> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lab4pay.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Terminal Pairing

Pairing establishes a trusted connection between your integration and a payment terminal.

<Warning>
  **Pairing is mandatory for all Pay-Connect integrations** before you can process any transactions.
</Warning>

## Pairing Principles

<Columns cols={2}>
  <Card icon="sparkles" title="Backend Initialization">
    Pairing is initialized only via backend APIs for security and control.
  </Card>

  <Card icon="sparkles" title="One-Time Code Required">
    Pairing requires a one-time code (OTP) generated on the terminal or provided by support team.
  </Card>

  <Card icon="sparkles" title="One-Time Setup">
    Each terminal is paired once per integration and environment.
  </Card>

  <Card icon="sparkles" title="Enables Transactions">
    Pairing enables all subsequent transaction operations on the terminal.
  </Card>
</Columns>

## Pairing High-Level flow

<Steps>
  <Step title="Generate OTP">
    The one-time pairing code (OTP) is:

    * Generated directly on the terminal, or
    * Provided by the support team
  </Step>

  <Step title="Initialize Pairing">
    Your backend submits the OTP to the Pay-Connect Pairing API to start the pairing process.
  </Step>

  <Step title="Terminal Ready">
    Once pairing is completed successfully, the terminal is connected and ready to process transactions.
  </Step>
</Steps>

<Check>
  After successful pairing, your terminal will remain paired unless explicitly unpaired or reset.
</Check>

## Pairing and App2App Integration

<Warning>
  **Important**

  Although App2App communication happens directly between applications, **pairing is still initialized by the backend**.

  App2App flows rely on an already paired terminal and do not perform pairing independently.
</Warning>

### Building an Android application?

Continue with the [**App2App Integration**](/pay-connect/app2app-integration/introduction) section after completing terminal pairing.