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

# AS/ERP Integration: Getting Started

This section contains everything you need to build a custom integration between
Pleo and an external Accounting System (AS) or ERP.

The documentation is structured to take you from understanding the integration
model through to a complete implementation. It covers three integration levels:
**Level 1: Expense Items Exporting**, which handles the full export workflow from
job detection to completion; **Level 2: Tags Sync**, which keeps Accounting
Dimensions and their values synchronised from the AS into Pleo as Tags; and
**Level 3: Chart of Accounts Sync**, which keeps the Chart of Accounts
synchronised from the Accounting System into Pleo.

## Before You Start

Before building, you need to be onboarded as a Pleo integration partner and
have authentication configured.

Pleo supports two authentication methods:

* **OAuth 2.0:** recommended for most integrations
* **API Keys:** for integrations where OAuth is not supported

See [Connection and Authorisation](/docs/current/integration-design/auth/integration-design-auth-overview)
for setup instructions.

## How This Section Is Organised

The documentation is organised into four layers. Each layer serves a different
purpose, so knowing which to reach for depends on where you are in your work.

### Background

Start here if you are new to Pleo accounting integrations. These pages explain
the integration model, capability levels, and deployment options. Read these
before looking at any implementation detail.

* [AS/ERP Integration Overview](/docs/current/getting-started/accounting-integrations-overview): what the integration covers, integration levels, and key capabilities
* [Deployment Decisions](/docs/current/getting-started/accounting-integrations-deployment-decisions): deployment models, OAuth 2.0 setup, and infrastructure considerations

### Integration Design

These pages explain the rules and requirements for each part of the
integration. They cover what your integration must do, how to handle each
scenario, and what Pleo expects. Read these when you need to understand the
logic behind a specific topic, such as bookkeeping methods or accounts mapping.

<CardGroup cols={3}>
  <Card title="Level 1: Exports" icon="upload" href="/docs/current/integration-design/exports/integration-design-exports-overview">
    <div className="text-sm mt-2">Required for all integrations. Covers bookkeeping methods, accounts mapping, data mapping, attachments, and posting behaviour.</div>
  </Card>

  <Card title="Level 2: Tags Sync" icon="tag" href="/docs/current/integration-design/accounting-integrations/imports/tags/integration-design-tags-overview">
    <div className="text-sm mt-2">Builds on Level 1. Covers Dimension selection, Tag Group and Tag synchronisation rules, data mapping, and sync scheduling.</div>
  </Card>

  <Card title="Level 3: Chart of Accounts Sync" icon="building-columns" href="/docs/current/integration-design/accounting-integrations/imports/accounts/integration-design-accounts-overview">
    <div className="text-sm mt-2">Covers Chart of Accounts synchronisation rules, reconciliation logic, data mapping, and sync scheduling.</div>
  </Card>
</CardGroup>

### Guides

Guides map the end-to-end workflow for each integration level. They are not
implementation references. Their purpose is to show you the complete sequence
of steps, why each step exists, and what the inputs and outputs are at each
stage. Read the relevant guide before writing code so you understand how
everything connects.

#### Level 1: Expense Items Exporting

Two guides work together to cover the full export workflow. Use them as a pair.

<CardGroup cols={2}>
  <Card title="Export Integration Workflow Guide" icon="route" href="/docs/current/guides/export-integration-workflow-guide">
    <div className="text-sm mt-2">The Pleo API side: detecting and starting Export Jobs, retrieving items, updating item statuses, and completing the job.</div>
  </Card>

  <Card title="AS/ERP Processing Workflow Guide" icon="server" href="/docs/current/guides/accounting-system-processing-workflow-guide">
    <div className="text-sm mt-2">The AS/ERP side: bookkeeping method resolution, accounts mapping, data mapping, attachments, and posting behaviour.</div>
  </Card>
</CardGroup>

#### Level 2: Tags Sync

<CardGroup cols={2}>
  <Card title="Tags Sync Workflow Guide" icon="tag" href="/docs/current/guides/accounting-integrations/imports/tags-sync-workflow-guide">
    <div className="text-sm mt-2">The full Tags Sync cycle: selecting Dimensions, syncing Tag Groups with Dimensions, and syncing Tags with Dimension Values.</div>
  </Card>
</CardGroup>

