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:
| Component | Points | What it measures |
|---|---|---|
| Health check | 0-30 | Can the server start and respond to list_tools? |
| Static scan | 0-40 | Regex-based detection of hardcoded secrets, prompt injection patterns in tool descriptions, typosquatting in package names, suspicious argument schemas |
| External scanner | 0-20 | Results from MCP-Scan if installed (optional) |
| Registry metadata | 0-10 | Verified publisher, publish date, download count (capped to 0 when critical findings present) |
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
| Command | Description |
|---|---|
mcpm search <query> | Search the MCP registry for servers |
mcpm install <name> | Install an MCP server from the registry |
mcpm info <name> | Show full details for an MCP server |
mcpm list | List all installed MCP servers across detected AI clients |
mcpm remove <name> | Remove an MCP server from client config(s) |
mcpm audit | Scan all installed servers and produce a trust report |
mcpm update | Check for newer versions and update installed servers |
mcpm outdated | Show version drift and trust regression for installed servers |
mcpm secrets | Manage MCP server credentials (AES-GCM encrypted at rest; key held in the OS keychain — macOS Keychain / libsecret / Windows DPAPI — so a copied store can't be decrypted off-machine, with a machine-derived-key fallback where no keychain is available). mcpm secrets migrate upgrades older entries |
mcpm publish scaffold | Create a .mcpm-publish.yaml manifest interactively |
mcpm publish check | Dry-run: show trust score and what would be submitted |
mcpm publish | Submit to the official MCP registry (requires GITHUB_TOKEN) |
mcpm doctor | Check MCP setup health and report issues |
mcpm init | Scaffold a starter mcpm.yaml stack file in the current directory |
mcpm disable <name> | Disable an MCP server without removing it from config |
mcpm enable <name> | Re-enable a previously disabled MCP server |
mcpm import | Import existing MCP servers from client config files |
mcpm alias | Create short aliases for long MCP server names |
mcpm export | Export installed servers as an mcpm.yaml stack file |
mcpm lock | Resolve versions and create mcpm-lock.yaml with trust snapshots |
mcpm up | Install all servers from mcpm.yaml with trust verification |
mcpm diff | Compare installed servers against mcpm.yaml and lock file |
mcpm completions <shell> | Generate shell completion scripts (bash, zsh, fish) |
mcpm why <name> | Explain a server's trust score (breakdown of all components) |
mcpm serve | Start mcpm as an MCP server (stdio transport) |
mcpm guard enable | Wrap detected client configs with the inspection relay |
mcpm guard disable | Restore original client configs |
mcpm guard status | Show what's wrapped and the per-server pin state |
mcpm guard demo | Run the synthetic prompt-injection scenario (visible block) |
mcpm guard accept-drift <server> | Re-pin a tool's schema after a legitimate upgrade |
mcpm guard mute <signature-id> | Disable a signature with optional --for <duration> |
mcpm guard unmute <signature-id> | Re-enable a muted signature |
mcpm guard pause | Pause all guard inspection (debugging escape hatch) |
mcpm guard cleanup | Prune pin entries for uninstalled servers |
mcpm guard list-signatures | Show the shipped OWASP MCP Top 10 signature catalog |
mcpm guard reset-integrity | Regenerate the pins.json or guard-policy.yaml integrity sidecar |
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/listdescriptions, 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
| Category | Attack class | Action |
|---|---|---|
| OWASP-MCP-1 | Tool-description injection (poisoning) | block |
| OWASP-MCP-1 | Schema / annotation drift since install (rug-pull) | block |
| OWASP-MCP-1 | Description-only drift (cosmetic tier) | warn |
| OWASP-MCP-1 | Injection in initialize instructions | block |
| OWASP-MCP-2 | Instruction injection in tool responses | block |
| OWASP-MCP-2 | Instruction injection in resource / prompt content | warn (forward) |
| OWASP-MCP-7 | Sensitive-path exfil in tool arguments | warn (promote to block via policy) |
| Hidden chars | Zero-width / bidi / non-printable in tool metadata | high (warn) |
| Sampling | Injection in a server-initiated sampling prompt | block (to the server) |
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 referencedocs/SIGNATURES.md— signature catalog + how to contribute new onesdocs/POLICY.md—~/.mcpm/guard-policy.yamlreference
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
| Client | Config path (macOS) |
|---|---|
| Claude Desktop | ~/Library/Application Support/Claude/claude_desktop_config.json |
| Cursor | ~/.cursor/mcp.json |
| VS Code | ~/Library/Application Support/Code/User/mcp.json |
| Windsurf | ~/.codeium/windsurf/mcp_config.json |
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
- Search and install query the official MCP Registry API (v0.1) maintained by the Model Context Protocol project.
- Trust assessment runs locally using built-in scanners (regex-based pattern detection) and optionally wraps MCP-Scan for deeper analysis.
- 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).
- 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 testand ensure all tests pass - Run
pnpm lintto 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.