mcp-debugger@0.1.1
VERIFIED· not startedPublisher claims: "Transparent proxy to debug, record, validate, and replay MCP (Model Context Protocol) sessions" Observed in sandbox: no network, touches nothing outside the project, writes no memory.
Registry PyPI (MCP server)Publisher sushant-mutnale · publishing for 138 daysInstalls 17Last detonated 7d ago
Coverage
Not started: dependency install failed; the server itself was not observed.- Tested
- the dependency install step · every file read, file written and host contacted by what ran
- Not tested
- server startup · the tool list · tool behavior
What this means for the label: Verified here covers what ran. The server's tools were not exercised with a real credential, so nothing about their behavior is asserted; the credential summary below says what to do with that.
Before you give it your token
Code inventory arrives with this version's next honeypot run.- It will ask for
- unknown until the next run
- Where it talks to
- unknown until the next run
- What the honeypot saw
- no credential files read · no network
- What we could not test
- server startup · the tool list · tool behavior
Not enough was observed to say yet. Not started: dependency install failed; the server itself was not observed. This version's code has not been inventoried for credentials and hosts either; both arrive with its next honeypot run (popular servers first). `vet-skills try mcp-debugger` runs it now and prints the full answer.
Never paste a credential into a chat, a ticket or a report, including ours. How the guard holds it.
Is [email protected] safe to install?
KillerSkills ran it in the KillerSkills honeypot sandbox (2 scenarios; not started: dependency install failed; the server itself was not observed) on 2026-11-07 and scored it 86/100 (Verified). In what ran, nothing we could detect went wrong: no undeclared network egress, no credential reads, no persistent instruction writes. What it does with a real credential was not observed; the static findings and the publisher carry the rest of the score. Summary: no network, touches nothing outside the project, writes no memory.
Behavior trace
Honeypot run · 0 s · 2 scenarios · 0 deviationst+CategoryObserved action
0.0sprocessno install scripts in bundle
0.1sprocessdependency install exit 1
0.2sprocessexec /usr/bin/date
0.2sprocessexec /usr/bin/timeout
0.2sprocessexec .venv/bin/mcp-debugger
0.2sclaimedno tools/list reply (exit 0)
0.2sprocessscript backend runs setup only
0.2sprocessno install scripts to re-run
Static findings
MEDIUM
npx invocation of non-well-known packagescripts/generate_demo_gif.py:195 · npx invocation of non-well-known package — may execute untrusted code
AST06cmd_4 = "mcp-debugger replay 1 --server \"npx -y @modelcontextprotocol/server-filesystem C:\\temp\""Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagesrc/mcp_debugger/cli.py:878 · npx invocation of non-well-known package — may execute untrusted code
AST06# 5. npx checkFix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagescripts/test_real_servers.py:5 · npx invocation of non-well-known package — may execute untrusted code
AST06python scripts/test_real_servers.py --server "npx -y @modelcontextprotocol/server-filesystem /tmp"Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagescripts/generate_demo_gif.py:143 · npx invocation of non-well-known package — may execute untrusted code
AST06[("│ ", BORDER_COLOR), ("OK", GREEN_COLOR), (" npx command found: C:\\Program Files\\nodejs\\npx │", TEXT_COLOR)],Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagesrc/mcp_debugger/cli.py:883 · npx invocation of non-well-known package — may execute untrusted code
AST06(EMOJI_CHECK, "green"), f" npx command found: {npx_path} (for Node.js MCP servers)"Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagesrc/mcp_debugger/cli.py:890 · npx invocation of non-well-known package — may execute untrusted code
AST06" npx command check: npx not found – MCP servers requiring Node.js may fail",Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_cli/test_cli_config.py:67 · npx invocation of non-well-known package — may execute untrusted code
AST06result = runner.invoke(app, ["config", "set", "aliases.myserver", "npx -y server"])Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagescripts/test_real_servers.py:64 · npx invocation of non-well-known package — may execute untrusted code
AST06"command": "npx -y @modelcontextprotocol/server-github",Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagescripts/test_real_servers.py:44 · npx invocation of non-well-known package — may execute untrusted code
AST06"command": "npx -y @modelcontextprotocol/server-filesystem {tmpdir}",Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagescripts/test_real_servers.py:74 · npx invocation of non-well-known package — may execute untrusted code
AST06"command": "npx -y @modelcontextprotocol/server-memory",Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagescripts/generate_demo_gif.py:172 · npx invocation of non-well-known package — may execute untrusted code
AST06l_1 = val_lines_base + ["Validating live server: npx -y @modelcontextprotocol/server-filesystem C:\\temp"]Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagescripts/generate_demo_gif.py:158 · npx invocation of non-well-known package — may execute untrusted code
AST06cmd_3 = "mcp-debugger validate --server \"npx -y @modelcontextprotocol/server-filesystem C:\\temp\""Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_cli/test_cli_edge_cases.py:1193 · npx invocation of non-well-known package — may execute untrusted code
AST06cfg._data = {"aliases": {"dev": "npx echo"}}Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_config/test_config.py:104 · npx invocation of non-well-known package — may execute untrusted code
AST06assert 'fs = "npx -y server /tmp"' in textFix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
File permission modification commandtests/test_config/test_config.py:325 · File permission modification command — agent changes file ownership/permissions
AST05@pytest.mark.skipif(os.name == "nt", reason="chmod not supported on Windows")Fix: Request the narrowest permission that works; replace wildcards with the exact paths or hosts.MEDIUM
