Tax Pundit

Tax Pundit lets people and browser agents turn scattered tax records into a cited, review-ready case to file tax return - while every consequential tax decision stays with the person.

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Inspiration

Tax filing often means sending the same income slips, receipts, mileage records and personal details to an accountant every year. The harder part is knowing what information is missing and which deductions or benefits may apply to your job, province or family situation.

During the busy filing season, it is difficult for taxpayers and accountants to discuss every possible opportunity. We built Tax Pundit to make this preparation more organized and proactive.

What it does

Tax Pundit is a shared tax-preparation workspace for a person, their browser agent and their tax professional. It organizes records, identifies missing information, performs bounded calculations and surfaces relevant deductions, benefits, CRA forms and official guidance.

Through WebMCP, a browser agent can work directly with the application using 15 structured tools. Each action produces a visible document, calculation or decision in the center workspace, while the WebMCP panel shows the live tool sequence.

The agent can gather information, calculate vehicle expenses and prepare recommendations, but it cannot approve a tax treatment. Important decisions and final export remain human-controlled.

The current demo uses synthetic Ontario and British Columbia cases and creates a cited, review-ready brief for a tax professional. It does not file a real return or calculate a complete refund.

How we built it

We built Tax Pundit with TypeScript, React, Vinext and Vite, then deployed it through ChatGPT Sites.

The interface and WebMCP tools share one canonical case store, so human and agent actions always update the same information. We added strict tool schemas, profile-based workflows, official CRA references, visible agent activity and human approval controls.

The project includes 40 automated tests covering all 15 WebMCP tools, calculations, invalid inputs, changed facts, approval invalidation, undo, reset and export behavior.

Challenges we ran into

Our main challenge was making agent activity easy to understand. Early versions looked like technical commands running in the background. We redesigned the experience so the current result stays in the user’s eye line while the WebMCP panel provides a transparent record of the supporting actions.

We also had to manage shared state safely. Reading a case should not change it, while editing an important fact—such as mileage—must invalidate an earlier approval. We deliberately prevented the agent from approving decisions or filing anything.

Accomplishments that we're proud of

We created a complete human-agent workflow rather than only a WebMCP technical demo. Tax Pundit exposes 15 functional tools, adapts the preparation flow to different profiles, presents agent results visually and stops for human approval when judgment is required.

The application is publicly available, requires no login for the demo and has a complete open-source repository with tests and setup instructions.

What we learned

WebMCP works best when tools have narrow responsibilities, strict inputs and clear limits. We also learned that users need to see what an agent produced—not just that a command ran.

Most importantly, agentic experiences become more trustworthy when responsibilities are clear: the agent handles repetitive preparation, while the person retains control over facts and consequential decisions.

What's next for Tax Pundit

Next, we would support secure document uploads, OCR and confirmation of extracted information. We would also add persistent user accounts, more Canadian tax scenarios and an accountant portal for reviewing evidence, calculations and unresolved questions.

The long-term goal is to make Tax Pundit a secure preparation layer between taxpayers, browser agents and tax professionals.

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