Engineering·March 29, 2026·4 min
Designing a response you never have to debug
Latency, dimensions, licensing and usage on every render. The thinking behind our JSON contract.
Latency, dimensions, licensing and usage on every render. The thinking behind our JSON contract.
EngineeringA good API response answers the next three questions before you ask them. For a render, those are: did it work, what did I get, and what did it cost.
Every Vela response includes status, latency, output dimensions, license state and credit usage. No second call to reconcile, no guessing.
We treat the contract as frozen. New capabilities arrive as new fields, never as breaking changes to the ones you already depend on.
Boring, stable responses are what let you build on top without fear. That is the whole point.
Start free with 250 generations. No card, no sales call, just an API key and the docs.