Sweep 19 Sep 2026 · 02:36Z Build v2.1.278 500 read Stable v2.1.267 Latest v2.1.278 Next v2.1.278 Feeds RSS JSON llms.txt Unofficial
Claude Code v2.1.269 ·

Headless SDK sessions gain an appendMessages method

Headless SDK sessions get a new appendMessages method to inject messages

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Headless SDK sessions get a new appendMessages method to inject messages

What

The session object returned when running Claude Code headlessly (without the interactive terminal UI, as used by the Agent SDK) now has an appendMessages method. Calling it either queues the messages for later or sends them through directly, depending on the session's state.

Why

This gives code driving a headless session a direct way to add messages into it, useful for SDK integrations that need to feed messages into an ongoing session programmatically.

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Names in the bundleappendMessages

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