# An OpenAPI description of the Fusion API

> ipor.io publishes an OpenAPI description of the read-only Fusion API, and the API docs now start from the v2 vault and market lists.

Source: https://ipor.io/developer-news/website-2026-10-22  
Published: 2026-10-22  
Website

## New features

- An OpenAPI 3.1 description of the read-only api.ipor.io endpoints is published at [/openapi.json](https://ipor.io/openapi.json) and [/openapi.yaml](https://ipor.io/openapi.yaml). It gives the meaning, unit and nullability of every field. An AI agent given that URL can call the API without further explanation.
- The [API docs](https://ipor.io/docs/build-on-fusion/developer-guide/api.md) start from `GET /v2/fusion/vaults`, every Fusion vault on every chain with its current statistics in one small file, and `GET /v2/fusion/markets`, current supply and borrow rates for every market.
- A new section, [Which APY to use](https://ipor.io/docs/build-on-fusion/developer-guide/api.md#which-apy-to-use), explains `netApy`, `grossApy`, `apy`, `underlyingAssetApy` and the reward fields, and which one is the after-fee yield.
- The API docs list how often each history bucket is regenerated: `7d` every 5 minutes, `30d` once a day, `1y` every 7 days and `all` every 30 days. The merge rule for `all` now includes `1y`.
- The v1 endpoints are listed as legacy and deprecated, each with the v2 endpoint to use in its place.