USP Logo

Universal Scheduling
Protocol

The open standard for agentic scheduling.

Enable platforms and AI agents to discover, check availability of, and book time-based services without custom integrations.

USP Logo

Learn

Read the specification, core concepts, and deployment modes to understand how USP fits your stack.

Get Started

Implement

Start with OpenAPI and OpenRPC bindings, JSON Schemas, and the interactive playground.

View on GitHub

Built for flexibility, security, and scale

Agentic scheduling requires interoperability. USP is built on industry standards — REST, MCP, A2A, and ESP transports — with UCP-Native and Standalone deployment modes so different systems can work together without custom integration.

Interoperable

Two deployment modes (UCP-Native for existing UCP platforms, Standalone for self-contained scheduling) share the same domain core and transport bindings.

Agent-First

Every operation is designed for programmatic consumption. AI agents autonomously discover, evaluate, and book services with continue_url handoff when human input is needed.

Secure & Private

OAuth 2.0 identity linking, HTTP Message Signatures for webhooks, structured buyer consent, and TLS 1.3 transport.

Open & Extensible

Apache 2.0 licensed. Vendor extensions via reverse-domain namespaces (e.g., com.wix.services.courses). JSON Schema composition for custom capabilities.

See it in action

USP is designed to facilitate the entire scheduling lifecycle, from discovery and availability to booking and post-confirmation management. The protocol supports catalog browsing, slot queries, holds, booking creation, and payment coordination across deployment modes.

Discovery & Checkout

In UCP-Native mode, scheduling capabilities register in /.well-known/ucp. Paid bookings use UCP atomic checkout so agents discover services and complete payment in one flow.

Learn more
UCP Profile — Scheduling Capability
GET /.well-known/ucp HTTP/1.1
Host: salon.example.com

{
  "ucp": { "version": "2026-01-11" },
  "capabilities": {
    "dev.usp.services.catalog": [{
      "version": "2026-02-21",
      "spec": "https://usp.dev/specification/",
      "schema": "https://usp.dev/schemas/catalog.json"
    }],
    "dev.usp.services.paid_bookings": [{
      "version": "2026-02-21"
    }]
  }
}
Checkout — Atomic Booking + Payment
POST /checkout-sessions HTTP/1.1
Host: platform.example.com
Idempotency-Key: idem_abc123

{
  "line_items": [{
    "item": { "id": "svc_haircut_001" },
    "quantity": 1,
    "booking": {
      "slot_id": "slot_20260315_0900",
      "service_id": "svc_haircut_001"
    }
  }],
  "buyer": { "email": "alice@example.com" }
}

Service Catalog

Browse services, pricing, policies, resources, and locations through a unified catalog API designed for agents and platforms.

Learn more
Request — List Services
POST /services/list HTTP/1.1
Host: business.example.com
Content-Type: application/json

{
  "filters": {
    "type": "appointment",
    "category_id": "beauty"
  },
  "pagination": {
    "limit": 20,
    "cursor": null
  }
}
Response
{
  "usp": {
    "version": "2026-02-21",
    "capabilities": [
      { "name": "dev.usp.services.catalog",
        "version": "2026-02-21" }
    ]
  },
  "services": [
    {
      "id": "svc_haircut_001",
      "name": "Women's Haircut & Style",
      "type": "appointment",
      "duration": { "fixed": "PT60M",
                    "buffer_after": "PT15M" },
      "pricing": { "model": "fixed",
                   "amount": 7500,
                   "currency": "USD" }
    }
  ]
}

Availability

Query open time slots, hold a slot during checkout, and release holds when buyers abandon the flow.

Learn more
Request — Query Availability
POST /availability/query HTTP/1.1
Host: business.example.com
Content-Type: application/json

{
  "service_id": "svc_haircut_001",
  "start_date": "2026-03-15",
  "end_date": "2026-03-16",
  "granularity": "slot",
  "timezone": "America/New_York",
  "resource_id": "staff_jane"
}
Response
{
  "service_id": "svc_haircut_001",
  "granularity": "slot",
  "slots": [
    {
      "id": "slot_20260315_0900",
      "start": "2026-03-15T09:00:00-04:00",
      "end": "2026-03-15T10:00:00-04:00",
      "duration": "PT60M",
      "state": "available",
      "resources": [
        { "id": "staff_jane",
          "type": "staff",
          "name": "Jane Smith" }
      ]
    }
  ]
}

Booking

Create confirmed bookings, manage lifecycle transitions, and coordinate payment when required.

Learn more
Request — Create Booking
POST /bookings HTTP/1.1
Host: business.example.com
Content-Type: application/json

{
  "service_id": "svc_haircut_001",
  "slot_id": "slot_20260315_0900",
  "hold_id": "hold_abc123",
  "buyer": {
    "first_name": "Alice",
    "last_name": "Williams",
    "email": "alice@example.com"
  },
  "party_size": 1,
  "resource_id": "staff_jane"
}
Response
{
  "id": "bkg_789ghi",
  "service_id": "svc_haircut_001",
  "slot": {
    "start": "2026-03-15T09:00:00-04:00",
    "end": "2026-03-15T10:00:00-04:00",
    "duration": "PT60M"
  },
  "status": "confirmed",
  "payment": {
    "status": "not_required",
    "timing": "at_service"
  },
  "created_at": "2026-03-14T22:05:00Z"
}

UCP-Native Mode

For platforms that already support UCP. Scheduling registers in /.well-known/ucp with atomic checkout for paid bookings and inherited UCP infrastructure.

Get Started

Standalone Mode

Self-contained scheduling at /.well-known/usp with generic payment context that works with any checkout system and IETF-native infrastructure.

See how it works

Designed for the entire scheduling ecosystem

For Developers

Build scheduling into any platform with OpenAPI, OpenRPC specs, JSON Schemas, and transport bindings — everything you need to implement USP.

View the technical spec

For Businesses

Retain control of your schedule, resources, and customer relationships. USP keeps you as the Merchant of Record while agents discover and book.

Get started with USP

For AI Platforms

Enable agents to autonomously discover and book services with MCP and A2A bindings, availability hints for reasoning, and continue_url for human handoff.

View transport bindings

For Payment Providers

Integrate through UCP atomic checkout or standalone payment context. USP handles scheduling; your checkout system handles payment.

See payment architecture

Get started today

USP is an open standard designed to let AI agents, apps, businesses, and payment providers schedule time-based services without custom, one-off integrations for every connection. We actively seek your feedback and contributions to help build the future of agentic scheduling.

The complete technical specification, documentation, schemas, and reference artifacts are hosted in our public GitHub repository.

Download

Read the getting started guide and machine-readable artifacts

Experiment

Walk through discovery, negotiation, and booking in the interactive playground

Contribute

Join the community and help shape the standard on GitHub

Visit the GitHub repository