mcp2cli

Universal CLI adapter that turns MCP servers, OpenAPI specs, and GraphQL APIs into interactive command-line tools.

Inspired by mcp2cli (Python) — this is a ground-up Rust rewrite with expanded protocol support.

Install

Precompiled binary (recommended)

curl -fsSL https://raw.githubusercontent.com/christopher-kapic/mcp2cli-rs/master/scripts/install.sh | bash

This installs the latest release to /usr/local/bin. Run it again at any time to update.

To install a specific version or to a custom directory:

# Specific version
curl -fsSL https://raw.githubusercontent.com/christopher-kapic/mcp2cli-rs/master/scripts/install.sh | bash -s v0.2.0

# Custom directory
curl -fsSL https://raw.githubusercontent.com/christopher-kapic/mcp2cli-rs/master/scripts/install.sh | INSTALL_DIR=~/.local/bin bash

From source

cargo install --git https://github.com/christopher-kapic/mcp2cli-rs.git

Quick start

MCP

# HTTP / SSE server
mcp2cli --mcp http://localhost:3000 --list
mcp2cli --mcp http://localhost:3000 get-user --id 42

# Stdio server
mcp2cli --mcp-stdio "npx -y @modelcontextprotocol/server-filesystem /" --list

OpenAPI

mcp2cli --spec https://petstore3.swagger.io/api/v3/openapi.json --list
mcp2cli --spec ./openapi.yaml findPetsByStatus --status available --pretty

GraphQL

mcp2cli --graphql https://countries.trevorblades.com --list
mcp2cli --graphql https://countries.trevorblades.com country --code US --pretty

Features

• Three protocols — MCP (HTTP, SSE, stdio), OpenAPI, and GraphQL through one binary
• Authentication — static headers (--auth-header) or OAuth 2.0 (PKCE and client-credentials flows)
• Sessions — persistent background daemons for long-lived MCP connections
• Bake — save and recall CLI configurations as named profiles, installable as shell commands
• Output — pretty-print, raw, --jq filters, --toon formatting, --head to limit arrays
• Caching — file-based response cache with configurable TTL
• Filtering — --search globally; --include / --exclude glob patterns and --methods in bake configs

Authentication

# Static header
mcp2cli --spec api.yaml --auth-header "Authorization:Bearer $TOKEN" list-items

# OAuth 2.0 PKCE (opens browser)
mcp2cli --spec api.yaml --oauth https://auth.example.com --oauth-client-id my-app list-items

# OAuth 2.0 client credentials
mcp2cli --spec api.yaml --oauth https://auth.example.com \
  --oauth-client-id my-app --oauth-client-secret $SECRET list-items

Sessions

Keep an MCP connection alive across invocations:

mcp2cli --mcp http://localhost:3000 --session-start my-session
mcp2cli --session my-session get-user --id 42
mcp2cli --session my-session --session-stop my-session
mcp2cli --session-list

Bake (saved configurations)

# Save a configuration
mcp2cli bake create petstore --spec https://petstore3.swagger.io/api/v3/openapi.json --pretty

# Use it
mcp2cli @petstore --list
mcp2cli @petstore findPetsByStatus --status available

# Install as a standalone shell command
mcp2cli bake install petstore
petstore findPetsByStatus --status available

Output formatting

mcp2cli --spec api.yaml list-items --pretty          # Pretty-print JSON
mcp2cli --spec api.yaml list-items --jq '.[0].name'  # jq filter
mcp2cli --spec api.yaml list-items --head 5           # First 5 items
mcp2cli --spec api.yaml list-items --raw              # Raw text

Requirements

• Rust 1.80+

License

MIT