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

# Authentication (Demo API)

> How to authenticate requests to the CoinGecko Demo API

<Card title="Upgrade to Pro" icon="rocket" href="https://www.coingecko.com/en/api/pricing" horizontal arrow="true">
  Get higher rate limits, more credits, and access to premium endpoints.
</Card>

<Steps>
  <Step title="Get your API key">
    [Sign up](https://www.coingecko.com/en/api/pricing) and grab your key from the [Developer Dashboard](https://www.coingecko.com/en/developers/dashboard#api-keys).
  </Step>

  <Step title="Choose an auth method">
    | Method                   | Key                 | Example                                |
    | ------------------------ | ------------------- | -------------------------------------- |
    | **Header** (recommended) | `x-cg-demo-api-key` | `-H "x-cg-demo-api-key: YOUR_API_KEY"` |
    | **Query string**         | `x_cg_demo_api_key` | `?x_cg_demo_api_key=YOUR_API_KEY`      |
  </Step>

  <Step title="Make a request">
    All requests use the Demo API root URL: `https://api.coingecko.com/api/v3/`

    <CodeGroup>
      ```bash Header (recommended) theme={null}
      curl "https://api.coingecko.com/api/v3/ping" \
        -H "x-cg-demo-api-key: YOUR_API_KEY"
      ```

      ```bash Query string theme={null}
      curl "https://api.coingecko.com/api/v3/ping?x_cg_demo_api_key=YOUR_API_KEY"
      ```
    </CodeGroup>

    > Replace `YOUR_API_KEY` with your key from the [Developer Dashboard](https://www.coingecko.com/en/developers/dashboard#api-keys).

    <Tip>
      Onchain endpoints use the same authentication — just include `/onchain` in the path.

      e.g. `https://api.coingecko.com/api/v3/onchain/simple/networks/...`
    </Tip>

    <Note>
      Store your API key in your backend and use a proxy to inject it into requests.

      Avoid query string parameters in production — they risk exposing your key in logs and browser history.
    </Note>
  </Step>
</Steps>

<Card title="Done setting up your key?" icon="arrow-right" href="/ai-integration">
  Connect it to AI agents via MCP, SDK prompts, and coding agent integrations.
</Card>

### Usage Credits

* Each successful request (HTTP 200) deducts 1 credit from your monthly quota.
* Monthly credits and rate limits depend on your [plan](https://www.coingecko.com/en/api/pricing).
* Check usage in the [Developer Dashboard](https://www.coingecko.com/en/developers/dashboard#usage-reports).