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Sweep 22 Oct 2026 · 21:04Z Build v2.1.309 528 read Stable v2.1.308 Latest v2.1.309 Next v2.1.309 Feeds RSS JSON llms.txt llms-full.txt Unofficial

Claude Code v2.1.51 ·

Duplicate Permission Response Handling

Entry
JSON All of v2.1.51
EntryKind: in v2.1.51,
ChangesSection of the release

The structured transport now tracks resolved tool-use IDs and silently ignores duplicate control_response messages, preventing race conditions where a late-arriving permission response could cause errors.

Evidence

"Ignoring duplicate control_response for already-resolved toolUseID=" (search for "Ignoring duplicate control_response")

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

How sure we are
One source agreesOne thing we can check says the same as this entry.
Anthropic's release notes agreeFixed a bug where duplicate control_response messages (e.g. from WebSocket reconnects) could cause API 400 errors by pushing duplicate…

See this entry in the whole of v2.1.51 →

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