Jonathon's AI Wiki

API Endpoints Overview

5 min read

Source: ai-research/ghl-2026-05-01/docs.md, ai-research/ghl-2026-05-01/docs-ghl-contacts-contacts.md, ai-research/ghl-2026-05-01/docs-ghl-conversations-conversations.md, ai-research/ghl-2026-05-01/docs-ghl-calendars-calendars.md, ai-research/ghl-2026-05-01/docs-ghl-opportunities-opportunities.md, ai-research/ghl-2026-05-01/docs-ghl-payments-integrations.md

This is the orientation map for HighLevel’s V2 REST API: the families of endpoints, what each one covers, and where to look in the official docs. Use it as the entry point when you know what you want to do but not which API family owns it. The official endpoint reference is the source of truth at https://marketplace.gohighlevel.com/docs/.

Key Takeaways

  • Six core families. Contacts, Conversations, Calendars, Opportunities, Payments, and Webhooks make up the primary surface developers reach for. The full V2 surface is much larger — see the full module list below.
  • Base URL: https://services.leadconnectorhq.com. All authenticated calls hit this host with Authorization: Bearer <token> and (where required) Version: 2021-07-28.
  • Endpoint reference is hosted on the Developer Marketplace at https://marketplace.gohighlevel.com/docs/. The legacy Stoplight documentation is being deprecated.
  • Versioned per resource. The reference docs are tagged with versions like 2023-02-21, 2021-07-28, 2021-04-15. New work targets the latest version; older versions are pinned for legacy callers.
  • Marketplace app token is required for some payment endpoints (specifically Create White-label Integration Provider).
  • The full V2 surface includes OAuth 2.0, Ad Manager, Affiliate Manager, AI Agent Studio, Associations, Blogs, Brand Boards, Business, Calendars, Campaigns, Companies, Contacts, Conversation AI, Conversations, Courses, Custom Fields V2, Custom Menus, LC Email, Email, Forms, Funnels, Invoice, Knowledge Base, Trigger Links, Sub-Account (formerly Location), Developer Marketplace, Media Storage, Objects, Opportunities, Payments, Phone System, Products, Proposals, SaaS, Snapshots, Social Planner, Store, Surveys, Users, Voice AI, Workflows.

Contacts API

CRM core. Manage contacts, leads, and customer data with full CRUD plus tagging, custom fields, and bulk operations.

Key operations:

  • Contacts — Get, Create, Update, Delete, Upsert, Get Contacts, Get Contacts By BusinessId
  • Tasks, Appointments, Tags, Notes, Campaigns, Workflow — sub-resources on a contact
  • Bulk — batch operations
  • Search — query contacts
  • Followers — manage follower relationships

Notable behavior. The Upsert API respects the location-level “Allow Duplicate Contact” setting. If both Email and Phone are configured for duplicate detection, upsert checks the priority sequence defined in the setting. If two existing contacts match (one by email, one by phone), the API updates the contact matching the first field in the configured sequence and ignores the second to prevent further duplication.

Docs: https://marketplace.gohighlevel.com/docs/ghl/contacts/contacts

Conversations API

Multi-channel messaging — SMS, email, calls. Send messages, manage threads, track conversations across channels.

Key operations:

  • Conversations — Get, Create, Update, Delete (by conversation ID)
  • Search — find conversations
  • Email — email-specific operations
  • Messages — message-level operations including the inbound-message endpoint covered in Conversations API: Add Inbound Message
  • Providers — custom conversation providers (paired with ProviderOutboundMessage webhook)

Docs: https://marketplace.gohighlevel.com/docs/ghl/conversations/conversations

Calendars API

Scheduling and bookings. The most operation-rich family — many sub-resources beyond the core CRUD.

Key operations:

  • Calendars — Get Free Slots, Get/Create/Update/Delete Calendar, Get Calendars (location-wide)
  • Calendar Groups — group multiple calendars
  • Service Bookings, Services, Service Locations — service-based scheduling
  • Calendar Events — event-level operations
  • Appointment Notes — notes on appointments
  • Calendar Resources: Rooms & Equipments — resource booking
  • Calendar Notifications — notification config
  • Availability — availability windows

Notable special endpoint: Get Free Slots returns available time windows for a calendar between a date range, optionally filtered by timezone and user — this is the endpoint a booking widget calls.

Docs: https://marketplace.gohighlevel.com/docs/ghl/calendars/calendars

Opportunities API

Sales pipeline. Manage deals, stages, status, and pipeline structure.

Key operations:

  • Opportunities — Get, Create, Update, Delete, Upsert, Update Status (status as a separate operation from full update)
  • Search — query opportunities
  • Pipelines — pipeline definitions
  • Lost reason — manage lost-reason values
  • Followers — follower relationships on opportunities

Docs: https://marketplace.gohighlevel.com/docs/ghl/opportunities/opportunities

Payments API

Payment processing, subscriptions, and white-label payment integrations.

Key operations called out in the docs:

  • Create White-label Integration Provider — adds a new payment provider built on top of Authorize.net or NMI. Can only be invoked using a Marketplace-app token.
  • List White-label Integration Providers — paginated list of integration providers, filterable by name.

Docs: https://marketplace.gohighlevel.com/docs/ghl/payments/integrations

Webhooks

50+ real-time event webhooks for state changes across the platform. Webhooks have their own dedicated article — see Webhooks for the full event list, the Webhook Logs Dashboard, and the integration guide.

Docs: https://marketplace.gohighlevel.com/docs/category/webhook

Quick Start

The official Quick Start is four steps:

  1. Choose Integration Type — Marketplace app or Private integration.
  2. Set Up Authentication — OAuth 2.0 or Private Integration Token.
  3. Make Your First API Call — use the interactive docs.
  4. Build & Deploy — leverage SDKs and code examples.

Example first call from the official docs:

curl -X GET \
  https://services.leadconnectorhq.com/contacts/ \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -H "Content-Type: application/json"

Try It

  1. Pick the API family that owns the resource you need (Contacts for CRM, Conversations for messaging, Calendars for scheduling, Opportunities for pipeline, Payments for billing).
  2. Open the family’s docs URL and find the specific endpoint.
  3. Decide auth method: PIT for single-location, OAuth for multi-location/Marketplace.
  4. For working request examples that have already been validated, cross-reference GoHighLevel API Guide.
  5. Subscribe to the relevant webhook events — see Webhooks — so your client stays in sync with state changes instead of polling.

Graph View

Backlinks