jacs-cli

Single binary for the JACS command-line interface and MCP server.

cargo install jacs-cli

This installs the jacs binary with CLI and MCP server built in.

Quick Start

# Developer / desktop workflow
export JACS_PRIVATE_KEY_PASSWORD='use-a-strong-password'

# Create an agent and start signing
jacs quickstart --name my-agent --domain my-agent.example.com
jacs document create -f mydata.json

# Start the MCP server (stdio transport)
jacs mcp

For Linux or other headless service environments, prefer a secret-mounted password file:

export JACS_CONFIG=/srv/my-project/jacs.config.json
export JACS_PASSWORD_FILE=/run/secrets/jacs-password
export JACS_KEYCHAIN_BACKEND=disabled
jacs mcp

Homebrew (macOS)

brew tap HumanAssisted/homebrew-jacs
brew install jacs

From Source

git clone https://github.com/HumanAssisted/JACS
cd JACS
cargo install --path jacs-cli

MCP Server

The MCP server is built into the binary. No separate install step needed.

jacs mcp

Configure in .mcp.json for Claude Code or similar clients:

{
  "mcpServers": {
    "jacs": {
      "command": "jacs",
      "args": ["mcp"],
      "env": {
        "JACS_CONFIG": "/srv/my-project/jacs.config.json",
        "JACS_PASSWORD_FILE": "/run/secrets/jacs-password",
        "JACS_KEYCHAIN_BACKEND": "disabled"
      }
    }
  }
}

The MCP server uses stdio transport only (no HTTP) for security.

JACS_PRIVATE_KEY_PASSWORD is still supported, but for Linux/headless services JACS_PASSWORD_FILE is the preferred deployment path.

Documentation