (the script throws), the message is retried up to `max_attempts`; after that it becomes
+   a [dead letter](composition.md#dead-letters) you can inspect and replay.
+
+There is no script-level peek/dequeue/purge — consumption is the trigger's job. Inspect queues from the
+dashboard, `pic queues`, or [the queues API](../rest-api/queues.md). The
+[webhook tutorial](../../examples/webhook-receiver.md) builds a full producer→queue→consumer flow.
+
+> **Make consumers idempotent.** A message can be delivered more than once (retry after a partial
+> success, visibility-timeout expiry). Use `ctx.event.queue.attempt` and a dedup key. See
+> [Best practices](../../operations/best-practices.md#idempotent-consumers).
--- a/docs/dev-guide/src/reference/sdk/overview.md
+++ b/docs/dev-guide/src/reference/sdk/overview.md
@@ -0,0 +1,96 @@
+# SDK reference — overview
+
+The SDK is the set of functions your Rhai scripts can call. It comes in two layers:
+
+- **Services** — stateful, app-scoped capabilities backed by the platform: `kv`, `docs`, `files`,
+  `http`, `email`, `users`, `pubsub`, `queue`, `secrets`, `invoke`, `retry`, `dead_letters`, and
+  `log`. These appear and disappear with releases (each is tagged with the SDK minor that added it).
+- **Standard library** — pure, stateless helpers: `json`, `base64`, `hex`, `url`, `regex`, `random`,
+  `time`. See [Standard library](stdlib.md).
+
+This page covers the conventions that hold across *every* service. The per-service pages give exact
+signatures.
+
+## Namespacing and the handle pattern
+
+Functions live in namespaces, called with `::`:
+
+```rhai
+let id = random::uuid();
+log::info("hi");
+```
+
+Storage services are **collection-scoped**: you first get a *handle* to a named collection, then call
+methods on it. This is intentional — it makes the `(app, collection, key)` identity explicit.
+
+```rhai
+let users = docs::collection("users");   // handle
+let id = users.create(#{ name: "Ada" }); // method on the handle
+let doc = users.get(id);
+```
+
+So it's `kv::collection("x").get(k)`, **not** `kv::get("x", k)`. Collections are mandatory; a
+collection name may not be empty.
+
+## App scoping is automatic and non-negotiable
+
+Every service call resolves the app from the server-side execution context. **Nothing your script
+passes can change which app's data it touches** — there is no `app_id` argument anywhere in the SDK.
+This is the isolation boundary described in [Core concepts](../../guide/concepts.md#apps); treat it as
+a hard guarantee, not a convention.
+
+## Error conventions
+
+Uniform across all services (also covered in [Writing scripts](../../guide/writing-scripts.md#errors)):
+
+| Situation | Behavior |
+|---|---|
+| Real failure (DB error, payload too large, authorization denied) | **throws** — catch with `try/catch`, or let it become a 502 |
+| Item not found / no result | returns **`()`** — test `== ()` |
+| Existence / was-present check | returns a **`bool`** |
+
+## Value encoding
+
+Values you store or send are JSON-encoded on the wire:
+
+- Maps, arrays, strings, numbers, booleans round-trip cleanly.
+- `()` (Rhai unit) becomes JSON `null`.
+- **Blobs** (byte arrays, e.g. from `base64::decode`) are base64-encoded inside JSON payloads
+  (`pubsub`, `queue`). `files` stores raw bytes directly.
+- **Function pointers / closures cannot be serialized** and are rejected by `queue`, `invoke`, etc.
