Tighten the UDS auth, framing, and response-reader boundaries while keeping the AgentSummary lifecycle covered so Codecov and CI fail on real regressions instead of missing coverage. The poorMode settings mock mirrors unrelated real settings defaults to avoid Bun mock retention changing later permission tests.
Constraint: PR #369 must fix Codecov/CI precisely without warning suppression, fallback masking, or mock pollution
Rejected: Delete AgentSummary lifecycle coverage | would hide Codecov loss and stale-summary behavior
Rejected: Store inline UDS rejection in a hidden input sentinel | cloned observable inputs can drop it and bypass rejection
Rejected: Ignore malformed UDS frames until timeout | leaves client slots and SendMessage calls open to exhaustion
Confidence: high
Scope-risk: moderate
Directive: Keep empty #token= markers rejected; do not require a non-empty token value in hasInlineUdsToken
Tested: bun test packages/builtin-tools/src/tools/SendMessageTool/__tests__/udsRecipientSanitization.test.ts src/utils/__tests__/udsMessaging.test.ts src/utils/__tests__/udsResponseReader.test.ts src/utils/__tests__/ndjsonFramer.test.ts
Tested: bunx tsc --noEmit --pretty false
Tested: bun run lint
Tested: bun test --coverage --coverage-reporter lcov --coverage-dir coverage
Tested: bun run test:all
Tested: bun audit
Tested: bun run build
Tested: bun run build:vite
Not-tested: GitHub-hosted Codecov upload until pushed PR checks rerun
UDS messaging now uses private local capabilities instead of exposing auth tokens through SDK metadata, environment variables, session registry, peer listing, or tool output. The receive path bounds NDJSON frames, response buffers, active clients, and pending inbox bytes, and strips auth metadata before messages enter the prompt queue.
Teammate mailboxes now validate file and message sizes, fail closed on corrupt mutation inputs, compact by count and retained bytes, and use stable message identity for in-process acknowledgements. Agent summaries now fork only a bounded recent context using lazy size estimation and content fingerprints instead of retaining or serializing unbounded histories.
Constraint: PR #361 was already merged; this branch is based on upstream/main@c2ac9a74.
Rejected: Default-disabling COORDINATOR_MODE/TEAMMEM only | explicit feature enablement still hit unbounded paths.
Rejected: Persisting UDS auth in SDK/env/session registry | bridge/remote metadata can leak local capability secrets.
Rejected: Inline uds #token addresses | observable/tool/classifier paths can reflect raw addresses outside the UDS request frame.
Rejected: Positional mailbox marking after compaction | compaction can shift indices across the lock boundary.
Confidence: high
Scope-risk: moderate
Directive: Do not expose UDS capability tokens through SDK messages, environment variables, session registry, peer-list output, or SendMessage result/classifier surfaces.
Directive: Do not reintroduce positional mailbox acknowledgements unless compaction is removed or read+mark is atomic under one lock.
Tested: bun test src/utils/__tests__/ndjsonFramer.test.ts src/utils/__tests__/udsMessaging.test.ts packages/builtin-tools/src/tools/SendMessageTool/__tests__/udsRecipientSanitization.test.ts
Tested: bunx tsc --noEmit --pretty false
Tested: bun run lint
Tested: bunx biome lint modified src/package files
Tested: bun run test:all (3704 pass, 0 fail, 6734 expects)
Tested: bun audit (No vulnerabilities found)
Tested: bun run build
Tested: bun run build:vite
Tested: git diff --check
Not-tested: End-to-end external UDS client driving a full production headless model turn.
