# API Integration Guide

Integrate third-party APIs with Provisioning infrastructure.

## API Client Development

Create clients for external APIs:

```rust
// src/api_client.rs
use reqwest::Client;

pub struct ApiClient {
    endpoint: String,
    api_key: String,
    client: Client,
}

impl ApiClient {
    pub async fn call(&self, path: &str) -> Result<Response> {
        let url = format!("{}{}", self.endpoint, path);
        self.client
            .get(&url)
            .bearer_auth(&self.api_key)
            .send()
            .await
    }
}
```

## Webhook Integration

Handle webhooks from external systems:

```rust
#[post("/webhooks/{service}")]
pub async fn handle_webhook(path: web::Path<String>, body: web::Bytes) -> impl Responder {
    let service = path.into_inner();
    match service.as_str() {
        "github" => handle_github_webhook(&body),
        "stripe" => handle_stripe_webhook(&body),
        _ => HttpResponse::NotFound().finish(),
    }
}
```

## Error Handling

Robust error handling for API calls with retries:

```rust
pub async fn call_api_with_retry(
    client: &ApiClient,
    path: &str,
    max_retries: u32,
) -> Result<Response> {
    for attempt in 0..max_retries {
        match client.call(path).await {
            Ok(response) => return Ok(response),
            Err(e) if attempt < max_retries - 1 => {
                let delay = Duration::from_secs(2_u64.pow(attempt));
                tokio::time::sleep(delay).await;
            }
            Err(e) => return Err(e),
        }
    }
    Err(ApiError::MaxRetriesExceeded.into())
}
```

## Related Documentation

- [Extension Development](./extension-development.md)
- [REST API Reference](../api-reference/rest-api.md)
