OAuth Token Refresh Script

[brent-at-aam]

Hello,

Do you think it would be possible to add another configuration option that allows delegation of OAuth token retrieval to an external script? I am using the MCP server in a Coder workspace (https://coder.com) which has its own mechanism for maintaining OAuth credentials for our GitLab instance. I can retrieve the access token with a command like:

coder external-auth access-token gitlab

Right now, I prepopulate ~/.gitlab-mcp-token.json, with this value which works great with the MCP server until the token expires. If I could set an env var like GITLAB_OAUTH_TOKEN_SCRIPT, and the mcp server could delegate token retrieval to that script, I think it would be a nice quality of life improvement.

I'm open to submitting a PR if you are open to the feature.