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Sweep 22 Sep 2026 · 17:19Z Build v2.1.280 501 read Stable v2.1.267 Latest v2.1.280 Next v2.1.280 Feeds RSS JSON llms.txt Unofficial
Claude Code v2.1.268 ·

Browser file_upload tool gains a direct base64 upload path

Browser file_upload tool can now accept file contents directly instead of only file paths

TierUse it nowhow much it should matter to you
Useful3my rating, 1 to 5
Signal2worth watching, 1 to 5
AreaChrome & Browserwhat it touches
KindNew Featuresin v2.1.268,
Use it now Notable

Browser file_upload tool can now accept file contents directly instead of only file paths

What

The browser automation file_upload tool now accepts an optional files array containing base64-encoded file data, a name, and a MIME type, in addition to its existing paths option. The files field is described as meant to be populated by the client itself after it reads the files under its own file-read permissions, not set directly by the model. A reference (ref) and tab ID (tabId) are still required, but paths is no longer required on its own.

Why

This gives the browser tool a way to upload file contents directly when the client has already read them, rather than always relying on a file path that must be resolved separately.

Read from
Names in the bundlefile_upload
Since it was published

The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.

Confirmed since Anthropic's documentation has since written up file_upload, on compliance-errors. **Fix:** Reconcile against recent `claude_file_uploaded` or `claude_file_deleted` activities. Files deleted along with a chat have no `claude_file_deleted` activity, so check for the chat's `claude_chat_deleted` activity as well. If the fi… manage-claude/compliance-errors see the edit
How sure we are
One source agreesOne thing we can check says the same as this entry.
Anthropic's documentation agreesAnthropic's documentation has since written up file_upload, on compliance-errors.

See this entry in the whole of v2.1.268 →

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