+
+## Size caps
+
+Several services cap payload size to protect Postgres. Defaults (all tunable, see
+[env vars](../config/env-vars.md)):
+
+| Service | Env var | Default |
+|---|---|---|
+| `kv` value | `PICLOUD_KV_MAX_VALUE_BYTES` | 256 KiB |
+| `docs` document | `PICLOUD_DOCS_MAX_VALUE_BYTES` | 256 KiB |
+| `pubsub` message | `PICLOUD_PUBSUB_MAX_MESSAGE_BYTES` | 256 KiB |
+| `queue` message | `PICLOUD_QUEUE_MAX_PAYLOAD_BYTES` | 256 KiB |
+| `files` blob | `PICLOUD_FILES_MAX_FILE_SIZE_BYTES` | 100 MiB |
+
+Exceeding a cap **throws**. For `kv`/`queue` the size is checked *before* authorization so a public
+script can't be used to hammer the database.
+
+## The full surface at a glance
+
+| Namespace | Since SDK | Page |
+|---|---|---|
+| `log` | 1.0 | [Writing scripts](../../guide/writing-scripts.md#logging) |
+| `kv` | 1.2 | [Storage](storage.md#kv) |
+| `docs` | 1.3 | [Storage](storage.md#docs) |
+| `files` | 1.6 | [Storage](storage.md#files) |
+| `http` | 1.5 | [Outbound HTTP](http.md) |
+| `pubsub` | 1.6 / 1.7 | [Messaging](messaging.md#pubsub) |
+| `secrets`, `email` | 1.8 | [Secrets](secrets.md), [Email](email.md) |
+| `users` | 1.9 | [Users & auth](users.md) |
+| `queue`, `invoke`, `retry` | 1.10 | [Messaging](messaging.md#queue), [Composition](composition.md) |
+| `dead_letters` | 1.2 | [Composition](composition.md#dead-letters) |
+| `json` `base64` `hex` `url` `regex` `random` `time` | 1.0 | [Standard library](stdlib.md) |
+
+Many services also have an **admin/inspection** side on the HTTP API and the `pic` CLI (e.g. browse KV,
+download files, read secret names). Those are read-mostly; *writing* data is the script's job. Each SDK
+page links to its admin counterpart.
--- a/docs/dev-guide/src/reference/sdk/secrets.md
+++ b/docs/dev-guide/src/reference/sdk/secrets.md
@@ -0,0 +1,51 @@
+# Secrets
+
+*Since SDK 1.8.* Per-app encrypted key/value storage for credentials — API keys, signing secrets, DB
+passwords for upstreams. Values are encrypted at rest with AES-256-GCM under the process master key
+(`PICLOUD_SECRET_KEY`). Unlike `kv`, secrets are **not** collection-scoped: a secret is just a name
+within the app.
+
+```rhai
+secrets::set("stripe_key", "sk_live_…");
+secrets::set("oauth", #{ client_id: "abc", client_secret: "xyz" });  // any JSON value
+
+let key = secrets::get("stripe_key");    // the value, or () if missing
+let was = secrets::delete("stripe_key"); // bool
+let page = secrets::list(#{ cursor: (), limit: 100 });
+//  page = #{ names: [...], next_cursor: () | "cursor" }   — names only, never values
+```
+
+| Function | Signature | Returns |
+|---|---|---|
+| `secrets::set(name, value)` | `(string, dynamic)` | `()` — upserts (overwrites if present) |
+| `secrets::get(name)` | `(string)` | the value, or `()` (also `()` if decryption fails) |
+| `secrets::delete(name)` | `(string)` | `bool` |
+| `secrets::list(#{ cursor?, limit? })` | | `#{ names, next_cursor }` |
+
+Strings round-trip as strings; other types round-trip via JSON.
+
+## Why use secrets instead of `kv`?
+
+- **Encrypted at rest.** A database dump leaks `kv` values in the clear, but secret values are
+  ciphertext.
+- **Redacted everywhere.** The admin API, dashboard, and `pic secrets` only ever show secret *names* —
+  values never leave the server after `set`.
+
+## Setting secrets out-of-band
+
+You usually don't want to hardcode a secret in a script. Set it from the CLI (value read from stdin so
+it never lands in shell history) or the dashboard:
+
+```sh
+printf 'sk_live_…' | pic secrets set --app myapp stripe_key
+pic secrets ls --app myapp
+```
+
+Then read it at runtime: `let k = secrets::get("stripe_key");`. See
+[the data-admin API](../rest-api/data-admin.md#secrets) and the
+[webhook tutorial](../../examples/webhook-receiver.md), which verifies an HMAC using a stored secret.