#### Level 3: Chart of Accounts Sync

<CardGroup cols={2}>
  <Card title="Chart of Accounts Sync Workflow Guide" icon="building-columns" href="/docs/current/guides/accounting-integrations/imports/accounts-sync-workflow-guide">
    <div className="text-sm mt-2">The full Chart of Accounts Sync cycle: fetching active accounts from the Accounting System, reconciling against Pleo, and applying all required changes.</div>
  </Card>
</CardGroup>

### How-to Articles

Each step in the workflow guides links to a corresponding how-to article. The
how-to articles are where the implementation detail lives. Each one covers a
single step and includes:

* step-by-step instructions
* example API requests with curl
* pseudo code explaining the checks and logic
* links to the relevant API reference endpoints

Reach for a how-to article when you are ready to implement a specific step and
need the API calls, request and response examples, and code-level guidance.

## Recommended Reading Order

If you are starting from scratch, follow the steps below. Complete each level in order before moving to the next.

#### Level 1: Expense Items Exporting

<CardGroup cols={3}>
  <Card title="1. Background" icon="book-open" href="/docs/current/getting-started/accounting-integrations-overview">
    <div className="text-sm mt-2">Read the Overview and Deployment Decisions to understand the integration model and capability levels.</div>
  </Card>

  <Card title="2. Authentication" icon="key" href="/docs/current/integration-design/auth/integration-design-auth-overview">
    <div className="text-sm mt-2">Configure OAuth 2.0 or API Keys before you start building.</div>
  </Card>

  <Card title="3. Integration Design" icon="ruler" href="/docs/current/integration-design/exports/integration-design-exports-overview">
    <div className="text-sm mt-2">Work through the Exports Integration Design pages for the rules behind each topic.</div>
  </Card>

  <Card title="4. Workflow Guides" icon="map" href="/docs/current/guides/export-integration-workflow-guide">
    <div className="text-sm mt-2">Read the Export Integration and AS/ERP Processing guides as a pair to understand the full sequence.</div>
  </Card>

  <Card title="5. Implement" icon="code" href="/docs/current/how-tos/accounting-integrations/how-to-queue-export-items-in-ui">
    <div className="text-sm mt-2">Use the how-to articles linked from each guide step when you are ready to build.</div>
  </Card>
</CardGroup>

#### Level 2: Tags Sync

<CardGroup cols={3}>
  <Card title="6. Integration Design" icon="ruler" href="/docs/current/integration-design/accounting-integrations/imports/tags/integration-design-tags-overview">
    <div className="text-sm mt-2">Work through the Tags Sync Integration Design pages for Dimension selection and sync rules.</div>
  </Card>

  <Card title="7. Workflow Guide" icon="map" href="/docs/current/guides/accounting-integrations/imports/tags-sync-workflow-guide">
    <div className="text-sm mt-2">Read the Tags Sync Workflow Guide to understand the full sync sequence.</div>
  </Card>

  <Card title="8. Implement" icon="code" href="/docs/current/how-tos/accounting-integrations/imports/tags/how-to-select-dimensions-for-tags-sync">
    <div className="text-sm mt-2">Use the how-to articles linked from the guide when you are ready to build.</div>
  </Card>
</CardGroup>

#### Level 3: Chart of Accounts Sync

<CardGroup cols={3}>
  <Card title="9. Integration Design" icon="ruler" href="/docs/current/integration-design/accounting-integrations/imports/accounts/integration-design-accounts-overview">
    <div className="text-sm mt-2">Work through the Chart of Accounts Sync Integration Design pages for the rules behind each topic.</div>
  </Card>

  <Card title="10. Workflow Guide" icon="map" href="/docs/current/guides/accounting-integrations/imports/accounts-sync-workflow-guide">
    <div className="text-sm mt-2">Read the Chart of Accounts Sync Workflow Guide to understand the full sync sequence.</div>
  </Card>

  <Card title="11. Implement" icon="code" href="/docs/current/how-tos/accounting-integrations/imports/accounts/how-to-sync-accounts">
    <div className="text-sm mt-2">Use the how-to articles linked from the guide when you are ready to build.</div>
  </Card>
</CardGroup>