QuoteSwap gRPC Service (grpc_cake)

QuoteSwap is a gRPC API that allows you to get quotes and execute token swaps on PancakeSwap V2 and V3 across multiple chains: Ethereum, BSC, and Base.

How to Run

1. Clone the repo: git clone https://github.com/github_username/repo_name.git

2. Configure environment variables in a .env file or export manually:

Environment Variables

Variable	Description
API_KEY	(Optional) API key for RPC provider if needed
CHAIN_BSC	RPC endpoint for Binance Smart Chain
CHAIN_ETH	RPC endpoint for Ethereum network
CHAIN_BASE	RPC endpoint for Base network
PRIVATE_KEY	Private key for signing transactions
RECIPIENT_ADDR	Address to receive tokens after swap
GRPC_PORT	gRPC server port (default: 50051)

# RPC URLs (Infura, Alchemy, or your own)
CHAIN_BSC=https://bsc-mainnet.infura.io/v3/
CHAIN_ETH=https://mainnet.infura.io/v3/
CHAIN_BASE=https://base-mainnet.infura.io/v3/

3. Run the server:

   go run main.go

Example Requests

GetQuote

grpcurl -plaintext -d '{
  "token_in": "0x4200000000000000000000000000000000000006",
  "token_out": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "amount": "1000000000",
  "dex": "v3",
  "slippage_bps": 30,
  "chain": "base"
}' localhost:50051 quoteswap.QuoteSwapService/GetQuote

###Response:
{
  "inputToken": "0x4200000000000000000000000000000000000006",
  "inAmount": "1000000000",
  "outputToken": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "outAmount": "1",
  "slippageBps": 30,
  "dex": "v3",
  "chain": "base"
}

ExecuteSwap

grpcurl -plaintext -d '{
  "quoting_response": {
     "inputToken": "0x4200000000000000000000000000000000000006",
  "inAmount": "1000000000",
  "outputToken": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",  
  "outAmount": "1",
  "slippageBps": 30,
  "dex": "v3",
  "chain": "base"

  }
}' localhost:50051 quoteswap.QuoteSwapService/ExecuteSwap

###Response:
{
  "transactionHash": "0x7c3ffabf6488b52cf480ba121753599174de637ce4b7c84459001ce3e9c5ac1e",
  "status": "PENDING",
  "sellTokenQty": 1e+09,
  "executedPrice": 1
}

NOTE: You must set RECIPIENT_ADDR and PRIVATE_KEY in the environment for swap execution.

Architecture Overview

• main.go initializes the gRPC server and sets up V2 and V3 services per chain.
• Service Routing:
  • The request’s chain and dex fields determine which implementation to use.
  • Internally routes to either V2 or V3 logic using a shared Swapper interface.
• QuoteSwapServiceServer is the main handler for:
  • GetQuote — estimates output amount.
  • ExecuteSwap — signs and sends a swap transaction.
• Blockchain client encapsulates JSON-RPC interactions per chain, and ABI gens.

Limitations

• Only supports PancakeSwap (V2 and V3).
• Requires reliable RPC endpoints for target chains.
• The outAmount in ExecuteSwap must come from a prior GetQuote call.
• Swap execution assumes sufficient token approvals and balances on sender.