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

# API keys

> Create an API key and make your first authenticated request

This guide walks you through creating an API key and using it to authenticate requests to the Kernel API.

## Create an API key

1. Open the [Kernel app](https://app.kernel.ai) and navigate to **Settings > API keys**
2. Click **Create key** — optionally name it (e.g. "Production API")
3. Copy the **key value** and **signing secret** — both are shown only once

<Tip>
  Save your key and signing secret somewhere secure, like a password manager or environment variable. You will not be able to see them again.
</Tip>

## Authenticate a request

Pass the key in the `x-api-key` header of every API request:

```bash curl theme={null}
curl -X POST https://api.kernel.ai/rest/v1/entity-resolution \
  -H "x-api-key: $KERNEL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"legal_name": "Stripe"}'
```

For full authentication details, see [API keys](/api-reference/endpoint/api-keys).

## What is the signing secret?

The signing secret (prefixed with `whsec_`) lets you verify that webhook payloads were sent by Kernel. It is different from your API key — the API key authenticates requests **to** Kernel, while the signing secret verifies that webhooks are **from** Kernel.

To learn how to verify webhook signatures, see [Webhooks](/api-reference/endpoint/webhooks).

## Next steps

<CardGroup cols={2}>
  <Card title="Resolve an entity" icon="search" href="/guides/quickstart">
    Submit a company and get back its resolved identity.
  </Card>

  <Card title="API reference" icon="book" href="/api-reference/introduction">
    Full endpoint documentation, authentication, and error handling.
  </Card>
</CardGroup>