<p align="center"> <picture> <source media="(prefers-color-scheme: dark)" srcset="./assets/banner-dark.svg"> <source media="(prefers-color-scheme: light)" srcset="./assets/banner-light.svg"> <img alt="mcpm - the MCP package manager" src="./assets/banner-light.svg" width="680"> </picture> </p>

mcpm

The MCP package manager that guards your AI's tools at runtime -- search, install, audit, and inspect every MCP server from your terminal.

The risky part of an MCP server doesn't show up at install -- it shows up while your agent is running: prompt injection hidden in a tool's output, a server that quietly rewrites its tools after you approved them, a sampling request that smuggles instructions into your model. mcpm scores every install for hardcoded secrets, prompt injection, and typosquatting (66% of MCP servers have security findings) -- then runs a live guard between your AI client and each server, pinning tool definitions against rug-pulls and blocking injection before it reaches the model.

<p align="center"> <img src="./assets/demo.gif" alt="mcpm demo" width="680"> </p>

Quick start

npm install -g @getmcpm/cli

mcpm search filesystem
mcpm info io.github.domdomegg/filesystem-mcp
mcpm install io.github.domdomegg/filesystem-mcp

Features

Search the MCP registry

Query the official MCP Registry and see results with trust indicators.

$ mcpm search filesystem

  Name                                              Description                    Score
  io.github.domdomegg/filesystem-mcp                 File system access via MCP     82/100
  io.github.Digital-Defiance/mcp-filesystem           Read-only filesystem server    67/100
  ...

Install with trust assessment

Every install runs a metadata-based trust assessment before writing config.

$ mcpm install io.github.domdomegg/filesystem-mcp

  Trust Score: 82/100 (safe)
    Health check:    30/30
    Static scan:     32/40
    External scan:    —  (install mcp-scan for full coverage)
    Registry meta:   10/10

  Install to Claude Desktop? (Y/n)

Audit installed servers

Scan everything you have installed. Get a trust report.

$ mcpm audit

  Server                                   Client          Score   Level
  servers-filesystem                        Claude Desktop  82/100  safe
  servers-github                            Cursor          74/100  caution
  some-sketchy-server                       VS Code         31/100  risky

Cross-IDE support

One tool for all your AI clients. mcpm reads and writes the correct config format for each.

$ mcpm list

  Client            Server Name                  Status     Command/URL
  Claude Desktop    servers-filesystem           active     npx -y servers-filesystem
  Claude Desktop    servers-github               active     npx -y servers-github
  Cursor            servers-fetch                disabled   npx -y servers-fetch

Doctor: check your MCP setup health

Find misconfigurations, missing runtimes, and broken servers.

$ mcpm doctor

  Checking MCP setup...
  [pass] Claude Desktop config found
  [pass] npx runtime available
  [warn] Cursor config not found
  [pass] 3 servers installed, 0 with errors

Stack files: docker-compose for MCP

Declare your project's MCP servers in mcpm.yaml, lock versions with trust snapshots, and let every team member replicate the setup with one command.

mcpm export > mcpm.yaml          # dump current setup
mcpm lock                        # resolve versions + trust snapshot
mcpm up                          # install everything from mcpm.yaml
mcpm diff                        # compare installed vs declared state

Stack files include a trust policy. If a server's trust score drops below the threshold, mcpm up blocks it.

version: "1"
policy:
  minTrustScore: 60
  blockOnScoreDrop: true
servers:
  io.github.domdomegg/filesystem-mcp:
    version: "^1.0.0"
  io.github.modelcontextprotocol/servers-github:
    version: "1.2.3"
    env:
      GITHUB_TOKEN: { required: true, secret: true }

Scaffold a stack file

Start a new project's MCP setup in one command. mcpm init writes a starter mcpm.yaml you fill in with servers from mcpm search.

$ mcpm init

  Created mcpm.yaml.

  Next steps:
    mcpm search <query>   find MCP servers in the registry
    edit mcpm.yaml        add them under `servers:`
    mcpm lock             resolve and lock versions
    mcpm up               install from the stack file

It refuses to clobber an existing mcpm.yaml (pass --force to overwrite). mcpm deliberately doesn't ship curated packs — blessing specific community servers is a trust decision a security tool shouldn't bake in.

Trust score

The trust score is a 0-100 assessment based on publicly available metadata. It is not a source code audit.

What it checks:

Levels: safe (80+), caution (50-79), risky (below 50).

Without an external scanner installed, the maximum possible score is 80/100. The static scan catches common patterns but cannot detect all vulnerabilities. Treat the score as a signal, not a guarantee.

Commands

Run mcpm <command> --help for options and flags.

