Meta Ads MCP OAuth fails: redirect_uri not registered

Description

Authenticating the Meta Ads MCP server (https://mcp.facebook.com/ads) fails with:

SDK auth failed: The provided redirect_uris are not registered for this client.

Steps to Reproduce

1. Add meta-ads MCP server to ~/.claude.json:

"meta-ads": {
  "type": "http",
  "url": "https://mcp.facebook.com/ads"
}

1. Run /mcp in Claude Code
2. Select "Authenticate"

Expected Behavior

OAuth flow completes successfully and the server authenticates.

Actual Behavior

Meta's OAuth server rejects the redirect URI sent by Claude Code's SDK. The redirect URI used by the SDK is not registered in the Facebook app backing the mcp.facebook.com/ads OAuth flow.

Environment

• Claude Code version: 2.1.141
• OS: macOS 25.1.0
• MCP server URL: https://mcp.facebook.com/ads

Notes

This appears to require coordination between Anthropic and Meta to register the correct redirect URI in the Facebook app used by the hosted MCP server.