[t3-code]

what changed

• isolates the framework-free reconciler from spike: compare plugin runtime models #7448 into a standalone poc
• keeps the shared manifest and runtime contract
• includes iterative stack-safe dependency planning and explicit finalizer ownership
• adds a single-variant demo for activation, replacement, cleanup, and a 250-plugin chain

why

this lets reviewers evaluate the planner without effect-scope or cordis lifecycle machinery in the same diff. it is the smallest runtime model and is useful as the deterministic planner half of the recommended hybrid.

validation

• 32 tests passed with node 24.13.1, including a 20,000-plugin dependency chain
• package typecheck passed
• lint with warnings denied passed
• formatting and frozen lockfile install passed
• demo completed successfully

limits

this is an isolated runtime poc. it does not load packages, add a sandbox, expose plugin rpc, or wire product ui.

checklist

• this pr is focused on one implementation
• i explained what changed and why
• no ui changes

request provenance

• requested by: @UtkarshUsername

---

Note

Medium Risk
The reconciler’s lifecycle and commit/rollback semantics are subtle and security-relevant for future plugin loading, but the change is an isolated private package with broad tests and no production wiring.

Overview
Adds a new private @t3tools/plugin-runtime-pure-poc package that extracts the framework-free plugin reconciler from the broader runtime experiment so it can be reviewed on its own.

createPureRuntime implements iterative capability-graph planning (stack-safe, cycle detection, missing-deps blocking), targeted restarts when definitions or upstream capabilities change, LIFO finalizers, staged activation with rollback on failure, frozen contribution snapshots, serialized transitions with reentrancy guards via AsyncLocalStorage, and dependent-first teardown with aggregated cleanup errors.

A shared defineRuntimeContract test suite (plus manifest tests and a 20k-plugin chain test) locks in lifecycle, rollback, observer, and edge-case behavior. PluginManifest Effect Schema validates namespaced ids, semver, capability ids, safe relative entrypoints, and declarative mobile surfaces. A demo script benchmarks a 250-plugin chain. Explicitly out of scope: package loading, sandbox, RPC, or product UI.

^{Reviewed by Cursor Bugbot for commit ae67af9. Bugbot is set up for automated code reviews on this repo. Configure here.}

Note

Add pure plugin reconciler POC with topological activation and lifecycle management

• Introduces a self-contained plugin runtime package (@t3tools/plugin-runtime-pure-poc) under packages/plugin-runtime-poc/ that manages plugin activation, deactivation, and reconciliation without recursion.
• pureRuntime.ts implements createPureRuntime: plugins are ordered via iterative DFS, staged activations run in dependency order, and finalizers execute LIFO on retirement or dispose.
• manifest.ts defines an effect/Schema-based PluginManifest that enforces namespaced IDs, strict semver, safe relative entrypoints, and disallows mobile executable entrypoints.
• runtimeContract.ts provides a reusable test harness (defineRuntimeContract) covering activation order, reentrancy rejection, rollback, LIFO cleanup, snapshot immutability, and cycle detection.
• A demo.ts script runs sample activations and benchmarks a 250-plugin dependency chain, printing a structured JSON report.

^{Macroscope summarized ae67af9.}

[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	12.6 KiB	12.6 KiB	−24 B (−0.2%)	15.1 KiB	✅
Codex	Thread snapshot wire	6.3 KiB	6.3 KiB	−8 B (−0.1%)	7.3 KiB	✅
Codex	Live turn WebSocket wire	6.3 KiB	6.3 KiB	−16 B (−0.2%)	7.8 KiB	✅
Codex	Live turn WebSocket decoded	51.8 KiB	51.8 KiB	0 B (0.0%)	66.4 KiB	✅
Codex	Live turn messages	16	16	0 (0.0%)	21	✅
Claude	Total thread wire	12.6 KiB	12.6 KiB	−1 B (−0.0%)	15.1 KiB	✅
Claude	Thread snapshot wire	6.3 KiB	6.3 KiB	−9 B (−0.1%)	7.3 KiB	✅
Claude	Live turn WebSocket wire	6.3 KiB	6.3 KiB	+8 B (+0.1%)	7.8 KiB	✅
Claude	Live turn WebSocket decoded	52.7 KiB	52.7 KiB	0 B (0.0%)	66.4 KiB	✅
Claude	Live turn messages	16	16	0 (0.0%)	21	✅

Baseline: bcfd485 · PR result: ae67af9 · Source CI: success

Scenario and decoded snapshot size

10 historical turns, 5 command tools per turn, 878.9 KiB retained MCP result per historical turn, and a 1.05 MiB retained result in the measured turn.

