dsh-provider-headers

DeepSeek Harness already supports per-provider request headers on the pi-ai routing layer, yet the model settings page ships no GUI entry for that field, leaving users to hand-edit settings.yaml. dsh-provider-headers drops a row-based "Custom Headers" editor into every pi-ai provider card on the settings page. You add, edit, and remove name/value pairs, hit Save, and the values land in the same native Harness field. Uninstalling the plugin restores everything; no dsh source code or packaged bundle is modified.

The native config cannot do one thing: make a header value change per session. On the host side the plugin listens on the llm/stream waterfall, wraps each streaming call in an AsyncLocalStorage scope that carries the call's session ID, and patches globalThis.fetch so that, only within that scope, header values containing the ${sessionId} token are expanded to the real session ID before the request goes out. Requests outside the scope pass through untouched, and wrappers installed by other plugins are never overwritten. Fixed-value headers still ride the native Harness path. A practical example: services like OpenCode Go that require a stable x-opencode-session header per request only need a single row with the ${sessionId} placeholder.

This plugin is aimed at dsh users who need to attach dynamic request headers to a specific pi-ai provider without editing YAML or patching the Harness core. Keep in mind it only covers pi-ai routes (the llm-deepseek official route has no headers field at all), user-agent is a reserved name skipped on both paths, ${sessionId} expansion applies exclusively to streaming model requests (not the one-shot model-discovery call), and header values are stored as plain text in settings.yaml, so credentials should go in the dedicated apiKeyEnv field instead.