[BUG] 500 and 529 API responses

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Bug Report: Persistent 500/529 Errors in Claude Code — March 17, 2026

Description

Experiencing repeated 500 Internal Server Errors and 529 Overloaded errors in Claude Code (IDE window) throughout the morning of March 17, 2026. Errors are persistent across multiple sessions and are blocking active development work mid-task.

Request IDs

First wave:

• req_011CZ9DR7FC921fFY5z7Gnjo
• req_011CZ9DWA3kYp86jw14JgzyS
• req_011CZ9Dq5D4x6gXBy7KzkseB
• req_011CZ9DxKoc8brVnCki6U2Uq

Second wave (after 529 → brief recovery):

• req_011CZ9F6EhrhHEeVJw182Rhd (529 Overloaded)
• req_011CZ9FuFWXz7HbKC7SviJQ2

Third wave:

• req_011CZ9KHFo7ozKbWfnDHywgt

Error Details

API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CZ9KHFo7ozKbWfnDHywgt"}

API Error: 529 {"type":"error","error":{"type":"overloaded_error","message":"Overloaded. https://docs.claude.com/en/api/errors"},"request_id":"req_011CZ9F6EhrhHEeVJw182Rhd"}

Timeline

• Errors began approximately 8:00 AM PT / 16:00 UTC, March 17, 2026
• Three distinct waves of failures with brief partial recovery between waves
• 529 errors appeared between the first and second 500 wave, suggesting intermittent recovery under load
• Errors are blocking mid-task execution (interrupted at step 5 of a multi-step workflow)

Environment

• Tool: Claude Code (IDE window)
• Model: Claude Sonnet 4.6
• OS: macOS
• Fresh sessions attempted — errors persist across new sessions

Expected Behavior

API requests should succeed or return meaningful, recoverable error codes. Persistent 500s across multiple sessions and request IDs indicate a backend infrastructure issue, not a client-side problem.

Notes

Status page (status.claude.com) showed incidents for elevated Sonnet 4.6 errors beginning ~8:08 AM PT today, consistent with this report. The request ID sequence above should allow server-side tracing across all three failure waves.

What Should Happen?

Claude should not have a 500/529 API repsonse when performing coding tasks.

Error Messages/Logs

## Bug Report: Persistent 500/529 Errors in Claude Code — March 17, 2026

### Description

Experiencing repeated 500 Internal Server Errors and 529 Overloaded errors in Claude Code (IDE window) throughout the morning of March 17, 2026. Errors are persistent across multiple sessions and are blocking active development work mid-task.

### Request IDs

First wave:
- `req_011CZ9DR7FC921fFY5z7Gnjo`
- `req_011CZ9DWA3kYp86jw14JgzyS`
- `req_011CZ9Dq5D4x6gXBy7KzkseB`
- `req_011CZ9DxKoc8brVnCki6U2Uq`

Second wave (after 529 → brief recovery):
- `req_011CZ9F6EhrhHEeVJw182Rhd` (529 Overloaded)
- `req_011CZ9FuFWXz7HbKC7SviJQ2`

Third wave:
- `req_011CZ9KHFo7ozKbWfnDHywgt`

### Error Details


API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CZ9KHFo7ozKbWfnDHywgt"}



API Error: 529 {"type":"error","error":{"type":"overloaded_error","message":"Overloaded. https://docs.claude.com/en/api/errors"},"request_id":"req_011CZ9F6EhrhHEeVJw182Rhd"}


### Timeline

- Errors began approximately 8:00 AM PT / 16:00 UTC, March 17, 2026
- Three distinct waves of failures with brief partial recovery between waves
- 529 errors appeared between the first and second 500 wave, suggesting intermittent recovery under load
- Errors are blocking mid-task execution (interrupted at step 5 of a multi-step workflow)

### Environment

- Tool: Claude Code (IDE window)
- Model: Claude Sonnet 4.6
- OS: macOS
- Fresh sessions attempted — errors persist across new sessions

### Expected Behavior

API requests should succeed or return meaningful, recoverable error codes. Persistent 500s across multiple sessions and request IDs indicate a backend infrastructure issue, not a client-side problem.

### Notes

Status page (status.claude.com) showed incidents for elevated Sonnet 4.6 errors beginning ~8:08 AM PT today, consistent with this report. The request ID sequence above should allow server-side tracing across all three failure waves.

Steps to Reproduce

Sending a prompt w/ the 'bypass permissions' option enabled.

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.72

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_