Shared TOPICS fanned out only to in-cluster trigger handlers; external clients
could not subscribe (per-app topics already can). Add SSE for shared topics.
- RealtimeBroadcaster gains a parallel (group_id, topic) channel map:
subscribe_group / publish_group / drop_group_topic (default no-ops so
NoopRealtimeBroadcaster + test doubles are untouched). InProcessBroadcaster
implements them with a second map; GC + channel_count span both.
- Route GET /realtime/shared/topics/{topic}: Host->app dispatch (as the per-app
route), then RealtimeAuthority::authorize_subscribe_shared resolves the OWNING
GROUP from the app's chain (kind=topic, root segment). Reads-open model — the
resolution IS the authorization, consistent with in-script shared reads; a
foreign-subtree app never resolves (404, the isolation boundary). No principal
machinery needed.
- GroupPubsubServiceImpl::with_realtime bridges a shared-topic publish to the
owning-group channel (best-effort) after the durable trigger fan-out.
- Host wires the broadcaster into the group pubsub service + the collection
resolver into the authority.
Auth-model note: chose reads-open (subtree app's Host is the grant) over
"authenticated principal + GroupKvRead" — it's both simpler and faithful to how
shared-collection reads already work. Pinned by realtime broadcaster group-map
tests, realtime_api shared-route tests (404 + stream), and
group_pubsub_service::publish_bridges_to_the_group_broadcaster. No migration.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
PiCloud
A lightweight, self-hosted, event-driven serverless compute platform. Upload a Rhai script, get an HTTP endpoint. Designed to run on a single modest server with no idle CPU cost, and to scale out to a small cluster when you need it.
Status: Phase 1 — MVP scaffolding in progress.
The authoritative design lives in
serverless_cloud_blueprint.md.
Why
Existing serverless platforms are either cloud-locked, heavyweight, or both. PiCloud aims for the opposite end of the spectrum: one binary, one database, one reverse proxy — running on hardware you already own.
Architecture (one paragraph)
PiCloud splits into three logical services — manager (control plane: scripts, schedules, dashboard), orchestrator (per-node event ingress and dispatch), and executor (per-node Rhai sandbox) — each backed by a *-core Rust library. In MVP they run in a single process; in cluster mode they run as three binaries with one manager and one orchestrator + executor per node. Caddy fronts everything; PostgreSQL is the single source of truth.
See CLAUDE.md for working notes and serverless_cloud_blueprint.md for the full design.
Quick Start
Coming as scaffolding lands. For now:
# Rust toolchain (pinned via rust-toolchain.toml)
cargo check --workspace
# Run the all-in-one MVP binary (once main.rs is wired up)
cargo run -p picloud
Repository Layout
crates/
shared/ cross-cutting types
executor-core/ Rhai engine + sandbox
orchestrator-core/ event ingress, dispatch
manager-core/ control plane
picloud/ MVP all-in-one binary
picloud-{manager,orchestrator,executor}/ cluster-mode binaries (skeleton)
dashboard/ SvelteKit
caddy/ Caddyfile
docker/ Dockerfiles
docs/
git-workflow.md Trunk-based workflow
Contributing
See docs/git-workflow.md for the branching and commit conventions. TL;DR: trunk-based, short-lived branches, Conventional Commits, no force-pushing main.
License
TBD.