> ## 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.

# OAuth Token

> Obtain access tokens for server-to-server API calls using OAuth 2.0 Client Credentials.

`POST /v1/authorizations/token`

Obtains access tokens for server-to-server API calls using the OAuth 2.0 Client Credentials grant type.

## Required Headers

<ParamField header="Authorization" type="string" required>
  Basic authentication in the format: `Basic Base64(client_id:client_secret)`
</ParamField>

<ParamField header="Signature" type="string" required>
  SHA256withRSA algorithm signature: `algorithm=SHA256withRSA, keyVersion=1, signature=****`
</ParamField>

<ParamField header="Client-Id" type="string" required>
  Identifier provided by A+ (e.g., `2022091495540562874792`)
</ParamField>

<ParamField header="Request-Time" type="string" required>
  RFC3339 formatted timestamp accurate to seconds
</ParamField>

<ParamField header="Content-Type" type="string">
  `application/json; charset=UTF-8`
</ParamField>

## Request Parameters

<ParamField body="grantType" type="string" required>
  Fixed value: `client_credentials`
</ParamField>

<ParamField body="scope" type="string">
  Permission scope. Use `openid` for Mini Program scenarios.
</ParamField>

## Response Parameters

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

<ResponseField name="responseTime" type="string">
  13-digit millisecond timestamp of the response.
</ResponseField>

<ResponseField name="accessToken" type="string">
  Bearer token for subsequent API calls.
</ResponseField>

<ResponseField name="tokenType" type="string">
  Always `Bearer`.
</ResponseField>

<ResponseField name="expiresIn" type="number">
  Token validity period in seconds.
</ResponseField>

<ResponseField name="scope" type="string">
  Granted permission scopes.
</ResponseField>

## Result Codes

| resultStatus | resultCode               | Description                             |
| ------------ | ------------------------ | --------------------------------------- |
| `S`          | `SUCCESS`                | Request successful                      |
| `F`          | `PARAM_ILLEGAL`          | Missing or invalid required parameter   |
| `F`          | `INVALID_AUTH_CLIENT`    | Client authentication failed            |
| `F`          | `UNSUPPORTED_GRANT_TYPE` | Unsupported `grantType` value           |
| `F`          | `ACCESS_DENIED`          | Missing or invalid authorization header |
| `F`          | `INVALID_SCOPE`          | Invalid scope value                     |
| `U`          | `UNKNOWN_EXCEPTION`      | Server error occurred                   |