Form-filling browser extension.

A companion Chrome extension that fills funding applications by reconciling what is on screen with the DOM through hybrid vision matching, with subscriptions and credit metering.

Stack: NestJS, Bun, Stripe, computer vision
Scale: Tiered plans, usage-metered
Role: Architect and lead

Flow

Application page
Screenshot + DOM
Vision field detection
Spatial IoU match
Profile data
Fill
Meter credit

How it works

Government and funder portals are inconsistent, and DOM structure alone often misidentifies fields. The extension captures both a screenshot and the DOM, detects fields visually, and reconciles the two by spatial overlap so each visible field maps to the right input.

Matched fields are filled from the organization's stored profile. The user reviews before submit; the extension never submits on its own.

A NestJS backend on Bun handles auth, Stripe subscriptions with webhooks and a customer portal, and credit-based metering per fill.

Hard parts

Iframes, shadow DOM, and portals that re-render forms mid-fill.
Making metering fair when a fill partially fails.

Outcome

Turned hours of repetitive application work into minutes, and became a paid tier with tiered plans.