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

# Prepare

> Prepare contract information for agreement-based payment scenarios including subscriptions.

`POST /v1/authorizations/prepare`

Prepares the contract information for agreement-based payment scenarios. Returns an `authUrl` to pass to `my.call("signContract")` in the Mini Program.

## Request Parameters

<ParamField body="referenceClientId" type="string" required>
  Merchant identifier used to distinguish different businesses.

  **Max length**: 16 characters
</ParamField>

<ParamField body="scopes" type="string" required>
  Permission scope. Value: `AGREEMENT_PAY`

  **Max length**: 16 characters
</ParamField>

<ParamField body="extendInfo" type="string">
  JSON object containing contract details.

  **Max length**: 4096 characters

  <Expandable title="extendInfo fields">
    | Field                   | Type   | Required | Max  | Description                                                                 |
    | ----------------------- | ------ | -------- | ---- | --------------------------------------------------------------------------- |
    | contractTitle           | String | M        | 64   | Title displayed on the authorization page                                   |
    | contractDesc            | String | M        | 2048 | Description shown to the user                                               |
    | agreedAmount            | Amount | O        | —    | Single transaction amount limit                                             |
    | startTime               | String | O        | —    | First deduction date (`yyyy-MM-dd` format)                                  |
    | contractStatusNotifyUrl | String | O        | —    | Webhook URL for contract status updates                                     |
    | paymentFrequency        | String | O        | —    | Deduction frequency: `DAILY`, `WEEKLY`, `MONTHLY`, `QUARTERLY`, or `YEARLY` |
    | amountType              | String | O        | —    | Amount type: `VARIABLE` or `FIXED`                                          |
    | maxAmount               | Amount | O        | —    | Maximum amount per transaction                                              |
  </Expandable>
</ParamField>

## Response Parameters

<ResponseField name="result" type="object" required>
  Standard result object with `resultCode`, `resultStatus`, `resultMessage`
</ResponseField>

<ResponseField name="authUrl" type="string">
  Authorization URL to pass to `my.call("signContract")` in the Mini Program.

  **Max length**: 256 characters
</ResponseField>

## Result Codes

| resultStatus | resultCode                    | Description                             |
| ------------ | ----------------------------- | --------------------------------------- |
| `S`          | `SUCCESS`                     | Contract prepared successfully          |
| `F`          | `PARAM_ILLEGAL`               | Invalid parameters                      |
| `F`          | `INVALID_AUTH_CLIENT`         | Invalid client ID                       |
| `F`          | `INVALID_AUTH_CLIENT_STATUS`  | Auth client status issue                |
| `F`          | `INVALID_SCOPE`               | Invalid scope value                     |
| `F`          | `AUTH_CLIENT_UNSUPPORT_SCOPE` | Client does not support requested scope |
| `F`          | `REDIRECT_URL_NOT_MATCH`      | Redirect URL is not permitted           |
| `U`          | `UNKNOWN_EXCEPTION`           | API failure                             |