Guides

Developer guides for the Billabex API

Comprehensive tutorials covering authentication, pagination, rate limiting, and best practices for building integrations.

Quick introduction to the Billabex API. Learn how to authenticate and make your first API call.

OAuth 2.1 Authorization Code flow with PKCE and optional OpenID Connect for Billabex.

Understand available OAuth scopes, how access is enforced, and how to request the right permissions for your integration.

Connect AI tools to Billabex using the Model Context Protocol (MCP) with OAuth 2.1.

Understand the OAuth token rate-limiting model, why it is designed this way, and what your integration should implement.

Understand Billabex cursor pagination, why it is designed this way, and what your integration should implement.

Learn how to link and unlink external data sources to accounts via the API.

Create or update resources in a single idempotent request using upsert endpoints.

Manage customer contacts and internal team members associated with accounts.

Upload invoice and credit note documents using binary or base64 encoding.

Respond to Billabex agent account tasks: list, get, cancel, and add user interactions.

Not finding what you need?

Explore the complete API reference for detailed endpoint documentation, or reach out to our developer support team.