Silica

AI-native EDA environment · MCP server for hardware design and verification

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What it does

Silica is an MCP server that gives coding agents structured access to an EDA toolchain. The agent lints, simulates, proves, synthesizes, places and routes, programs a board and reads its UART through MCP tools, and gets parsed results back (errors with file and line, timing per clock, utilization, inferred memories, counterexample traces) instead of raw logs.

That closes the loop without copy-paste: run the simulation, read the failure, fix the RTL, re-run. The server also tells the agent the order to work in and the pitfalls to avoid, and a doctor tool reports which EDA tools are installed and how to install the rest.

Silica drives tools you install yourself: open-source tools (mostly from OSS CAD Suite), and commercial ones (VCS, Questa, Xcelium, Vivado, …) when they're on PATH. How well each is tested is listed under Supported tools.

What works today

The full flow has been run end to end on a Digilent Arty A7-100T (Xilinx Artix-7) with a PicoRV32 RISC-V SoC whose firmware prints a banner, echoes UART input and drives LEDs from a timer:

1. RTL and lint: Verilator, Verible and svlint, with Verilator elaborating the whole multi-file design.
2. Simulation: Icarus and Verilator running the real firmware from $readmemh, with waveform (read_waveform) and line coverage (read_coverage).
3. Formal: SymbiYosys prove, cover and bounded checks on the UART and FIFO, a deliberately false assertion reported as FAIL with its counterexample, and eqy equivalence.
4. Synthesis: Yosys synth_xilinx, with utilization and the firmware ROM reported as block RAM with init data.
5. Place and route: openXC7's nextpnr-xilinx (100 MHz target, routed at 153 MHz), and the .bit assembled with fpga-as.
6. Programming: program_device (openFPGALoader) into SRAM, with the FPGA's DONE status checked.
7. Serial check: capture_serial confirming the banner and the echo over the board's UART.

These runs were manual, on one machine (OSS CAD Suite 2026-10-14, openXC7 toolchain-nix 1.0.0, Verible v0.0-4296, svlint 0.9.5). CI covers the open-source tools in a weekly integration job; see Supported tools.

Known limitations

• Vivado is synthesis only: there's no implementation or bitstream step.
• VCS, Questa and Xcelium adapters are tested only with mocked tool calls, never against a real install; the same goes for Quartus, DC Shell, JasperGold, VC Formal, SpyGlass and Verdi. If one misbehaves, please open an issue with the tool version and output.
• iCE40 and ECP5 bitstreams are packed with icepack/ecppack and checked against the real tools, but program_device has only been tested on these boards with mocked openFPGALoader calls: no iCE40 or ECP5 board has been available. get_project_structure doesn't list iCE40 .pcf files.
• cocotb needs a Python whose glibc is compatible with the simulator it loads into. With OSS CAD Suite's simulators and a newer system Python (glibc newer than the suite's), run_cocotb fails at import.
• Formal: an UNKNOWN prove with induction_failures is inconclusive (k-induction didn't close), not a bug. Deep bounded checks can be slow; 120 steps on the example UART took 16 minutes.
• Offline: clients configured with uvx silica-eda@latest (including the Claude Code plugin) can't start the server without network; see Offline under the install instructions for the --offline workaround.
• Serial: capture_serial needs the port named explicitly and read/write access to it. A boot banner is usually missed by a capture started after programming.
• Windows: the serial existence and permission pre-checks are POSIX-only, and the pty-based serial tests skip there.

Quick start

1. Install [uv](https://docs.astral.sh/uv/getting-started/installation/). silica itself needs no separate install: your agent starts it with uvx silica-eda@latest, and uv's uvx downloads silica-eda from PyPI on first use and runs it. To check, run uvx silica-eda@latest --version.
2. Add silica to your agent. Run the setup wizard, uvx silica-eda@latest setup, which writes each client's config for you (see Setup wizard), or follow Install in your agent.
3. Install the EDA tools you need: OSS CAD Suite for most open-source tools, Verible and svlint for linting, openXC7 for Xilinx place and route. Then ask the agent to run doctor.
4. Try the UART example in examples/uart/:

Run the UART TX simulation in examples/uart/ and tell me if it passes.

Then break it and let the agent find the bug:

In examples/uart/uart_tx.sv, change the DATA state's shift to shift_reg <= {shift_reg[6:0], 1'b0};. Run the simulation, find the bug and fix it.

The testbench then prints [FAIL] lines such as bit[2] is 0, expected 1, and the agent should trace them to the shift direction.

