GitHub MCP server: "Bad credentials" / 401 errors

The error

Why it happens

The token is missing, expired, or lacks scopes. With Docker, the variable also has to be forwarded into the container (-e GITHUB_PERSONAL_ACCESS_TOKEN) and set in the env block.

How to fix it

1. Create a token with the right access
   Fine-grained or classic PAT with repo access for the repos you need.
2. Forward the variable into Docker
   Both parts are required.

   {
     "mcpServers": {
       "github": {
         "command": "docker",
         "args": ["run", "-i", "--rm", "-e", "GITHUB_PERSONAL_ACCESS_TOKEN", "ghcr.io/github/github-mcp-server"],
         "env": { "GITHUB_PERSONAL_ACCESS_TOKEN": "ghp_your_token" }
       }
     }
   }

3. Make sure Docker is running
   If Docker Desktop is stopped, the server exits with "Connection closed".

Related servers

Sources

• https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/managing-your-personal-access-tokens
• https://github.com/github/github-mcp-server
• Not able to work with `Github` MCP sever . Tool calls fail with `401 Bad credentials` (GitHub issue, 1 comments)