2 Commits

Include renames

Author	SHA1	Message	Date
lukaszraczylo	8afb903227	fix(mcp): backend timeouts, response validity, session handshake fallback ... Review round 2 fix batch for the federated /mcp endpoint, driven by a live probe against all 11 production MCP servers behind this gateway through the byte-pipe proxy (session-less tools/list): 8 answer bare, readitall and fetch reject it and need a session handshake, playwright is a legacy HTTP+SSE-transport server (400 Missing sessionId) that no handshake fixes. MF1: every backend call now runs under its own context.WithTimeout derived from r.Context() — toolsListBackendTimeout (20s) per fan-out call, toolsCallBackendTimeout (120s) for tools/call, named constants. MF2: doBackendJSONRPC rejects any non-2xx upstream status as an error (previously unchecked — a non-JSON-RPC error body only failed by accident of not parsing). parseBackendJSONRPC additionally rejects a validly-JSON body that carries neither "result" nor "error" — the exact silent-failure shape that would otherwise decode into an all-zero jsonrpcResponse and hand the client a bare {"jsonrpc":"2.0","id":1}. mcpFederatedToolsCall carries a defensive final guard against the same shape before relaying. MF3: mcpBackendCall is now bare-first-with-fallback — attempt the bare call; on a JSON-RPC error OR HTTP 4xx (never a network failure, timeout, or 5xx), retry once via initialize -> capture Mcp-Session-Id -> retry with the header -> best-effort DELETE close. A legacy HTTP+SSE-transport server (URL path ending "/sse") is excluded from federation entirely before ever reaching this — isLegacySSETransportURL, folded into allowedMCPServerNames — since no handshake fixes a different transport; it stays reachable via the per-server proxy. When every attempted server fails, tools/list returns a JSON-RPC internal error ("no MCP server reachable") instead of a silently-empty list. SF6: defaultMCPProtocolVersion -> "2025-11-25"; a caller's own protocolVersion is echoed back only from a small explicit allowlist (knownMCPProtocolVersions), falling back to the default otherwise — never echoes an arbitrary caller string as this gateway's own claimed capability. SF8: GET/DELETE/etc. on exactly /mcp is now 405 with Allow: POST, checked before auth (llmgateway.go). Folded minors: countTargetRequests batches per-target counter writes for tools/list's whole fan-out into ONE storeIncrMulti call after wg.Wait() (was one call per server); every "actually contacted" doc comment now says "attempted" (attribution is attempt-, not success-, accounting); lastSSEDataLine documents its no-cross-message- id-correlation limitation; routes_unified.go's stale buildLimitScopes/ withTotalScope comments (which claimed handleAdminAPI calls buildLimitScopes directly — it never has) are corrected; jsonrpcRequest documents why its "jsonrpc" field is decoded but never validated. Tests: ~30 new/updated cases covering per-backend timeout derivation (via the shorter-of-two-context-deadlines technique, no real 20s/120s waits), non-2xx rejection, the empty-envelope guard end-to-end, handshake-trigger classification (table-driven: JSON-RPC error and HTTP 4xx trigger, HTTP 500 and network failure do not), the full handshake sequence (bare -> initialize -> retry -> close, asserted call-by-call), handshake-gives-up-too, all-servers-failed, legacy-SSE exclusion (never contacted, in both tools/list and tools/call), protocol-version allowlist (all 4 versions + one rejected), 405/Allow, and best-effort session-close failure never surfacing to the caller.	2026-08-21 19:13:36 +01:00
lukaszraczylo	d565c1d4ea	feat(mcp): federated /mcp aggregation endpoint ... New POST /mcp: a single JSON-RPC 2.0 endpoint aggregating every MCP server the caller's group can reach, for clients built against the earlier pre-plugin gateway's one aggregated endpoint (pugbot's mcpclient, agentkit) rather than this plugin's per-server /mcp/{name}/... proxy. Unlike the per-server proxy, this cannot be a byte-level reverse proxy: aggregating N servers' tools/list results, or routing one tools/call to the single right server, both require actually parsing the JSON-RPC envelope. The gateway answers initialize/ping locally and, for tools/list/tools/call, issues its own outbound JSON-RPC call(s) to the relevant backend server(s) per incoming request — no session state persisted across separate client requests, matching the per-server proxy's own complete absence of gateway-side session tracking. A backend may answer bare JSON or an SSE stream; both are accepted (parseBackendJSONRPC). - tools/list fans out concurrently to every allowed server and merges results, prefixing each tool "<serverName>_<toolName>" — the underscore convention the earlier agentgateway used and that pugbot/agentkit already persist in their own tool-id records (e.g. brave-search_brave_web_search, verified live). A failing/unreachable server is skipped, not a whole-call failure. - tools/call resolves the target by LONGEST matching "<serverName>_" prefix against the caller's allowed servers (disambiguates a server name that prefixes another), strips it, forwards, and relays the result/error under the CLIENT's own id. An unresolvable prefix (unconfigured, or authz-excluded) is a JSON-RPC invalid-params error, not a 404. - Reuses Feature B's countTargetRequest for per-target attribution — every backend server actually contacted increments its own scope. - notifications/* -> 202 no body; unknown method -> JSON-RPC method-not-found; malformed body -> JSON-RPC parse error with id:null (spec-required, not omitted). No new limits config surface. Tests cover prefix resolution (table-driven, incl. the ambiguous-prefix case), SSE/JSON backend parsing, group-restricted aggregation (a denied server is never even contacted), call routing/prefix-stripping, backend error relay, unreachable-server handling, unknown-prefix errors, and per-target counter attribution. README's MCP and A2A section documents the federation contract and naming convention; the architecture diagram and the total-scope/rejected-before-quota notes are updated to include the new route.	2026-08-21 18:38:28 +01:00