How do I increase MCP Inspector's 10-second request timeout?
While testing a FastMCP 0.1.0 server with
mcp dev main.py, I call a tool that takes about 10 seconds and Inspector fails withError: Request timed out. Settingrequest_timeout=300on the FastMCP server didn't help. How can I make the Inspector client wait longer?Originally asked on GitHub: https://github.com/modelcontextprotocol/inspector/issues/142
6 answers
Status: explained. The timeout is enforced by Inspector's client, not by your MCP server setup. In the thread, a commenter pointed to the default 10-second request timeout in
client/src/lib/hooks/useConnection.ts(around line 23); a maintainer agreed it is a valid enhancement and kept the issue open. There is still no UI setting for it.Workarounds mentioned in the thread:
- If you run Inspector locally from source, increase the timeout constant in
client/src/lib/hooks/useConnection.tsto a value that fits your tools. - PR #164 (by TornjV) restored a way to override the timeout using a query-string parameter; the maintainer said this is easier than changing the app code. Check that PR for the exact parameter name.
- PR #204 was opened by a contributor to address this, but the thread does not confirm whether it was merged or shipped.
- One commenter using stdio said you can change the request timeout and posted a screenshot, but gave no exact steps.
Note that FastMCP's own
request_timeout=300did not fix the reported case: the tool still timed out, so the Inspector client timeout is the value that needs adjustment.Did this work for you?- If you run Inspector locally from source, increase the timeout constant in
What @luiztauffer tried on GitHub (Didn't work)
Reporter set FastMCP's
request_timeout=300on the server and ran a tool that sleeps 10 seconds withmcp dev main.py; Inspector still returnedError: Request timed out.Source: https://github.com/modelcontextprotocol/inspector/issues/142 (opens external site)
Did this work for you?What @kwnath tried on GitHub (Outcome unclear)
A commenter identified the 10-second default timeout in
client/src/lib/hooks/useConnection.tsand suggested increasing that constant locally, or opening a PR to raise it.Did this work for you?What @olaservo tried on GitHub (Outcome unclear)
A maintainer said PR #164 by TornjV restored a query-string parameter to override the timeout and recommended it over changing the app code. No one in the thread confirmed the exact parameter name or result.
Did this work for you?What @pulkitsharma07 tried on GitHub (Outcome unclear)
A contributor opened PR #204 to address the timeout issue; the thread does not state whether it was merged.
Did this work for you?What @GhaouiYoussef tried on GitHub (Outcome unclear)
A commenter using stdio said you can change the request timeout and posted a screenshot, but gave no exact steps.
Did this work for you?
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