Runtime defense (mcpm-guard)

Install-time trust scoring catches most poisoned servers before they ship. But what about rug-pulls — a server that changes its tool definitions after you've already approved them? Or prompt-injection in tool responses — adversarial text embedded in a Slack message, web page, or calendar invite that the agent reads through your trusted MCP server?

mcpm guard adds a runtime inspection layer. It wraps every installed MCP server with a stdio relay, scans tool descriptions / responses / arguments for OWASP MCP Top 10 attack patterns, pins each tool's schema at install time, and blocks calls when the live response drifts from the pin (rug-pull defense).

What happens on every tool call

The guard sits inline on the stdio channel between your AI client and each MCP server, so it sees both halves of every tool call and inspects them as they pass:

• The request your agent sends — the tool name and arguments, checked for sensitive-path exfil and injection smuggled into call parameters.
• The response the server returns — checked for instruction injection hidden in the tool's output (the Slack message, web page, or calendar invite your agent is about to read).
• The tool's own definition — tools/list descriptions, schemas, and annotations, checked against the schema pinned at approval time, so a server can't quietly rewrite a tool you already trusted.

When a frame trips a signature, drift check, or policy rule, the guard drops it and hands your agent a JSON-RPC error in its place — carrying the signature id and a remediation string — so the poisoned content never reaches your model. Clean calls pass straight through (p99 ~0.065 ms on small frames). Server-initiated sampling / elicitation requests are inspected the same way, with the error routed back to the server rather than to your agent.

Quick start

npm install -g @getmcpm/cli@latest

mcpm guard enable           # wrap detected client configs (Claude Desktop / Cursor / VS Code / Windsurf)
# → restart your IDE so it re-spawns the wrapped server processes
mcpm guard demo             # synthetic prompt-injection scenario — see a live block in your terminal
mcpm guard status           # what's protected, what's still in first-session-pin mode

The demo command boots an in-process synthetic malicious server that returns a canned prompt-injection payload; the relay blocks it. Total time from npm install to a screenshot-worthy block: ~5 minutes (most of which is the IDE restart).

What it catches

Detection is regex + structural; NFKC + zero-width-char stripping defeats the common Unicode evasions, and a separate hidden-character presence check flags evasion carriers before they're normalized away. See mcpm guard list-signatures for the current shipped set.

Day-1 commands

mcpm guard enable [--client <name>] [--server <name>] [--dry-run]    # wrap detected configs
mcpm guard disable [--client <name>] [--server <name>]               # unwrap
mcpm guard status                                                    # what's wrapped + pin state
mcpm guard demo                                                      # synthetic attack-block demo
mcpm guard list-signatures [--json]                                  # show shipped signatures

When a block fires

The relay returns a JSON-RPC error response to your IDE with the signature id + a remediation string telling you exactly which command to run. Two typical cases:

# False positive on a legitimate signature
mcpm guard mute owasp-mcp-2-instruction-injection-in-response --for 5m

# Schema drift on a legitimate server upgrade
mcpm guard accept-drift slack-mcp --tool send_message --new-hash sha256:abc... --yes

Audit the log

Every block / warn is appended to ~/.mcpm/guard-events.jsonl. Inspect with jq:

# Last hour's blocks
tail -n 1000 ~/.mcpm/guard-events.jsonl | jq 'select(.action == "block")'

# Group by signature id
jq -s 'group_by(.findings[0].signature_id) | map({sig: .[0].findings[0].signature_id, n: length})' \
   < ~/.mcpm/guard-events.jsonl

# Top-N most-blocked servers
jq -s 'group_by(.server_name) | map({server: .[0].server_name, n: length}) | sort_by(-.n) | .[:10]' \
   < ~/.mcpm/guard-events.jsonl

When you're debugging and need to turn it off briefly

mcpm guard pause --for 10m     # disables all inspection for 10 minutes
mcpm guard pause --off         # cancel an active pause

Read more

• docs/GUARD.md — full command reference
• docs/SIGNATURES.md — signature catalog + how to contribute new ones
• docs/POLICY.md — ~/.mcpm/guard-policy.yaml reference

Agent mode

mcpm can run as an MCP server itself, letting AI agents search, install, and audit MCP servers programmatically.

{
  "mcpServers": {
    "mcpm": {
      "command": "npx",
      "args": ["-y", "@getmcpm/cli", "serve"]
    }
  }
}

This exposes 9 tools: mcpm_search, mcpm_install, mcpm_info, mcpm_list, mcpm_remove, mcpm_audit, mcpm_doctor, mcpm_setup, and mcpm_up.

The mcpm_setup tool takes a natural language description like "filesystem and GitHub" and handles everything: search, trust scoring, install. One tool call to assemble a working MCP toolchain.

