@maxencerb/foundry-mcp

A comprehensive Model Context Protocol (MCP) server for the Foundry Ethereum development toolkit. This server enables AI assistants like Claude to interact with Forge, Cast, Anvil, and Chisel directly.

Features

• 80+ Tools covering all major Foundry commands
• Resources for project configuration, ABIs, bytecode, and documentation
• Prompts for common workflows (deployment, testing, security review)
• Self-documenting with live --help integration and official docs fetching

Tools Overview

| Category | Tools | Description | |----------|-------|-------------| | Forge | 18 | Build, test, deploy, verify contracts | | Cast | 38 | Interact with EVM chains, encode/decode data | | Anvil | 16 | Local node management, state manipulation | | Chisel | 6 | Solidity REPL operations | | Help | 6 | Live documentation from --help flags |

Prerequisites

• Bun runtime
• Foundry installed and in PATH

# Install Foundry
curl -L https://foundry.paradigm.xyz | bash
foundryup

Installation

# Using bun
bunx @maxencerb/foundry-mcp

# Or install globally
bun install -g @maxencerb/foundry-mcp

Usage

With Claude Desktop

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

{
  "mcpServers": {
    "foundry": {
      "command": "bunx",
      "args": ["@maxencerb/foundry-mcp"],
      "env": {
        "RPC_URL": "http://localhost:8545"
      }
    }
  }
}

With Other MCP Clients

# Run the server directly
bunx @maxencerb/foundry-mcp

# Or if installed globally
foundry-mcp

Environment Variables

| Variable | Description | Default | |----------|-------------|---------| | RPC_URL | Default RPC endpoint for chain interactions | - | | PRIVATE_KEY | Default private key for transactions (⚠️ testing only) | - | | FOUNDRY_PROJECT | Path to Foundry project | Current directory |

Available Tools

Forge Tools

| Tool | Description | |------|-------------| | forge_init | Initialize a new Foundry project | | forge_build | Compile Solidity contracts | | forge_test | Run tests with filtering and forking | | forge_coverage | Generate test coverage reports | | forge_script | Execute deployment scripts | | forge_create | Deploy a single contract | | forge_verify | Verify contracts on block explorers | | forge_inspect | Inspect ABI, bytecode, storage layout | | forge_flatten | Flatten contract sources | | forge_remappings | Show import remappings | | forge_tree | Show dependency tree | | forge_clean | Remove build artifacts | | forge_install | Install dependencies | | forge_update | Update dependencies | | forge_fmt | Format Solidity code | | forge_snapshot | Generate gas snapshots | | forge_doc | Generate documentation | | forge_selectors | List function selectors |

Cast Tools

Chain & Block: cast_block, cast_block_number, cast_chain, cast_chain_id, cast_client, cast_gas_price, cast_base_fee

Account: cast_balance, cast_nonce, cast_code, cast_storage

Transactions: cast_call, cast_send, cast_publish, cast_tx, cast_receipt, cast_run, cast_estimate, cast_logs

Encoding/Decoding: cast_abi_encode, cast_abi_decode, cast_calldata, cast_calldata_decode, cast_sig, cast_sig_event, cast_4byte, cast_4byte_decode

Utilities: cast_to_wei, cast_from_wei, cast_to_hex, cast_to_dec, cast_to_base, cast_keccak, cast_resolve_name, cast_lookup_address, cast_compute_address, cast_create2, cast_interface, cast_age, cast_wallet_new, cast_wallet_address, cast_wallet_sign, cast_format_bytes32, cast_parse_bytes32, cast_concat_hex

Anvil Tools

| Tool | Description | |------|-------------| | anvil_start | Start a local Ethereum node | | anvil_stop | Stop a running node | | anvil_status | Check node status | | anvil_mine | Mine blocks | | anvil_setBalance | Set account balance | | anvil_setCode | Set contract bytecode | | anvil_setStorageAt | Set storage slot value | | anvil_impersonateAccount | Impersonate an account | | anvil_stopImpersonatingAccount | Stop impersonating | | anvil_snapshot | Create state snapshot | | anvil_revert | Revert to snapshot | | anvil_setNextBlockTimestamp | Set next block timestamp | | anvil_increaseTime | Increase block time | | anvil_setAutomine | Toggle auto-mining | | anvil_reset | Reset fork state | | anvil_getAccounts | List dev accounts |

Chisel Tools

| Tool | Description | |------|-------------| | chisel_eval | Evaluate Solidity expression | | chisel_run | Run Solidity statements | | chisel_list | List saved sessions | | chisel_load | Load a session | | chisel_view | View session source | | chisel_clear_cache | Clear cache |

Help Tools

| Tool | Description | |------|-------------| | forge_help | Get forge CLI help (supports subcommands) | | cast_help | Get cast CLI help (supports subcommands) | | anvil_help | Get anvil CLI help | | chisel_help | Get chisel CLI help | | foundry_version | Get installed Foundry versions | | foundry_list_commands | List available commands for a tool |

Available Resources

| Resource | URI | Description | |----------|-----|-------------| | Config | foundry://config | Project's foundry.toml | | Remappings | foundry://remappings | Import remappings | | Contracts | foundry://contracts | List of .sol files | | ABI | foundry://abi/{contract} | Contract ABI | | Bytecode | foundry://bytecode/{contract} | Contract bytecode | | Storage Layout | foundry://storage-layout/{contract} | Storage layout | | Method IDs | foundry://method-identifiers/{contract} | Function selectors | | Gas Estimates | foundry://gas-estimates/{contract} | Gas estimates | | Documentation | foundry://docs | Official Foundry docs | | Doc Links | foundry://docs/links | Documentation URLs |

Available Prompts

| Prompt | Description | |--------|-------------| | deploy_contract | Guide for deploying a contract | | debug_test | Help debug a failing test | | write_test | Generate tests for a contract | | explain_storage | Explain storage layout | | gas_optimization | Review for gas optimization | | security_review | Security review checklist | | fork_test | Test against forked state | | create_script | Create deployment script | | lookup_docs | Look up command documentation |

Development

# Clone the repository
git clone https://github.com/maxencerb/foundry-mcp.git
cd foundry-mcp

# Install dependencies
bun install

# Run in development mode
bun run dev

# Type check
bun run typecheck

# Test with MCP Inspector
bun run inspect

Contributing

1. Fork the repository
2. Create a feature branch
3. Add a changeset: bunx changeset
4. Submit a pull request

Security Notice

⚠️ Never use private keys with real funds when using this MCP server. LLMs can make mistakes and send unintended transactions. Use only for testing and development with test accounts.

Documentation

• Foundry Book
• Foundry LLM Docs
• MCP Documentation

License

MIT