---
title: "OpenAPI specifications"
description: "Download the customer-facing API contracts."
---

## Number Lookup

[Download Number Lookup OpenAPI](/openapi/lookup.json)

Includes the supplied LRN request format and query-key authentication. The response is left unspecified until a deployed response contract is verified.

## BusinessPhoneSystem

[Download A1PBX OpenAPI](/openapi/a1pbx.json)

Contains only the selected customer operations. It describes the version 7 interface; endpoint availability and header authentication require account confirmation. It contains no administrative operations.

## Import into your API client

Import a specification into your preferred OpenAPI-compatible client. Replace the account identifier locally and add credentials in that client's secure environment. Review generated requests before sending them: originate initiates a real call despite using GET.

## Read with an assistant

Use the [documentation index](/llms.txt) or the Copy Markdown action on a documentation page. These contain the same public customer documentation.