+
+> **Master-key caveat:** secrets are encrypted under `PICLOUD_SECRET_KEY`. **Rotating that key makes
+> existing secrets undecryptable** — `secrets::get` will return `()` for them. There is no automatic
+> re-encryption in 1.1.9; rotate deliberately and re-`set` your secrets afterward. See
+> [Security](../../operations/security.md#secrets-and-the-master-key).
--- a/docs/dev-guide/src/reference/sdk/stdlib.md
+++ b/docs/dev-guide/src/reference/sdk/stdlib.md
@@ -0,0 +1,100 @@
+# Standard library
+
+*Since SDK 1.0.* Pure, stateless helpers for everyday glue. No app scope, no I/O, no failure modes
+beyond bad input (which throws). For the deep design notes see the engineering reference
+`docs/stdlib-reference.md` in the repo; this page is the working reference.
+
+> **Heads-up:** `ctx.request.body` is already parsed when the request is JSON — don't `json::parse` it
+> again. Use `json::parse` only on raw strings (e.g. an `http` response's `body_raw`).
+
+## `json` — parse / stringify
+
+| Function | Signature | Returns |
+|---|---|---|
+| `json::parse(s)` | `(string)` | a Rhai value (map/array/scalar/`()` for null) — throws on invalid JSON |
+| `json::stringify(v)` | `(dynamic)` | compact JSON string |
+| `json::stringify_pretty(v)` | `(dynamic)` | 2-space-indented JSON |
+
+## `base64` — standard & URL-safe
+
+Encoders accept a string or a blob; decoders return a blob.
+
+| Function | Notes |
+|---|---|
+| `base64::encode(input)` | standard alphabet, padded |
+| `base64::decode(s)` | → blob; throws on invalid |
+| `base64::encode_url(input)` | URL-safe alphabet, **no** padding |
+| `base64::decode_url(s)` | → blob; throws on invalid |
+
+```rhai
+let bytes = base64::decode(ctx.request.body.b64);   // → Blob, e.g. for files::create
+let token = base64::encode_url(random::bytes(32));
+```
+
+## `hex`
+
+| Function | Notes |
+|---|---|
+| `hex::encode(input)` | lowercase hex (string or blob in) |
+| `hex::decode(s)` | → blob; case-insensitive; throws on invalid |
+
+## `url` — percent-encoding
+
+| Function | Notes |
+|---|---|
+| `url::encode(s)` | percent-encode one component |
+| `url::decode(s)` | percent-decode; throws on invalid UTF-8 |
+| `url::encode_query(map)` | build `k1=v1&k2=v2` (keys & values encoded, keys sorted) |
+
+## `regex` — non-backtracking regular expressions
+
+Linear-time engine (no catastrophic backtracking). Patterns are cached. Use backticks for literal
+backslashes: `` regex::find_all(`\d+`, text) ``.
+
+| Function | Returns |
+|---|---|
+| `regex::is_match(pattern, text)` | `bool` |
+| `regex::find(pattern, text)` | first match string, or `()` |
+| `regex::find_all(pattern, text)` | array of match strings |
+| `regex::replace(pattern, text, repl)` | replace first |
+| `regex::replace_all(pattern, text, repl)` | replace all |
+| `regex::split(pattern, text)` | array |
+| `regex::captures(pattern, text)` | `[full, g1, g2, …]`, or `()` |
+
+Invalid patterns throw.
+
+## `random` — cryptographically secure
+
+Backed by the OS CSPRNG; safe for tokens and IDs.
