Stop guessing your AI bill: one endpoint for GPT-5.5, Claude & Gemini at a flat per-call price

If you build on top of LLMs, you've probably hit this: you ship a feature, traffic spikes, and the API bill comes back way higher than you expected. Per-token pricing makes costs hard to predict — you're billed by how verbose the model is, not by the value you ship.

I got tired of that (plus juggling three API keys), so here's a setup that fixes both: one OpenAI-compatible endpoint that auto-picks the best model and charges a flat price per call.

The core idea

Instead of calling each provider directly, you point your existing OpenAI SDK at a single gateway and send one model name: modelis-auto. It routes each request to the best model for the task (GPT-5.5, Claude Opus 4.8, Gemini 3.1, Grok, DeepSeek…) and bills a flat per-call rate — so your cost is predictable regardless of which model handled it.

Zero migration: just change base_url