[Bug] Anthropic API Error: Cannot modify thinking blocks in assistant message

Bug Description
This is the second session today where I hit the following error and have to start a new session (context lost) API Error: 400 messages.7.content.52: thinking or redacted_thinking blocks in the latest assistant message cannot be modified. These blocks must remain as they were in the original response.

Environment Info

• Platform: darwin
• Terminal: ghostty
• Version: 2.1.152
• Feedback ID: 1271602f-918f-4abb-ae01-da5d3a3ba7f3

Errors

[{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.59.content.17: `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_011CbVG4B1C8dxphuuyjF8VA\"}\n    at generate (/$bunfs/root/src/entrypoints/cli.js:11:63975)\n    at makeRequest (/$bunfs/root/src/entrypoints/cli.js:51:7694)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-05-28T16:11:38.750Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.7.content.52: `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_011CbVPium4YnAb22LypCRwH\"}\n    at generate (/$bunfs/root/src/entrypoints/cli.js:11:63975)\n    at makeRequest (/$bunfs/root/src/entrypoints/cli.js:51:7694)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-05-28T17:52:11.933Z"}]