# Avalara Property tax API access and architecture

Source: https://developer.avalara.com/products/property-tax/integration-guides/avalara-property-tax/jdd4042148520992/

Guide: Avalara Property Tax

# Avalara Property tax API access and architecture

Learn how the Avalara Property Tax API works, including its read-only GraphQL architecture, tenant-based access requirements, and authentication model.

Avalara Property Tax provides a GraphQL API designed for programmatic data extraction, system synchronization, and reporting. This document describes the API architecture, communication protocols, tenant access requirements, and authentication mechanisms.

## Architectural overview

The Property Tax API operates as a read-only query interface over an active Avalara Property Tax tenant.

-   Read-only query model: The API supports only GraphQL queries. It does not provide mutations. All state-changing operations—such as document ingestion, optical character recognition corrections, return generation, appeal filings, and payment approvals—occur within the web application interface.

-   Single endpoint design: Client applications send all GraphQL query payloads via HTTP POST requests to a single environment endpoint.

-   Tenant-isolated data layer: Queries execute within the security boundary of the authenticated tenant, ensuring complete isolation of client and property records.

-   Downstream integration: The API functions as a data egress pipeline to synchronize property tax records, assessment values, bill schedules, and compliance deadlines with downstream systems, including enterprise resource planning systems, data warehouses, and business intelligence dashboards.

## Access and authentication

-   Tenant requirement: API access is provisioned directly against an active Avalara Property Tax for Enterprise or Avalara Property Tax for Accountants tenant. Public trial or self-service sandbox environments are not available without a provisioned tenant account.

-   Authentication: API requests authenticate using credentials provisioned for your tenant. Each query request must include the appropriate authorization header.

-   Supported environments: Endpoint access is provisioned across production, sandbox, and quality assurance environments to support development and verification workflows.