+
+| Function | Returns |
+|---|---|
+| `random::int(min, max)` | uniform int in `[min, max]` (throws if `min > max`) |
+| `random::float()` | uniform in `[0.0, 1.0)` |
+| `random::bytes(n)` | blob of `n` bytes (`n ∈ [0, 65536]`) |
+| `random::string(n)` | `n` alphanumeric chars (`n ∈ [0, 4096]`) |
+| `random::uuid()` | UUID v4 string |
+
+```rhai
+let code = random::string(7);     // e.g. a short URL slug
+let id   = random::uuid();
+```
+
+## `time` — UTC, milliseconds
+
+Canonical unit is `i64` milliseconds since the Unix epoch; ISO 8601 / RFC 3339 strings for I/O. All
+UTC.
+
+| Function | Returns |
+|---|---|
+| `time::now()` | current time as ISO 8601 string (with ms) |
+| `time::now_ms()` | current ms since epoch |
+| `time::parse(iso)` | ms since epoch (throws on bad input) |
+| `time::format(ms)` | ISO 8601 string |
+| `time::add_seconds(ms, secs)` | `ms + secs*1000` (throws on overflow) |
+| `time::diff_seconds(a_ms, b_ms)` | `(b_ms - a_ms)/1000`, truncated |
+
+```rhai
+let now = time::now_ms();
+let deadline = time::add_seconds(now, 3600);   // one hour from now
+```
--- a/docs/dev-guide/src/reference/sdk/storage.md
+++ b/docs/dev-guide/src/reference/sdk/storage.md
@@ -0,0 +1,117 @@
+# Storage: kv, docs, files
+
+Three collection-scoped storage services. All share the [handle pattern](overview.md#namespacing-and-the-handle-pattern)
+and [error conventions](overview.md#error-conventions). The identity of any item is the tuple
+`(app, collection, key/id)` — collections are mandatory and app scoping is automatic.
+
+Each also has a read-mostly admin surface: [Secrets, KV & files](../rest-api/data-admin.md) on the
+HTTP API and `pic kv` / `pic files` on the CLI.
+
+---
+
+## `kv` — key/value store {#kv}
+
+*Since SDK 1.2.* Simple string-keyed JSON values. Best for counters, flags, small lookups, caches.
+
+```rhai
+let c = kv::collection("settings");
+
+c.set("theme", "dark");              // value can be any JSON-serializable value
+let t = c.get("theme");              // "dark", or () if absent
+let exists = c.has("theme");         // bool
+let was = c.delete("theme");         // bool — was it present?
+let page = c.list();                 // #{ keys: [...], next_cursor: () | "cursor" }
+```
+
+| Method | Signature | Returns |
+|---|---|---|
+| `kv::collection(name)` | `(string)` | a `KvHandle` |
+| `.set(key, value)` | `(string, dynamic)` | `()` — throws if value exceeds `PICLOUD_KV_MAX_VALUE_BYTES` (256 KiB) |
+| `.get(key)` | `(string)` | the value, or `()` if absent |
+| `.has(key)` | `(string)` | `bool` (cheap; no deserialization) |
+| `.delete(key)` | `(string)` | `bool` (was-present) |
+| `.list()` / `.list(cursor)` / `.list(cursor, limit)` | | `#{ keys, next_cursor }` |
+
+Pagination: `list()` returns a page plus `next_cursor` (`()` when exhausted); pass it back to
+`list(cursor)` for the next page.
+
+---
+
+## `docs` — document store {#docs}
+
+*Since SDK 1.3.* Auto-IDed JSON documents with a query filter. Best for entities (users, posts,
+orders) where you want to find by field.
