stacklok / toolhive / 34976529838

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push

github

Committed by web-flow

Commit Message

Tolerate MethodNotFound for optional capabilities in ListCapabilities (#6660)

Tolerate -32601 in ListCapabilities path

The ListCapabilities path (used by health checks and capability
aggregation) was missing the -32601 tolerance that the session-init
path already had. A backend that advertises the resources or prompts
capability but answers the corresponding list method with JSON-RPC
-32601 (Method not found) caused the entire backend to be marked
degraded/unavailable, silently dropping all of its tools.

The parent revision already gates on serverCaps.Resources/Prompts
before probing, so unadvertised capabilities are not called. This
change defends the remaining edge case where a backend advertises a
capability but does not implement the list method (e.g. Atlassian
Rovo, see #5231), aligning the ListCapabilities path with the
existing session-init tolerance.

Legacy path (queryResources, queryPrompts):
  - Detect mcp.ErrMethodNotFound and return an empty result set with
    a WARN log instead of propagating the error.

Modern path (modernEnumerate):
  - Set degradeNotFound=true for resources/list and prompts/list in
    modernListOptional, matching the existing resources/templates/list
    behavior. Update the modernListOptional doc comment to reflect
    that resources/list and prompts/list are no longer fatal.

tools/list remains strict when the backend advertises the tools
capability; advertising tools while returning MethodNotFound for
tools/list is treated as an inconsistent backend implementation.

Closes #6339

Signed-off-by: hellouz818 <hellouz818@gmail.com>

Coverage Stats

12 of 12 new or added lines in 1 file covered. (100.0%)

10 existing lines in 4 files now uncovered.

81546 of 115366 relevant lines covered (70.68%)

96.68 hits per line