Bymera

Universal crypto payment bridge — pay with crypto on sites that only accept cards.

Demo

https://www.bymera.xyz/demo

Bymera is a browser extension + backend system that lets users pay with cryptocurrency anywhere a card is accepted. The extension detects card checkout forms, funds a virtual card (via a backend that talks to Lithic and smart contracts), and auto-fills the merchant's card form so the merchant processes a normal card payment.

Why this project

Most merchants only accept cards, forcing users to off-ramp crypto to fiat. Bymera removes that friction by creating a merchant-agnostic virtual card funded by crypto, enabling seamless payments without requiring merchants to integrate Web3.

Key features

• Works on any site with a card checkout form
• One-click payments from crypto wallets
• Virtual cards issued via Lithic (sandbox/support)
• Privacy-first: merchants only see card data, not crypto details
• Cross-chain / EVM-compatible support

Repository layout

• extension/ — browser extension source and manifest
• backend/ — FastAPI backend that listens to events and creates virtual cards
• evm/ — smart contracts, Foundry project and tests
• landing-page/ — marketing / demo Next.js app
• shared/ — shared types and utilities

Prerequisites

• Node (or Bun) — used for extension & web UI tooling
• Python 3.10+ (for backend) and uvicorn
• Docker (optional) — for running the backend in a container
• Foundry (optional) — for building/running solidity contracts in evm/

Quick start — local development

1. Backend

cd backend
cp .env.example .env   # or create .env with values listed in backend/README.md
# Edit .env and set BACKEND_API_KEY, LITHIC_API_KEY (sandbox), DATABASE_URL, WEB3_PROVIDER_URI, CONTRACT_ADDRESS, etc.
uv run uvicorn src.app:app --reload --host 0.0.0.0 --port 8000
# or build/run via Docker: docker build -t vymera-backend . && docker run -d -p 8000:8000 --env-file .env vymera-backend

API notes: all backend endpoints require header X-API-Key: <BACKEND_API_KEY> (see backend/README.md for endpoints and examples).

2. Extension (development)

# From repo root
bun install     # or npm/yarn install if you prefer
bun run build:extension   # builds/transpiles extension files

To load in Chrome/Edge: open chrome://extensions, enable Developer mode, click "Load unpacked" and select the repository root (or the build output folder if your build script writes to a dist/ or extension/ folder).

3. Smart contracts (optional)

cd evm
# Requires Foundry (forge)
forge test
forge build

Running tests

• Solidity tests: cd evm && forge test
• Backend: add pytest-based tests in backend/ and run with pytest

Environment variables

The backend expects a .env file with at least the variables described in backend/README.md (BACKEND_API_KEY, DATABASE_URL, WEB3_PROVIDER_URI, CONTRACT_ADDRESS, LITHIC_API_KEY, LITHIC_ENVIRONMENT, POLL_INTERVAL_SECONDS).

Security & notes

• Use Lithic sandbox keys for local/dev. Do not commit secrets.
• When CONTRACT_ADDRESS is set to the zero address the listener runs in no-op mode (useful for local dev).

Contributing

Contributions are welcome. Please open issues or PRs. For development guidelines, add a CONTRIBUTING.md with code style and PR process.

License

MIT

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If you'd like, I can also:

• add a small CONTRIBUTING.md with PR checklist
• add example .env.example to backend/ if missing
• update package scripts to make local dev commands clearer