claude-code - 💡(How to fix) Fix [Bug] HTTP 500 Error Response from Anthropic API [2 comments, 3 participants]

[{"error":"Error: ensureToolResultPairing: repaired missing tool_result blocks (43 -> 43 messages). Message structure: [0] user; [1] assistant(id=msg_01MnxWCEJACEoH21ZhstnufQ, tool_uses=[toolu_01RMLtdxug5VsobMwJgBy7oW]); [2] user(tool_results=[toolu_01RMLtdxug5VsobMwJgBy7oW]); [3] assistant(id=msg_01CMpufwbuAdhZXStJ6o7o5G, tool_uses=[toolu_019sZdCPBSm6fhJrtodgrjGB]); [4] user(tool_results=[toolu_019sZdCPBSm6fhJrtodgrjGB]); [5] assistant(id=msg_016a324LEXQmZYY6PLjiNznh, tool_uses=[toolu_01VJdb1sbvWWfTyckDjwutHV]); [6] user(tool_results=[toolu_01VJdb1sbvWWfTyckDjwutHV]); [7] assistant(id=msg_01UCfKWdjx6SQiDS6yhjvmn1, tool_uses=[toolu_016KGTm9YA6m2b4Gsg9MWkEH]); [8] user(tool_results=[toolu_016KGTm9YA6m2b4Gsg9MWkEH]); [9] assistant(id=msg_019DszKZnauuJWFt4BGbh6dt, tool_uses=[toolu_012A8PBvg7yUPdexbx1vr6KH]); [10] user(tool_results=[toolu_012A8PBvg7yUPdexbx1vr6KH]); [11] assistant(id=msg_01KtV1JVyfU51UeXaVM9DHK3, tool_uses=[toolu_01TbQJoNYgRffKoi1KFNinhS]); [12] user(tool_results=[toolu_01TbQJoNYgRffKoi1KFNinhS]); [13] assistant(id=msg_01NiFAicDumRhAo82nJmVYEq, tool_uses=[], server_tool_uses=[srvtoolu_01U7vyx4VrkRuWgTuCNxwYnD]); [14] user; [15] assistant(id=msg_01RHPQkFxErEAWVLjsJxGNiG, tool_uses=[toolu_01T8ccF2kSxy6hEkSK9zbxGa], server_tool_uses=[srvtoolu_01GfsQKDJfBDx9VhwHtJ3x66]); [16] user(tool_results=[toolu_01T8ccF2kSxy6hEkSK9zbxGa]); [17] assistant(id=msg_01CmA73UyzkyZqctNhBUXxV1, tool_uses=[toolu_01YbYNnC4DQ8oBY5U3BCWojM]); [18] user(tool_results=[toolu_01YbYNnC4DQ8oBY5U3BCWojM]); [19] assistant(id=msg_018pub6ofp67N8vRraNCnQaX, tool_uses=[toolu_011ZAuPV8hDyQW8E1xmC45ME]); [20] user(tool_results=[toolu_011ZAuPV8hDyQW8E1xmC45ME]); [21] assistant(id=msg_015wxQ4htyMCKUHidaEX5Swd, tool_uses=[toolu_014Rqzu4HeKvZMB6gDRTJvJZ]); [22] user(tool_results=[toolu_014Rqzu4HeKvZMB6gDRTJvJZ]); [23] assistant(id=msg_01DmDgKVGG3tJEHLGgJGQYit, tool_uses=[toolu_01PSDTZzrcMpB6BtFgaWSD9Y]); [24] user(tool_results=[toolu_01PSDTZzrcMpB6BtFgaWSD9Y]); [25] assistant(id=msg_01Tkbp6VTvaYS6Pa42Pdx9Y4, tool_uses=[toolu_01QsCNv43uNS2HAUyzFkrUgN]); [26] user(tool_results=[toolu_01QsCNv43uNS2HAUyzFkrUgN]); [27] assistant(id=msg_01Np5FBeRUg2afTVKNjaGz9z, tool_uses=[toolu_01YUPEq3iUzrvgCMmfrxBcyg]); [28] user(tool_results=[toolu_01YUPEq3iUzrvgCMmfrxBcyg]); [29] assistant(id=msg_01VJuASLmLvNredRWmGqhg93, tool_uses=[toolu_01KxXDvAsQgWBZ1GPskjZLoX]); [30] user(tool_results=[toolu_01KxXDvAsQgWBZ1GPskjZLoX]); [31] assistant(id=msg_01Y89m4qBToP7ETTHCGAU9uv, tool_uses=[toolu_01WpN1WZ9n8LFyLTvgfkWbB9]); [32] user(tool_results=[toolu_01WpN1WZ9n8LFyLTvgfkWbB9]); [33] assistant(id=msg_01T2AW9uNLfz9XAuYKvTCZjd, tool_uses=[toolu_01GqaHkBNL3BTrHD74jrrJ2a]); [34] user(tool_results=[toolu_01GqaHkBNL3BTrHD74jrrJ2a]); [35] assistant(id=msg_01TYr6Aon6hg3FTrC3NRTEk1, tool_uses=[]); [36] user; [37] assistant(id=msg_01FRinaxjdFFuTW9gmcUSxUH, tool_uses=[toolu_01Sc6yiJse3u1hFZ6B3z6o55]); [38] user(tool_results=[toolu_01Sc6yiJse3u1hFZ6B3z6o55]); [39] assistant(id=msg_013bdgQgRZ8KM26ycNQjLbLm, tool_uses=[toolu_01AbyVv916qxFDNoZKC59W61]); [40] user(tool_results=[toolu_01AbyVv916qxFDNoZKC59W61]); [41] assistant(id=msg_01QfJttwS6bizKYwVqq8VxBx, tool_uses=[toolu_01KEwYGapShdC9DE2ypt9QmS]); [42] user(tool_results=[toolu_01KEwYGapShdC9DE2ypt9QmS])\n at Aj7 (/$bunfs/root/src/entrypoints/cli.js:5080:9954)\n at Pp7 (/$bunfs/root/src/entrypoints/cli.js:8032:12201)\n at processTicksAndRejections (native:7:39)","timestamp":"2026-04-15T14:16:00.504Z"},{"error":"Error: ensureToolResultPairing: repaired missing tool_result blocks (45 -> 45 messages). Message structure: [0] user; [1] assistant(id=msg_01MnxWCEJACEoH21ZhstnufQ, tool_uses=[toolu_01RMLtdxug5VsobMwJgBy7oW]); [2] user(tool_results=[toolu_01RMLtdxug5VsobMwJgBy7oW]); [3] assistant(id=msg_01CMpufwbuAdhZXStJ6o7o5G, tool_uses=[toolu_019sZdCPBSm6fhJrtodgrjGB]); [4] user(tool_results=[toolu_019sZdCPBSm6fhJrtodgrjGB]); [5] assistant(id=msg_016a324LEXQmZYY6PLjiNznh, tool_uses=[toolu_01VJdb1sbvWWfTyckDjwutHV]); [6] user(tool_results=[toolu_01VJdb1sbvWWfTyckDjwutHV]); [7] assistant(id=msg_01UCfKWdjx6SQiDS6yhjvmn1, tool_uses=[toolu_016KGTm9YA6m2b4Gsg9MWkEH]); [8] user(tool_results=[toolu_016KGTm9YA6m2b4Gsg9MWkEH]); [9] assistant(id=msg_019DszKZnauuJWFt4BGbh6dt, tool_uses=[toolu_012A8PBvg7yUPdexbx1vr6KH]); [10] user(tool_results=[toolu_012A8PBvg7yUPdexbx1vr6KH]); [11] assistant(id=msg_01KtV1JVyfU51UeXaVM9DHK3, tool_uses=[toolu_01TbQJoNYgRffKoi1KFNinhS]); [12] user(tool_results=[toolu_01TbQJoNYgRffKoi1KFNinhS]); [13] assistant(id=msg_01NiFAicDumRhAo82nJmVYEq, tool_uses=[], server_tool_uses=[srvtoolu_01U7vyx4VrkRuWgTuCNxwYnD]); [14] user; [15] assistant(id=msg_01RHPQkFxErEAWVLjsJxGNiG, tool_uses=[toolu_01T8ccF2kSxy6hEkSK9zbxGa], server_tool_uses=[srvtoolu_01GfsQKDJfBDx9VhwHtJ3x66]); [16] user(tool_results=[toolu_01T8ccF2kSxy6hEkSK9zbxGa]); [17] assistant(id=msg_01CmA73UyzkyZqctNhBUXxV1, tool_uses=[toolu_01YbYNnC4DQ8oBY5U3BCWojM]); [18] user(tool_results=[toolu_01YbYNnC4DQ8oBY5U3BCWojM]); [19] assistant(id=msg_018pub6ofp67N8vRraNCnQaX, tool_uses=[toolu_011ZAuPV8hDyQW8E1xmC45ME]); [20] user(tool_results=[toolu_011ZAuPV8hDyQW8E1xmC45ME]); [21] assistant(id=msg_015wxQ4htyMCKUHidaEX5Swd, tool_uses=[toolu_014Rqzu4HeKvZMB6gDRTJvJZ]); [22] user(tool_results=[toolu_014Rqzu4HeKvZMB6gDRTJvJZ]);…

TL;DR

The error 500 after sending a request is likely due to an issue with tool result pairing, as indicated by the "ensureToolResultPairing" error message.

Guidance

• The error message suggests that there is a problem with the pairing of tool results, which could be caused by a mismatch in the number of tool uses and tool results.
• The message structure provided in the error message shows a sequence of user and assistant interactions, with each assistant interaction including a list of tool uses and each user interaction including a list of tool results.
• To troubleshoot this issue, it may be helpful to review the code that handles tool result pairing and ensure that it is correctly matching tool uses with their corresponding tool results.
• Additionally, it may be useful to check the data being passed to the ensureToolResultPairing function to ensure that it is in the correct format and that there are no missing or duplicate tool results.

Notes

The provided error message is truncated, which may limit the ability to fully diagnose the issue. Further investigation and logging may be necessary to determine the root cause of the problem.

Recommendation

Apply workaround: Review and modify the code that handles tool result pairing to ensure correct matching of tool uses and tool results, and verify that the data being passed to the ensureToolResultPairing function is correct.