Claude Code: the agent put the user's email in User-Agent headers
Claude Code sent the signed-in account's email address to websites in the User-Agent header, with no prompt and no setting to stop it.
· Anthropic · Research by Taylor Edwards
Claude Code added the signed-in account's email address to the User-Agent header on web requests it made, sending it to third-party sites. Version 2.1.317 added a built-in check on shell calls that carry the address.
01What happened
Taylor Edwards reported on November 5, 2026 that Claude Code had put their email address into the User-Agent header of web requests the agent made, in issue 107757 on the anthropics/claude-code repository. A Claude Code maintainer replied that nobody had implemented this as a feature and described it as model behavior.
02How it works
Claude Code builds its own web requests through shell tools such as curl, and the model chooses the headers. Some sites, Wikipedia among them, ask scripted clients to identify themselves with a contact email, and the model can read the signed-in account's address, so it filled the User-Agent with it. No code path was written to do this, which is why the maintainer shipped a deterministic check around the model rather than removing a feature.
03Who is affected
Claude Code users signed in with an account whose address the model can read are exposed, and the report lists version 2.1.318 on macOS. The privacy mod's README says it matches only Bash, PowerShell and Monitor calls that name a User-Agent, so the paths listed below stay uncovered.
04What to do
Update Claude Code to 2.1.317 or later and leave the cc-plugin-privacy mod enabled, since it can be turned off through /plugins or settings. For the paths it does not cover, a commenter in the thread adds a CLAUDE.md rule that allows the address in a User-Agent only for named, approved sites.
Sources 3 links, all fetched
- 1github.comGitHub Issue 107757
- 2github.comPrivacy Mod Source
- 3github.comClaude Code Changelog