mcp-compressor 0.15.0a3

Rust-backed experimental Python package for mcp-compressor.

mcp-compressor Python SDK

Python SDK and CLI wrapper for mcp-compressor.

The public Python import is mcp_compressor:

from mcp_compressor import CompressorClient

Quick start

The primary SDK object is CompressorClient. It starts a local Rust-backed proxy in-process and returns a CompressorProxy; no mcp-compressor stdio subprocess is required.

from mcp_compressor import CompressorClient

servers = {
    "alpha": {
        "command": "python",
        "args": ["alpha_server.py"],
    },
    "atlassian": {
        "url": "https://mcp.atlassian.com/v1/mcp",
    },
}

with CompressorClient(
    servers=servers,
    mode="compressed",
    compression_level="medium",
    include_tools=["getConfluencePage", "updateConfluencePage"],
    toonify=True,
) as proxy:
    print([tool.name for tool in proxy.tools])
    result = proxy.invoke(
        "getAccessibleAtlassianResources",
        {},
        server="atlassian",
    )
    print(result)

Modes

CompressorClient accepts these modes:

• compressed — expose compressed wrapper tools such as <server>_get_tool_schema and <server>_invoke_tool.
• cli — expose CLI/help transform metadata through the shared Rust runtime.
• bash — expose Just Bash provider metadata through the shared Rust runtime.

Generated Python and TypeScript clients are produced with proxy.write_client(...) rather than by selecting a long-lived session mode.

Just Bash metadata

Just Bash mode exposes the compressed proxy bridge plus typed provider metadata. Language hosts can use this metadata to register backend MCP tools as Just Bash commands without the Rust runtime executing shell commands itself:

from mcp_compressor import CompressorClient, create_just_bash_commands

with CompressorClient(servers=servers, mode="bash") as proxy:
    commands = {cmd.command_name: cmd for cmd in create_just_bash_commands(proxy)}
    print(commands["atlassian_get-accessible-atlassian-resources"]([]))

Duplicate backend command names are prefixed with the provider name, for example alpha_echo and beta_echo.

Generated clients

A connected proxy can write shell, Python, or TypeScript clients that call the live proxy:

with CompressorClient(servers=servers, compression_level="max") as proxy:
    proxy.write_client("cli", "./bin", name="atlassian")
    proxy.write_client("python", "./generated-py", name="atlassian")
    proxy.write_client("typescript", "./generated-ts", name="atlassian")

Packaging smoke test

Build a local wheel and verify it imports from a clean virtualenv:

uvx maturin build --release --out dist
python -m venv /tmp/mcp-compressor-wheel-test
/tmp/mcp-compressor-wheel-test/bin/python -m pip install "$PWD"/dist/*.whl
cd /tmp
/tmp/mcp-compressor-wheel-test/bin/python -c "from mcp_compressor import CompressorClient, ToolSpec"

CI runs the same kind of wheel smoke test before uploading the built wheel as an artifact.

Advanced helpers

Low-level helpers such as compress_tool_listing, parse_tool_argv, and ToolSpec remain available for tests and advanced integrations, but the primary SDK entry point is CompressorClient.