External MCP tools (web search, crawl) had no per-call timeout: a hung
tool call was only broken by the 15-min transport silence timeout shared
with the chat provider, and a server that kept the socket warm but never
returned could spin until the user cancelled.
Add two independent, composing bounds for external MCP traffic (the chat
provider path is unchanged):
- Silence 5 min: buildPinnedDispatcher now overrides headersTimeout/
bodyTimeout with mcpStreamTimeoutMs() (AI_MCP_STREAM_TIMEOUT_MS,
default 300000) on the external-MCP dispatcher only, so a byte-silent
upstream is severed in ~5 min instead of 15.
- Total per-call 15 min: wrapToolWithCallTimeout wraps each external
tool's execute with a fresh AbortController + timer composed with the
turn signal via AbortSignal.any (AI_MCP_CALL_TIMEOUT_MS, default
900000). It RACES the call against the abort signal because
@ai-sdk/mcp does not settle its in-flight promise on abort, so a
warm-but-stuck call would otherwise hang forever.
On timeout the call surfaces as a tool-error and the agent loop recovers.
Add tests (incl. a never-settling real-client-style stub) and document
both env vars in .env.example.
27c91e4a69