[Bug] Anthropic API Error: Cannot Modify Thinking Blocks in Assistant Messages

Bug Description
Impossible to use Claude Code due to recurrent issue of ⎿  API Error: 400 messages.1.content.33: thinking or redacted_thinking blocks in the latest assistant message cannot be modified. These blocks must remain as they were in the original response. since recent update to 4-8

Environment Info

• Platform: darwin
• Terminal: iTerm.app
• Version: 2.1.154
• Feedback ID: 88a9d7ce-e8ea-48fd-ac26-af6b50bfa0eb

Errors

[{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.1.content.33: `thinking` or `redacted_thinking` blocks in the latest assistant message cannot be modified. These blocks must remain as they were in the original response.\"},\"request_id\":\"req_011CbVSp1PP6atiAtE9ESxJs\"}\n    at generate (/$bunfs/root/src/entrypoints/cli.js:11:63816)\n    at makeRequest (/$bunfs/root/src/entrypoints/cli.js:51:7694)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-05-28T18:32:48.789Z"}]