Abi To MCP Guide

UCAI — ABI-to-MCP Server Generator

UCAI (Universal Contract AI Interface) turns any smart contract ABI into a ready-to-use MCP server. One command — any contract on any EVM chain — and your AI agent can interact with it.

The Concept

Smart Contract ABI (JSON)
    │
    ▼
  UCAI CLI
    │
    ▼
MCP Server with tools for every function
    │
    ▼
AI Agent calls contract functions naturally:
  "What's the total supply of this ERC20?"
  "How much can I borrow on Aave?"

Quick Start

Install

pip install abi-to-mcp

Generate MCP Server

# From a verified contract on Etherscan
ucai generate 0xD74f5255D557944cf7Dd0E45FF521520002D5748 --chain arbitrum

# From a local ABI file
ucai generate ./my-contract-abi.json --chain ethereum

# From a well-known protocol
ucai generate uniswap-v3-router --chain ethereum

Use with Claude Desktop

{
  "mcpServers": {
    "my-contract": {
      "command": "ucai",
      "args": ["serve", "0xD74f5255D557944cf7Dd0E45FF521520002D5748", "--chain", "arbitrum"]
    }
  }
}

How It Works

1. ABI Parsing — Reads contract ABI (from Etherscan, local file, or known protocol)
2. Tool Generation — Creates one MCP tool per contract function
3. Type Mapping — Solidity types → JSON Schema types
4. Read/Write Split — Read functions (view/pure) are safe; write functions need signing
5. Documentation — Auto-generates descriptions from function signatures and NatSpec

Generated Tool Example

For a function like:

function balanceOf(address account) external view returns (uint256)

UCAI generates:

{
  "name": "balanceOf",
  "description": "Get the token balance of an account",
  "parameters": {
    "account": { "type": "string", "description": "The account address (address)" }
  }
}

Supported Chains

Security Scanner

UCAI includes a built-in security scanner that checks:

ucai scan 0x... --chain ethereum

Web Builder

For non-developers, UCAI provides a web interface at mcp.ucai.tech:

1. Paste contract address
2. Select chain
3. Click "Generate"
4. Download MCP server config

Common Recipes

ERC-20 Token Tools

ucai generate 0x... --chain arbitrum
# → balanceOf, totalSupply, transfer, approve, allowance, etc.

Aave V3 Lending

ucai generate aave-v3-pool --chain arbitrum
# → supply, borrow, repay, withdraw, getUserAccountData, etc.

Sperax USDs

ucai generate 0xD74f5255D557944cf7Dd0E45FF521520002D5748 --chain arbitrum
# → balanceOf, totalSupply, mint, redeem, getCollateralRatio, etc.

The UCAI Standard

UCAI defines a standard for mapping Solidity ABIs to MCP tool definitions:

• Every view/pure function → read-only MCP tool
• Every state-changing function → write MCP tool (requires signing)
• Events → subscription tools (where supported)
• Structs → nested JSON Schema objects

Links

• PyPI: https://pypi.org/project/abi-to-mcp/
• Web Builder: https://mcp.ucai.tech
• GitHub: https://github.com/nirholas/UCAI
• Docs: https://docs.ucai.tech
• Anthropic MCP Registry: https://registry.modelcontextprotocol.io