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

# API Overview

> Base URL, authentication, errors, and versioning for the OpenContract API.

## Base URL

```
https://api.opencontract.io/v1
```

## Authentication

Include your API key as a bearer token in every request:

```bash theme={null}
curl https://api.opencontract.io/v1/contracts \
  -H "Authorization: Bearer <YOUR_API_KEY>"
```

## Request Format

All request bodies must be JSON. Set the `Content-Type` header accordingly:

```
Content-Type: application/json
```

## Response Format

All responses return JSON with a consistent envelope:

```json theme={null}
{
  "data": { ... },
  "meta": {
    "requestId": "req_abc123",
    "timestamp": "2026-06-02T00:00:00Z"
  }
}
```

## Error Codes

| Status | Code              | Description                          |
| ------ | ----------------- | ------------------------------------ |
| 400    | `invalid_request` | Missing or malformed parameters      |
| 401    | `unauthorized`    | Invalid or missing API key           |
| 404    | `not_found`       | Resource does not exist              |
| 409    | `conflict`        | Bid too low or auction already ended |
| 429    | `rate_limited`    | Too many requests                    |
| 500    | `internal_error`  | Server-side error                    |

Error responses follow this shape:

```json theme={null}
{
  "error": {
    "code": "invalid_request",
    "message": "reservePrice must be a positive number"
  }
}
```

## Rate Limits

| Plan       | Requests / minute |
| ---------- | ----------------- |
| Free       | 60                |
| Pro        | 600               |
| Enterprise | Unlimited         |