[BUG] Persistent ECONNRESET + 500 errors on all tasks — Max plan, macOS, 4 days

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?

Environment

• macOS, Apple Silicon
• Claude app v2.1.141
• Max plan subscriber
• 16 Cowork agents configured (all disabled)

What's wrong
Every API call fails with either:

• API Error: Unable to connect to API (ECONNRESET)
• API Error: 500 status code (no body)

Affects Claude Code and Cowork. Claude.ai in browser works fine.

Duration
4 days, started May 13 2026. Has not resolved.

What I've tried

• Full app reinstall + cache clear
• Updated to v2.1.141
• Killed all Claude processes
• Firewall disabled
• Network confirmed healthy (curl returns 404 in 0.05s)
• Multiple new sessions
• Disabled all Cowork agents
• Restarted app many times

Pattern
Simple tasks occasionally work. Anything compute-heavy (reading multiple files, running tests, deep research) fails immediately with ECONNRESET or 500.

Related issues
#37077 #13657 #5674 #29591

Additional context
Concurrent with spike in product API costs suggesting possible account-level rate limiting or session corruption. Simple claude.ai chat works fine throughout.

What Should Happen?

Claude Code and Cowork should complete compute-heavy tasks without connection errors, as they did reliably before May 13 2026. The app should maintain stable API connections throughout multi-step tasks on a Max plan subscription.

Error Messages/Logs

Steps to Reproduce

1. Open Claude Code on macOS (v2.1.141)
2. Start a new session with any compute-heavy task (e.g. read multiple files, run benchmarks, deep research)
3. Observe ECONNRESET or 500 error — either immediately or after 1-2 messages
4. Simple tasks ("hi", single file read) may occasionally succeed
5. Reproducible across new sessions, new projects, after full app reinstall
6. Has been consistent for 4 days across hundreds of attempts

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.143

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Other

Additional Information

Claude Desktop app (macOS, Apple Silicon)