+
+```rhai
+let posts = docs::collection("posts");
+
+let id  = posts.create(#{ title: "Hi", tag: "intro", views: 0 });  // returns the new id (string)
+let doc = posts.get(id);                  // envelope, or () if missing
+let hits = posts.find(#{ tag: "intro" }); // array of envelopes
+let one  = posts.find_one(#{ tag: "intro" });
+posts.update(id, #{ title: "Hi", tag: "intro", views: 1 });        // replaces `data`
+let was = posts.delete(id);               // bool
+let page = posts.list();                  // #{ docs: [...], next_cursor: () | "cursor" }
+```
+
+Every read returns an **envelope**, with your fields under `data`:
+
+```rhai
+#{ id: "…", data: #{ title: "Hi", tag: "intro", views: 1 },
+   created_at: "2026-…Z", updated_at: "2026-…Z" }
+```
+
+| Method | Signature | Returns |
+|---|---|---|
+| `docs::collection(name)` | `(string)` | a `DocsHandle` |
+| `.create(data)` | `(map)` | new id (string) — throws if over `PICLOUD_DOCS_MAX_VALUE_BYTES` (256 KiB) |
+| `.get(id)` | `(string)` | envelope, or `()` |
+| `.find(filter)` | `(map)` | array of envelopes |
+| `.find_one(filter)` | `(map)` | one envelope, or `()` |
+| `.update(id, data)` | `(string, map)` | `()` |
+| `.delete(id)` | `(string)` | `bool` |
+| `.list()` / `.list(#{ cursor, limit })` | | `#{ docs, next_cursor }` |
+
+The `find` filter is a map of field equality matches (`#{ tag: "intro", published: true }` matches docs
+where both hold). It is a deliberately small subset for 1.1.9; richer query operators are roadmap.
+
+> `update(id, data)` **replaces** the whole `data` map. To change one field, `get` it, mutate, and
+> `update` with the full map.
+
+---
+
+## `files` — blob storage {#files}
+
+*Since SDK 1.6.* Binary objects (images, uploads, generated artifacts) stored on the filesystem under
+`PICLOUD_FILES_ROOT`, with metadata in Postgres. Bytes are passed as Rhai **blobs**.
+
+```rhai
+let bucket = files::collection("avatars");
+
+// data must be a Blob — e.g. base64::decode(ctx.request.body.b64)
+let id = bucket.create(#{ name: "a.png", content_type: "image/png", data: bytes });
+let meta  = bucket.head(id);   // metadata map, or ()  (no bytes)
+let bytes = bucket.get(id);    // the Blob, or ()
+bucket.update(id, #{ data: new_bytes });   // data required; name/content_type optional
+let was = bucket.delete(id);   // bool
+let page = bucket.list();      // #{ files: [...], next_cursor: () | "cursor" }
+```
+
+| Method | Signature | Returns |
+|---|---|---|
+| `files::collection(name)` | `(string)` | a `FilesHandle` |
+| `.create(#{ name, content_type, data })` | | new id (string) — `data` is a Blob; throws over `PICLOUD_FILES_MAX_FILE_SIZE_BYTES` (100 MiB) |
+| `.head(id)` | `(string)` | metadata `#{ id, collection, name, content_type, size, checksum, created_at, updated_at }`, or `()` |
+| `.get(id)` | `(string)` | the Blob, or `()` |
+| `.update(id, #{ data, name?, content_type? })` | | `()` |
+| `.delete(id)` | `(string)` | `bool` |
+| `.list()` / `.list(cursor)` / `.list(cursor, limit)` / `.list(#{ cursor, limit })` | | `#{ files, next_cursor }` |
+
+Reads are checksum-verified (SHA-256). **Serving the bytes back:** a script response is always JSON, so
+you can't stream a raw blob through the response body (a blob body serializes to a hex JSON string).
+Return base64 in JSON for the client to decode, or use the
+[admin files endpoint](../rest-api/data-admin.md#files) for true raw bytes — see the
+[file-upload tutorial](../../examples/file-upload.md).
+
+> Mutating any of these services can fire a [trigger](../rest-api/triggers.md) (`kv`/`docs`/`files`
+> kinds), letting another script react to the change.
