Foundry Zksync

foundry-zksync-mcp

An MCP (Model Context Protocol) server that exposes foundry-zksync CLI tools to AI assistants like Claude.

Tools

Prerequisites

• Node.js >= 18
• foundry-zksync installed (foundryup-zksync)

Quick Start (npx)

No install needed — run directly with npx:

claude mcp add foundry-zksync -- npx -y foundry-zksync-mcp

Or add to claude_desktop_config.json / ~/.claude.json:

{

"mcpServers": { "foundry-zksync": { "command": "npx", "args": ["-y", "foundry-zksync-mcp"] } } }

Install from Source

git clone https://github.com/Jrigada/foundry-zksync-mcp.git

cd foundry-zksync-mcp npm install npm run build

Then register with Claude Code:

claude mcp add foundry-zksync node /absolute/path/to/foundry-zksync-mcp/dist/index.js

Key Management

All signing tools (deploy, cast_send, run_script) support multiple wallet methods. Choose based on your security needs:

Local Development (anvil-zksync)

For local dev with well-known test keys, use privateKey directly:

privateKey: "0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80"

These are the default anvil-zksync test accounts — they hold no real value.

Warning: Never use privateKey with keys that hold real funds. MCP tool parameters are visible to the AI assistant and may be logged.

Recommended for Production: Named Keystores

Keys are encrypted on disk — only the account name travels through MCP.

# Import a private key into a named keystore (interactive, key never shown)

cast wallet import deployer --interactive

List your keystores

ls ~/.foundry/keystores/

Then use account: "deployer" in any signing tool. Forge will prompt for the password at runtime, or you can point to a password file with passwordFile.

Keystore Files

If you have an existing encrypted keystore JSON file (e.g. from Geth, MetaMask export):

keystore: "/path/to/keystore.json"

passwordFile: "/path/to/password.txt"

Hardware Wallets

ledger: true    # Ledger

trezor: true # Trezor

Cloud KMS

aws: true       # AWS KMS (set AWS_KMS_KEY_ID env var)

gcp: true # Google Cloud KMS (set GCP_PROJECT_ID, GCP_LOCATION, etc.)

Signing Method Summary

Project Structure

src/

index.ts MCP server entry point, registers all 21 tools knowledge.ts Knowledge base (45+ entries) and system addresses tools/ shared.ts Profile field and env builder shared across forge tools init.ts forge init with zkSync config compile.ts forge build --zksync test.ts forge test --zksync run_script.ts forge script --zksync deploy.ts forge create --zksync (structured output) verify.ts forge verify-contract --zksync install.ts forge install clean.ts forge clean gas_report.ts forge test --gas-report snapshot.ts forge snapshot read_foundry_toml.ts Read project config explain.ts Error/log explanation with knowledge base get_zksync_docs.ts Documentation lookup with embedded content cast_abi_encode.ts cast abi-encode cast_abi_decode.ts cast abi-decode cast_calldata_decode.ts cast calldata-decode cast_call.ts cast call cast_send.ts cast send cast_balance.ts cast balance cast_nonce.ts cast nonce anvil_zksync.ts anvil-zksync node management tests/ 133 tests (vitest)