09.24.2025: Custom HTTP headers for requests in Playground 🛠️

Available in Phoenix 11.36+

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.

feat(playground): custom http headers for playground requests by RogerHYang · Pull Request #9560 · Arize-ai/phoenixGitHub