Developer Documentation

Build with OpenTax

A deterministic tax engine you can run as a standalone web app or embed as an AI-agent plugin. One engine, two modes.

Two ways to use OpenTax

Whether you're building a direct-to-user product or powering an AI agent, the same rules engine is underneath.

Standalone Web App

Run OpenTax as a full-featured, client-side tax preparation app. Users upload documents, walk through a guided interview, and download IRS-ready PDFs. All computation happens in the browser—no server required.

Quickstart guide

OpenClaw Plugin

Embed OpenTax inside any OpenClaw-compatible AI agent. 16 tool definitions, SSE streaming, and a REST API let conversational agents do tax filing with full traceability—no UI needed.

Integration guide

How the pieces fit together

Both modes share the same deterministic rules engine. The difference is how data gets in and results get out.

Architecture
┌─────────────────────────────────────────────────────────┐
  Standalone Web App          OpenClaw Plugin           
  React UI + Interview       REST API + SSE + Tools    
  Client-side only           Node.js server            
└──────────┬───────────────────────────┬──────────────────┘
                                      
                                      
┌─────────────────────────────────────────────────────────┐
                  TaxService API                        
      createReturn · setIncome · compute · trace       
└──────────────────────┬──────────────────────────────────┘
                       
                       
┌─────────────────────────────────────────────────────────┐
              Rules Engine (deterministic)               
  IRS rules · Tax brackets · Credits · Deductions      
  Trace tree · Explainability · Source citations       
└─────────────────────────────────────────────────────────┘

Jump in

Everything you need to start building.

Quickstart

Clone, install, run. Get OpenTax running locally in under a minute.

Plugin Guide

Install the OpenClaw plugin and wire tax tools into your AI agent.

Architecture

Understand the rules engine, data flow, and boundary between modes.

Source Code

Browse the full repository, report issues, and contribute on GitHub.