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

# API keys

> Create an API key in Seamless and authenticate REST API requests with the Token header.

Use an API key when you want the fastest path to calling the REST API — scripts, Postman, server backends, and most first integrations start here.

<Note>
  The **Public API** menu appears only if your account has Public API access. If you do not see it, contact your Seamless administrator or [support](https://seamless.ai/customers/education).
</Note>

## Create an API key

<Steps>
  <Step title="Open Public API settings">
    Sign in at [login.seamless.ai](https://login.seamless.ai), go to **Settings → Public API**, open the **API Key** tab, and click **Create New Connection**.
  </Step>

  <Step title="Copy the key">
    Copy the key value immediately. Store it in a password manager or secrets manager — treat it like a password.
  </Step>

  <Step title="Send it on every request">
    Pass the key in the `Token` header on every authenticated request to `https://api.seamless.ai/api/client/v1`.
  </Step>
</Steps>

```bash theme={null}
curl -X POST "https://api.seamless.ai/api/client/v1/search/companies" \
  -H "Content-Type: application/json" \
  -H "Token: $SEAMLESS_API_KEY" \
  -d '{"companyName": ["Acme Corp"], "limit": 5}'
```

## API key vs OAuth

|            | API key                                  | OAuth 2.0                                        |
| ---------- | ---------------------------------------- | ------------------------------------------------ |
| Best for   | Scripts, Postman, single-tenant backends | Multi-user apps that sign users in with Seamless |
| Header     | `Token: YOUR_API_KEY`                    | `Authorization: Bearer ACCESS_TOKEN`             |
| Setup time | Minutes                                  | Register client + authorization flow             |

For user-facing apps, use [OAuth](/authentication/oauth). For everything else, an API key is usually enough.

## Next steps

<CardGroup cols={2}>
  <Card title="First API request" icon="rocket" href="/authenticate-and-make-your-first-request">
    Search, research, and poll in one runnable tutorial.
  </Card>

  <Card title="Try in Postman" icon="play" href="/explore-with-postman">
    Import the OpenAPI spec and run requests without writing code.
  </Card>

  <Card title="MCP for AI agents" icon="robot" href="/mcp/quickstart">
    Connect Cursor, Claude, or ChatGPT to Seamless tools — no REST boilerplate.
  </Card>

  <Card title="Rate limits & credits" icon="gauge" href="/rate-limits-and-credits">
    Understand quotas, response headers, and 429 errors.
  </Card>
</CardGroup>