> ## Documentation Index
> Fetch the complete documentation index at: https://arizeai-433a7140-ehutt-trail-benchmark-new-tasks.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# 09.24.2025: Custom HTTP headers for requests in Playground

> Available in Phoenix 11.36+

<Update label="09.24.2025">
  <Frame>
    <img src="https://storage.googleapis.com/arize-phoenix-assets/assets/images/custom-headers-playground.png" alt="" />
  </Frame>

  This feature allows users to add custom HTTP headers to playground requests, enabling injection of provider-specific metadata (e.g. request IDs) via a JSON editor in the model config panel. The change extends the `GenerativeModelInput` schema to include `customHeaders`, with validation, per-provider storage, and conditional support.&#x20;
</Update>