[Bug] Anthropic API Error: Invalid `signature` in `thinking` block

Resolved 💬 3 comments Opened Apr 2, 2026 by Co-Messi Closed Apr 5, 2026

Bug Description
❯ hihttps://github.com/jarrodwatts/claude-hud

i wnt to use this thing, help me set it up
⎿  API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.1.content.0: Invalid
signature in thinking block"},"request_id":"req_011CZeGmrJK7Hoq6N9UqVP4j"}

❯ /debug
⎿  API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"messages.1.content.0: Invalid
signature in thinking block"},"request_id":"req_011CZeGnt1Xw5yKCXGGW3ZFJ"}

Environment Info

  • Platform: darwin
  • Terminal: iTerm.app
  • Version: 2.1.90
  • Feedback ID: e92537ef-2990-42d1-ab6b-8f01cf39ecbe

Errors

[{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/siewbrayden/.local/share/claude/versions/2.1.90 (expected in multi-process scenarios)\n    at Cu_ (/$bunfs/root/src/entrypoints/cli.js:1894:2138)\n    at uQ6 (/$bunfs/root/src/entrypoints/cli.js:1894:1218)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-02T03:54:24.655Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.1.content.0: Invalid `signature` in `thinking` block\"},\"request_id\":\"req_011CZeGYzWK64Wmxn5k3qv9F\"}\n    at generate (/$bunfs/root/src/entrypoints/cli.js:11:51662)\n    at makeRequest (/$bunfs/root/src/entrypoints/cli.js:50:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-02T03:54:36.103Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.1.content.0: Invalid `signature` in `thinking` block\"},\"request_id\":\"req_011CZeGmrJK7Hoq6N9UqVP4j\"}\n    at generate (/$bunfs/root/src/entrypoints/cli.js:11:51662)\n    at makeRequest (/$bunfs/root/src/entrypoints/cli.js:50:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-02T03:57:30.290Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"messages.1.content.0: Invalid `signature` in `thinking` block\"},\"request_id\":\"req_011CZeGnt1Xw5yKCXGGW3ZFJ\"}\n    at generate (/$bunfs/root/src/entrypoints/cli.js:11:51662)\n    at makeRequest (/$bunfs/root/src/entrypoints/cli.js:50:5435)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-02T03:57:44.199Z"}]

View original on GitHub ↗

This issue has 3 comments on GitHub. Read the full discussion on GitHub ↗