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

# Common concepts and parameters

> Flow, environments, and objects shared by the Android and iOS SDKs.

## SDK flow

<Steps>
  <Step title="Build the request">
    Configure the operation, currency, billing data, and optional features.
  </Step>

  <Step title="Select the environment">
    Use Development during integration and switch to Production only after certification.
  </Step>

  <Step title="Authorize">
    The SDK runs risk assessment, 3DS authentication when applicable, and authorization.
  </Step>

  <Step title="Process the response">
    Observe internal actions and update the order only from the final response.
  </Step>
</Steps>

## Integration environment

* Available 24 hours a day, Monday through Sunday.
* Support from 09:00 to 18:00 on business days.
* Times are expressed in Peru time, GMT-5.
* Test results must be sent to the responsible integration specialists.

## `PaymeRequest` structure

| Object                     | Use                                                            | Required |
| -------------------------- | -------------------------------------------------------------- | -------- |
| `setting`                  | Language and brands displayed in the form.                     | Yes      |
| `merchant` / purchase data | Operation, amount, currency, billing, and shipping.            | Yes      |
| `feature`                  | Wallet, installments, 3DS authentication, and reserved fields. | No       |

### Settings

* `locale`: `es_PE` or `en_US`.
* `brands`: `VISA`, `MSCD`, `AMEX`, and `DINC`, according to merchant configuration.

### Operation

| Field                  | Rule                                                                        |
| ---------------------- | --------------------------------------------------------------------------- |
| `operationNumber`      | Unique 6-character identifier.                                              |
| `operationDescription` | Description up to 30 characters.                                            |
| `amount`               | String with a decimal point and no more than two decimals, such as `10.55`. |
| `currency.code`        | 3-digit ISO-4217 code.                                                      |
| `currency.symbol`      | Display symbol up to 5 characters; it does not affect the transaction.      |

### Person data

`PaymePersonData` contains first name, last name, email, address, alphabetic and numeric country codes, ZIP code, city, state, and mobile phone. `addrLine2`, home phone, and work phone are optional.

### Optional features

* `reserved`: additional merchant data.
* `wallet`: Wallet must be enabled; `userID` is required when `enable` is `true`.
* `installments`: enables plans and installments configured for the merchant.
* `authentication.tdsChallengeInd`: 3DS preference (`01` no preference, `02` no challenge, `03` challenge preferred, `04` challenge required).

<Warning>
  Enable Wallet, installments, or 3DS only when the corresponding service is configured for the merchant. Never include the merchant Key in source control or diagnostic logs.
</Warning>

[Continue to responses and errors →](/en/sdk/responses-and-errors)