> ## Documentation Index
> Fetch the complete documentation index at: https://docs.stackone.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Unified CRM API

> Unified CRM API for customer relationship management across platforms, with consistent data models for contacts, accounts, and sales workflows.

## What is a Unified API?

A **unified API** provides a single, standardized interface to interact with multiple third-party providers. Instead of learning each provider's unique API format, authentication scheme, and data model, you write code once, and StackOne handles the differences.

**What StackOne normalizes:**

* **Data models** – Consistent field names and structures across providers (e.g., `files` in Google Drive, SharePoint, and Dropbox all return the same schema; `users` in Google Workspace, Okta, and 1Password all return the same schema)
* **Authentication** – OAuth, API keys, and tokens are managed per-provider; you just pass an `x-account-id` header
* **Pagination** – Cursor-based pagination works the same regardless of whether the provider uses offsets, pages, or cursors
* **Error formats** – Standardized error responses with provider-specific details when available

<Tip>
  **Building AI agents?** Use the [MCP Server](/mcp/quickstart), an [AI Toolset SDK](/agents/typescript/introduction), or the [Actions API (RPC)](/platform/api-reference/actions/make-an-rpc-call-to-an-action) instead — same data, optimized for LLM tool calling.
</Tip>

## Benefits of the CRM API

<AccordionGroup>
  <Accordion title="Unified Contact and Account Management" defaultOpen={false}>
    Manage customer contacts and accounts through a single standardized API, regardless of the underlying CRM platforms, ensuring a consistent view of customer data.
  </Accordion>

  <Accordion title="Real-Time Data Synchronization">
    StackOne's APIs support real-time data polling, allowing for immediate updates and synchronization across platforms.
  </Accordion>

  <Accordion title="Privacy-First Design Ensuring Compliance">
    With a [focus on security](https://www.stackone.com/blog/why-your-choice-of-unified-api-could-make-or-break-compliance), StackOne's architecture avoids unnecessary data storage, maintaining compliance with data protection regulations.
  </Accordion>

  <Accordion title="Synthetic and Native Webhooks for Updates">
    The platform provides both [synthetic and native webhooks](/guides/webhooks), enabling real-time notifications for customer and opportunity changes.
  </Accordion>
</AccordionGroup>

## Key Features

The table below shows key features of the CRM API that make customer relationship management easier, from real-time contact tracking to opportunity management:

| **Feature**                      | **Description**                                                                                                        |
| -------------------------------- | ---------------------------------------------------------------------------------------------------------------------- |
| Comprehensive Contact Management | Easily create, update, and retrieve customer profiles, including contact details, interaction history, and engagement. |
| Real-Time Data Synchronization   | Ensure that customer information, sales opportunities, and interactions are updated across systems instantly.          |
| Real-Time Webhooks               | Receive instant notifications for changes in customer profiles, opportunities, or lead statuses.                       |

## StackOne SDKs & OpenAPI Specification

<p class="sdk-text">Use our official SDKs for faster integration. Build with language-native libraries. Full list [here](/guides/stackone-api-sdks).</p>

<CardGroup cols={2}>
  <Card title="OpenAPI Specification" icon="link" href="https://api.eu1.stackone.com/oas/crm.json" arrow="true" cta="Click here" />

  <Card title="Popular SDKs" icon="download" class="sdk-card">
    [Node.js](https://www.npmjs.com/package/@stackone/stackone-client-ts)
    [Java (JVM)](https://mvnrepository.com/artifact/com.stackone/stackone-client-java)
    [PHP](https://packagist.org/packages/stackone/client-sdk)
    [Ruby](https://rubygems.org/gems/stackone_client)
  </Card>
</CardGroup>

## Entity Model and Relationships

The following diagram illustrates the key entities within the CRM API:

```mermaid theme={null}
erDiagram
    Contact ||--o{ Account : ""
    List }o--o{ Contact : ""
    List }o--o{ Account : ""

    Contact {
        string id
        string remote_id
        string name
        string address
        string communicationPreferences
        string email
        string phoneNumber
    }

    Account {
        string id
        string status
        string transactionHistory
        date createdAt
        date updatedAt
    }

    List {
        string id
        string name
        string type
        date createdAt
        date updatedAt
    }

```

The following table outlines key entities within the CRM system and provides a brief description of each.

| Entity   | Description                                                                                                              |
| -------- | ------------------------------------------------------------------------------------------------------------------------ |
| Contacts | Manages individual contact details, including names, addresses, and communication preferences.                           |
| Accounts | Handles organizational accounts, encompassing details like account status, associated contacts, and transaction history. |
| Lists    | Manage your custom data lists across your service providers.                                                             |