• Codex decoded thread snapshot: 99.9 KiB
• Claude decoded thread snapshot: 100.6 KiB

Updated in place by a trusted workflow. PR artifacts are strictly validated and never executed.

[macroscopeapp]

Approvability

Verdict: Not approved

Macroscope's review found this PR not approvable — This PR introduces a complete new plugin runtime system (~1300 lines of new code) with complex async lifecycle management. Beyond the scope being significant new capability rather than a minor change, there is an unresolved High severity finding about a potential deadlock with function-valued thenables that warrants attention.

Not approved because:

• 1 blocking correctness issue found at or above your repo's Minimum Blocking Severity

^{Adjust the Minimum Blocking Severity for this repo — including turning it Off — in Settings. You can add or adjust custom eligibility rules. Learn more.}

[t3-code]

addressed the review findings in 39f328f9c:

• definition equality is order-insensitive and includes activation callback identity
• lifecycle events are emitted only after a composition commits
• rollback preserves the activation error while cleanup failures go to onCleanupError
• retirement cleanup failures are reported without rejecting an already committed snapshot
• entrypoints reject .. escape segments, semver validation is strict, and snapshot maps are typed as sparse records

23 tests pass with node 24.13.1, including the 20,000-plugin chain, plus typecheck, lint, formatting, frozen install, and the demo.

[t3-code]

addressed the latest findings in 8c606a64c:

• plugin activation and finalizers run in an async callback context
• reentrant reconcile or dispose calls now fail immediately instead of deadlocking the serialized queue
• lifecycle observer failures are isolated and reported without interrupting commit or cleanup

26 tests, including the 20,000-plugin chain, typecheck, lint with warnings denied, formatting, and frozen install pass on node 24.13.1.

[cursor]

Cursor Bugbot has reviewed your changes using high effort and found 1 potential issue.

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit c72d46c. Configure here.}

[t3-code]

addressed the latest review findings in 617cd2973:

• synchronous callback microtasks can use the runtime after the callback returns
• direct reentrant calls from active callbacks still reject immediately
• timeout sentinels are cancelled after each test
• the shared queued-input and late-context contract cases pass

30 tests, typecheck, lint with warnings denied, formatting, frozen install, and the demo pass on node 24.13.1.

Dismissing prior approval to re-evaluate 9b33da6

[t3-code]

synced the plain-function callback return regression test and fix in 9b33da605. callback lifetime tracking now treats only thenables as asynchronous.

31 tests and the full local validation pass on node 24.13.1.

[macroscopeapp]

🟠 High src/pureRuntime.ts:188

A function-valued thenable returned by a plugin clears callbackState.active before it settles, so a reentrant runtime.reconcile() or dispose() queues behind the current transition and deadlocks when that transition awaits the thenable. The check only recognizes object results; detect function thenables as well before clearing the callback state.

Suggested change

	if (typeof result === "object" && result !== null && "then" in result) {
	if ((typeof result === "object" || typeof result === "function") && result !== null && "then" in result) {

🚀 Reply "fix it for me" or copy this AI Prompt for your agent:

In file @packages/plugin-runtime-poc/src/pureRuntime.ts around line 188:

A function-valued thenable returned by a plugin clears `callbackState.active` before it settles, so a reentrant `runtime.reconcile()` or `dispose()` queues behind the current transition and deadlocks when that transition awaits the thenable. The check only recognizes `object` results; detect function thenables as well before clearing the callback state.

[t3-code]

Consolidated into #8007 as one PR targeting main.