logix-engine

One open engine to build and test FPGA designs and program boards, for any IDE or AI agent.

The engine is a single native executable, written in Rust, that offers FPGA operations as MCP tools over stdin/stdout. Frontends such as Logix IDE, Logix CLI, IceStudio, IDE extensions, CI scripts and AI coding agents launch it as a child process and call its tools. The engine installs and drives proven open source tools, such as Yosys, nextpnr and openFPGALoader, so each frontend can focus on its own user experience instead of reimplementing the toolchain.

Status

In development, macOS on Apple Silicon only.

• Milestone 1, done: a proof of concept for iCE40 boards with seven tools: get_engine_info, install_packages, get_catalog (22 iCE40 boards), build, clean_build, list_devices and program_board. An AI agent, Claude Code, changed a design, built it and programmed an Alhambra II board through the engine alone.
• Milestone 2, next: Logix IDE running on the engine, keeping every feature it has today: lint, test, simulate, format, graph, live tool output, and the same boards across iCE40, ECP5, Gowin and Xilinx 7 Series. See Acceptance and phasing.

Daily development builds are on the Releases page.

Documentation

Document	What it covers
Requirements	Goals and non-goals, supported platforms, required capabilities, file safety, versioning, error model, phasing and open questions
Architecture	The proposed design: components, technology choices, testing, distribution and host code examples
Tool API (Milestone 1)	The MCP tools, their inputs, outputs and errors
Command line (Milestone 1)	Launch arguments and logging

Development

The engine is written in Rust. Install it with rustup, which reads the Rust version pinned in rust-toolchain.toml and installs it automatically on first build.

• macOS with Homebrew: run brew install rustup. The scripts below find it on their own. To use cargo directly, also add $(brew --prefix rustup)/bin to your PATH.
• Other platforms: follow the instructions at rustup.rs.

Check the setup with cargo --version.

Script	What it does
scripts/test.sh	All checks and tests: format, lint, unit, schema, command-line, build and end-to-end MCP tests. Run it before committing. CI runs it too. The first run downloads the FPGA toolchain (526 MB) for the build tests
scripts/build.sh	Builds the release binary, target/release/logix-engine
scripts/run-in-claude.sh	Builds if needed and starts Claude Code with the engine connected, so you can prompt it. Claude works in ~/.logix-dev/playground, and the engine uses ~/.logix-dev/engine
scripts/run-in-grok.sh	The same with Grok as the host. It writes the engine into the playground's .grok/config.toml
scripts/engine-cmd.sh	Sends one prompt to Claude Code with the engine connected and prints the answer as plain text, such as scripts/engine-cmd.sh --add-dir ~/proj "Build ~/proj for the Alhambra II". -c continues the previous conversation. See --help
scripts/serve.sh	Builds if needed and runs the engine as an MCP server on stdin/stdout, for other MCP clients
scripts/clean.sh	Deletes the build output
scripts/update-schemas.sh	Regenerates schemas/tools.json, the published copy of the tool schemas, after a deliberate change

To try the engine with Claude Code as the host, run scripts/run-in-claude.sh and type prompts, such as "What version is the Logix engine?". It uses the claude command, or the one bundled with the Claude Code VS Code extension. scripts/run-in-grok.sh does the same with Grok. Both start the agent from a clean slate for reproducible hand tests: none of your own agent settings, instructions or memories, a copy of the engine outside the repo, and rules asking the agent to start only from what the engine provides. To try it with another MCP client, such as the MCP Inspector, point the client at scripts/serve.sh:

npx @modelcontextprotocol/inspector /path/to/logix-engine/scripts/serve.sh

License

Apache-2.0. The packaged open source tools keep their own licenses.