stacklok / toolhive / 29740184376

69%

Build Type

push

github

Committed by web-flow

Commit Message

Add stateless routing to streamable MCP proxy (#5839)

The MCP 2026-07-28 (Modern) revision is stateless: requests carry
protocol metadata per-request in _meta and there is no Mcp-Session-Id.
The streamable proxy multiplexes every request onto one stdio pipe and
demuxes responses by compositeKey(sessID, idKey), so a Modern request
that carried a client-supplied session id would fall through to the
session-lookup path and could collide with a concurrent request on the
same key, cross-delivering one client's response to another.

Classify each single POST via mcp.ClassifyRevision. Modern requests get
a fresh per-request routing token, ignore any Mcp-Session-Id header, and
never touch the session manager; classification errors are rejected with
an HTTP 400 JSON-RPC error. Legacy behavior is unchanged.

Add mcp.ExtractMeta to pull _meta from raw params, deduped with the
parser's existing extraction via a shared helper.

Message-shape enforcement (batches, client-sent responses, GET/DELETE)
is deferred; those paths remain Legacy-only by construction.

Part of #5830.

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Coverage Stats

61 of 68 new or added lines in 3 files covered. (89.71%)

19 existing lines in 4 files now uncovered.

75182 of 109499 relevant lines covered (68.66%)

73.09 hits per line