[15.5.1] - 2026-07-27 - "MCP Client Compatibility"
Restored AAS MCP connectivity for newer clients while preserving an explicit, fail-closed protocol boundary.
Start here:
- AAS Core setup: configure the exact
aasruntime with the Core guide - Direct skill distribution:
npx agentic-awesome-skills - Choose your tool
- Best skills by tool
- Bundles
- Workflows
Fixed
- Fixed AAS MCP initialization for newer clients such as Claude Code 2.1.x by negotiating the server-supported protocol revision instead of rejecting every request that advertises a different revision (#1003).
Who should care
- Claude Code 2.1.x users whose MCP clients advertise protocol revision
2025-11-25. - Other MCP clients that advertise a revision newer than the server-supported
2025-06-18revision. - Integrators that require malformed or missing protocol revisions to remain rejected.
Validation
- Passed direct server, stdio binary, isolated packed-runtime, and release-preview negotiation tests.
- Passed the 150-test AAS Core suite, the 102-file repository suite, catalog integrity, reference validation, documentation security, warning-budget enforcement, protected CI, and CodeQL.
Credits
- @rk2kaler for reporting the protocol negotiation regression with a complete reproduction in issue #1003.