const client = new JustackClient({ apiKey: 'jstk_...' });

const session = await client.sessions.create({
name: 'Deploy',
recipients: [{ email: 'reviewer@company.com' }],
});

const { env, approve } = await session.ask('Ship it?', {
inputs: [
  { type: 'select', name: 'env', options: ['staging', 'production'] },
  { type: 'confirm', name: 'approve' },
] as const,
});
// env: string, approve: boolean — inferred from inputs

Justack

Typesafe human-in-the-loop API for AI agents. Ask humans questions with typed inputs, get typed responses.

Get Started View on GitHub

Developer-First Experience

Typesafe API

Define inputs (confirm, select, text), get typed responses inferred at compile time. No parsing, no validation.

Zero UI to Build

Recipients get a hosted inbox with magic link auth. No frontend to build or maintain.

Real-time Notifications

Recipients are notified instantly and see messages and asks as they stream in.

Simple Control Flow

ask() returns when a human responds, so agent code stays linear. Use callbacks for async.