# One catalogue of the APIs and data your tools can use

> Substrait's API Library lists your company's APIs, the tools your people built and your warehouse data sets. Builders browse it in conversation with their AI model, and see only what their groups allow.

URL: https://substrait.build/capabilities/api-library/  
Last updated: 2026-11-06

Substrait's API Library is the catalogue of what a tool can be built against: your company's APIs, the APIs of tools your people built on Substrait, and your warehouse data sets. Builders browse it in conversation with their AI model, and see only what their groups allow.

## What is in the library

| Entry | Where it comes from |
|---|---|
| Company APIs | Registered by an admin, with a full specification |
| Tools built on Substrait | Added automatically when a tool is deployed |
| Warehouse data sets | Reviewed, parameterised and versioned queries over your data warehouse |
| External APIs | Proposed by a member, approved by a curator |

Each entry says what it is for and what it is not for, so a builder's AI can choose the right one.

## Browsing in conversation with the AI model

A builder asks their AI model what data exists, and the Substrait plugin answers from the library.
Once the data owner grants development access, the builder can see real responses while building, read-only and for a set time.

## Invisible until granted

An entry in no group is seen only by a super admin.
A builder sees nothing of what they are not cleared for.

## Brokered calls

Once a data owner approves a tool, the tool calls the API through Substrait's gateway.
Substrait issues, stores, attaches, rotates and revokes the credential.
Neither the builder nor the data owner ever handles a secret.

<figure>
  <img src="/screenshots/65_api-library-tab@2x.png" alt="Substrait console: the API Library, listing company APIs with their owners and data groups." width="2570" height="509" loading="lazy" />
  <figcaption>The API Library. Product UI. Sample data.</figcaption>
</figure>

## Related

- [Company data, granted by its owner](https://substrait.build/capabilities/governed-data-access/): A tool on Substrait reads company data only after the data owner approves it, for a set time, through one gateway that holds the credential, checks every call and records every read.
- [Build with the AI model you already use](https://substrait.build/capabilities/build-with-your-own-ai-model/): Substrait does not replace your people's AI model. A plugin for Claude Code, the Claude desktop app and Cursor connects it to Substrait, and a scaffold fitted to your company shapes what it produces.
- [Right-sized authority for every person](https://substrait.build/capabilities/roles-and-access/): Substrait keeps four kinds of access apart: data groups for what a person may see and read, capability groups for what they may do on the platform, app roles for what they may do on one tool, and each tool's own sign-in.
- [How to give AI-built tools access to company data, safely](https://substrait.build/problems/give-ai-built-tools-access-to-company-data-safely/): On Substrait, a tool reads company data only after the data owner approves it, for a set time, through a gateway that holds the credential and records every read.