> ## 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.

# OpenAPI Overview

> Introduction to the Rebell OpenAPI platform, message structure, and developer workflow.

Mini programs provide a comprehensive set of OpenAPIs enabling developers to integrate various capabilities including payments, user authorization, and messaging. Communication occurs via HTTPS POST requests with structured request/response patterns.

## API Version

* **Current Version**: v1
* **URL Format**: `https://{domainName}/v1/{endpoint}`

<Note>
  Different API versions represent distinct interfaces. Ensure you use the correct version for your integration.
</Note>

## Message Structure

### Request Components

All API requests follow this structure:

| Component          | Description                              |
| ------------------ | ---------------------------------------- |
| **URL**            | `https://{domainName}/v1/{endpoint}`     |
| **Method**         | POST (HTTPS)                             |
| **Authentication** | SHA256withRSA digital signature required |

### Required Headers

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

<ParamField header="Client-Id" type="string" required>
  Your assigned client identifier, used to identify your application and associated keys
</ParamField>

<ParamField header="Request-Time" type="string" required>
  ISO 8601 timestamp with minimum second accuracy (e.g., `2024-01-10T12:00:00+01:00`)
</ParamField>

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

### Response Structure

All responses include a standardized `result` object:

```json theme={null}
{
  "result": {
    "resultStatus": "S",
    "resultCode": "SUCCESS",
    "resultMessage": "Success"
  },
  // ... additional response fields
}
```

<ResponseField name="result.resultStatus" type="string" required>
  Status indicator:

  * `S` - Success
  * `F` - Failed
  * `U` - Unknown
  * `A` - Accepted (processing)
</ResponseField>

<ResponseField name="result.resultCode" type="string">
  Error or success code (max 64 characters)
</ResponseField>

<ResponseField name="result.resultMessage" type="string">
  Detailed description of the result (max 256 characters)
</ResponseField>

## Developer Workflow

<Steps>
  <Step title="Understand Requirements">
    Review API idempotency requirements and authentication specifications
  </Step>

  <Step title="Generate Keys">
    Create a 2048-bit RSA key pair for signing requests
  </Step>

  <Step title="Construct Request">
    Build signed, encoded requests per the message structure specification
  </Step>

  <Step title="Send Request">
    Submit HTTPS POST requests to the appropriate endpoint
  </Step>

  <Step title="Validate Response">
    Verify the response signature using the platform's public key
  </Step>

  <Step title="Handle Result">
    Process result codes and implement appropriate error handling
  </Step>
</Steps>

## Security Requirements

<CardGroup cols={2}>
  <Card title="Request Signing" icon="signature">
    All requests must be digitally signed using RSA-SHA256
  </Card>

  <Card title="Response Validation" icon="shield-check">
    Always verify response signatures before processing data
  </Card>

  <Card title="Key Management" icon="key">
    Use 2048-bit RSA keys exclusively for the SHA256withRSA algorithm
  </Card>

  <Card title="Message Encoding" icon="code">
    Proper encoding prevents character ambiguities during transmission
  </Card>
</CardGroup>

## Next Steps

<CardGroup cols={2}>
  <Card title="Idempotency" icon="repeat" href="/openapis/idempotency">
    Learn how to handle retries safely
  </Card>

  <Card title="Message Encoding" icon="binary" href="/openapis/message-encoding">
    Understand encoding requirements
  </Card>

  <Card title="API Signing" icon="pen" href="/openapis/message-transmission-security/call-api">
    Step-by-step signing guide
  </Card>

  <Card title="Data Dictionary" icon="book" href="/openapis/data-dictionary">
    Common data types and models
  </Card>
</CardGroup>