---
title: "API · the agent index as a citable data product · Agent Fieldbook"
url: https://agentfieldbook.org/developers/api/
description: "The Fieldbook read REST API, in build. Every response carries its source, source tier and confidence, so anything you build on the agent catalogue, models, supply-chain graph and adoption data stays citable. Auth and base URL on launch."
section: "Developer · API"
source: Agent Fieldbook — generated from the published page
---

# The index as a data product

**In build**

A read REST API over the same relational backbone the site runs on, every response carries its **source**, **source_tier** and **confidence**, so anything you build on it stays citable. Auth + base URL on launch.

## Planned endpoints

## Common questions

### Is the Fieldbook API live?

Not yet, it is in build. The endpoints listed above are the planned surface, and the base URL and authentication will be published at launch. The data behind them is already live and citable on the site.

### What does each API response include?

The record, plus where it came from. Every row carries its **source**, that source's **tier**, and a **confidence** grade. Those are the same fields used internally, so anything you build stays traceable back to the evidence.

### Which endpoints are planned?

The agent catalogue and single-agent spec sheets, the foundation-model list, the supply-chain graph, MCP adoption, and a universal entity search. All GET, all JSON.

### How will the API be authenticated?

Auth and the base URL will be confirmed at launch. It is a read-only API, so access is scoped to retrieval and there is nothing to mutate.

### Should I use the API, the CLI or the dataset?

They return the same records. Use the API for live lookups from an application, the CLI for quick queries in a terminal, and the dataset when you want the whole index locally.

## Next in the learning path

- [Developer CLI The same index, streamed to your terminal](https://agentfieldbook.org/developers/cli/)

- [Provenance How every record earns its source tier](https://agentfieldbook.org/provenance/)

- [Examples Reference implementations to build on](https://agentfieldbook.org/software/cookbooks/)

- [Models Context window, cost, function-calling](https://agentfieldbook.org/software/models/)

- [Network The supply-chain graph the API traverses](https://agentfieldbook.org/network/)