[BUG] API Error: 400: ... invalid JSON .. in prompt.

[WKassebaum]

Environment

• Platform (select one):
  • Anthropic API
  • AWS Bedrock
  • Google Vertex AI
  • Other:
• Claude CLI version:
• Operating System:
• Terminal:
  Claude Code v1.0.88
  OSX 15.6
  Terminal App
  Context size 90k of 200k

Bug Description

API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"The request body is not valid JSON: no low surrogate in string: line 1 column 131554 (char
131553)"},"request_id":"req_011CSPWrWStU2RzGjKwZWGLo"}

fix typecheck error
⎿  API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"The request body is not valid JSON: no low surrogate in string: line 1 column 85080 (char
85079)"},"request_id":"req_011CSPWuSeGyfchdCvE8CsiV"}

/compact
⎿ Error: Error during compaction: Error: API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"The request body is not valid JSON: no low surrogate in
string: line 1 column 54528 (char 54527)"},"request_id":"req_011CSPWvpYBRSwJALFbwS8VC"}

This cannot be cleared by /compact. No further API commands will work. I have to exit claude and start a new session in order to continue working.

Steps to Reproduce

1. debugging and editing code - prompt

Expected Behavior

I would expect Claude to not send a prompt to Opus or Sonnet which is mal-formed exciting an Error:400

Actual Behavior

API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"The request body is not valid JSON: no low surrogate in string: line 1 column 131554 (char
131553)"},"request_id":"req_011CSPWrWStU2RzGjKwZWGLo"}

This cannot be cleared by /compact. No further API commands will work. I have to exit claude and start a new session in order to continue working.

Additional Context

BashOutput(Reading shell output)
⎿  > @claude-codeindex/claude-code-integration@0.9.0 start-service
> node dist/service-cli.js
… +549 lines (ctrl+r to expand)
⎿  API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"The request body is not valid JSON: no low surrogate in string: line 1 column 131554 (char
131553)"},"request_id":"req_011CSPWYyPP23SKr4HaQp3Wb"}

[github-actions]

Found 3 possible duplicate issues:

1. API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"The request body is not valid JSON: no low surrogate in string: #6310
2. [BUG] Session broken -> API Error: 400 {"type":"error","error":{"type":"invalid_request_error","message":"The request body is not valid JSON: no low surrogate in string: line 1 column 410559 (char 410558)"}} #1709
3. Invalid JSON Request: Malformed Low Surrogate in API Payload #6273

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