--- a/docs/dev-guide/src/reference/sdk/users.md
+++ b/docs/dev-guide/src/reference/sdk/users.md
@@ -0,0 +1,87 @@
+# Users & auth
+
+*Since SDK 1.9.* The `users` namespace manages **your app's end-users** — registration, login,
+sessions, email verification, password reset, invitations, and per-user roles. Passwords are hashed
+with Argon2id; sessions are opaque tokens.
+
+> **This is the only way to do app-user auth — PiCloud ships no `/signup` or `/login` HTTP endpoints.**
+> You write scripts that call `users::*` and bind them to *your own* routes (e.g. `POST /auth/signup`).
+> The [TODO API tutorial](../../examples/todo-api.md) builds the complete flow. (Distinct from
+> [admin users](../rest-api/access.md), who manage the platform.)
+
+## The user map
+
+Reads return:
+
+```rhai
+#{ id, email, display_name,          // display_name is () if unset
+   email_verified_at, last_login_at, // RFC 3339 or ()
+   created_at, updated_at,
+   roles: ["editor", ...] }
+```
+
+## CRUD
+
+| Function | Signature | Returns |
+|---|---|---|
+| `users::create(#{ email, password, display_name? })` | | the user map — throws if email taken |
+| `users::get(id)` | `(string)` | user map, or `()` |
+| `users::find_by_email(email)` | `(string)` | user map or `()` — **requires an authenticated principal** |
+| `users::email_available(email)` | `(string)` | `bool` — anonymous-safe pre-check |
+| `users::update(id, #{ display_name? })` | | updated user map |
+| `users::delete(id)` | `(string)` | `bool` |
+| `users::list(#{ "$limit"?, cursor? })` | | `#{ users: [...], next_cursor }` — `limit` is accepted as an alias for `$limit` |
+
+> **Enumeration:** `find_by_email` is blocked for anonymous (public) scripts to stop attackers probing
+> who's registered; call it only from authenticated paths. `email_available` *is* anonymous-safe (a
+> signup form needs it) but is unthrottled — rate-limit it yourself if abuse is a concern. See
+> [Security](../../operations/security.md#user-enumeration).
+
+## Authentication
+
+```rhai
+let token = users::login(email, password);   // session token string, or () on bad credentials
+let user  = users::verify(token);             // user map (and bumps the sliding TTL), or () if invalid/expired
+users::logout(token);                         // invalidate
+```
+
+A typical gated route:
+
+```rhai
+let tok = ctx.request.headers["authorization"].sub_string(7);  // strip "Bearer "
+let me  = users::verify(tok);
+if me == () { return #{ statusCode: 401, body: #{ error: "unauthorized" } }; }
+// ... me.id, me.roles available
+```
+
+## Email-tied flows
+
+These send mail (need SMTP configured, or dev mode), templated by the options you pass:
+
+| Function | Purpose |
+|---|---|
+| `users::send_verification_email(id, #{ link_base, from, subject, body_template })` | send a verify link |
+| `users::verify_email(token)` | mark verified — returns user map or `()` |
+| `users::request_password_reset(email, #{ link_base, from, subject, body_template })` | send reset link |
+| `users::complete_password_reset(token, new_password)` | apply — user map or `()` |
+| `users::invite(email, #{ link_base?, from?, subject?, body_template?, display_name?, roles? })` | invite |
+| `users::accept_invite(token, password)` / `(token, password, display_name)` | accept — returns a session token or `()` |
+
+`body_template` / `link_base` are required only when email sending is configured; the platform builds
+the link as `link_base` + the one-time token.
+
+## Roles
+
+Per-app, string-tagged. Define whatever vocabulary your app needs (`"editor"`, `"pro"`, …).
+
+| Function | Returns |
+|---|---|
+| `users::add_role(id, role)` | `()` |
+| `users::remove_role(id, role)` | `bool` (was-present) |
+| `users::has_role(id, role)` | `bool` |
+
+## Admin & CLI side
+
+Operators can list/inspect app users, mint a reset token, and revoke sessions via
+[the app-users API](../rest-api/app-users.md) and `pic users`. They cannot read passwords (only hashes
+are stored).