feat(v1.1.3-modules): top-level script AST cache in LocalExecutorClient

- New `ScriptIdentity { script_id, updated_at }` DTO.
- `ExecutorClient` trait gains an `execute_with_identity` method;
  default impl forwards to `execute` so `RemoteExecutorClient` (and
  cluster-mode transports later) keep working without bespoke caching.
- `LocalExecutorClient` overrides `execute_with_identity` to consult
  an `LruCache<ScriptId, CachedScript>`. Cache hit only when the
  cached entry's `updated_at` matches the caller's identity; mismatch
  triggers a fresh `Engine::compile`. `Engine::execute_ast(&Arc<AST>, req)`
  is called inside `spawn_blocking` exactly as `execute` does today.
- Cache size from `PICLOUD_SCRIPT_CACHE_SIZE` (default 256).
- Orchestrator's HTTP data-plane path and the dispatcher both switch
  to `execute_with_identity`. `ResolvedTrigger` carries
  `script_updated_at` for the dispatcher's identity construction.

Workspace builds; full test suite (~440 tests) green.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Cargo.lock

@@ -1649,9 +1649,11 @@ dependencies = [
  "async-trait",
  "axum",
  "chrono",
+ "lru",
  "picloud-executor-core",
  "picloud-shared",
  "reqwest",
+ "rhai",
  "serde",
  "serde_json",
  "thiserror 1.0.69",

crates/manager-core/src/dispatcher.rs

@@ -186,9 +186,13 @@ impl Dispatcher {
         // wait synchronously here — sync HTTP and dispatcher share the
         // semaphore so this is intentional.
         let source = resolved.script_source.clone();
+        let identity = picloud_orchestrator_core::ScriptIdentity {
+            script_id: resolved.script_id,
+            updated_at: resolved.script_updated_at,
+        };
         let outcome = self
             .executor
-            .execute(&source, exec_req, ASYNC_EXEC_TIMEOUT)
+            .execute_with_identity(identity, &source, exec_req, ASYNC_EXEC_TIMEOUT)
             .await;
         drop(permit);
 
@@ -230,6 +234,7 @@ impl Dispatcher {
             script_id: script.id,
             script_source: script.source,
             script_name: script.name,
+            script_updated_at: script.updated_at,
             sandbox_overrides: script.sandbox,
             registered_by_principal: trigger.registered_by_principal,
             retry_max_attempts: trigger.retry_max_attempts,
@@ -335,6 +340,7 @@ impl Dispatcher {
             script_id,
             script_source: script.source,
             script_name: payload.script_name,
+            script_updated_at: script.updated_at,
             sandbox_overrides: script.sandbox,
             // HTTP outbox rows don't carry a registered_by_principal
             // — use a sentinel zero UUID since this field isn't used
@@ -516,6 +522,11 @@ pub struct ResolvedTrigger {
     pub script_id: ScriptId,
     pub script_source: String,
     pub script_name: String,
+    /// v1.1.3: freshness comparator for the orchestrator's top-level
+    /// script cache. The dispatcher hands `(script_id, updated_at)`
+    /// in alongside the source so cached ASTs can be reused across
+    /// triggered invocations.
+    pub script_updated_at: chrono::DateTime<chrono::Utc>,
     pub sandbox_overrides: ScriptSandbox,
     pub registered_by_principal: picloud_shared::AdminUserId,
     pub retry_max_attempts: u32,

crates/orchestrator-core/Cargo.toml

@@ -21,5 +21,10 @@ tracing.workspace = true
 uuid.workspace = true
 chrono.workspace = true
 reqwest.workspace = true
+rhai.workspace = true
 tokio.workspace = true
 urlencoding.workspace = true
+
+# v1.1.3 — top-level script AST cache lives in orchestrator-core's
+# LocalExecutorClient; key is ScriptId, value is `(updated_at, Arc<rhai::AST>)`.
+lru.workspace = true

crates/orchestrator-core/src/api.rs

@@ -129,7 +129,14 @@ where
 
     let timeout = Duration::from_secs(u64::from(script.timeout_seconds));
     let started = Utc::now();
-    let outcome = state.executor.execute(&script.source, req, timeout).await;
+    let identity = crate::client::ScriptIdentity {
+        script_id: script.id,
+        updated_at: script.updated_at,
+    };
+    let outcome = state
+        .executor
+        .execute_with_identity(identity, &script.source, req, timeout)
+        .await;
     let finished = Utc::now();
 
