Hermes Gateway turns an agent into a local HTTP service that a custom app can call from its own backend. The useful pattern is a loop: configure the runtime, start the gateway, send a task, poll for completion, return a response to the UI, then iterate on the prompt or route code. That loop keeps the browser simple. Next.js owns the product experience, Hermes owns the agent run, and .env keeps model keys and gateway tokens on the server. 1. Put Secrets in .env Use .env as the boundary between your application code and provider credentials. The browser should never receive OPENROUTER_API_KEY or the gateway API key. OPENROUTER_API_KEY=sk-or-v1-... API_SERVER_KEY=change-me-local-dev GATEWAY_ALLOW_ALL_USERS=true…