[BUG] Dispatch unresponsive: a-api.anthropic.com blocked by CSP in Electron webview — dispatch_agent_name stays null (Max plan, macOS 26.4)

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?

Dispatch (Cowork) is unresponsive. Messages sent from the Claude iOS app receive no response. The desktop session initializes but stays idle indefinitely.

Root cause identified in logs: a-api.anthropic.com is missing from the connect-src directive in the Electron webview CSP. Every Dispatch session attempt triggers a CSP violation that blocks the required API call, leaving dispatch_agent_name as null and the session never fully initializes.

Regular Chat and Claude Code CLI both work fine on the same account.

What Should Happen?

Dispatch should accept messages from the Claude iOS app and return responses on the desktop.

Error Messages/Logs

From ~/Library/Logs/Claude/claude.ai-web.log (first occurrence 2026-02-25, recurring to present):

2026-02-25 06:04:21 [error] Connecting to 'https://a-api.anthropic.com/v1/m' violates
the following Content Security Policy directive: "connect-src 'self'
https://api.segment.io https://*.segment.io https://*.segment.com
https://a-cdn.anthropic.com https://*.google.com https://*.facebook.com
https://*.facebook.net https://*.doubleclick.net". The action has been blocked.

2026-03-28 10:16:13 [error] Fetch API cannot load https://a-api.anthropic.com/v1/m.
Refused to connect because it violates the document's Content Security Policy.

From ~/Library/Logs/Claude/main.log (repeats on every app restart):

2026-03-28 10:15:38 [info] [transport:ccr] reportMetadata {"permission_mode":"default","dispatch_agent_name":null}
2026-03-28 10:15:38 [info] [sessions-bridge] Session work received, waiting for user message via transport
2026-03-28 10:15:38 [info] [sessions-bridge] Session cse_01Ra82FescncDyr1ubSYkefg already has content; writing idle result only

Note: a-cdn.anthropic.com IS in the CSP allowlist but a-api.anthropic.com is NOT.

Note: Dispatch DID work intermittently on 2026-03-27 (permission forwarding logs present), then stopped again. Suggests timing/race condition.

Steps to Reproduce

1. Open Claude Desktop → Cowork tab → Dispatch
2. Pair with Claude iOS app via QR code
3. Send any message from iPhone
4. Observe: no response on desktop or iPhone, session stays idle indefinitely
5. Check ~/Library/Logs/Claude/claude.ai-web.log → CSP violation for a-api.anthropic.com
6. Check ~/Library/Logs/Claude/main.log → dispatch_agent_name: null on every session init

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Worked intermittently: 2026-03-27 21:16-21:23 (permission forwarding logs confirmed). Broken before and after.

Claude Code Version

2.1.86 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Other

Additional Information

• Claude Desktop version: 1.1.9310
• Plan: Max
• Related issue: #39270 (same a-api.anthropic.com CSP root cause identified independently)
• Chat and Claude Code CLI work normally on same account
• MCP tools intentionally skipped for Dispatch sessions (by design, not the bug)
• No HTTP 403 errors in logs — block occurs at Electron webview CSP layer before any HTTP request is made
• Fix: add https://a-api.anthropic.com to connect-src in Electron webview CSP