[Bug]: MiniMax Code sign-in always opens the Mainland China login host (agent.minimaxi.com) with no Global region or API key option#17601

Summary

The MiniMax Code provider sign-in in T3 Code always opens the Mainland China login host (agent.minimaxi.com). There is no way to select the Global region (agent.minimax.io), and no way to paste an API key instead of using OAuth.

For users with a global MiniMax account this makes the provider effectively unusable: the OAuth flow sends them to a regional platform where their account does not exist.

Steps to reproduce

1. Open the Add provider dialog.
2. Select the MiniMax Code provider and continue to the Sign in step.
3. T3 Code opens a browser to the Mainland login host.

The URL printed in the terminal pane is:

The callback_state value is a per-session token and has been redacted. The shape of the URL is what matters for this report.

Expected behaviour

Either of the following would resolve this:

1. A region selector in the sign-in step, defaulting to Global and falling back to an explicit choice for Mainland accounts.
2. An API key option, so a user with a global key can paste it directly and skip the regional OAuth flow entirely.

MiniMax already exposes both in its own tooling, so there is prior art to follow.

The mcode CLI already has the exact flag

From the official MiniMax Agent docs:

The default region is mainland China; pass --region global for a Global account.

T3 Code's MiniMax Code provider is driving exactly this CLI (target=mcode-internal), and it is invoking the login step as if every account were a Mainland one.

The API key path is documented too

The sibling mmx CLI has the same shape: mmx auth login --recommend --region=global|cn and mmx auth login --api-key sk-xxxxx.

Regional hosts

MiniMax runs two fully separate backends that do not share credentials or endpoints. A key from one region will not authenticate against the other's host.

Worth noting there are two distinct host families, not one. The agent.* hosts serve the mcode agent login and the coding-plan usage endpoint (GET /v1/api/openplatform/coding_plan/remains), while account.* hosts serve the OAuth device-code exchange (/oauth2/device/code). agent.minimax.io/login returns 200 and mirrors the endpoint T3 Code currently calls, so it is the closest drop-in for a global login. Because the region is a property of the stored credential rather than a global setting, whichever region the sign-in uses has to be consistent with the API host used afterwards.

Notes

• Both hosts return HTTP 200, so this is not a broken link. It silently routes international users to the wrong regional login rather than surfacing an error, which is likely why it has gone unnoticed.
• The URL parameters (download_source=mcode-internal, callback_port=5007) suggest the host is resolved through T3 Connect rather than hardcoded in the app. Grepping the shipped macOS bundle for agent.minimax*, account.minimax*, api.minimax* and platform.minimax* returns no matches, and a codebase search for agent.minimaxi returns nothing either. Flagging this in case it points at where the fix belongs.
• Other providers in the dialog appear to support both OAuth and API key entry, which makes MiniMax Code the outlier here.

Environment