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The Sauce MCP server connects a coding agent to the SDK through the Model Context Protocol. Start it with sauce mcp, or let your agent start it from its configuration. Use AI agents to understand the workflow from a request to a program. This section covers the server’s tools, configuration and wallet access.

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Connect your agent

Follow Installation for Node.js requirements and configuration for Claude Code, Codex, Cursor, VS Code, Gemini CLI or Claude Desktop. Project configuration can pin the server to a specific package version. Once configured, ask the agent to list its sauce_ tools. The default local server lists 27 tools. A server started with --no-stores, or over HTTP, lists 18. See which tools a server lists.

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What the server provides

MCP tools documents the inputs and outputs. AI agents explains the program-writing workflow.

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Choose a transport

A local agent usually starts the server over stdio, communicating through the process’s standard input and output. Use HTTP when agents need to connect to a shared server by URL. Local server storage covers the stdio stores. Self-hosting over HTTP covers authentication, endpoint restrictions and deployment.

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Wallet access

Transaction-building tools return unsigned transactions. No tool input accepts a private key, seed or password, and no result returns one. You can sign with your own wallet or a separate wallet MCP server. The local stdio server also exposes your Sauce wallet directory. A password source enables its signing tools; an agent can enable them by naming a source the server can read. Start with --no-wallets to remove wallet tools, or --no-stores to remove wallet tools and Pot records. See Wallets over stdio and Agents, wallets and keys.

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Chain access

A tool selects an endpoint from its rpcUrl input, then the server’s --config file, then a built-in public endpoint. RPC URLs are not included in results, logs or error messages. See How a tool reaches a chain for the full order and offline behavior. The server builds and sends transactions on Ethereum, Base, Arc and Solana, and on the testnets Arc Testnet, Base Sepolia, Ethereum Sepolia, Solana Devnet and Solana Testnet. On preview chains, compiling and reading work; simulation also requires the release’s engine and Kitchen to be deployed. Transaction building is refused. See supported and preview chains.

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Runtime packages

The server needs the MCP SDK and zod at the versions pinned by the package. It uses matching project dependencies when available, or installs them in ~/.sauce/runtime/<version> on first use. sauce mcp setup prepares this directory during setup. Offline startup requires those dependencies to be installed already. Use sauce runtime to inspect or install runtime packages. For startup failures, see MCP setup troubleshooting.

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Next steps