pi-mem0-gateway

A pi extension that exposes every tool your organization has connected to the mem0 gateway as a single agent tool.

The gateway stores the credentials and audits each call, so pi never prompts for a connector login and no third-party API key is kept on the machine.

mem0_gateway(operation: "find", task: "list my open issues")
mem0_gateway(operation: "invoke", tool_name: "<connector>__<tool>", arguments: { limit: 3 })

Requirements

• pi
• A mem0 gateway agent key

Install

pi install npm:pi-mem0-gateway
export MEM0_GATEWAY_TOKEN="mg_..."

Restart pi.

Design

pi ships no MCP client by design: tool definitions are verbose, and a connected server consumes context on every turn whether it is used or not.

The mem0 gateway is itself a meta-gateway — five verbs in front of an entire catalogue. This extension registers one tool carrying those five operations, so context cost stays constant as an organization adds connectors. The model queries the catalogue on demand rather than holding it.

No connector is named in this package's source. An organization connects any MCP server or OpenAPI specification and grants tools per agent key, so each catalogue differs and changes during a session. Every discover and find is a live call, and a tool granted during a session is usable immediately, with no restart.

Connected apps in the tool description

After a discover, the granted connector names are written to ~/.pi/agent/mem0-gateway-connectors.json and appended to the tool description at the next start, so the model can see which applications are connected without spending a call:

Connected apps seen in an earlier session: linear, notion, posthog, sentry.

Names only, taken verbatim from the gateway, capped at twelve. The description marks them as a hint rather than the current grant, because the list is written by an earlier session and discover and find stay authoritative. Entries are keyed by a digest of the token and URL, so two organizations on one machine stay separate and the token never reaches the file. Delete the file to clear it.

Operations

The standard sequence is find → describe → invoke.

discover returns a summary, because a full catalogue is large and remains in context for the rest of the session. Pass connector for one connector's tools:

mem0_gateway(operation: "discover")
mem0_gateway(operation: "discover", connector: "<connector>")

An empty find result is a confirmed no-match rather than an error. When a granted search returns nothing, search again with requestable: true, then request the tools that apply.

Error recovery

Gateway errors are descriptive, but acting on one costs an extra turn. Three follow-ups are deterministic and are applied automatically:

The denial cases matter because invoke answers a misspelled name with out_of_scope, the same code used for a tool the key does not hold. Without the distinction, the documented path requests access to an already-granted tool.

Attached schemas are shortened: long property descriptions are cut while required fields, property names, and types are kept, and the full text remains available through describe.

Probes run only on the failures listed above. A successful call costs exactly one request, and a failed probe leaves the original error unchanged.

Configuration

Resolution order is MEM0_GATEWAY_TOKEN, then MEM0_GATEWAY_API_KEY, then pi settings.

// ~/.pi/agent/settings.json
{
  "pi-mem0-gateway": {
    "token": "${MEM0_GATEWAY_TOKEN}",  // ${VAR} is expanded
    "url": "https://gateway-mcp.mem0.ai/mcp",
    "timeoutMs": 60000
  }
}

token and url are read from the environment and from global settings only. A project-local .pi/settings.json is committed to a repository, so accepting a token or URL from that file would let a cloned repository redirect every gateway call along with the key. A project may set timeoutMs, which cannot carry a credential.

Errors

Each failure returns readable text rather than a stack trace.

Access requests are asynchronous and may take hours to approve.

Development

npm install
npm run check    # tsc --noEmit, then node --test
npm run release  # bump, tag, push; CI publishes

src/client.ts is a small MCP Streamable HTTP client. The gateway is stateless — no initialize handshake and no session id — so no SDK is required. Responses are parsed as JSON or as SSE data: frames, since the endpoint may return either.

All tests are offline. CI never calls the gateway, so no key is required and no run fails because a connector is unavailable.

Links

• npm package
• Releases
• Issues
• mem0 gateway connectors
• pi

License

MIT