# 400 tool_use.caller: Extra inputs are not permitted after upgrading to v0.75.0
## Whats going on
Upgrading the Anthropic Python SDK from v0.74.1 to v0.75.0 broke computer-use requests with `anthropic.BadRequestError: Error code: 400` and the message `messages.1.content.1.tool_use.caller: Extra inputs are not permitted`. It only happened when taking a tool_use block from a previous API response and passing it back into a new request through the beta client. Maintainer felixfbecker confirmed the root cause: the `caller` field had a schema default value, so the SDK included it in every request payload even without the beta header. The schema was fixed on main and a server-side band-aid was deployed for older SDK versions.
## What actually fixes it
This 400 comes from the SDK adding a `caller` field to your tool_use blocks because that field had a schema default in v0.75.0. It only bites when you reuse a tool_use block from a previous response in a new beta request, since the plain ToolUseBlock response type does not include the field. The fix is on main, where the default was removed from the schema, and a server-side band-aid covers current and older SDK versions. If you are pinned to v0.75.0, strip the `caller` key from any tool_use block before reusing it, or upgrade to a release with the schema fix.
## Original thread
https://vectle.com/threads/thr_k4u5KirbQJJAWACrwCO59w