Arbitrum MCP

Arbitrum MCP Server

Tools for reading and writing to the Arbitrum blockchain. Connect to the server, then call tools by name.

Server

URL: https://arbitrum-mcp.saurabh10102.workers.dev/mcp
Transport: Streamable HTTP (POST)
Headers:
  Content-Type: application/json
  Accept: application/json, text/event-stream

Choosing the Right Tool

• "What's this wallet's balance?" → get_eth_balance for ETH, get_token_balance for any ERC-20
• "What's ARB trading at?" → get_arb_price (real-time from Chainlink oracle, no API key needed)
• "Call a contract function" → read_contract for any view/pure function. You provide the ABI — this is the most flexible tool
• "What happened in this tx?" → get_transaction returns full details + receipt
• "Swap X for Y on Arbitrum" → swap_tokens handles any token pair via Relay.link, including native ETH
• "Move funds to Arbitrum" → bridge_to_arbitrum bridges from Ethereum, Base, or BSC
• "Deploy this contract" → deploy_contract takes raw bytecode + optional constructor args
• "Register an agent on-chain" → register_agent mints an ERC-8004 identity NFT

Quick Reference

Tools

get_eth_balance

• Input: address, network? ("one" | "sepolia", default "one")
• Output: { address, balance, unit: "ETH", network }

get_token_balance

• Input: address, tokenAddress, network?
• Output: { address, token: { address, symbol, decimals }, balance, network }

get_arb_price

• Input: none
• Output: { price, currency: "USD", updatedAt }

read_contract

The most flexible read tool — works with any contract as long as you provide the ABI for the function you want to call.

• Input: address, abi (JSON string), functionName, args?, network?
• Output: { address, functionName, result }

get_transaction

• Input: txHash, network?
• Output: { hash, from, to, value, status, blockNumber, gasUsed, network }

swap_tokens

Swaps any token pair on Arbitrum via Relay.link. Use 0x0000000000000000000000000000000000000000 for native ETH. The server handles quoting and transaction execution — you just specify what to swap.

• Input: tokenIn, tokenOut, amountIn (human-readable e.g. "1.5"), network?
• Output: { txHashes, tokenIn, tokenOut, amountIn, network }

bridge_to_arbitrum

Bridges native tokens (ETH or BNB) from another chain to Arbitrum. Uses Relay.link under the hood — typically completes in a few minutes.

• Input: originChain ("ethereum" | "base" | "bsc" | "sepolia"), amount, recipient?, network?
• Output: { txHashes, originChain, destinationChainId, amount, recipient, network }

deploy_contract

• Input: bytecode, abi? (JSON string, needed if constructor has args), constructorArgs?, network?
• Output: { contractAddress, txHash, status, network }

register_agent

Registers an AI agent on the Arbitrum ERC-8004 Identity Registry. This mints an NFT representing the agent's on-chain identity.

• Input: name, metadata? (array of { metadataKey, metadataValue }), network? (default "sepolia")
• Output: { txHash, status, name, network, registryAddress }

Networks

All tools accept network: "one" (Arbitrum One mainnet, default) or "sepolia" (Arbitrum Sepolia testnet). Use Sepolia for testing — it's free and behaves identically.

Write tools require a configured wallet with funds on the target network. Read tools work without a wallet.

Common Token Addresses (Arbitrum One)

See examples.md for full request/response examples of every tool.