cast invoke my-agent "What files are here?"

┌──────────┐    prompt    ┌──────────────┐    stdin    ┌─────────┐
│   You    │ ──────────▶  │  Castari API │ ─────────▶  │  Agent  │
└──────────┘              └──────────────┘             └─────────┘
     ▲                           │                          │
     │         response          │         stdout           │
     └───────────────────────────┴──────────────────────────┘

// Agent reads from stdin
let prompt = "";
process.stdin.on("data", (chunk) => (prompt += chunk));
process.stdin.on("end", () => {
  // Process prompt
});

// Agent writes to stdout
console.log(response);

{
  invocation_id: "inv_abc123",
  session_id: "sess_xyz789",
  response_content: "The current directory contains...",
  input_tokens: 124,
  output_tokens: 1110,
  total_cost_usd: 0.02,
  duration_ms: 2341,
  status: "completed"
}

cast usage

// These run concurrently in separate sandboxes
const results = await Promise.all([
  client.agents.invoke('my-agent', { prompt: 'Task 1' }),
  client.agents.invoke('my-agent', { prompt: 'Task 2' }),
  client.agents.invoke('my-agent', { prompt: 'Task 3' }),
]);

cast invoke my-agent "Bad request"
# Error: Agent execution failed

try {
  const result = await client.agents.invoke('my-agent', { prompt });
} catch (error) {
  if (error instanceof CastariError) {
    console.log(error.status);  // 500
    console.log(error.message); // "Agent execution failed"
  }
}