bribe-maxxer

Capital-free MEV liquidation bot for Morpho Blue on Ethereum mainnet.

Seizes collateral via Morpho's native onMorphoLiquidate callback, swaps to loan token on-chain (Uniswap V3), and Morpho pulls repayment — zero upfront capital required. Submits via Flashbots MEV-Share for frontrunning protection.

How it works

Oracle price drops
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Bot detects unhealthy position (in-memory, event-driven)
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Simulate liquidation via eth_call
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Quote swap: collateral -> loan token (Uniswap V3)
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Calculate profit (minus gas + 90% builder bribe)
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Sign EIP-1559 tx, send Flashbots bundle
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MorphoLiquidator.liquidate()
   -> Morpho seizes collateral, sends to our contract
   -> onMorphoLiquidate callback fires
   -> Swap collateral for loan token on Uniswap
   -> Morpho pulls repayment
   -> Profit stays in contract

Architecture

/                         Foundry root (contracts)
├── src/                  Solidity — MorphoLiquidator with callback swap routing
├── test/                 Fork tests against live Morpho Blue markets
├── script/               Deployment + token approval scripts
├── bot/                  TypeScript off-chain bot
│   └── src/
│       ├── core/         Event-driven orchestrator + position cache
│       ├── markets/      Market discovery (Morpho API + on-chain events)
│       ├── positions/    Health checking, interest accrual, borrower scanning
│       ├── simulation/   eth_call simulation, Uniswap quoting, profit calc
│       ├── execution/    Flashbots bundles, tx signing, nonce management
│       ├── db/           SQLite persistence
│       └── monitoring/   HTTP health server
├── docker-compose.yml    One-command deployment
└── .github/workflows/    CI: Solidity + Bot type-check + Docker build

On-chain: MorphoLiquidator.sol

Single contract, no proxies. Immutable MORPHO + owner.

• liquidate() encodes swap steps as calldata, calls MORPHO.liquidate() with callback data
• onMorphoLiquidate callback executes swap steps sequentially, Morpho pulls repayment, profit swept to caller
• approvedTargets mapping gates which DEX contracts can be called (prevents drain via malicious calldata)
• approvedCallers mapping restricts who can call liquidate()
• On-chain minProfit parameter as safety backstop

Off-chain: TypeScript bot

Event-driven architecture — reacts to oracle price changes and Morpho position events instead of polling every borrower every block.

• Market discovery: Morpho GraphQL API bootstrap + CreateMarket event scanning
• Position cache: In-memory position state, updated from Morpho events (Borrow, Repay, SupplyCollateral, WithdrawCollateral, Liquidate)
• Oracle diffing: Compares oracle prices block-to-block, only evaluates markets where price changed
• Health check: Exact Morpho math — two-step truncating division, virtual share offsets, off-chain interest accrual via IRM Taylor expansion
• Execution: Flashbots MEV-Share bundles with 90% MEV refund, Flashbots Protect fallback
• Safety: Gas circuit breaker, Chainlink staleness validation, on-chain minProfit, graceful shutdown

Setup

Prerequisites

• Foundry
• Node.js 22+
• pnpm

Install

git clone --recursive https://github.com/SidharthK2/bribe-maxxer.git
cd bribe-maxxer

# Contracts
forge build

# Bot
cd bot && pnpm install

Configure

cp .env.example .env
# Fill in:
#   PRIVATE_KEY          — bot wallet (needs ~0.01 ETH for gas)
#   HTTP_RPC_URL         — Alchemy/Infura HTTP endpoint
#   WS_RPC_URL           — Alchemy/Infura WebSocket endpoint
#   FLASHBOTS_AUTH_KEY   — generate with: cast wallet new
#   FLASH_LIQUIDATOR     — set after deploying contract

Deploy contract

# Deploy MorphoLiquidator
forge script script/Deploy.s.sol --rpc-url $MAINNET_RPC_URL --broadcast --verify

# Set your bot as approved caller
cast send $FLASH_LIQUIDATOR "setApprovedCaller(address,bool)" $BOT_ADDRESS true --rpc-url $MAINNET_RPC_URL --private-key $PRIVATE_KEY

Run

# Dry run (logs opportunities, doesn't execute)
cd bot && pnpm start:dry

# Live
cd bot && pnpm start

# Docker
docker compose up -d
docker compose logs -f bot

Monitor

curl localhost:3000/health       # uptime, block, cached positions
curl localhost:3000/markets      # tracked markets + LLTV/LIF
curl localhost:3000/liquidations # recent liquidations + profit stats

Development

Contracts

forge build                                              # compile
forge test --fork-url $MAINNET_RPC_URL -vvv              # fork tests (19 tests)
forge test --gas-report --fork-url $MAINNET_RPC_URL      # gas profiling
forge fmt                                                # format

Bot

cd bot
pnpm install          # install deps
npx tsc --noEmit      # type-check
pnpm start:dry        # run in dry-run mode

Key addresses (mainnet)

Contract	Address
Morpho Blue	0xBBBBBbbBBb9cC5e90e3b3Af64bdAF62C37EEFFCb
Uniswap V3 SwapRouter02	0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45
Uniswap V3 QuoterV2	0x61fFE014bA17989E743c5F6cB21bF9697530B21e
Chainlink ETH/USD	0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419

License

MIT