mcpx

mcpx

Turn MCP servers into composable CLIs.

mcpx turns MCP tools into shell commands so agents can use standard CLI composition (|, redirection, jq, head) and skill workflows.

mcpx keeps the command contract simple:

• mcpx lists servers
• mcpx <server> lists tools
• mcpx <server> <tool> calls a tool

Tool names are used exactly as exposed by each server (no client-side renaming/aliasing).

Utility commands:

• mcpx add <source> [--name <server>] [--header KEY=VALUE]... [--overwrite] bootstraps a server config from an install link, manifest URL, direct MCP endpoint URL, or local manifest file
• mcpx shim install <server> installs a local passthrough command shim (<server> ... -> mcpx <server> ...)
• mcpx shim remove <server> and mcpx shim list manage installed shims
• mcpx completion <bash|zsh|fish> prints shell completion scripts
• mcpx skill install installs the built-in mcpx skill to ~/.agents/skills and links it for Claude Code (optional flags also link for Codex/Kiro)
• mcpx skill install [<server>] installs the built-in mcpx skill (no server) or generates a server-specific skill when a server name is provided.

It is designed for agent workflows and shell composition:

• schema-aware --help (inputs + declared outputs)
• native flag surface from MCP inputSchema
• standardized exit mapping (0/1/2/3)
• optional response caching with TTL and config overrides
• optional Codex Apps compatibility via virtual per-app servers
• stdio + HTTP transports via a local daemon
• generated shell completions and packaged root man page (man mcpx)

Install

Homebrew

brew tap lydakis/mcpx
brew install --cask mcpx

npm

npm install -g mcpx-go
mcpx --version

PyPI

pip install mcpx-go
mcpx --version

Build from source

go build ./...
./mcpx --version

Windows users: use WSL2 and run install commands inside your Linux distro shell.

Quick Start

If you already use MCP in Cursor/Claude Code/Cline/Codex/Kiro, mcpx will auto-discover those server configs. Start with:

mcpx
mcpx <server>
mcpx <server> <tool> --help

When Codex Apps are enabled in local Codex config and authenticated, mcpx also exposes connected apps as MCP servers.

If mcpx shows no servers, create ~/.config/mcpx/config.toml:

[servers.github]
command = "npx"
args = ["-y", "@modelcontextprotocol/server-github"]
env = { GITHUB_TOKEN = "${GITHUB_TOKEN}" }
default_cache_ttl = "30s"

Run:

mcpx
mcpx github
mcpx github search-repositories --help
mcpx github search-repositories --query=mcp
mcpx shim install github
github search-repositories --query=mcp | jq -r '.items[:3][].full_name'

Command Shims (Optional)

mcpx shim install github
mcpx shim install github --skill
mcpx shim list
mcpx shim remove github

Shims are pass-through wrappers (<server> ... -> mcpx <server> ...) installed in $XDG_BIN_HOME (if set) or ~/.local/bin. Ensure that directory is in your PATH. Install is collision-safe: it fails if that command name already resolves elsewhere in PATH.

Use mcpx shim install <server> --skill to also install a generated server skill after shim install succeeds. Add --skill-strict to fail the command if skill generation/install fails.

Server Skill Generation (Optional)

mcpx skill install github
mcpx skill install github --codex-link

This writes a generated server skill to ~/.agents/skills/mcpx-<server> by default and can optionally link it into Codex/Kiro/Claude skill directories using the same flags as mcpx skill install.

Output Modes

--json applies only to mcpx-owned output surfaces:

• mcpx
• mcpx <server>
• mcpx <server> <tool> --help

Normal tool-call output (mcpx <server> <tool> ...) is not transformed by --json.

Use mcpx -v (or mcpx --json -v) to include per-server origin metadata (config/fallback-derived kind; JSON also includes optional path).

More Examples

mcpx --json
mcpx github --json
mcpx github -v
mcpx github search-repositories --help --json
mcpx add "cursor://anysphere.cursor-deeplink/mcp/install?name=postgres&config=..."
mcpx add https://mcp.deepwiki.com/mcp
mcpx add https://mcp.devin.ai/mcp --name deepwiki --header "Authorization=Bearer \${DEEPWIKI_API_KEY}"
mcpx skill install

Codex Apps (Optional)

When Codex Apps are enabled in local Codex config, mcpx can expose connected apps as normal MCP servers (for example, linear or zillow) through the same command contract:

mcpx linear
mcpx linear <tool> --help
mcpx linear <tool> ...

Auth is still managed by Codex. mcpx does not run OAuth flows or store third-party app credentials.

MCP Smoke Test Commands

Use these to validate a local MCP quickly:

mcpx <server>
mcpx <server> --json       # machine-readable list output
mcpx <server> -v            # full tool descriptions
mcpx <server> <tool> --help
mcpx <server> <tool> --help --json
mcpx <server> <tool> -v
echo $?    # inspect exit code contract

For your current fallback setup, a working browser-tools entry should use -y:

[servers.browser-tools]
command = "npx"
args = ["-y", "@agentdeskai/browser-tools-mcp@1.1.0"]

Performance Benchmarks

Benchmarks are manual by design (not part of CI):

make perf

To compare current work against a baseline ref:

./scripts/perf_bench.sh <git-ref>

To measure warm CLI throughput (mcpx --json) for 500 calls:

make perf-loop
./scripts/perf_cli_loop.sh <git-ref>

For summarized comparisons, install benchstat:

go install golang.org/x/perf/cmd/benchstat@latest

Versioning Behavior

• Local/dev builds show mcpx dev.
• Tagged release builds show the tag version in mcpx --version (for example mcpx v0.1.0) via GoReleaser ldflags.

Release

• Tag pushes v* run the release workflow.
• GoReleaser publishes artifacts and updates lydakis/homebrew-mcpx.
• Notarization uses standard Apple Developer and App Store Connect secrets.

Detailed docs:

• design
• usage
• release
• roadmap

License

MIT