Invalid redirect URI (Linear MCP OAuth via mcp.linear.app)

Not specified by the original author.

Invalid redirect URI (Linear MCP OAuth via mcp.linear.app)

TL;DR: Skip the broken OAuth dance: use a Linear personal API key as a Bearer token in the Authorization header instead. The redirect URI mismatch comes from the OAuth client registration, which you cannot fix client-side. Personal API keys work with the remote endpoint and avoid the callback entirely.

The error

Invalid redirect URI

Fix it

1. Create a personal API key in Linear settings. Expected: You have the lin_api key.

2. Configure the MCP client to send your auth header the key to mcp.linear.app. Expected: The header carries the key.

3. Connect. Expected: The server authenticates without any redirect.

When this applies

Linear MCP OAuth via mcp.linear.app fails with Invalid redirect URI during the browser flow.

When this does NOT apply

If you already use an API key and get 401, the key is wrong. Local community servers use LINEARAPIKEY env instead.

Tool compatibility

mcp.linear.app remote server, OAuth flow

Also seen as

• Linear MCP OAuth redirect error
• mcp.linear.app invalid redirect
• Linear MCP skip OAuth API key

Why it happens

The OAuth app registration lists specific redirect URIs; MCP clients that open random local ports do not match, so Linear rejects the flow. A personal API key authenticates directly with no redirect involved.

Edge cases

• Some clients need --callback-port to pin the OAuth port; try that before giving up on OAuth.
• API keys inherit your permissions; scope them by using a dedicated user.
• Revoke the key if it leaks; Linear shows key usage.

Documented in community Linear MCP troubleshooting (gist): the mcp.linear.app OAuth flow fails on redirect URI mismatch and the Bearer API key workaround fixes it. https://gist.github.com (Linear MCP OAuth notes)