Fix custom MCP OAuth redirect in Grok Bot

Some custom MCP OAuth flows fail in Grok Bot with redirect_uri must be HTTPS or HTTP loopback, even when the same server works on the Grok marketplace. Staff: Grok Bot speaks remote MCP only (no stdio bridge). That is separate from the official X plugin OAuth path in Fix Grok Bot X plugin OAuth.

Confirm the Bot constraint

1. Add the server as a remote MCP URL in Bot plugins (HTTPS endpoint), not a local stdio command.
2. Retry OAuth. If redirect_uri is rejected, the IdP registered URIs likely expect a loopback or marketplace redirect Grok Bot does not present.
3. Note the exact error string and whether marketplace or another client succeeds with the same server.

Documented IDE workaround

Staff pointed at Cursor IDE with a remote bridge, for example:

npx mcp-remote <your-mcp-https-url>

Run that pattern in the IDE MCP config when you need the toolset on a machine that can complete the OAuth redirect the IdP allows. Keep secrets in the IDE/MCP config, not in chat.

What will not fix it today

• Expecting a first-class IBKR (or other broker) Bot plugin that does not exist in the catalog.
• Reusing marketplace-only redirect URIs inside Grok Bot remote MCP.
• Treating this as the X connector enrollment bug.

If remote OAuth still fails after a correct HTTPS remote URL, track the Cursor forum thread and wait for a Bot-side redirect fix; use the IDE bridge for work that cannot wait.

Pitfalls

• Local stdio MCP configs are not a Grok Bot path.
• A marketplace success does not prove Bot remote OAuth will pass the same redirect_uri checks.
• Do not paste client secrets into the Bot chat to “force” OAuth.