[Bug] Anthropic API Error: Tool input_schema doesn't support oneOf/allOf/anyOf at top level

[Ddell12]

Bug Description

⎿ API Error: 400
{"type":"error","error":{"type":"invalid_request_error","message":"tools.202.custom.input_schema:
input_schema does not support oneOf, allOf, or anyOf at the top
level"},"request_id":"req_011CYLgB47FVWL38MHHAS38t"}

Environment Info

• Platform: darwin
• Terminal: cursor
• Version: 2.1.50
• Feedback ID: f97ec9df-cfcb-403e-9536-8f28124b989d

Errors

[{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/desha/.local/share/claude/versions/2.1.50 (expected in multi-process scenarios)\n    at OzR (/$bunfs/root/claude:2600:2098)\n    at SbA (/$bunfs/root/claude:2600:1209)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-02-21T05:28:32.180Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"tools.177.custom.input_schema: input_schema does not support oneOf, allOf, or anyOf at the top level\"},\"request_id\":\"req_011CYLfbmjaodSMpcRFStp4s\"}\n    at generate (/$bunfs/root/claude:262:28230)\n    at makeRequest (/$bunfs/root/claude:301:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-02-21T05:31:40.130Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"tools.177.custom.input_schema: input_schema does not support oneOf, allOf, or anyOf at the top level\"},\"request_id\":\"req_011CYLfbnWicYFYJuG7SGzkw\"}\n    at generate (/$bunfs/root/claude:262:28230)\n    at makeRequest (/$bunfs/root/claude:301:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-02-21T05:31:40.310Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"tools.193.custom.input_schema: input_schema does not support oneOf, allOf, or anyOf at the top level\"},\"request_id\":\"req_011CYLfctacyA2JqeAPYTw8d\"}\n    at generate (/$bunfs/root/claude:262:28230)\n    at makeRequest (/$bunfs/root/claude:301:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-02-21T05:31:55.315Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"tools.193.custom.input_schema: input_schema does not support oneOf, allOf, or anyOf at the top level\"},\"request_id\":\"req_011CYLfdNTuqayWPyPD6tqkd\"}\n    at generate (/$bunfs/root/claude:262:28230)\n    at makeRequest (/$bunfs/root/claude:301:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-02-21T05:32:01.858Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"tools.193.custom.input_schema: input_schema does not support oneOf, allOf, or anyOf at the top level\"},\"request_id\":\"req_011CYLfdvjsr1KqfSRERgJY9\"}\n    at generate (/$bunfs/root/claude:262:28230)\n    at makeRequest (/$bunfs/root/claude:301:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-02-21T05:32:09.478Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"tools.202.custom.input_schema: input_schema does not support oneOf, allOf, or anyOf at the top level\"},\"request_id\":\"req_011CYLgB47FVWL38MHHAS38t\"}\n    at generate (/$bunfs/root/claude:262:28230)\n    at makeRequest (/$bunfs/root/claude:301:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-02-21T05:39:11.822Z"}]

[github-actions]

Found 3 possible duplicate issues:

1. [BUG] input_schema does not support oneOf, allOf, or anyOf at the top level #4886
2. [BUG] Strict MCP schema validation in v2.0.21+ breaks working MCPs with no opt-out or migration path #10606
3. [BUG] API Error 400: tools.17.custom.input_schema invalid JSON schema - occurs with empty mcpServers #20720

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

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[github-actions]

This issue has been automatically closed as a duplicate of #4886.

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

🤖 Generated with Claude Code

[github-actions]

This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.