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

# Authentication

> Use your existing Waterfall key from your backend or data workflow.

These guides use the existing Waterfall API at `https://api.waterfall.io`. Authenticate with the `x-api-key` header.

```bash theme={null}
export WATERFALL_API_KEY='YOUR_API_KEY'
```

```bash theme={null}
curl --get 'https://api.waterfall.io/v1/enrichment/contact' \
  --header "x-api-key: $WATERFALL_API_KEY" \
  --data-urlencode 'job_id=YOUR_JOB_ID'
```

Replace placeholders before running requests. Keep API keys on your server or in your workflow tool's secret store, not in browser code or source control.

Use the [existing API key management reference](https://docs.waterfall.io/v1/api-keys-overview) to manage access. [Contact Waterfall](https://www.waterfall.io/book-a-call) if you need API access or a setup for your signup volume.