Cordierite

Cordierite is a CLI and host workflow for connecting to a Cordierite-enabled React Native app, discovering its registered tools, invoking those tools from the terminal, and ending the session cleanly after use.

Agent workflow

1. Run cordierite session --json. The response includes data.sessions (each entry has session_id, status, endpoint info, etc.). If sessions is empty, no Cordierite host is registered for this machine (for this registry).
2. If you need a new session for a device, follow Establish a session below. Record host.session_id from the host JSON—you must pass it to tools and invoke.
3. After the user opens the deep link on the device and the app connects, confirm with cordierite session --session-id <session_id> --json until data.selected reflects an active connection (or re-check session --json and infer from the listed session).
4. cordierite tools --session-id <session_id> --json — list tools registered in the app.
5. cordierite tools --session-id <session_id> <tool-name> --json — inspect one tool’s input/output schema before calling it.
6. cordierite invoke --session-id <session_id> <tool-name> --input '{"key":"value"}' --json — invoke the tool with JSON args.

Establish a session

Start the host with --json using the same TLS key and app URL scheme as the project (see Setup if you are wiring Cordierite into an app). The CLI generates the host certificate automatically from the resolved local IP. If the project does not already have a trusted host key, create one first with cordierite keygen in an interactive terminal and add the printed fingerprint to the app’s cliPins. If the default listen port is in use, add --port <port>.

cordierite host --tls-key /path/to/key.pem --scheme myapp --json

Run cordierite host in the background. It blocks; keep the foreground shell free for session, tools, and invoke.

From the host JSON output, use at least:

• host.deep_link — full URL (e.g. myapp:///?cordierite=…) for the app to open.
• host.session_id — pass this as --session-id to tools / invoke / session --session-id.

Then:

1. Give the user the deep link (or QR from interactive host UI on a TTY) so they can open it on a device or simulator.
2. Or open it yourself when you know the target (e.g. iOS Simulator xcrun simctl openurl booted '<url>', Android via adb, or device automation skills).

After the app opens the link and claims the session, poll cordierite session --session-id <session_id> --json (or session --json) until the session is active.

Terminate the connection

When the user wants to disconnect or stop Cordierite for that session: stop the matching background cordierite host process (end the job, SIGTERM, etc.). That tears down the host and the session. If several hosts run (e.g. different --port), stop the one that corresponds to the session_id you were using.

Declaring tools

The app must register tools before cordierite tools / cordierite invoke can do anything useful. Define schemas with Zod and register with registerTool:

import { registerTool } from "@cordierite/react-native";
import { z } from "zod";

const echoInput = z.object({
  value: z.unknown(),
});

const echoOutput = z.object({
  echoed: z.unknown(),
});

registerTool(
  {
    name: "echo",
    description: "Return the input unchanged",
    inputSchema: echoInput,
    outputSchema: echoOutput,
    handler: async (args) => ({ echoed: args.value }),
  },
);

Notes

• Use --json for structured CLI output in agent flows.
• cordierite keygen is the normal setup command for new host keys. It is interactive-only in v1: it writes a PEM private key and prints the exact sha256/... fingerprint the app should trust.
• tools and invoke always require --session-id (the value from host.session_id or sessions[].session_id).
• Prefer cordierite session --json first rather than assuming a session exists.
• If sessions is empty or tools / invoke fail with connection or session errors, establish a session (host running, deep link opened on the correct device).
• If the app registers no tools, cordierite tools returns an empty list.
• You may run multiple cordierite host processes (e.g. different --port for different devices); use the session_id that belongs to the host you care about.

Setup

For project integration guidance, see setup.md.