litellm/tests/test_litellm/proxy/_experimental
tin-berri 0de60a2ff2
fix(mcp): stop reporting failed OpenAPI tool calls as successes (#37496)
An OpenAPI-backed MCP tool whose upstream answered 401 came back as a
successful tool result carrying the upstream's rejection as its content, so a
caller saw {"error":"invalid_token"} presented as data and the gateway recorded
the request in its own spend log as call_mcp_tool | success.

Three layers each erased the outcome. The request function returned
response.text whatever the status, _handle_local_mcp_tool caught every exception
and returned it as ordinary TextContent, and both dispatch sites then stamped
isError=False unconditionally. Fixing only the first, which is the obvious fix,
changes nothing, because the two above it still map failure onto the
success-shaped value.

The status is now classified where the response is held: a 401 becomes
MCPUpstreamAuthError so the caller is told to re-authenticate, and every other
non-2xx becomes MCPOpenApiUpstreamError, which carries the status and drops the
upstream body rather than serving it as tool content. _handle_local_mcp_tool no
longer swallows, and the call_tool arm keeps the auth error's type. Nothing new
renders these: call_mcp_tool and call_tool_rest_api already turn them into an
isError result naming the status and into a real 401 with WWW-Authenticate, and
the OpenAPI path simply never reached them.

The result is now byte-identical to the regular MCP path for the same failure.
2026-08-19 14:26:02 -07:00
..
mcp_server fix(mcp): stop reporting failed OpenAPI tool calls as successes (#37496) 2026-08-19 14:26:02 -07:00