Confidential Payments Prototype on Base

A concept website and a separate Solidity experiment for paying agency contractors without publishing individual allocations.

Live concept site · Engineering notes · Contract experiment

Project status

Part	What you can use
Website	Hosted design prototype with an interactive visibility explainer and a local text-file download. No accounts, wallet connection, or payment execution.
Escrow experiment	A local Foundry model of encrypted allocations, release accounting, and pre-release refunds. It is not deployed or audited for production.
Network	Base is the intended settlement chain. The experiment restricts execution to Base Sepolia, chain ID 84532.
Background	Prepared alongside a Base Batches application draft. The application was not submitted. The hackathon-projects/base category is portfolio organization, not a claim of event participation or an award.

No customer funds are accepted. The website does not call the contracts. The proposed backend, milestones, disputes, document storage, and recovery flows are not implemented.

The engineering problem

A client, an agency, and its contractors need different views of the same payment agreement. The client needs to know whether work is funded; contractors need their own allocation without access to each other's rates.

This repository separates two questions: how to explain those boundaries in the browser, and how confidential transfers affect escrow accounting. In the local token model, a transfer can return zero without reverting. The escrow therefore tracks returned amounts rather than treating a successful call as proof of payment.

Stack

Area	Implementation
Website	Next.js 16, React 19, TypeScript, native CSS, Canvas 2D, self-hosted Inter
Frontend checks	Node test runner, Playwright desktop/mobile projects, axe-core
Contract experiment	Solidity 0.8.30, Foundry 1.7.1, Inco Lightning 1.0.2
Network inspection	viem; read-only Base Sepolia RPC calls
Delivery	Vercel, optional Docker Compose, GitHub Actions

Exact JavaScript versions are pinned in package.json, pnpm-lock.yaml, and the separate contract package. Go, PostgreSQL, and Clerk appear in design documents only; they are not part of the running application.

Run locally

Use Node.js 24 and pnpm 12.3.4. The website needs no credentials or environment file.

git clone https://github.com/SourceSenseiTheRealOne/hackathon-projects-base-confidential-payments-prototype.git
cd hackathon-projects-base-confidential-payments-prototype
npm install --global pnpm@12.3.4
pnpm install --frozen-lockfile
pnpm dev

Open http://127.0.0.1:4180. For a production build, run pnpm build followed by pnpm start. Stop an existing native preview before rebuilding its .next output.

Docker is optional: docker compose up -d --build exposes http://127.0.0.1:4182. The container runs without root, with a read-only filesystem and dropped capabilities.

Run the checks

pnpm test
pnpm typecheck
pnpm build
pnpm exec playwright install chromium
pnpm test:e2e

Playwright owns port 4181 and tests the production build. Its checks cover responsive layout, assets and browser errors, keyboard interaction, reduced motion, automated accessibility, and the download-only form's network behavior. pnpm audit --prod checks production dependencies separately.

For the isolated contracts:

cd contracts
npm ci --ignore-scripts
npm test

The pinned native Foundry binary is invoked through a wrapper that preserves its exit code. npm run preflight performs public network reads only; it neither deploys nor sends payments. See the contract setup and limitations.

Read the implementation

app/          Pages, metadata, and styles
components/   Canvas, keyboard-accessible tabs, and brief-download form
lib/          Input validation and explanatory visibility policies
contracts/    Independent Solidity sources, test double, tests, and RPC probe
tests/        Unit, CI-policy, and browser checks
docs/         Engineering notes, research, and dated verification records

The engineering notes explain the browser data flow, animation budget, contract decisions, and what the tests do not establish. The Inco feasibility notes cover provider trust, disclosure, and deployment gaps.

Earlier documents use the names Scopeveil or Pactrail. Historical reports retain their original names, hashes, and deployment addresses; they are not verification of later revisions. Current repository identity and collection placement are recorded in context/brand.md.

Use and limitations

This is a study artifact, not a payment service. Confidential amounts do not imply anonymous activity. The local test token is not the deployed cToken implementation, and its decryption helpers do not prove unauthorized-decryption resistance.

This repository has no repository-wide open-source license. Solidity files carry their own SPDX notices, and third-party dependencies retain their licenses. Inco's license and provider trust model require separate assessment before reuse in a commercial system.