io.github.siriuslattice/evmcp

Official

by siriuslattice · TypeScript

Multi-chain EVM blockchain data with companion smart contracts

Access multi-chain EVM blockchain data with companion smart contracts.

README.md9 KBView on GitHub

evmcp

EVM + MCP — give your AI assistant blockchain superpowers.

MCP server providing real-time access to on-chain data across Base, Optimism, Avalanche, Celo, and Arbitrum, with companion smart contracts deployed on-chain for batch queries and cross-chain data.

How it Works

EVMCP implements the Model Context Protocol (MCP), a standard that lets AI assistants call external tools. When connected, your AI assistant gains 28 read-only blockchain tools it can invoke to query balances, decode transactions, compare gas prices, and more across five EVM chains.

What sets EVMCP apart is its companion smart contracts — four Solidity contracts deployed on Avalanche and Celo that enable batch queries via Multicall3, an on-chain tool registry, event aggregation, and cross-chain balance caching. The MCP server reads from these contracts; all write operations are performed separately by an admin CLI.

Quick Start

With Claude Desktop

Add to your Claude Desktop config (~/Library/Application Support/Claude/claude_desktop_config.json):

json

{
  "mcpServers": {
    "evmcp": {
      "command": "npx",
      "args": ["-y", "evmcp"],
      "env": { "ALCHEMY_API_KEY": "your_key_here" }
    }
  }
}

With Claude Code

bash

claude mcp add evmcp -- npx -y evmcp

Supported Chains

Chain	Chain ID	Native Token	Companion Contracts
Base	8453	ETH	Not yet deployed
Optimism	10	ETH	Not yet deployed
Avalanche C-Chain	43114	AVAX	Deployed
Celo	42220	CELO	Deployed
Arbitrum One	42161	ETH	Not yet deployed

Ethereum mainnet (chain ID 1) is also supported for ENS resolution only.

Tools (29 total)

Balance (3)

Tool	Description
`getBalance`	Get the native token balance (ETH/AVAX/CELO) of an address on a specific chain
`getTokenBalance`	Get the ERC20 token balance of an address on a specific chain
`getMultiChainBalance`	Get the native token balance of an address across all 5 supported chains in parallel

Block (3)

Tool	Description
`getBlock`	Get a block by its hash on a specific chain
`getBlockByNumber`	Get a block by its number on a specific chain, or pass "latest" for the most recent block
`getLatestBlock`	Get the latest block number, timestamp, and base fee for a specific chain

Transaction (3)

Tool	Description
`getTransaction`	Get a transaction by its hash on a specific chain
`getTransactionReceipt`	Get the receipt for a transaction including status, gasUsed, and logs
`decodeTransaction`	Decode a transaction's function call using a provided ABI

Contract (3)

Tool	Description
`readContract`	Call a read-only function on a smart contract with a provided ABI
`getContractCode`	Check if an address has contract code deployed, with bytecode length and hash
`getStorageAt`	Read the raw value of a storage slot at a specific address

Token (2)

Tool	Description
`getERC20Info`	Get ERC20 token metadata including name, symbol, decimals, and total supply
`getTokenAllowance`	Get the ERC20 token allowance granted by an owner to a spender

Gas (3)

Tool	Description
`getGasPrice`	Get current gas price and EIP-1559 fee data for a specific chain
`estimateGas`	Estimate gas for a transaction on a specific chain
`compareGasAcrossChains`	Compare current gas prices across all 5 supported chains

ENS (2)

Tool	Description
`resolveENS`	Resolve an ENS name (e.g. vitalik.eth) to an Ethereum address via Ethereum L1
`lookupAddress`	Reverse lookup an address to its ENS name via Ethereum L1

Events (2)

Tool	Description
`getContractEvents`	Get event logs emitted by a contract on a specific chain
`decodeEventLog`	Decode a raw event log using a provided ABI

Chain and Health (3)

Tool	Description
`getChainInfo`	Get chain name, chain ID, current block number, block time, and native symbol
`isContractDeployed`	Check if an address has contract code deployed on all 5 supported chains
`healthCheck`	Test connectivity to all 6 RPC endpoints (Ethereum, Base, Optimism, Avalanche, Celo, Arbitrum)

Batch (1)

Tool	Description
`batchQuery`	Execute multiple read calls in a single RPC request using Multicall3

Cross-Chain (2)

Tool	Description
`compareBalances`	Compare native token balances for an address across all 5 chains
`crossChainActivity`	Check transaction counts for an address across all 5 chains

Registry (1)

