Meta Ads MCP OAuth fails on Claude Code desktop: redirect_uri not registered

Bug Report

Environment:

• Claude Code desktop (Windows 11)
• Version: native install
• MCP: Meta Ads official MCP (https://mcp.facebook.com/ads)

Description

The Meta Ads MCP authenticates successfully on claude.ai web app but fails on Claude Code desktop with the following error:

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

This error appears both:

1. When clicking "Authenticate" in the /mcp dialog for the project-level MCP (type: "http", url: "https://mcp.facebook.com/ads")
2. When calling the mcp__meta-ads__authenticate tool programmatically

Config (~/.claude.json)

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

Root Cause (suspected)

The claude.ai web app uses a redirect URI (e.g. https://claude.ai/...) that Meta has registered for their OAuth app powering the MCP. Claude Code desktop likely uses a different redirect URI (e.g. http://localhost:PORT) that is not registered on Meta's side.

Expected Behavior

OAuth flow completes successfully in Claude Code desktop, same as in claude.ai web.

Workaround

None currently. Users are forced to use the Meta Graph API directly with manual credentials.

Steps to Reproduce

1. Add { "type": "http", "url": "https://mcp.facebook.com/ads" } as a project MCP in Claude Code desktop
2. Open /mcp dialog and click "Authenticate"
3. Error appears immediately: SDK auth failed: The provided redirect_uris are not registered for this client.