@justfortytwo/runner

Thin shared library that wraps headless claude -p --output-format json invocations for fortytwo daemons and bridges.

Usage

import { createRunner } from '@justfortytwo/runner';

const run = createRunner(); // uses `claude` binary from PATH or CLAUDE_BIN env
const result = await run('What is the weather in Paris?');
if (result.ok) {
  console.log(result.text);
}

API

createRunner(opts?: RunnerOptions): (prompt: string, extraArgs?: string[]) => Promise<RunResult>

Creates a runner function. Options:

• spawn — injectable child_process.spawn (useful for testing)
• bin — path to the claude binary (default: CLAUDE_BIN env or "claude")
• timeoutMs — turn timeout in ms (default: FORTYTWO_TURN_TIMEOUT env × 1000, or 300 000 ms)
• cwd — working directory for the subprocess

RunResult

interface RunResult {
  ok: boolean;    // true if exit code 0 and is_error is not set
  text: string;   // the `result` field from claude's JSON output
  raw: unknown;   // the full parsed JSON (or null on parse error)
}

Environment variables

| Variable | Default | Description | |---|---|---| | CLAUDE_BIN | claude | Path to the claude CLI binary | | FORTYTWO_TURN_TIMEOUT | 300 | Turn timeout in seconds |