Posting to see if anyone else has hit this and figured out a fix.
For about a week, my Claude Chat conversations (opus 4.7) have been showing what looks like tool-registration leakage at the end of every user message I send. It started as simple tool declarations, escalated to full function schemas with parameter docs, and then began including userStyle content alongside the tool blocks.
What I've tested:
- Starting a new thread: No fix. The leak follows across thread boundaries on the same account.
- Turning userStyle off: Removes the userStyle component cleanly. The function-schema component continues.
- Disconnecting all my MCP connectors: Did NOT stop the function-schema leak. After disconnecting, the leak switched to dumping schemas of Anthropic's first-party available connectors (Atlassian, Cloudflare, Notion, Stripe, Vercel, Zapier) — services I have never used, set up, or connected. These appear to be platform-default available connectors rather than anything tied to my account.
- Other threads on the same account: A separate parallel thread does NOT show the leak. Suggests it's session-state-dependent at some level, not purely account-wide.
The leak appears to be in the platform's tool/connector registration layer, not at the user-controllable connector layer. I have no apparent control surface for stopping the function-schema component. (edit to add: I see the same tool injected when running Chat in the web browser, desktop app, and mobile app.)
This doesn't impact Claude Code or existing (long-running) Opus 4.6 chat threads.
Bug report to Anthropic via email. No response or fix.
Questions for the community:
- Has anyone else seen this? Is it widespread or just me?
- If you've seen it, what does your payload look like? (Userstyle leakage, function schemas, both, neither?)
- Has anyone found a user-side fix or workaround?
- Has anyone gotten an actual response from Anthropic on this?
The token cost is non-trivial across long conversations. I'd love to know if this is a known issue or if I should escalate further.