BridgX

BridgX is a prototype cross-chain bridge composed of a Next.js frontend, a Python + FastAPI backend, and a Solidity source/destination-chain executor contracts. Hackathon MVP focused on WETH and wrapped BTC moving from Avalanche to Base, which can be easily expanded to 10+ chains and 100+ tokens.

The unique idea is to chain Circle CCTP allowing for zero-fee cross-chain USDC transfers with cutting-edge smart routing by Odos for the best swap rates. In internal tests it beats other bridges in ~50% of cases.

How it works

1. BridgX queries Odos to compute the optimal swap route for the token to USDC on the source chain.
2. USDC is burned through CCTP.
3. CCTP attestates the burnt USDC for the cross-chain transfer, minting the same amount of the USDC on the destination chain.
4. Upon arrival on the destination chain, the USDC swaps to the target token via Odos, and gets delivered to the user.

Current status

What is implemented in code:

• Full cycle (the bridge is fully operational):
  • Frontend UI for wallet connect, chain/token selection, quoting, and transaction submission.
  • Backend integration with Odos quote/assemble APIs, token pricing API.
  • Backend swap + attestation / receipt from CCTP.
  • Transfer of the tokens to the user on the destination network.

Limitations:

• Supported wallets:
  • Only Metamask browswer extension is supported
• Supported chains: Avalanche --> Base
• Supported tokens:
  • Input: WETH, BTC.b, WBTC.e
  • Output: WETH, CBBTC, WBTC, TBTC
• No audit :] Use at your own risk!

Contracts deployed:
SourceExecutor: 0xeC20cbb6C99e4b8b78cbd81b27Ce0B7aaD222A2d (Avalanche)
DestinationExecutor: 0x25c66179bd654cde97fA4aF6C926Ad4689815E05 (Base)

Repository layout

BridgX/
├── frontend/                  # Next.js App Router client
│   ├── app/                   # Routes/pages
│   ├── components/            # Reusable UI components
│   ├── lib/                   # API client + wallet helpers
│   └── types.ts               # Shared frontend types
├── backend/                   # FastAPI API service
│   ├── api.py                 # Route handlers + chain/CCTP logic
│   ├── libs/provider.py       # Odos API client helpers
│   ├── libs/token.py          # Token registry helpers
│   ├── libs/quote_store.py    # SQLite quote storage with TTL
│   ├── libs/swap_intent_store.py # SQLite swap-intent storage with TTL
│   └── tests/test_fastapi.py  # API tests
├── solidity/
|   ├── tests/                 # end-to-end testing
│   ├── SourceExecutor.sol
|   ├── DestinationExecutor.sol
│   └── *.ipynb                # deployment notebooks
└── docs/

Local development

1) Backend

cd backend
python -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
cd ..
uvicorn backend.api:app --reload --port 8001

2) Frontend

cd frontend
npm install
npm run build 
npm run start -- -p 3003

Backend loads .env from backend/.env when present; otherwise it falls back to repo-level .env.

DEPLOYER_PRIVATE_KEY="..."
RELAYER_PRIVATE_KEY="..."
DESTINATION_EXECUTOR_BASE="0x25c66179bd654cde97fA4aF6C926Ad4689815E05"
DESTINATION_EXECUTOR_ARBITRUM="0x24EE15Eb102dA77EA3946c5011326b3487642982"

Backend FastAPI endpoints

• POST /quote
• POST /assemble
• POST /output-amount
• POST /token-price
• GET /tokens
• GET /networks
• GET /token-balance
• POST /swap-intent
• POST /attestation
• POST /receipt