transaction-mcp-server 1.0.0

MCP Server for Ethereum transaction building, signing, and serialization

Transaction MCP Server

An MCP (Model Context Protocol) server providing comprehensive Ethereum transaction capabilities including building, signing, decoding, and analysis for both legacy and EIP-1559 transactions.

Features

Tools (15 total)

Transaction Building & Signing

• build_transaction - Build an unsigned transaction
• sign_transaction - Sign a transaction with a private key
• build_and_sign_transaction - Build and sign in one step

Transaction Decoding

• decode_raw_transaction - Decode a signed raw transaction
• decode_unsigned_transaction - Decode an unsigned transaction
• recover_transaction_signer - Recover signer from signed transaction

Transaction Analysis

• estimate_transaction_cost - Estimate gas cost in ETH
• validate_transaction - Validate transaction fields
• compare_transactions - Compare two transactions

Gas Utilities

• convert_gas_units - Convert between wei, gwei, ether
• calculate_max_cost - Calculate maximum transaction cost

Data Encoding

• encode_transfer - Encode ERC-20 transfer calldata
• encode_function_call - Encode arbitrary function call
• decode_calldata - Decode transaction input data

Serialization

• serialize_transaction - RLP encode a transaction

Resources (4 total)

• transaction-types - Documentation on transaction types (Legacy, EIP-2930, EIP-1559)
• gas-estimation - Guide to gas estimation and optimization
• chain-ids - Chain ID reference for all networks
• eip-1559 - EIP-1559 fee mechanism explained

Prompts (4 total)

• build_transfer_workflow - Guide through building an ETH transfer
• token_transfer_workflow - Guide through ERC-20 token transfers
• decode_transaction_workflow - Help decode and analyze transactions
• gas_optimization_workflow - Optimize transaction gas costs

Installation

pip install transaction-mcp-server

Or install from source:

cd transaction-mcp-server
pip install -e .

Usage

Run the server

transaction-mcp-server

Configure in Claude Desktop

{
  "mcpServers": {
    "transaction": {
      "command": "transaction-mcp-server"
    }
  }
}

Tool Examples

Sign a Simple Transfer

# Input
{
    "to": "0x742d35Cc6634C0532925a3b844Bc9e7595f5b4E2",
    "value": "1000000000000000000",  # 1 ETH in wei
    "nonce": 0,
    "chain_id": 1,
    "max_fee_per_gas": "30000000000",
    "max_priority_fee_per_gas": "2000000000",
    "private_key": "0x..."
}

# Output
{
    "raw_transaction": "0x02f8...",
    "transaction_hash": "0x...",
    "from": "0xABC...",
    "to": "0x742...",
    "value_eth": "1.0",
    "type": "EIP-1559"
}

Decode a Transaction

# Input
{
    "raw_transaction": "0x02f8..."
}

# Output
{
    "type": "EIP-1559 (Type 2)",
    "chain_id": 1,
    "nonce": 0,
    "to": "0x742...",
    "value_wei": "1000000000000000000",
    "value_eth": "1.0",
    "max_fee_per_gas_gwei": "30.0",
    "max_priority_fee_per_gas_gwei": "2.0"
}

Transaction Types

Type	EIP	Description
Legacy (0)	-	Original Ethereum transactions
Access List (1)	EIP-2930	With access list for gas savings
Dynamic Fee (2)	EIP-1559	Base fee + priority fee model

Security Notes

1. Private keys are NEVER logged or persisted
2. Transactions are signed OFFLINE - no network connection
3. Raw transactions must be broadcast separately
4. For educational and development purposes only

Chain IDs

Chain	ID
Ethereum Mainnet	1
Goerli	5
Sepolia	11155111
Polygon	137
Arbitrum One	42161
Optimism	10
Base	8453

License

MIT