OpenAPI Specs & llms.txt

Everything RealtyAPI exposes is machine-readable. Each provider publishes a public OpenAPI 3.1 spec, and a site-wide llms.txt indexes every API and endpoint for LLM agents. Both are public — no API key needed to read them.

OpenAPI 3.1 specs

Every provider serves its full spec — endpoints, parameters, and response schemas — from its own base URL:

URL pattern

https://{provider}.realtyapi.io/openapi.json

For example:

redfin.realtyapi.io/openapi.json realtor.realtyapi.io/openapi.json airbnb.realtyapi.io/openapi.json zoopla.realtyapi.io/openapi.json rightmove.realtyapi.io/openapi.json

What to do with a spec

Generate typed clients

Feed the spec to openapi-generator, orval, or openapi-typescript for a fully typed SDK in your language.

Import into API tools

Postman, Insomnia, and Bruno import the spec directly — every endpoint pre-configured.

Power custom GPTs & actions

Paste the spec URL as an Action schema so ChatGPT (or any OpenAPI-aware agent) can call the provider.

Point coding agents at it

Agents read the spec and write the integration for you — parameters, paths, and response shapes included.

llms.txt

llms.txt is a convention for making a site legible to language models. Ours indexes all providers and 400+ endpoints — each with its method, path, and a link to full documentation:

URL

https://www.realtyapi.io/llms.txt

Paste that URL into your agent's context (or just mention it in a prompt) and the agent can navigate our entire catalog on its own — pick the provider, find the endpoint, and read its docs page before writing code.

The one-paragraph integration prompt

No spec tooling at hand? This snippet is all an AI agent needs to wire up RealtyAPI:

Paste into your agent

You can call the RealtyAPI real estate data API.

Base URL:  https://{provider}.realtyapi.io
           (provider = redfin, airbnb, rightmove, zoopla, ...)
Auth:      header  x-realtyapi-key: YOUR_API_KEY
Format:    every response is JSON
Index:     https://www.realtyapi.io/llms.txt  (all APIs & endpoints)
OpenAPI:   https://{provider}.realtyapi.io/openapi.json  (3.1)

Example:
  GET https://redfin.realtyapi.io/properties/search?location=Seattle,WA

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