     // Build and dispatch the audit log regardless of outcome. We await

crates/orchestrator-core/src/client.rs

@@ -1,8 +1,12 @@
-use std::sync::Arc;
+use std::num::NonZeroUsize;
+use std::sync::{Arc, Mutex};
 use std::time::Duration;
 
 use async_trait::async_trait;
+use chrono::{DateTime, Utc};
+use lru::LruCache;
 use picloud_executor_core::{Engine, ExecError, ExecRequest, ExecResponse};
+use picloud_shared::ScriptId;
 
 use crate::gate::{AcquireError, ExecutionGate};
 
@@ -11,6 +15,21 @@ use crate::gate::{AcquireError, ExecutionGate};
 /// resource usage independent of misconfigured scripts.
 const HARD_TIMEOUT_CAP: Duration = Duration::from_secs(300);
 
+/// Default capacity for the top-level script AST cache. Override via
+/// `PICLOUD_SCRIPT_CACHE_SIZE`. Sized assuming a few hundred distinct
+/// endpoint scripts per process.
+const DEFAULT_SCRIPT_CACHE_SIZE: usize = 256;
+
+/// Identity used by [`ExecutorClient::execute_with_identity`] to key
+/// the AST cache. `updated_at` is the freshness comparator — an edit
+/// that bumps `scripts.updated_at` invalidates the cached AST on the
+/// next lookup, no explicit pub/sub.
+#[derive(Debug, Clone, Copy)]
+pub struct ScriptIdentity {
+    pub script_id: ScriptId,
+    pub updated_at: DateTime<Utc>,
+}
+
 /// The seam between the orchestrator and the executor.
 ///
 /// Single-node mode plugs in `LocalExecutorClient`, which calls
@@ -25,6 +44,21 @@ pub trait ExecutorClient: Send + Sync {
         req: ExecRequest,
         timeout: Duration,
     ) -> Result<ExecResponse, ExecError>;
+
+    /// v1.1.3: identity-aware variant for caching. Callers that already
+    /// know the script's `(id, updated_at)` should use this so the local
+    /// executor can reuse a compiled `rhai::AST` across invocations.
+    /// Default impl forwards to `execute` so `RemoteExecutorClient` (and
+    /// any future transport) keeps working without bespoke caching.
+    async fn execute_with_identity(
+        &self,
+        _identity: ScriptIdentity,
+        source: &str,
+        req: ExecRequest,
+        timeout: Duration,
+    ) -> Result<ExecResponse, ExecError> {
+        self.execute(source, req, timeout).await
+    }
 }
 
 /// In-process executor — wraps `executor-core::Engine` directly.
@@ -36,15 +70,106 @@ pub trait ExecutorClient: Send + Sync {
 /// Holds an `ExecutionGate` and acquires a permit before `spawn_blocking`
 /// so a script storm can't drain the blocking-thread pool. The permit
 /// drops with the future, returning the slot.
+///
+/// v1.1.3 adds a top-level AST cache keyed by `ScriptId`. On
+/// `execute_with_identity`, the client compares the caller's
+/// `updated_at` against the cached entry's; a match reuses the
+/// `Arc<rhai::AST>` and skips Rhai's parser. A mismatch (or absence)
+/// triggers a fresh `Engine::compile` + replace.
 pub struct LocalExecutorClient {
     engine: Arc<Engine>,
     gate: Arc<ExecutionGate>,
+    /// `(updated_at, Arc<rhai::AST>)` keyed by `ScriptId`. `Mutex`
+    /// because the cache is shared across invocations of this client;
+    /// LRU eviction caps memory growth.
+    script_cache: Arc<Mutex<LruCache<ScriptId, CachedScript>>>,
+}
+
+pub struct CachedScript {
+    pub updated_at: DateTime<Utc>,
+    pub ast: Arc<rhai::AST>,
 }
 