npx invocation of non-well-known packagetests/test_config/test_config.py:101 · npx invocation of non-well-known package — may execute untrusted code
AST06data = {"aliases": {"fs": "npx -y server /tmp", "gh": "npx -y github"}}Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
File permission modification commandtests/test_config/test_config.py:371 · File permission modification command — agent changes file ownership/permissions
AST05"""Verify save() handles chmod OSError gracefully (e.g. Windows permissions)."""Fix: Request the narrowest permission that works; replace wildcards with the exact paths or hosts.MEDIUM
npx invocation of non-well-known packagetests/test_cli/test_cli_edge_cases.py:808 · npx invocation of non-well-known package — may execute untrusted code
AST06assert "npx command found" in result.stdoutFix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_cli/test_cli_edge_cases.py:378 · npx invocation of non-well-known package — may execute untrusted code
AST06assert "npx not found" in result.stdoutFix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_cli/test_inspect.py:154 · npx invocation of non-well-known package — may execute untrusted code
AST06assert "npx command found:" in result.stdoutFix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_config/test_config.py:184 · npx invocation of non-well-known package — may execute untrusted code
AST06assert cfg.get("aliases.fs") == "npx server"Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_exporters/test_otlp.py:101 · npx invocation of non-well-known package — may execute untrusted code
AST06"server_command": "npx mcp-server",Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_exporters/test_json.py:92 · npx invocation of non-well-known package — may execute untrusted code
AST06server_command="npx mcp-server",Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_exporters/test_json.py:129 · npx invocation of non-well-known package — may execute untrusted code
AST06assert s["server_command"] == "npx mcp-server"Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_proxy/test_stdio_proxy.py:75 · npx invocation of non-well-known package — may execute untrusted code
AST06cmd = 'npx -y @server --arg "nested spaces"'Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_exporters/test_json.py:12 · npx invocation of non-well-known package — may execute untrusted code
AST06"server_command": "npx mcp-server",Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_exporters/test_markdown.py:66 · npx invocation of non-well-known package — may execute untrusted code
AST06server_command="npx mcp-server",Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
Process kill commandtests/test_replay/test_engine.py:451 · Process kill command — agent can terminate processes
AST05raise RuntimeError("Simulated kill failure")Fix: Build commands from fixed arguments; do not interpolate untrusted strings into a shell.MEDIUM
Process kill commandtests/test_replay/test_engine.py:440 · Process kill command — agent can terminate processes
AST05# 5. Process terminate/kill exception handling during cleanupFix: Build commands from fixed arguments; do not interpolate untrusted strings into a shell.MEDIUM
npx invocation of non-well-known packagetests/test_exporters/test_markdown.py:8 · npx invocation of non-well-known package — may execute untrusted code
AST06"server_command": "npx mcp-server",Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_replay/test_engine.py:202 · npx invocation of non-well-known package — may execute untrusted code
AST06# Check if npx is installedFix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_exporters/test_otlp.py:27 · npx invocation of non-well-known package — may execute untrusted code
AST06"server_command": "npx mcp-server",Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_config/test_config.py:180 · npx invocation of non-well-known package — may execute untrusted code
AST06toml = '[aliases]\nfs = "npx server"\n'Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_exporters/test_markdown.py:105 · npx invocation of non-well-known package — may execute untrusted code
AST06assert "npx mcp-server" in mdFix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_replay/test_engine.py:205 · npx invocation of non-well-known package — may execute untrusted code
AST06pytest.skip("npx not found, skipping filesystem integration test")Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_replay/test_engine.py:209 · npx invocation of non-well-known package — may execute untrusted code
AST06server_cmd = f"npx -y @modelcontextprotocol/server-filesystem {tmpdir}"Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_storage/test_database.py:47 · npx invocation of non-well-known package — may execute untrusted code
AST06server_command="npx -y mock-server",Fix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
npx invocation of non-well-known packagetests/test_replay/test_engine.py:224 · npx invocation of non-well-known package — may execute untrusted code
AST06# Wait for npx startupFix: Pin versions and sources; vendor anything fetched at install time.MEDIUM
File permission modification commandtests/test_storage/test_database.py:660 · File permission modification command — agent changes file ownership/permissions
AST05# 2. Test chmod exception handlingFix: Request the narrowest permission that works; replace wildcards with the exact paths or hosts.MEDIUM
npx invocation of non-well-known packagetests/test_storage/test_database.py:62 · npx invocation of non-well-known package — may execute untrusted code
AST06assert session["server_command"] == "npx -y mock-server"Fix: Pin versions and sources; vendor anything fetched at install time.Cost to the agent
Instructions loaded
≈60 tok
1 file · 80 in bundle
Tool list per prompt
≈0 tok
0 tools · 0 per tool
Handshake
no reply
launch to tools/list, stdio
Undocumented tools
0
description under 20 chars · avg 0
Tokens estimated at four characters each. The tool list is re-read by the agent on every turn, so it is the number to compare between servers that do the same job: ranked across the index.
Known vulnerabilities
No advisories in OSV for mcp-debugger@0.1.1 as of 7d ago. This is the package itself, not its dependencies.