stdio

Stdio is the smallest trust boundary: the MCP client launches the compiled server and communicates over its standard input and output streams. No network listener is opened.

Build the server

Local source builds require Node.js 24 and the repository’s pinned pnpm version:

git clone https://github.com/enthouan/trello-mcp.git
cd trello-mcp
corepack enable
corepack prepare [email protected] --activate
corepack pnpm install --frozen-lockfile
corepack pnpm build

Cross-platform MCP client process configuration

{
  "mcpServers": {
    "trello": {
      "command": "node",
      "args": ["/absolute/path/to/trello-mcp/dist/index.js"],
      "env": {
        "TRANSPORT": "stdio",
        "TRELLO_API_KEY": "replace-with-your-api-key",
        "TRELLO_TOKEN": "replace-with-your-token"
      }
    }
  }
}

Build the checkout first. Stdio opens no network listener and does not use MCP_AUTH_TOKEN; keep the client configuration private because it contains the Trello credentials.

Configure a client

1. Build the server. Run the commands above after cloning the repository.

2. Use absolute executable and entry paths. Point the client at this checkout’s dist/index.js. Desktop apps may also need the absolute path to node because they inherit a smaller PATH than a shell.

3. Set the transport and credentials. Create a Trello API key and token, then pass TRANSPORT=stdio, TRELLO_API_KEY, and TRELLO_TOKEN in the child-process environment.

4. Restart the client. Reopen it so the process configuration is reloaded and the server’s tools are rediscovered.

Keep the client configuration private

MCP_AUTH_TOKEN is not needed for stdio because there is no HTTP endpoint. The client configuration still contains or forwards TRELLO_TOKEN, which grants the authorized member’s Trello access. Never commit or share it.

The server writes diagnostics to stderr because stdout is reserved for MCP protocol messages.

Verify through MCP

After the client reports that trello-mcp is connected and its tools are discovered, verify a read-only account call.

Verify it works

After the client discovers the server, review and approve only this named read-only call:

Read-only verification prompt

Which Trello account is connected? Use auth_whoami and do not change anything.

Expected result

Review the proposed call and approve only auth_whoami. It has no required inputs, is read-only, and returns the authenticated Trello member without changing Trello. That account metadata still passes through the MCP client and its configured model.

Sanitized example response

{
  "id": "member-id",
  "username": "your-username",
  "fullName": "Your Name"
}