FieldCard

Field spend, orchestrated by text.

Inspiration

Field crews buy materials every day, often in the middle of a job. A plumber might need a $186 fitting immediately, but getting approval can mean calling the owner, waiting for a response, or using a personal card.

For small contractors managing several projects, keeping track of purchases, receipts, and job budgets quickly becomes difficult.

We wanted to make purchasing as simple as sending a text, while giving business owners control over where their money goes.

What it does

FieldCard is an AI-powered purchasing assistant for field-service businesses.

Workers can request materials through messaging. The system interprets the request, connects it to a job, and evaluates purchasing rules.

Our interactive sandbox prototype demonstrates:

AI interpretation of purchasing requests
Job budget and worker spending-limit checks
Merchant category restrictions
Owner approval thresholds
Single-use sandbox virtual cards
Approved and declined purchase simulations
Real-time budget and activity updates

Owners can inspect transactions, review spending policies, and see how purchases affect individual jobs.

How we built it

We built a React and TypeScript frontend with an interactive owner dashboard, a cinematic 3D landing page, and a guided purchasing simulation.

The system separates AI request interpretation from deterministic purchasing controls. AI helps understand what a worker needs, while explicit policy rules determine whether a purchase can proceed.

Our deployed application connects a streamlined owner dashboard to the backend and supports a text-based approval workflow.

Challenges

The biggest challenge was connecting messaging, purchasing decisions, virtual cards, and job budgets into one understandable experience.

We also had to maintain consistent financial calculations, handle approval states, and ensure that declined transactions never affected spending totals.

Building and integrating these components within a single hackathon weekend required careful coordination across our team.

Accomplishments

We're proud of creating a polished purchasing experience that makes financial controls understandable to both workers and business owners.

Our sandbox demonstrates how a $186.50 material request can pass policy checks, receive a restricted card, and update the correct job budget. It also demonstrates how a purchase from a disallowed merchant category is declined.

What we learned

We learned how important it is to combine AI flexibility with predictable business rules. Financial decisions need to be explainable, testable, and reliable.

We also learned a lot about integrating independently developed components under a tight deadline.

What's next

We want to continue connecting the complete purchasing lifecycle to live financial infrastructure, improve messaging reliability, and test FieldCard with real field-service businesses.

Demo note

Our video includes a guided walkthrough of the interactive sandbox prototype followed by footage of the deployed application at fieldcard.us. The deployed version currently uses a streamlined dashboard, so some sandbox-only screens shown in the video are not available as separate routes on the public site.

All demonstrated card authorizations are sandbox simulations. No real payments are processed.