Install in your agent

Every client below starts the server with uvx silica-eda@latest, so there is no separate install step for silica: uvx downloads it into a cached environment on first use and picks up new releases when the client next starts the server. Install uv first; that's what provides uvx. If you'd rather install silica yourself, uv tool install silica-eda or pip install silica-eda puts a silica command on your PATH, and the client's command becomes silica with the argument serve. uvx silica-eda needs a silica-eda release newer than 0.3.1; on 0.3.1 use uvx --from silica-eda@latest silica instead.

silica drives EDA tools you install separately (Verilator, Yosys, SymbiYosys, nextpnr, …); see Installing the EDA tools. Once connected, ask the agent to run the doctor tool: it lists what's installed and how to install what's missing.

Claude Code (plugin, with a workflow skill)

In Claude Code:

/plugin marketplace add simaanc/silica-eda

/plugin install silica-eda@silica-eda

On Claude Code 2.1.275 or later this also works in one step: /plugin install silica-eda --marketplace simaanc/silica-eda.

Updates: the plugin's server always runs uvx silica-eda@latest. To also receive plugin updates (new skills, config changes) automatically, turn on auto-update for the marketplace, which is off by default: /plugin → Marketplaces → silica-eda → Enable auto-update. Admins can set "autoUpdate": true on the marketplace's extraKnownMarketplaces entry in managed settings. Without auto-update, run /plugin marketplace update silica-eda.

Without the plugin, add just the server:

claude mcp add --transport stdio --scope user silica -- uvx silica-eda@latest

Claude Desktop

Open Settings → Developer → Edit Config and add the server to claude_desktop_config.json, then quit and restart Claude Desktop:

{

"mcpServers": { "silica": { "command": "uvx", "args": ["silica-eda@latest"] } } }

If the server doesn't start, Claude Desktop may not see your shell's PATH: put the full path from which uvx in command.

Codex CLI

codex mcp add silica -- uvx silica-eda@latest

or in ~/.codex/config.toml:

[mcp_servers.silica]

command = "uvx" args = ["silica-eda@latest"]

The first launch downloads silica; Codex's default start timeout is 10 s.

startup_timeout_sec = 60

Cursor

Add to ~/.cursor/mcp.json (all projects) or .cursor/mcp.json (one project):

{

"mcpServers": { "silica": { "type": "stdio", "command": "uvx", "args": ["silica-eda@latest"] } } }

One-click install: open this link in your browser (GitHub doesn't make cursor:// links clickable):

cursor://anysphere.cursor-deeplink/mcp/install?name=silica&config=eyJjb21tYW5kIjoidXZ4IiwiYXJncyI6WyJzaWxpY2EtZWRhQGxhdGVzdCJdfQ==

VS Code (GitHub Copilot)

code --add-mcp '{"name":"silica","type":"stdio","command":"uvx","args":["silica-eda@latest"]}'

or in .vscode/mcp.json (workspace) or your user-profile mcp.json:

{

"servers": { "silica": { "type": "stdio", "command": "uvx", "args": ["silica-eda@latest"] } } }

Gemini CLI

gemini mcp add -s user silica uvx silica-eda@latest

or in ~/.gemini/settings.json (user) or .gemini/settings.json (project):

{

"mcpServers": { "silica": { "command": "uvx", "args": ["silica-eda@latest"] } } }

Setup wizard

uvx silica-eda@latest setup (or silica setup from a pip install) asks which clients and EDA tools you use, saves the tool choices to ~/.silica/config.toml, and adds a silica server that runs uvx silica-eda@latest to each client's config. It shows each change and asks before writing it; other servers and settings in the file are kept. uvx is written as a full path when it's on PATH, because desktop apps may not see your shell's PATH.

Where a client's documentation gives no config path for your platform (Zed on macOS and Windows, OpenCode on Windows), or the existing file can't be read as plain JSON (for example a Zed settings.json with comments), the wizard leaves the file alone and prints the block to add by hand.

Optional extras. capture_serial needs pyserial and run_cocotb needs cocotb. With uvx, add them to the arguments: "args": ["--with", "pyserial", "silica-eda@latest"] (or --with cocotb). With pip, install silica-eda[serial] or silica-eda[cocotb].

Offline. @latest makes uvx ask PyPI for the newest release every time the client starts the server, so without network the server doesn't start (error: Request failed after 3 retries), even when silica is already cached. To work offline, put --offline before the package, `"args": ["--offline", "silica-eda@lat