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

# SDK configuration

> Configure the VulcxSDK client: pass your API key and base URL, tune timeout and retry/backoff behavior, and point it at a self-hosted Vulcx instance.

## `SDKConfig`

Pass a config object to the `VulcxSDK` constructor:

```typescript theme={"theme":"github-dark"}
import { VulcxSDK } from "@vulcx/sdk";

const sdk = new VulcxSDK({
  apiKey: "vulcx_your_api_key",
  baseUrl: "https://api.vulcx.xyz",
  timeout: 30000,
  retries: 2,
});
```

***

## Options

| Option    | Type     | Default                   | Required | Description                                                                                                 |
| --------- | -------- | ------------------------- | -------- | ----------------------------------------------------------------------------------------------------------- |
| `apiKey`  | `string` | --                        | yes      | Your Vulcx API key. Sent as `Authorization: Bearer <apiKey>`.                                               |
| `baseUrl` | `string` | `"https://api.vulcx.xyz"` | no       | API base URL. Trailing slashes are stripped automatically.                                                  |
| `timeout` | `number` | `30000`                   | no       | Per-request timeout in milliseconds. Uses `AbortController`.                                                |
| `retries` | `number` | `2`                       | no       | Number of retry attempts for retryable errors (429, 5xx, network failures). Total attempts = `retries + 1`. |

***

## Retry Behavior

The SDK retries automatically on transient failures:

| Condition               | Retried | Backoff                               |
| ----------------------- | ------- | ------------------------------------- |
| HTTP 429 (rate limit)   | yes     | Exponential: 1s, 2s, 4s, ... (max 8s) |
| HTTP 5xx (server error) | yes     | Exponential: 1s, 2s, 4s, ... (max 8s) |
| Network error / timeout | yes     | Exponential: 1s, 2s, 4s, ... (max 8s) |
| HTTP 400 (bad request)  | no      | --                                    |
| HTTP 401/403 (auth)     | no      | --                                    |
| HTTP 404 (no route)     | no      | --                                    |

With the default `retries: 2`, the SDK makes up to 3 attempts before throwing.

***

## Self-Hosted API

If you run your own route-engine instance, point the SDK at it:

```typescript theme={"theme":"github-dark"}
const sdk = new VulcxSDK({
  apiKey: "any-value",
  baseUrl: "http://localhost:8080",
});
```


## Related topics

- [SDK quickstart](/sdk/quickstart.md)
- [Self-hosted](/get-started/self-hosted.md)
- [sdk.instructions()](/sdk/instructions.md)
- [sdk.swap()](/sdk/swap.md)
- [sdk.quote()](/sdk/quote.md)