Part of #977.
On the 2026-07-28 suite (0.2.0-alpha.9), tools-call-with-progress fails against the stateless conformance server:
Failed: HTTP 200: expected a JSON-RPC result for 'tools/call', got unexpected body
{"jsonrpc":"2.0","method":"notifications/progress","params":{"message":"Starting","progress":0,"progressToken":"progress-test-1","total":100}}
In stateless mode the progress notification is emitted as the POST response body instead of (or before) the final tools/call result. The scenario passes against the stateful server on the 2025-11-25 suite, so this is specific to the stateless lifecycle.
Repro:
cargo build -p mcp-conformance
STATELESS=1 PORT=8002 ./target/debug/conformance-server &
npx -y @modelcontextprotocol/conformance@0.2.0-alpha.9 server \
--url http://127.0.0.1:8002/mcp \
--scenario tools-call-with-progress -o results
Part of #977.
On the 2026-07-28 suite (
0.2.0-alpha.9),tools-call-with-progressfails against the stateless conformance server:In stateless mode the progress notification is emitted as the POST response body instead of (or before) the final
tools/callresult. The scenario passes against the stateful server on the 2025-11-25 suite, so this is specific to the stateless lifecycle.Repro:
cargo build -p mcp-conformance STATELESS=1 PORT=8002 ./target/debug/conformance-server & npx -y @modelcontextprotocol/conformance@0.2.0-alpha.9 server \ --url http://127.0.0.1:8002/mcp \ --scenario tools-call-with-progress -o results