2 Commits

Author	SHA1	Message	Date
spud	eadc1e230e	feat(mcp): reuse unchanged per-server tool discovery results (#6795) ... * feat(mcp): add per-server discovery cache scaffolding Introduce the per-server tool cache entry, canonical parsed-config snapshots on the applied revision, and the shared _binding_matches reuse predicate. Identity reuse is object-identity based on the pool's current binding (no value equality); snapshots and ownership handles stay out of repr. No selection, eviction or publication is wired yet. * feat(mcp): selectively evict stale per-server tool cache entries Evict per-server discovery results during selective reconciliation, after the new binding epoch is installed, so unchanged servers keep their exact entry objects while changed, removed or re-bound servers (including lifecycle-token rotations) are dropped. Delegate the binding verdict to _binding_matches so reuse and eviction cannot diverge. Clear _server_tool_cache on every full reset, and count retained entries in the reconciliation state predicates so a lingering entry can never let a later config change be silently skipped. * feat(mcp): reuse unchanged per-server results during initialization Initialize MCP tools from per-server discovery instead of a single full pass: select reusable entries under the claim lock, discover only the missing servers with get_mcp_tools_by_server, then publish atomically after re-validating every candidate binding against the pool's current binding via _binding_matches. Failed servers stay absent (never cached as empty), and superseded or partially bound candidates are discarded whole. Test fixtures now drive the grouped entry point. * fix(mcp): close T4 review gaps in per-server cache publication Address four findings from the adversarial review: treat retained entries as unverifiable when the applied baseline is None so an interceptor change still forces a full reset; count retained entries in the claim-time shared-reset predicate; refuse to publish a false-success empty cache when every enabled server failed discovery; and hoist the lazy imports inside the initializer's try/finally so an import failure releases the initialization claim. * fix(mcp): sanitize cache failure logging and document per-server cache The outer lazy-initialization handler now logs only the exception type, never the raw message or traceback, so a discovery error cannot print a resolved $VAR credential. The committed-writer planner mirrors the reader's no-baseline guard so retained entries are never reused under an unknown interceptor chain. Document the per-server tool cache (reuse, invalidation, failure handling, remote tool changes) in MCP_SERVER.md and mcp/AGENTS.md, and drop phase-staging wording from the new code and tests. * docs(mcp): keep the agent-guidance chain under its hard limit F2's cache notes pushed the effective AGENTS.md instruction chain 905 bytes past its 98304-byte hard limit, failing the agent-guidance CI job. Compress the selective-reconciliation bullet to its invariants (the full cache behaviour lives in docs/MCP_SERVER.md), and reword the total-failure comment so it no longer implies that build-invalid connections were attempted. * fix(mcp): fence cached tools by interceptor chain --------- Co-authored-by: Willem Jiang <willem.jiang@gmail.com>	2026-10-14 08:44:21 +08:00
spud	75ce6f4920	fix(mcp): preserve server binding history across gateway workers (#6617) ... * fix(mcp): preserve server binding history across gateway workers A peer Gateway worker could keep a stale pooled session after another worker deleted and identically re-added a stdio server, because the final effective MCP slice matched the revision it had already applied. Record a per-server lifecycle generation in the shared extensions config and consume it in the reader, discovery claim, and committed handoff so an observed generation change force-rebinds only the affected server. Legacy configs derive a stable in-memory token; deletions leave permanent tombstones. * fix(mcp): fail closed on an invalid mcpLifecycle instead of retrying An unverifiable mcpLifecycle made initialize_mcp_tools() unpublishable, so get_cached_mcp_tools() retried discovery forever and could keep respawning stdio servers. Abort discovery on an invalid ledger after conservatively retiring local MCP state; a fixed config recovers on the next call. Also documents the rolling-upgrade prerequisite: cross-worker ABA detection requires configuration writes to go through a lifecycle-aware writer. * refactor(mcp): share stdio fingerprinting across lifecycle paths Reuse lifecycle._stdio_fingerprints from the applied-revision builder so the connection-identity rule has a single implementation, and move the unusable-server diagnostic into the shared helper. Add a regression proving the Gateway Skills writer preserves mcpLifecycle byte-for-value, and document that DeerFlowClient.update_mcp_config can raise RuntimeError after the config was committed. * docs(mcp): condense lifecycle guidance under the AGENTS chain limit The effective mcp/AGENTS.md chain was 15 bytes under the 98,304-byte CI hard limit, so the standalone cross-worker lifecycle bullet pushed it over. Fold the mcpLifecycle and rolling-upgrade facts into the existing selective-reconciliation bullet and condense it, keeping the chain under the limit while preserving the contract. * docs: trim inherited agent guidance below CI size limit --------- Co-authored-by: Willem Jiang <willem.jiang@gmail.com>	2026-10-11 11:45:28 +08:00