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

# SDK overview

> Choose the official Biqli SDK for browser or server tracking.

Biqli provides separate SDKs for public browser tracking and trusted server tracking.

<CardGroup cols={3}>
  <Card title="Browser SDK" icon="browser" href="/docs/api-reference/sdks/browser">
    Use `@biqli/analytics` with a publishable key in HTML or React.
  </Card>

  <Card title="TypeScript SDK" icon="node-js" href="/docs/api-reference/sdks/typescript">
    Use `@biqli/sdk` on Node.js 18 or newer with a secret API key.
  </Card>

  <Card title="PHP SDK" icon="php" href="/docs/api-reference/sdks/php">
    Use `biqli/sdk` on PHP 8.1 or newer with a secret API key.
  </Card>
</CardGroup>

## Choose by runtime

| Runtime                                      | Package                                  | Credential                     |
| :------------------------------------------- | :--------------------------------------- | :----------------------------- |
| Browser JavaScript                           | `@biqli/analytics`                       | `biqli_pk_...` publishable key |
| React client component                       | `@biqli/analytics/react`                 | `biqli_pk_...` publishable key |
| Plain script tag                             | `https://biq.li/sdk/dist/auto.global.js` | `biqli_pk_...` publishable key |
| Node.js, Next.js server, React Router server | `@biqli/sdk`                             | `biqli_...` secret API key     |
| PHP or Laravel                               | `biqli/sdk`                              | `biqli_...` secret API key     |
| Other server languages                       | REST API                                 | `biqli_...` secret API key     |

<Warning>
  Never substitute one credential type for the other. The server SDKs reject browser use, and the browser SDK rejects secret API keys.
</Warning>

## SDKs versus endpoint reference

SDKs provide typed inputs, request IDs, idempotency handling, structured errors, and bounded retries. Endpoint pages define the wire-level JSON contract and remain the source of truth for field validation.

* Follow [Developer Docs](/developers/introduction) for tutorials and architecture.
* Use [Track a lead](/docs/api-reference/conversions/track-lead) and [Track a sale](/docs/api-reference/conversions/track-sale) for complete server request fields.
* Use [API authentication](/docs/api-reference/authentication) for permissions and key lifecycle.