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deps: bump rmcp to >=3.5.1 to fix discover->initialize tools/list failure - #218
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…lure A client that probes `server/discover` before `initialize` (e.g. Claude Code) permanently latched rmcp's internal `request_metadata_required` flag on the session, even after falling back to the classic (`initialize`-negotiated) lifecycle. Every later request without per-request `_meta` -- including an ordinary `tools/list` -- was then rejected with -32602, so the client loaded zero tools. Upstream fix: modelcontextprotocol/rust-sdk#1248, shipped in rmcp 3.5.1. Adds a stdio regression test driving the exact discover -> initialize -> notifications/initialized -> tools/list sequence over an in-memory duplex transport; it reproduces the -32602 failure against the prior rmcp 3.5.0 pin and passes against 3.5.1. Closes #217 Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
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Summary
server/discoverbootstrap probe beforeinitialize(Claude Code, and any client following the same pattern) permanently latched rmcp's internalrequest_metadata_requiredflag on the stdio session, even after the session fell back to the classic (initialize-negotiated) lifecycle. Every later request without per-request_meta-- including an ordinarytools/list-- was then rejected with-32602 request _meta is missing or has malformed required fields, so the client loaded zero tools.rmcpfrom the previously-locked 3.5.0 to>=3.5.1,<4inCargo.toml/Cargo.lock. Upstream fix: fix(server): keep discover lifecycle bootstrap-neutral modelcontextprotocol/rust-sdk#1248, merged 2026-09-07, first shipped in rmcp 3.5.1 (2026-10-05).Closes #217
Test plan
crates/rustsdcmcp/tests/stdio_discover_before_initialize.rsdrives the exact wire sequence from the issue over an in-memory stdio-shaped duplex transport:server/discover(with the 2026-07-28 draft's required_metakeys) ->initialize(protocolVersion2025-11-25) ->notifications/initialized->tools/listwith no_meta, and assertstools/listsucceeds and returns every tool inKNOWN_TOOLS.-32602failure from the issue against the prior rmcp 3.5.0 pin (verified in a scratch build), and passes against 3.5.1.cargo fmt --all -- --checkcargo clippy --workspace --all-targets --all-features --locked -- -D warningscargo build --workspace --lockedcargo test --workspace --locked(all 248 tests pass, including the new regression test)RUSTDOCFLAGS="-D warnings" cargo doc --workspace --no-deps --lockedcargo +1.89 check --workspace --all-targets --locked(MSRV)python3 -m unittest discover -s scripts/testsandpython3 scripts/spec-drift.py self-check(unaffected by this change, confirmed still green)🤖 Generated with Claude Code