Source Intelligence

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 v2.1.248

Local IPC sends verify the peer's owner and process identity

Under the hood
Useful2 Signal3
Cross-Session Messaging

Messages to other local Claude Code processes now verify socket ownership and process identity.

What

When Claude Code sends a message to another local Claude Code process over its messaging socket and expects a specific process id, it now also checks that the socket endpoint is owned by your uid and that the peer's process start token matches, so a recycled pid or another user's socket is refused.

Details
  • Refusal message: "Refusing to send: connected endpoint is a different process with the expected pid".
  • Callers pass a new expectPeerProcStart option; the session-rename notice path supplies both pid and start token.
  • No flag; applies whenever a peer pid is expected, and not on Windows.
Evidence

Refusing to send: connected endpoint is a different process with the expected pid

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 v2.1.248 →