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

Bug Description
I'm getting API Error " thinking or redacted_thinking blocks in the latest assistant
message cannot be modified. These blocks must remain as they were in the original
response.". I didn't modify anything, Claude Code is messign something up.

Environment Info

• Platform: darwin
• Terminal: tmux
• Version: 2.1.27
• Feedback ID: 1a473154-2f89-4bf8-a8af-6cdcb2eda2a4

Errors

[{"error":"Error: Request was aborted.\n    at n5R (/$bunfs/root/claude:1522:23441)\n    at vpB (/$bunfs/root/claude:4717:7450)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-31T22:23:56.088Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"thinking.enabled.budget_tokens: Input should be greater than or equal to 1024\"},\"request_id\":\"req_011CXgEuHRgsNxXiHRBas5cV\"}\n    at generate (/$bunfs/root/claude:343:8698)\n    at makeRequest (/$bunfs/root/claude:360:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-31T22:25:12.636Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"thinking.enabled.budget_tokens: Input should be greater than or equal to 1024\"},\"request_id\":\"req_011CXgEzEkbNdnkVQLLtktz7\"}\n    at generate (/$bunfs/root/claude:343:8698)\n    at makeRequest (/$bunfs/root/claude:360:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-31T22:26:20.115Z"},{"error":"Error: Request was aborted.\n    at makeRequest (/$bunfs/root/claude:360:3940)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-31T22:27:29.193Z"},{"error":"Error: Request was aborted.\n    at makeRequest (/$bunfs/root/claude:360:3940)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-31T22:28:02.644Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"thinking.enabled.budget_tokens: Input should be greater than or equal to 1024\"},\"request_id\":\"req_011CXgFBncK8inqhPaxZWWrz\"}\n    at generate (/$bunfs/root/claude:343:8698)\n    at makeRequest (/$bunfs/root/claude:360:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-31T22:28:56.702Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"thinking.enabled.budget_tokens: Input should be greater than or equal to 1024\"},\"request_id\":\"req_011CXgGMdU355TFxG2CdU1X9\"}\n    at generate (/$bunfs/root/claude:343:8698)\n    at makeRequest (/$bunfs/root/claude:360:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-31T22:44:16.900Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"thinking.enabled.budget_tokens: Input should be greater than or equal to 1024\"},\"request_id\":\"req_011CXgGVVcEpLD4Aospk5G14\"}\n    at generate (/$bunfs/root/claude:343:8698)\n    at makeRequest (/$bunfs/root/claude:360:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-31T22:46:03.597Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"thinking.enabled.budget_tokens: Input should be greater than or equal to 1024\"},\"request_id\":\"req_011CXgGibnREqiwJFw79Z86U\"}\n    at generate (/$bunfs/root/claude:343:8698)\n    at makeRequest (/$bunfs/root/claude:360:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-31T22:49:01.473Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"thinking.enabled.budget_tokens: Input should be greater than or equal to 1024\"},\"request_id\":\"req_011CXgGpq2KMJ1tupugQQ3wR\"}\n    at generate (/$bunfs/root/claude:343:8698)\n    at makeRequest (/$bunfs/root/claude:360:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-31T22:50:25.868Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"thinking.enabled.budget_tokens: Input should be greater than or equal to 1024\"},\"request_id\":\"req_011CXgHKbEQdh62nba3z2n9z\"}\n    at generate (/$bunfs/root/claude:343:8698)\n    at makeRequest (/$bunfs/root/claude:360:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-31T22:56:56.095Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"thinking.enabled.budget_tokens: Input should be greater than or equal to 1024\"},\"request_id\":\"req_011CXgHhtCVMphPyh6LNTHGo\…

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