[Bug] Anthropic API Error: Invalid tool_use_id in tool_result block

[anatoly314]

Suddenly during conversation with claude this error appeared. I couldn't continue this conversation because every time I was sending message I was receiving the same error.

When I ctrl+c (closed) chat and than opened it and resumed conversation it started to work.

Bug Description
API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.16.content.0: unexpected tool_use_id found in tool_result blocks: toolu_01K8c26nCWAzMiDxmSAW9hNt. Each tool_result block must have
a corresponding tool_use block in the previous message."},"request_id":"req_011CUezjj6TsMwHN8wGaNLGV"}

Environment Info

• Platform: darwin
• Terminal: iTerm.app
• Version: 2.0.30
• Feedback ID: 2bdbd895-5964-49be-91c7-a5cc1ebf490a

Errors

[{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.16.content.0: unexpected `tool_use_id` found in `tool_result` blocks: toolu_01K8c26nCWAzMiDxmSAW9hNt. Each `tool_result` block must have a corresponding `tool_use` block in the previous message.\"},\"request_id\":\"req_011CUezfpkv9WzfTwiSZJu9W\"}\n    at M4.generate (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:204:83066)\n    at Jk.makeStatusError (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:358:2117)\n    at Jk.makeRequest (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:358:5330)\n    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)\n    at async Gd2.geA.model (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:3389:14755)\n    at async geA (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:2741:39781)\n    at async Gd2 (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:3389:14909)\n    at async file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:3389:8646\n    at async _e1 (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:3389:1970)\n    at async j8A (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:3389:8616)","timestamp":"2025-10-31T08:54:36.183Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.16.content.0: unexpected `tool_use_id` found in `tool_result` blocks: toolu_01K8c26nCWAzMiDxmSAW9hNt. Each `tool_result` block must have a corresponding `tool_use` block in the previous message.\"},\"request_id\":\"req_011CUezgaauRzyPvnb1xQTAx\"}\n    at M4.generate (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:204:83066)\n    at Jk.makeStatusError (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:358:2117)\n    at Jk.makeRequest (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:358:5330)\n    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)\n    at async Gd2.geA.model (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:3389:14755)\n    at async geA (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:2741:39781)\n    at async Gd2 (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:3389:14909)\n    at async file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:3389:8646\n    at async _e1 (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:3389:1970)\n    at async j8A (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:3389:8616)","timestamp":"2025-10-31T08:54:46.284Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.16.content.0: unexpected `tool_use_id` found in `tool_result` blocks: toolu_01K8c26nCWAzMiDxmSAW9hNt. Each `tool_result` block must have a corresponding `tool_use` block in the previous message.\"},\"request_id\":\"req_011CUezjj6TsMwHN8wGaNLGV\"}\n    at M4.generate (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:204:83066)\n    at Jk.makeStatusError (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:358:2117)\n    at Jk.makeRequest (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:358:5330)\n    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)\n    at async Gd2.geA.model (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:3389:14755)\n    at async geA (file:///Users/anatoly/.nvm/versions/node/v22.18.0/lib/node_modules/@anthropic-ai/claude-code/cli.js:2741:39781)\n    at async Gd2 (file:///Users/anatoly/.n

Note: Error logs were truncated.

[github-actions]

Found 3 possible duplicate issues:

1. [Bug] Anthropic API Error: Tool result block without corresponding tool use block #10650
2. [BUG] Conversation Compaction Corrupts Tool Use/Result Pairs #8484
3. [BUG] "invalid_request_error" tool_use ids were found without tool_result blocks immediately after #8187

This issue will be automatically closed as a duplicate in 3 days.

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🤖 Generated with Claude Code

[github-actions]

This issue has been automatically closed as a duplicate of #10650.

If this is incorrect, please re-open this issue or create a new one.

🤖 Generated with Claude Code