Pi Integration

Use Pi's built-in MCP support with Tanda's endpoint, https://agents.testandaccept.com/mcp, and your Tanda account.

Configure and Sign In

Run these commands in your terminal:

pi --version
pi mcp add tanda --url https://agents.testandaccept.com/mcp
pi mcp login tanda
pi mcp list

Approve Read access in the browser and Write if you want Pi to create or update Tanda records. Your existing organization and project permissions still apply.

Pi saves this server in ~/.pi/agent/mcp.json. Add --local to pi mcp add for a project-specific .pi/mcp.json; Pi requires project trust to use it. These commands are documented in Pi's CLI reference.

Inside Pi, /mcp shows connection details; /mcp login tanda starts sign-in. Run /reload after editing configuration outside the session. Use Pi's default OAuth registration; no API key, client secret, or manual Authorization header is needed. See Pi's MCP guide.

Choose an Organization

To default to one organization, add its name, slug, or ID as a header:

pi mcp add tanda --url https://agents.testandaccept.com/mcp --header 'Tanda-Organization=acme'

Replace acme with your organization. Pi's CLI uses KEY=VALUE for headers. Alternatively, merge this entry into your Pi MCP configuration:

{
  "mcpServers": {
    "tanda": {
      "url": "https://agents.testandaccept.com/mcp",
      "headers": { "Tanda-Organization": "acme" }
    }
  }
}

The header is optional. Once connected, you can ask "Work in Acme from now on" to save a default for this connection. See choosing a default organization.

Verify the Connection

pi mcp list must show Tanda connected with tools available. A browser success page alone does not verify this. Then ask:

List my Tanda organizations, then list my projects in Acme.

Pi normally exposes MCP tools through codemode, so they need not appear as separate tools in the model's initial tool list. Inspect /mcp for the server's actual tools. See Pi tool exposure.

Protocol Version Error

If browser sign-in succeeds but Pi reports State: failed and HTTP 400 with this error:

{
  "code": -32022,
  "message": "Unsupported protocol version: 2025-11-25",
  "data": {
    "supported": ["2026-07-28"],
    "requested": "2025-11-25"
  }
}

Authentication succeeded. The connection fails because Pi requests a protocol revision that the server does not accept; tool discovery cannot proceed.

As of October 19, 2026, Pi's MCP client documentation lists 2025-11-25 and older revisions. It does not list 2026-07-28. There is no verified Pi configuration workaround for this mismatch.

• Use the Tanda web app while compatibility is being resolved.
• Repeated sign-in, clearing credentials, changing organizations, or manually setting a protocol-version header will not provide the missing protocol support.
• A fix requires Tanda to support Pi's protocol or a Pi release that supports Tanda's. Updating Pi only helps once that compatibility is available.
• When contacting Tanda support, include pi --version, the server URL, and the error's requested and supported values. Omit tokens and authorization codes.

After compatibility is confirmed, run /mcp reconnect tanda inside Pi or pi mcp list from the terminal to retry.

Update Pi

Pi can update itself from the terminal:

pi update
pi --version

Restart Pi afterward. Use pi update --all to update Pi and installed extensions together. If another package manager installed Pi, such as Nix, use that manager to update it. See Pi's update instructions.

An update is not a confirmed fix for the error above: the installed release must support a protocol version that Tanda accepts. Check its release notes, then run pi mcp list to verify the connection.

For invalid_redirect, follow native client callback troubleshooting. That is a separate failure during sign-in; it does not explain this protocol error.