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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.

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Claude Code v2.1.242

MCP servers reconnect automatically when the connection drops

You'll notice
Useful4 Signal2
MCP

Dropped MCP connections now retry with backoff, showing attempt counts before being marked failed.

What

Connected MCP servers over HTTP or SSE now retry the connection with backoff when the transport closes, showing the server as pending with the current attempt number and the maximum, and marking it failed only after the attempts run out.

Details
  • Applies only to non-stdio, non-SDK servers; locally spawned stdio servers and in-process SDK servers are unaffected.
  • Pending state carries reconnectAttempt and maxReconnectAttempts; the terminal failure reads "Connection closed again while reconnecting".
  • The watcher is installed unconditionally with no flag, and stands down while another reconnect is already in flight or the run is shutting down.
Evidence

Connection closed again while reconnecting

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

See this entry in the whole of v2.1.242 →