GoHighLevel API Guide for Contractors

One-line verdict: One of the broadest documented APIs in this directory — contacts, pipelines, estimates, invoices, even payment records — with the full OAuth version sitting on the top plan and a 5-agency wall for apps built for other shops. Openness: 4 / 5 — rated 4 because HighLevel documents a deep REST API with 50+ webhook events, held back from 5 by the plan split on its own pricing pages and the review gates on public apps.

The connection that works

Rung 1 — Direct connection. HighLevel (the product most shops know as GoHighLevel) documents a REST API on its developer portal — “access all HighLevel platform features through our REST API” — running on its LeadConnector service. Two credential patterns: a Private Integration Token for your own shop’s internal use, and OAuth 2.0 for public Marketplace apps, with access divided into per-object scopes so an app asks only for what it needs.

The verified surface, from the vendor’s own scopes reference, is unusually complete: Contacts read and write (create, update, delete, tags, notes); Opportunities — HighLevel’s pipeline object, its closest thing to a job — read and write including stage and status updates; Estimates read and write, including send and convert-to-invoice; Invoices read and write, including send, void, and record-payment; Payments read across orders, transactions, and subscriptions, with narrow writes (order fulfillment and recording a payment against an invoice or order). There is no “jobs” object — anyone mapping your world onto HighLevel does it through Opportunities. Webhooks are documented for 50+ events (ContactCreate, OpportunityStageUpdate, and kin), with an automatic circuit breaker that pauses a subscription failing too often. Rate limits are published: 100 requests per 10 seconds and 200,000 per day, per resource.

Now the two gates, both vendor-documented. HighLevel’s own pricing pages split the API: Starter and Unlimited carry “Basic API,” while OAuth 2.0 sits in the $497/mo SaaS Pro “Advanced API” tier. Its current developer docs present OAuth without repeating that split — so we publish the split as the pricing page states it, and note the docs don’t repeat it; treat your own plan’s API level as a question to confirm on your account. Second: private Marketplace apps created after November 18, 2025 can install in up to 5 Agencies — past that, installs block until the app is publicly listed (Marketplace review) or passes a Security Review.

Bridge apps: the official Zapier app is named LeadConnector (there is no Zapier app called “GoHighLevel”) — triggers like Pipeline Stage Changed, actions like Add/Update Contact and Add/Update Opportunity. No native Make app was verified.

Can automate

• Speed-to-Lead — contacts are fully writable and events fire in real time, so a new lead can be in the pipeline and in follow-up within seconds.
• Estimate Follow-Up — estimates are real API objects: create, send, and convert to invoice are all documented, the strongest estimate surface in this directory.
• Invoice Chase / AR — invoices are readable and writable and payments are readable, so balances, sends, and payment recording can all be automated.
• Pipeline-driven everything — opportunity stage and status events are documented webhooks; every stage change can start the next workflow.

Can’t automate

• General payment processing through the API — UNVERIFIED. The verified payment writes are order fulfillment and recording a payment. Charging cards or creating payments generally is not in the scopes reference — don’t let a builder quote it.
• A reputation reviews API — none exists. Trap alert: HighLevel’s only “reviews” endpoints sit under its products scopes and are for e-commerce product reviews (“Fetch Product Reviews”). For all its reputation marketing, no Google/Facebook/reputation reviews endpoint appears in the vendor’s documentation. Like every platform here: no verified reviews API.
• OAuth on any plan, as a settled fact — the pricing page gates it to SaaS Pro; the docs don’t repeat the split. Verify your plan.
• Scaling a private app past 5 agencies without Marketplace review or a Security Review — vendor policy, enforced at install.
• The old V1 API — end of support was December 31, 2025 per the vendor. Builds belong on the current API.

Hidden gate: The full API (OAuth) sits on the $497/mo SaaS Pro plan on HighLevel’s own pricing page, and an app you build for other shops hits a wall at 5 agencies unless HighLevel reviews it. Your shop’s own private token works far sooner than an agency-wide product does.

Build fit — what this platform supports well

• Speed-to-Lead — the strongest fit: real-time events plus writable contacts and pipelines.
• Estimate Follow-Up — strong: estimates are first-class, sendable, convertible API objects.
• Invoice Chase / AR — strong: invoices and payment reads are documented end to end.
• Review Engine — like every platform here, HighLevel has no verified reputation reviews API (product reviews are not reputation reviews), so the review ask runs on our system triggered by a job-completion signal — an opportunity stage change supplies it cleanly.

What this means for your shop

If your marketing already runs on HighLevel, you hold one of the deepest connection surfaces a contractor can buy — the automations most shops piece together across three tools can live on documented endpoints here. The discipline is plan math and scope: confirm which API tier your plan actually carries, and if you’re an agency reselling apps, the 5-agency wall and review process are part of your roadmap whether your pitch deck mentions them or not.