Short answer
The ServiceTitan API is a REST API covering CRM, jobs, dispatch, accounting, pricebook, estimates and more. It uses OAuth 2.0 client credentials only, with 15-minute tokens and no refresh tokens. Customers need the Works or Ent Plus package to build their own apps; third-party apps are reviewed and need each customer to generate and share credentials. The limit is 600 calls per 10 seconds per app per tenant. If the goal is an AI assistant working with field service data rather than a system-to-system integration, an MCP server is the faster route.
Authentication
OAuth 2.0 client credentials only (machine-to-machine, no user sign-in flow). Access tokens last 15 minutes and there are no refresh tokens: you request a new token with the client ID and secret. You register an app in the Developer Portal to get an App Key; the customer's ServiceTitan admin generates the tenant-specific client ID and secret.
Getting access
- Customer-built apps: the customer must be on the Works or Ent Plus package and request an integration environment.
- Third-party apps: developers get integration-environment credentials only; for production, each customer generates and shares credentials.
- App registrations are reviewed before tenants can connect. A Marketplace listing needs Partner Program membership, a signed agreement and an information security review.
- Sharing a customer's App Key with a third party ("tunneling") is not allowed.
- Fees: not published.
What you can reach
- Accounting: invoices, payments, GL accounts, journal entries, AP bills and payments
- CRM: customers, locations, contacts, leads, bookings
- Jobs and appointments, projects, job notes and types
- Dispatch: appointment assignments, arrival windows, capacity, technician shifts and skills, GPS tracking, zones, teams
- Estimates and proposal templates; pricebook (services, materials, equipment, pricing)
- Memberships, service agreements, equipment, inventory and purchase orders, payroll, timesheets, forms, marketing, reporting, telecom
Webhooks, rate limits and test environment
| ServiceTitan | |
|---|---|
| Webhooks | In transition. V2 webhooks are in beta for accounts with webhook access (HMAC verification, retries at 10, 30, 60 and 300 seconds); new subscriptions to V1 webhooks are restricted and V1 is due to be deprecated. The event list is not published publicly. |
| Rate limits | 600 calls per 10 seconds per application per tenant; reporting APIs allow 1 run of the same report per minute per tenant. |
| Sandbox / test environment | Yes: a separate integration environment. Customers can ask for a copy of production data; third-party developers get demo data. |
Known limitations
From ServiceTitan's published documentation:
- No user-delegated (authorization code) flow and no refresh tokens
- Jobs cannot be deleted, only canceled; appointment and technician statuses cannot be transitioned via API
- Merging, deactivating or reactivating customers and locations is not supported via API
- Bills and purchase order status cannot be updated via API
- New payment terms and tax zones must be created in ServiceTitan itself
Building on the API versus connecting AI through MCP
If you want an integration (syncing ServiceTitan with another system), the API is the route. If you want your team to ask an AI assistant about jobs, schedules and invoices, or have it do the work, you would be building and hosting that yourself on top of the API.
Fieldproxy takes the other route: its official MCP server gives Claude, ChatGPT and Microsoft Copilot 145 field service tools directly, with scoped access and a confirm step before every change, and it can also change the software itself (fields, screens, automations) in a sandbox.
| Build on the ServiceTitan API | Fieldproxy MCP server | |
|---|---|---|
| Time to first answer in ChatGPT or Claude | Build, host and maintain a server | Add a connector and sign in |
| Auth and permissions | You implement them | Per-person sign-in, scopes, row and column limits |
| Changes to data | Raw API writes | Proposed, confirmed by a person, undoable |
| Changing the software itself | Not available through an API | Fields, screens, automations, in a sandbox |
Sources
- ServiceTitan Developer Portal: OAuth 2.0
- Environments
- Developer FAQs (rate limits, webhooks)
- Integration paths
- API reference
Read from the vendor's own developer documentation on September 27, 2026. Anything the docs do not publish is marked "not published".
Fieldproxy facts on this page come from the Fieldproxy MCP reference. Competitor details are from each vendor's own documentation as of September 27, 2026; see the comparison table and sources.