[BUG] cache_control cannot be set for empty text blocks at messages.N.content.1.text

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

request_id: req_011CaUi2ayLNCHz6AUbBYtoQ
Repro: paste screenshot from clipboard with no accompanying text
The fix is on their side (skip cache_control when text is empty) — not something patchable from a project repo.

400 invalid_request_error: cache_control cannot be set for empty text blocks

What Should Happen?

request_id: req_011CaUi2ayLNCHz6AUbBYtoQ
Repro: paste screenshot from clipboard with no accompanying text
The fix is on their side (skip cache_control when text is empty) — not something patchable from a project repo.

Error Messages/Logs

request_id: req_011CaUi2ayLNCHz6AUbBYtoQ
Repro: paste screenshot from clipboard with no accompanying text
The fix is on their side (skip cache_control when text is empty) — not something patchable from a project repo.

400 invalid_request_error: cache_control cannot be set for empty text blocks

Steps to Reproduce

Paste screenshot from clipboard with no accompanying text

request_id: req_011CaUi2ayLNCHz6AUbBYtoQ
Repro: paste screenshot from clipboard with no accompanying text
The fix is on their side (skip cache_control when text is empty) — not something patchable from a project repo.

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.119

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_