Try it -- add the config above to your MCP client, restart, then ask your agent:

You have mcpm tools available (from @getmcpm/cli, the MCP package manager, not the Minecraft one). Use them to find MCP servers for filesystem access and GitHub. Check their trust scores and install anything above 60.

Supported clients

Linux and Windows paths are also supported. See mcpm doctor to verify which clients are detected on your system.

How it works

mcpm is a local-first CLI. There is no mcpm backend or account system.

flowchart TD
subgraph user["User / Terminal"]
    CLI["mcpm CLI<br/>Commander entry point"]
end

subgraph commands["Commands (src/commands/)"]
    SEARCH["search"]
    INSTALL["install"]
    AUDIT["audit"]
    GUARD["guard<br/>enable/disable/status"]
end

subgraph registry["Registry API<br/>(Only Remote)"]
    REGAPI["https://registry.<br/>modelcontextprotocol.io<br/>v0.1"]
end

subgraph scanning["Local Scanning & Trust<br/>(src/scanner/)"]
    HEALTH["Health Check<br/>(0-30): spawn +<br/>verify response"]
    TIER1["Tier 1: Static Patterns<br/>(0-40): secrets, injection,<br/>typosquatting, exfil"]
    TIER2["Tier 2: External Scan<br/>(0-20): optional<br/>MCP-Scan"]
    META["Registry Metadata<br/>(0-10): publisher,<br/>age, downloads"]
    SCORE["Trust Score<br/>(max 80; 100 with<br/>external scan)"]
end

subgraph config["Config Management<br/>(src/config/adapters/)"]
    DETECT["Detect AI clients<br/>Claude Desktop / Cursor<br/>VS Code / Windsurf"]
    ATOMIC["Atomic writes<br/>0o600 + symlink-safe<br/>.tmp/.bak"]
end

subgraph guard_runtime["Guard Runtime<br/>(src/guard/)"]
    WRAP["Config entry wrap<br/>via run --inner"]
    RELAY["Stdio MITM Relay<br/>per-server"]
    PATTERNS["Pattern Engine<br/>OWASP MCP Top 10"]
    PINS["Schema Pins<br/>+ Drift Detection"]
    FAILCLOSED["Fail-closed on<br/>pins.json error"]
    EVENTS["Event Log<br/>guard-events.jsonl"]
end

subgraph local_state["Local State<br/>(~/.mcpm/)"]
    SERVERS["servers.json"]
    CACHE["cache/"]
    PINS_STORE["pins.json"]
    POLICY["guard-policy.yaml"]
end

subgraph clients["Native AI Clients"]
    CD["Claude Desktop"]
    CURSOR["Cursor"]
    VSCODE["VS Code"]
    WINDSURF["Windsurf"]
end

CLI --> commands
commands -->|searchServers| REGAPI
commands -->|scan| HEALTH
commands -->|scan| TIER1
commands -->|if available| TIER2
commands -->|registry meta| META
HEALTH --> SCORE
TIER1 --> SCORE
TIER2 --> SCORE
META --> SCORE
commands -->|detect| DETECT
commands -->|merge & write| ATOMIC
DETECT -->|config paths| clients
ATOMIC -->|config| clients
GUARD -->|wrap| WRAP
WRAP -->|modifies config<br/>to invoke| clients
WRAP -->|setup| RELAY
RELAY -->|parse frames<br/>inspect msg| PATTERNS
PATTERNS -->|check pins| PINS
PINS -->|read| PINS_STORE
PATTERNS -->|read policy| POLICY
PINS -->|fail-closed| FAILCLOSED
RELAY -->|record| EVENTS
commands -->|store| SERVERS
commands -->|cache| CACHE

1. Search and install query the official MCP Registry API (v0.1) maintained by the Model Context Protocol project.
2. Trust assessment runs locally using built-in scanners (regex-based pattern detection) and optionally wraps MCP-Scan for deeper analysis.
3. Config management reads and writes the native config file for each AI client. All writes use atomic file operations with restricted permissions (0o600 files, 0o700 directories).
4. Local state lives in ~/.mcpm/ (installed server registry, scan results, response cache).

No telemetry. No analytics. No account required.

Contributing

Contributions are welcome.

git clone https://github.com/getmcpm/cli.git
cd cli
pnpm install
pnpm test
pnpm build

Before submitting a PR:

• Run pnpm test and ensure all tests pass
• Run pnpm lint to check types
• Keep commits focused -- one change per commit
• Follow conventional commit format

This project is MIT licensed. See LICENSE.

Security

If you discover a security vulnerability, please use GitHub's private vulnerability reporting instead of opening a public issue. We will respond within 48 hours.

For trust assessment issues (false positives/negatives in the scanner), regular GitHub issues are fine.

License

MIT