Introduction

Emissary lets you replace slow, expensive frontier-model calls with small, purpose-built classifiers that return the same decision in milliseconds for a fraction of the cost. Define what you want to measure or route on, and Emissary handles the rest — no prompt engineering, no full-size model in the loop.

Quickstart

The fastest way to get started is one of our quick start guides. Each walks you through building your first model three ways — the public playground (no signup), the dashboard UI, and the API:

• Create Your First Judge — score any text against criteria you define (e.g. helpfulness, factual accuracy) and get back a calibrated probability instead of a vague verdict.
• Create Your First ModelRouter — automatically send each query to the model best suited to handle it, so you stop hard-coding one model for every request.

Want to train your own models? See the Fine-Tuning Quickstart to fine-tune and deploy a model on your own data.