---
title: "OnePageCRM Developers"
description: "Build on OnePageCRM, the action-focused CRM — REST API, OAuth 2.1, webhooks, OQL, and an MCP server for AI agents. Guides, references, and tutorials."
canonical_url: https://developer.onepagecrm.com/
source: Markdown mirror of https://developer.onepagecrm.com/
---

Let's build your action-focused CRM, together. Integrate with OnePageCRM using
our REST API, OAuth, webhooks, and MCP server — and ship the workflows your
customers ask for.

## What you can build

**Build integrations.** Wire OnePageCRM into the rest of your stack — sync
contacts, automate follow-ups, push deals into your data warehouse.

**Automate workflows.** React to CRM events the moment they happen — webhooks
for contacts, companies, deals, actions, notes, calls, and meetings.

**Connect AI agents.** Query and update CRM data from agents and copilots via
OQL and the MCP server. Real-time, structured access.

## The surfaces

**Read and write CRM data.** A REST API for contacts, companies, deals, actions,
notes, calls, and meetings. HTTP Basic auth, JSON in, JSON out. Everything is
documented in the OpenAPI spec, and the API reference gives you copy-ready curl
for every endpoint. See <https://developer.onepagecrm.com/api/reference/>.

**React to changes in real time.** Subscribe to webhooks for created, updated,
and deleted events on every resource — plus action completions and deal status
changes. See <https://developer.onepagecrm.com/webhooks/overview/>.

**Authorize third-party apps.** OAuth 2.1 lets your app act on behalf of a
OnePageCRM user with the right scopes — authorization-code flow with PKCE and
rotating refresh tokens. See <https://developer.onepagecrm.com/oauth/overview/>.

**Build with AI.** Agent-readable docs for your AI coding assistant, and a live
MCP server that lets AI agents query and update the CRM. See
<https://developer.onepagecrm.com/build-with-ai/>.

**Ask questions of your data.** OQL is a JSON query language over all seven core
entities — filters, lookups, aggregates, and grouping, instead of paging
everything down. It runs through the MCP server. See
<https://developer.onepagecrm.com/oql/overview/>.

**Connect without a full integration.** Map records to your own system with
External ID, add a Custom Button to the contact and deal menus, or pre-fill the
Add Contact form from a link. See
<https://developer.onepagecrm.com/integrations/overview/>.

## Built for agents

Every documentation page on this site is published as clean markdown, indexed in
llms.txt and described in agents.json — so your coding assistant works from real
endpoints and real field names. Agents that need live data connect to the MCP
server and query or update the CRM through the Model Context Protocol.

- <https://developer.onepagecrm.com/llms.txt>
- <https://developer.onepagecrm.com/llms-full.txt>
- <https://developer.onepagecrm.com/.well-known/agents.json>

## Featured tutorials

- **Make your first API call** — authenticate, list your contacts, and parse the
  response in under five minutes.
  <https://developer.onepagecrm.com/tutorials/first-api-call/>
- **Subscribe to webhook events** — react to CRM changes in real time. Register a
  webhook, receive a payload, and respond correctly.
  <https://developer.onepagecrm.com/tutorials/webhooks/>
- **Query CRM data with OQL** — use OQL to read contacts, deals, actions, and
  notes with filters, aggregates, and date helpers.
  <https://developer.onepagecrm.com/tutorials/oql/>