Tool	Description
`queryRegistry`	Read registered tool metadata from the on-chain MCPRegistry companion contract

Optimizer (1)

Tool	Description
`gasOptimizer`	Recommends the cheapest chain for a transaction, accounting for L1 data fees on Base/Optimism/Arbitrum

Resources (4)

URI Pattern	Description	Cache TTL
`chain://{chainId}/status`	Current block height and gas price for a chain	12s
`chain://{chainId}/gas`	Base fee, gas price, and priority fee in gwei	12s
`chain://{chainId}/tokens/popular`	Popular token addresses and decimals (hardcoded for v1)	1 hour
`evmcp://chains`	All supported chains with IDs, symbols, and companion contract addresses	Static

Supported chain IDs for templated resources: 8453 (Base), 10 (Optimism), 43114 (Avalanche), 42220 (Celo), 42161 (Arbitrum).

Prompts (4)

Prompt	Arguments	Description
`analyze-wallet`	`address`	Multi-chain balance and activity analysis of a wallet
`audit-contract`	`contractAddress`, `chain`	Basic inspection and audit workflow for a smart contract
`compare-chains`	(none)	Compare gas costs, speed, and characteristics across all chains
`investigate-tx`	`txHash`, `chain`	Decode, analyze, and trace a transaction in detail

Companion Contracts

Four Solidity contracts are deployed on Avalanche and Celo. The MCP server reads from these contracts to provide batch queries, on-chain tool metadata, and cross-chain data. Base and Optimism deployments are planned.

Avalanche C-Chain (43114)

Contract	Address
MCPRegistry	`0x62402b65bfb4Fd022285A6FC2F26d8caEEc3D055`
BatchQuery	`0xfDc19e0617AdF1811A68Aa1575409F3769f39491`
EventAggregator	`0xECE24a53A28F088351EC2Da258f78479e81A8007`
CrossChainCache	`0x0899a6Ef23c6B39A4D9B877B219645B89209A670`

Celo (42220)

Contract	Address
MCPRegistry	`0x62402b65bfb4Fd022285A6FC2F26d8caEEc3D055`
BatchQuery	`0xfDc19e0617AdF1811A68Aa1575409F3769f39491`
EventAggregator	`0xECE24a53A28F088351EC2Da258f78479e81A8007`
CrossChainCache	`0x0899a6Ef23c6B39A4D9B877B219645B89209A670`

Contract Descriptions

MCPRegistry -- On-chain metadata for all EVMCP tools (names, descriptions, versions). Owner-only writes.
BatchQuery -- Optimized batch reads via Multicall3. Includes multi-balance, multi-contract-check, and multi-token-balance helpers.
EventAggregator -- Caches event count summaries per contract. Updated by the admin CLI.
CrossChainCache -- Stores balance snapshots for cross-chain queries. Updated by the admin CLI.

Environment Variables

Variable	Required	Description
`ALCHEMY_API_KEY`	Yes*	Alchemy API key (covers all chains)
`BASE_RPC_URL`	No*	Override RPC URL for Base
`OPTIMISM_RPC_URL`	No*	Override RPC URL for Optimism
`AVALANCHE_RPC_URL`	No*	Override RPC URL for Avalanche
`CELO_RPC_URL`	No*	Override RPC URL for Celo
`ARBITRUM_RPC_URL`	No*	Override RPC URL for Arbitrum
`ETHEREUM_RPC_URL`	No	Override RPC URL for ENS resolution
`CACHE_TTL_SECONDS`	No	Cache TTL in seconds (default: 15)
`CACHE_MAX_ENTRIES`	No	Max cache entries (default: 1000)
`LOG_LEVEL`	No	debug, info, warn, or error (default: info)
`USE_TESTNETS`	No	Use testnet chains (default: false)

*Provide either ALCHEMY_API_KEY or all five individual chain RPC URLs. **Required when X402_ENABLED=true.

Development

bash

pnpm install
pnpm build
pnpm inspect          # MCP Inspector UI at localhost:6274
pnpm test             # Unit tests
pnpm typecheck        # Type check
pnpm lint             # ESLint

License

MIT

Install

Configuration

Environment variables

ALCHEMY_API_KEYrequiredsecret

Alchemy API key for RPC access

claude_desktop_config.json

{
  "mcpServers": {
    "evmcp": {
      "command": "npx",
      "args": [
        "-y",
        "evmcp@0.1.3"
      ],
      "env": {
        "ALCHEMY_API_KEY": "<YOUR_ALCHEMY_API_KEY>"
      }
    }
  }
}