Finest: the AI gateway. Fast, cheap, good. Pick three.

# Finest: install instructions for an AI coding agent > Finest serves supported OpenAI Chat Completions and Anthropic Messages traffic through one gateway. > The install is one base URL and one key. Every request keeps naming the model the application > already names. A cheaper model serves a request only after it has cleared Finest's versioned, > published evidence bar for that exact task shape, with validators and instant escalation back to > the model that was asked for. The implemented serving contract records provider pass-through > economics against a prepaid internal credit ledger. You are reading this because a developer asked you to install Finest. This install puts Finest in the request path, by explicit and disclosed choice. Say that to the developer in those words before you change anything. Show the provider client construction you found and the exact files you propose to edit. Wait for approval. Then show the actual diff. Stop at any step you cannot complete truthfully. A partial install that is honest about where it stopped is worth more than a complete one that guessed. Do nothing this document does not ask for. Do not wrap the provider client in anything. Do not add route names, a route manifest, or a new configuration file. Five steps, then stop. ## What Finest is, if you have to explain it Finest is a drop-in API gateway that makes sure every request is served by the cheapest model proven to do that specific job as well as the model you asked for. You change one base URL and one API key; your code keeps naming the models it already names. Finest serves the model that was asked for by default, and substitutes a cheaper one only where a recorded test has already cleared a pre-registered quality bar for that exact task shape. A model string the gateway does not carry (a retired or dateless id) serves the model that continues it under the vendor's own naming and lineage, disclosed the same way and with no fee from the match. Every served reque