Slotlock

Slotlock is a calendar for AI agents. It books vehicles, rooms, machines, people or anything else reservable, answers "when is this free?" from weekly availability rules, and lets PostgreSQL reject double bookings, however many writers race. Agents call it over MCP or A2A; your code calls it as a TypeScript library.

Why it is built for agents

• Resources own calendars, not users, and the tenant comes only from the authenticated caller.
• Intervals are half-open [start, end), so back-to-back bookings never collide.
• A PostgreSQL exclusion constraint decides overlaps; a conflict comes back as data, not an error.
• Writes are idempotent and take an expected revision.
• Free/busy says whether it is certain: a calendar not yet synced makes time unproven, not free.
• Tool names, schemas and errors work on Claude, OpenAI and every MCP host.

Get started

The documentation is at slotlock.pylota.io/docs, with a page each for the booking MCP server, the booking API, use cases and pricing. There are three ways to run Slotlock:

• Slotlock Cloud: nothing to run. Sign in with GitHub or Google at https://app.slotlock.pylota.io/dashboard, create a key, and connect an agent to https://slotlock-api.pylota.io/mcp. Start on Free, with no card; Developer and Team add room for agents in production (pricing). Best effort, with no service level agreement.
• Self-host with Docker, or from npm with Self-hosting.
• As a TypeScript library inside your own Node.js service.

Self-host with Docker

From a clone of this repository:

scripts/quickstart-env.sh > .env    # .env.example, its four secrets set to openssl rand -hex 32
docker compose up --build --detach
docker compose exec slotlock slotlock resource add vehicle-42 --timezone Europe/London

The server listens on 127.0.0.1:8080, as a database role that cannot bypass row-level security. .env.example makes every resource bookable on weekdays 09:00 to 17:00 and every write wait for a person. The Quickstart walks through it with Claude Code; Self-hosting covers the published image, configuration and commands, and Operations the production checklist.

Quick start: the next free slot

npm install slotlock postgres

Node.js 22.12+, PostgreSQL 16 or newer with btree_gist (created for you if missing), and postgres ^3.4.5 as a peer dependency. TypeScript declarations are included. The availability maths needs no database:

import { expandRules, findNextAvailable } from 'slotlock';

const searchWindow = {
  start: new Date('2026-09-14T00:00:00Z'),
  end: new Date('2026-09-21T00:00:00Z'),
};

const windows = expandRules(
  [{ rrule: 'FREQ=WEEKLY;BYDAY=MO,TU,WE,TH,FR', startMinutes: 9 * 60, durationMinutes: 8 * 60 }],
  se

... [View full README on GitHub](https://github.com/pilotaai/slotlock#readme)