macOS Keychain: SSH Authentication Failure for Pro Plan Users

Bug Description
Subject: SSH Authentication Failure After macOS Keychain Integration - Critical Issue for Pro Plan Users

Description:
I am experiencing a critical authentication issue with Claude Code that has severely impacted my workflow. This problem started approximately 2-3 days ago and appears to be related to the recent change that moved API key storage to macOS Keychain.

Issue Details:

• For the past month, Claude Code worked perfectly via SSH connections
• Since ~2-3 days ago, SSH authentication completely fails with "Missing API key · Run /login"
• Physical machine access still works normally
• I am a Claude.ai Pro Plan subscriber (not API account user)
• The issue occurs specifically when accessing Claude Code through SSH clients like Terminus

Timeline:

• Previous month: SSH access worked flawlessly
• Recent days: Complete SSH authentication failure
• Physical machine: Still functional

Technical Analysis:
Based on the changelog, Claude Code now stores "(Mac-only) API keys in macOS Keychain". This change appears to have broken SSH access because:

1. SSH sessions cannot access the macOS Keychain that requires GUI session context
2. OAuth authentication completes successfully in browser but tokens are not accessible to SSH sessions
3. Physical machine works because it has full GUI session access to Keychain

Steps to Reproduce:

1. SSH into macOS host with Claude Code installed
2. Run claude command
3. Execute /login
4. Complete OAuth authentication in browser (shows "Login successful")
5. Claude Code still displays "Missing API key · Run /login"
6. /status shows "Auth Token: [REDACTED] despite successful login

Impact:
This is a critical regression that has completely broken my development workflow. As a Pro Plan subscriber, I cannot use the environment variables workaround since that requires API account access. I believe many SSH users are experiencing this same issue.

Environment:

• macOS host system
• Claude Code version: [current version]
• Installation: npm global
• Account: Claude.ai Pro Plan subscription
• Access method: SSH (Terminus, etc.)

Request:
This issue severely impacts user experience and appears to affect many SSH users. Please:

1. Provide immediate acknowledgment of this regression
2. Prioritize a fix for SSH authentication with macOS Keychain
3. Consider reverting the Keychain-only approach or providing SSH-compatible alternatives
4. Send email updates on progress and resolution

I rely heavily on Claude Code for my development work and this regression has made the tool completely unusable in my primary workflow. Please treat this as a high-priority issue and provide email feedback on the resolution timeline.

Thank you for your urgent attention to this matter.

Environment Info

• Platform: darwin
• Terminal: WarpTerminal
• Version: 1.0.83
• Feedback ID: 4847d7f2-8d1e-4df8-af8b-69e147886d4c

Errors

[{"error":"RangeError [ERR_CHILD_PROCESS_STDIO_MAXBUFFER]: stdout maxBuffer length exceeded\n    at Socket.onChildStdout (node:child_process:482:14)\n    at Socket.emit (node:events:507:28)\n    at Socket.emit (node:domain:489:12)\n    at addChunk (node:internal/streams/readable:559:12)\n    at readableAddChunkPushByteMode (node:internal/streams/readable:510:3)\n    at Readable.push (node:internal/streams/readable:390:5)\n    at Pipe.onStreamRead (node:internal/stream_base_commons:189:23)","timestamp":"2025-08-17T03:13:27.668Z"}]