ServiceTitan API Guide for Contractors

One-line verdict: A powerful, full API for bigger shops — if your own admin opens the door, because ServiceTitan will not open it for you. Openness: 3 / 5 — rated 3 because the V2 REST API is genuinely broad, but access is gated per tenant by a human admin, integrations face vendor governance review, and the webhook story is UNVERIFIED.

The connection that works

Rung 1 — Direct connection, human-gated. ServiceTitan offers a full V2 REST API covering the areas a shop actually runs on: CRM, jobs and dispatch, estimates, and accounting. It is fast on paper, too — up to 60 calls per second per app per tenant — so capacity is not your problem.

Access is. Your shop’s admin has to go into your own tenant (Settings → Integrations → API Application Access) and generate the Client ID and Secret that let an outside system in. No admin, no connection — that step belongs on the checklist before any build is priced, not discovered during it. And when the permissions (scopes) an app needs change, your tenant has to re-consent. Plan for a short admin session any time an automation expands.

A second design note worth knowing: API content reportedly cannot be cached for more than 24 hours, so automations on ServiceTitan sync fresh data rather than warehousing yours. That is fine — it just has to be designed that way from the start. Third-party apps also face ServiceTitan governance review, which adds lead time you should hear about up front.

Can automate

• Lead capture with booking write-back — New leads can flow in and appointments and tags can be written back to your board, so dispatch keeps working from one screen.
• Speed-to-Lead — Inbound leads can trigger an immediate text or call, then land in the CRM side of ServiceTitan.
• Invoice Chase / AR — The accounting family of the API gives automations a real surface for seeing what is owed and following up.
• CRM Pipeline work — Customer and job data can move between ServiceTitan and your other tools for follow-up and reporting.
• Estimate Follow-Up — Possible through the estimates API: an estimate that sits too long can trigger a nudge sequence.

Can’t automate

• Webhook-triggered workflows — plan carefully. ServiceTitan claims native webhooks, but no public event catalog exists — UNVERIFIED. Without a documented list of events, a responsible build plans triggers on API polling or a bridge app instead of promising instant event-driven automation.
• Zapier as a strong bridge — Zapier support is Works/Legacy-only, offered “not supported, as-is,” and it lacks New Job, New Customer, and New Invoice triggers. Make has a native app that can watch and create jobs and is the better bridge of the two.
• Self-serve access — There is no way around the tenant-admin step, and no connection at all if your admin will not generate credentials.

Hidden gate: The gate is a person, not a paywall. Your own ServiceTitan admin must create the API credentials inside your tenant, and re-approve whenever the app’s permissions change. Add scope changes needing tenant re-consent and undocumented webhooks (UNVERIFIED), and the honest summary is: powerful API, human door.

Build fit — what this platform supports well

• Missed-Call / After-Hours Capture and Speed-to-Lead — strong, because bookings and tags write back to the board your team already watches.
• Invoice Chase / AR — supported through the accounting side of the API.
• CRM Pipeline — supported through the CRM side of the API.
• Estimate Follow-Up — supported through the estimates API, with triggers planned on polling or a bridge rather than webhooks.
• Review Engine — no verified reviews API here either, so the ask runs on our system off the best job-completion signal available.

What this means for your shop

ServiceTitan shops tend to be the biggest in this directory, and the API matches that scale — the raw capability is not the issue. Your real project plan is about people and proof: name the admin who will generate credentials, expect a re-approval step when scopes grow, and do not let anyone sell you “instant webhook automation” that the vendor has not documented.