[BUG] Code tab: session dies in 0s (no_response) on macOS 26.5 — binary works perfectly when invoked directly with identical flags

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?

The Code tab (</>) in Claude Desktop produces no response to any message. Every session dies immediately with unhealthy cycle (0s, hadFirstResponse=false, reason=no_response) before the subprocess can initialize. The message appears briefly then disappears with no error shown to the user. The Chat tab works normally.

What Should Happen?

The Code tab should start a Claude Code session and respond to messages, as it did prior to approximately May 16, 2026.

Error Messages/Logs

From `~/Library/Logs/Claude/main.log` on every attempt:


[info] Starting local session local_28a3c629-20d1-474e-81d0-0994cccad7d0 in /Users/vitaliy/Documents
[info] Using Claude Code binary at: /Users/vitaliy/Library/Application Support/Claude/claude-code/2.1.138/claude.app/Contents/MacOS/claude
[info] [CCD] [replaceRemoteMcpServers] Calling SDK with 7 total servers {
  serverNames: ['Claude in Chrome', 'mcp-registry', 'Claude Preview', 'ccd_session', 'ccd_directory', 'ccd_session_mgmt', 'scheduled-tasks']
}
[info] Session local_28a3c629-20d1-474e-81d0-0994cccad7d0 query iterator completed
[info] [CCD CycleHealth] unhealthy cycle for local_28a3c629-20d1-474e-81d0-0994cccad7d0 (0s, hadFirstResponse=false, reason=no_response)


No `[error]` lines appear — the subprocess exits silently with no stdout captured by the Desktop app. No crash reports in `~/Library/Logs/DiagnosticReports/`.

**Key finding:** Running the bundled binary directly with the exact flags the Desktop app uses works perfectly:


"/Users/vitaliy/Library/Application Support/Claude/claude-code/2.1.138/claude.app/Contents/MacOS/claude" \
  --output-format stream-json --verbose --input-format stream-json \
  --effort medium --model claude-sonnet-4-6 \
  --permission-prompt-tool stdio \
  --setting-sources=user,project,local \
  --permission-mode acceptEdits \
  --allow-dangerously-skip-permissions \
  --include-partial-messages \
  --plugin-dir "/Users/vitaliy/Library/Application Support/Claude/local-agent-mode-sessions/skills-plugin/..." \
  --replay-user-messages --settings {} \
  -p "hello"


This returns a full stream-json response successfully. The failure is in the IPC/socket handshake between the Electron parent process and the subprocess, not in the binary itself.

**Exact subprocess flags captured via `ps aux`:**


/Users/vitaliy/Library/Application Support/Claude/claude-code/2.1.138/claude.app/Contents/MacOS/claude
  --output-format stream-json --verbose --input-format stream-json
  --effort medium --model claude-sonnet-4-6
  --permission-prompt-tool stdio
  --allowedTools mcp__computer-use,mcp__ccd_session__spawn_task,mcp__ccd_session__mark_chapter,mcp__ccd_session_mgmt__list_sessions
  --setting-sources=user,project,local
  --permission-mode acceptEdits
  --allow-dangerously-skip-permissions
  --include-partial-messages
  --plugin-dir .../skills-plugin/...
  --plugin-dir .../superpowers/5.1.0
  --replay-user-messages --settings {}

Steps to Reproduce

1. Open Claude Desktop 1.7196.0 on macOS 26.5 (Apple Silicon)
2. Log in with a Google SSO account
3. Click the </> Code tab
4. Type any message (e.g. "hello") and send
5. Observe: message briefly appears as "working", then disappears with no response and no error message

Claude Model

claude-sonnet-4-6

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Claude Desktop approximately version 1.7xxx.0 prior to May 16, 2026. The exact last working Desktop app version is unknown, but the issue was first noticed on May 18, 2026 after a weekend where no changes were made to the machine.

Claude Code Version

2.1.138 (bundled in Claude Desktop) 2.1.143 (Homebrew CLI, works correctly from Terminal)

Platform

Anthropic API

Operating System

macOS 26.5, Apple Silicon (arm64)

Terminal/Shell

iTerm2

Additional Information

Extensive troubleshooting performed — all ruled out:

• SSL/TLS: openssl s_client confirms no MITM/inspection; Verify return code: 0 (ok); issuer is legitimate Google Trust Services WE1
• API connectivity: curl https://api.anthropic.com works on both HTTP/1.1 and HTTP/2
• Binary health: binary runs correctly standalone and with all Desktop app flags
• Plugins: removed commit-commands@unknown (corrupt cache entry); tested with zero plugins; same failure
• TCC permissions: Accessibility, Full Disk Access, Developer Tools, App Management all granted to Claude.app; rebooted; same failure
• effortLevel: xhigh removed from ~/.claude/settings.json; same failure
• OAuth: token exchange succeeds on every attempt; auth is healthy
• Anthropic service status: all services operational at time of testing

TCC state:

kTCCServiceAccessibility|com.anthropic.claudefordesktop|2
kTCCServiceSystemPolicyAllFiles|com.anthropic.claudefordesktop|2
kTCCServiceDeveloperTool|com.anthropic.claudefordesktop|2

App Management enabled in System Settings UI but not reflected in TCC.db query (possibly user-level cache).

This issue is not a user migration issue (unlike #57858) — this is a fresh, single-user account with no username changes. The Code tab simply stopped working after a weekend with no local changes.

Workarounds: Chat tab in Claude Desktop works. claude CLI via Terminal (2.1.143) works.