Alire MCP

A Python Model Context Protocol server for Alire, the Ada package manager.

The server exposes a curated set of Alire operations to MCP clients. It does not expose an unrestricted shell or arbitrary alr argument execution.

Features

• Search for and inspect crates in the Alire index
• Inspect project dependency solutions and trees
• Build Alire projects
• Add, remove, and update dependencies
• Initialize new executable or library crates
• Fetch published crate sources
• Non-interactive subprocess execution with no shell
• Optional workspace-root confinement
• Configurable time and output limits
• Read-only and destructive MCP tool annotations

Requirements

• Python 3.10 or later
• Alire (alr) installed and available on PATH

Verify Alire before starting the server:

alr --version

Installation

Install from a source checkout:

python3 -m pip install .

For an isolated development environment:

python3 -m venv .venv

.venv/bin/python -m pip install -e '.[dev]'

Run the stdio server:

alire-mcp

The server communicates using MCP messages on standard input and standard output. Diagnostic output from Alire is captured and returned by each tool, not written into the MCP transport stream.

MCP client configuration

A typical MCP client configuration is:

{
  "mcpServers": {
    "alire": {
      "command": "alire-mcp",
      "args": [],
      "env": {
        "ALIRE_MCP_WORKSPACE_ROOT": "/absolute/path/to/ada/workspaces"
      },
      "disabled": false,
      "autoApprove": []
    }
  }
}

If the executable is installed in a virtual environment, use its absolute path for command:

{
  "mcpServers": {
    "alire": {
      "command": "/absolute/path/to/alire-mcp/.venv/bin/alire-mcp",
      "args": [],
      "env": {
        "ALIRE_MCP_WORKSPACE_ROOT": "/absolute/path/to/ada/workspaces"
      },
      "disabled": false,
      "autoApprove": []
    }
  }
}

Restart or reload the MCP client after changing its configuration.

Tools

Tool	Effect
alire_version	Show detailed Alire version and environment information
search_crates	Search crate names and descriptions
show_crate	Show metadata for a crate or exact release
project_dependencies	Inspect direct, solved, tree, graph, or version dependency views
build_project	Build a project
update_dependencies	Update all or selected dependencies
add_dependency	Add a dependency constraint to a manifest
remove_dependency	Remove a dependency from a manifest
initialize_crate	Create an executable or library crate
fetch_crate	Fetch a crate release

Every tool result contains:

• command: the exact argument vector used
• cwd: the effective working directory
• exit_code: Alire's process exit status
• success: whether the exit status was zero
• stdout and stderr: captured output
• stdout_truncated and stderr_truncated: output-limit indicators

A nonzero Alire exit code is returned as command data so an MCP client can inspect Alire's diagnostic text. Server-level failures, such as an invalid workspace path or timeout, are reported as tool errors.

Configuration

The server is configured through environment variables:

Variable	Default	Description
ALIRE_MCP_ALR	alr	Alire executable name or path
ALIRE_MCP_WORKSPACE_ROOT	unset	Restrict project directories to this directory tree
ALIRE_MCP_TIMEOUT	300	Per-command timeout in seconds
ALIRE_MCP_MAX_OUTPUT_BYTES	1000000	Maximum captured bytes for each output stream

When ALIRE_MCP_WORKSPACE_ROOT is configured:

• omitted tool directories use the workspace root;
• relative directories resolve below the workspace root;
• absolute directories outside the root are rejected;
• symlink resolution cannot escape the root.

Without a workspace root, omitted directories inherit the MCP server process working directory and explicitly supplied paths may point to any accessible directory.

Security

Alire MCP applies the following boundaries:

• Commands are launched with asyncio.create_subprocess_exec; no shell is involved.
• Global --non-interactive, --no-color, and --no-tty options are always used.
• Standard input is disabled for child processes.
• Tool parameters are validated and map to a fixed set of Alire commands.
• Commands have a timeout and bounded captured output.
• MCP annotations identify read-only and potentially destructive operations.

Alire itself may download, compile, and execute code from package sources. Treat third-party crates as untrusted and review requested mutating operations. For stronger isolation, run this server in a container or restricted user account and configure ALIRE_MCP_WORKSPACE_ROOT.

Development

Install development dependencies:

python3 -m pip install -e '.[dev]'

Run tests:

pytest

Run linting and formatting checks:

ruff check .

ruff format --check .

Run type checking:

mypy

Build distribution artifacts:

python3 -m build

License

Alire MCP is distributed under the MIT License.