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DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

← All of v2.1.221 Home All releases ←olderv2.1.220 v2.1.222newer→
Claude Code v2.1.221

MCP connection-failure telemetry records negotiation outcome

Under the hood
Useful1 Signal0
MCP

Failed MCP connections now record how the handshake was negotiated and whether it fell back.

What

tengu_mcp_server_connection_failed now describes how the connection was negotiated and whether the modern probe fell back.

Details
  • Two new field names, both absent from 2.1.220.
  • A fallback records the reason probe_failed.
Evidence

probeFellBack

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

Related

Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.

See this entry in the whole of v2.1.221 →