initialize(). In practice most apps wire the following env vars to the SDK options:
Benchmark harness variables
If your code runs inside a Belvedir benchmark sandbox, three extra variables are injected at run time —FRACTAL_API_KEY (a per-run ingest key), FRACTAL_BASE_URL, and FRACTAL_RUN_ID. The SDK does not read them automatically; pass them to initialize() and use FRACTAL_RUN_ID as the sessionId.
Local development
Set the vars in.env.local (Next.js) or export them in your shell. If traces aren’t arriving, check your terminal for SDK warnings on startup and verify FRACTAL_API_KEY is loaded before initialize() runs.