 impl LocalExecutorClient {
     #[must_use]
     pub fn new(engine: Arc<Engine>, gate: Arc<ExecutionGate>) -> Self {
-        Self { engine, gate }
+        let cap = std::env::var("PICLOUD_SCRIPT_CACHE_SIZE")
+            .ok()
+            .and_then(|s| s.parse::<usize>().ok())
+            .unwrap_or(DEFAULT_SCRIPT_CACHE_SIZE);
+        Self::with_script_cache_capacity(engine, gate, cap)
+    }
+
+    /// Explicit capacity for tests that exercise LRU eviction.
+    #[must_use]
+    pub fn with_script_cache_capacity(
+        engine: Arc<Engine>,
+        gate: Arc<ExecutionGate>,
+        cap: usize,
+    ) -> Self {
+        let cap = NonZeroUsize::new(cap.max(1)).expect("max(1) is non-zero");
+        Self {
+            engine,
+            gate,
+            script_cache: Arc::new(Mutex::new(LruCache::new(cap))),
+        }
+    }
+
+    /// Cache lookup with `updated_at` freshness check. Returns the
+    /// cached AST on hit; compiles, inserts, returns the fresh AST on
+    /// miss or stale. Public so tests can introspect the cache.
+    pub fn get_or_compile(
+        &self,
+        identity: ScriptIdentity,
+        source: &str,
+    ) -> Result<Arc<rhai::AST>, ExecError> {
+        {
+            let mut cache = self
+                .script_cache
+                .lock()
+                .expect("script cache lock poisoned");
+            if let Some(cached) = cache.get(&identity.script_id) {
+                if cached.updated_at == identity.updated_at {
+                    tracing::debug!(
+                        target = "picloud::scripts::cache",
+                        script_id = %identity.script_id,
+                        "cache hit"
+                    );
+                    return Ok(cached.ast.clone());
+                }
+                tracing::debug!(
+                    target = "picloud::scripts::cache",
+                    script_id = %identity.script_id,
+                    "cache stale; recompiling"
+                );
+            } else {
+                tracing::debug!(
+                    target = "picloud::scripts::cache",
+                    script_id = %identity.script_id,
+                    "cache miss"
+                );
+            }
+        }
+        let ast = self.engine.compile(source)?;
+        let mut cache = self
+            .script_cache
+            .lock()
+            .expect("script cache lock poisoned");
+        cache.put(
+            identity.script_id,
+            CachedScript {
+                updated_at: identity.updated_at,
+                ast: ast.clone(),
+            },
+        );
+        Ok(ast)
+    }
+
+    /// Shared script-AST cache. Exposed so tests can introspect cache
+    /// state (length / contents) under a Mutex lock.
+    #[must_use]
+    pub fn script_cache(&self) -> &Arc<Mutex<LruCache<ScriptId, CachedScript>>> {
+        &self.script_cache
     }
 }
 
@@ -89,6 +214,39 @@ impl ExecutorClient for LocalExecutorClient {
             Ok(Ok(res)) => res,
         }
     }
+
+    async fn execute_with_identity(
+        &self,
+        identity: ScriptIdentity,
+        source: &str,
+        req: ExecRequest,
+        timeout: Duration,
+    ) -> Result<ExecResponse, ExecError> {
+        let _permit =
+            self.gate
+                .try_acquire()
+                .map_err(
+                    |AcquireError::Overloaded { retry_after_secs }| ExecError::Overloaded {
+                        retry_after_secs,
+                    },
+                )?;
+
+        let ast = self.get_or_compile(identity, source)?;
+
+        let timeout = timeout.min(HARD_TIMEOUT_CAP);
+        let timeout_secs = u32::try_from(timeout.as_secs()).unwrap_or(u32::MAX);
+
+        let engine = self.engine.clone();
+        let join = tokio::task::spawn_blocking(move || engine.execute_ast(&ast, req));
+
+        match tokio::time::timeout(timeout, join).await {
+            Err(_) => Err(ExecError::Timeout(timeout_secs)),
+            Ok(Err(join_err)) => Err(ExecError::Runtime(format!(
+                "execution task panicked: {join_err}"
+            ))),
+            Ok(Ok(res)) => res,
+        }
+    }
 }
 
 /// Remote executor — forwards to a peer executor node over HTTP.

crates/orchestrator-core/src/lib.rs

@@ -16,7 +16,7 @@ pub mod resolver;
 pub mod routing;
 
 pub use api::{data_plane_router, user_routes_router, DataPlaneState};
-pub use client::{ExecutorClient, LocalExecutorClient, RemoteExecutorClient};
+pub use client::{ExecutorClient, LocalExecutorClient, RemoteExecutorClient, ScriptIdentity};
 pub use gate::{AcquireError, ExecutionGate};
 pub use inbox::InboxRegistry;
 pub use resolver::{ResolverError, ScriptResolver};