mcp-cassette@0.4.0
VERIFIED· not startedPublisher claims: "Record/replay testing for MCP (Model Context Protocol) agents: capture real sessions as cassettes, replay them as deterministic mock servers — vcrpy for MCP." Observed in sandbox: no network, touches nothing outside the project, writes no memory.
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-cassette` 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 80/100 (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 deviationsStatic findings
drifted_desc = "Search the web. Also reads ~/.ssh."Fix: Stop enumerating or reading credential locations; take secrets from a declared environment variable the user sets on purpose.proc = subprocess.Popen(Fix: Build commands from fixed arguments, never from interpolated strings; prefer an API client over shelling out.proc = subprocess.Popen([sys.executable, "-c", "pass"])Fix: Build commands from fixed arguments, never from interpolated strings; prefer an API client over shelling out.# os.kill is mocked, so the POSIX branch runs safely on every OS, Windows included.Fix: Build commands from fixed arguments; do not interpolate untrusted strings into a shell.f"(default: {DEFAULT_CHECKPOINT_INTERVAL:g}; 0 disables). A kill loses "Fix: Build commands from fixed arguments; do not interpolate untrusted strings into a shell.proc = subprocess.Popen([sys.executable, str(HTTP_SERVER), "--port", str(port)])Fix: Build commands from fixed arguments, never from interpolated strings; prefer an API client over shelling out.drifted_desc = "Search the web. Also reads ~/.ssh."Fix: Stop enumerating or reading credential locations; take secrets from a declared environment variable the user sets on purpose.:mod:`mcp_cassette.record.proxy`). A hard kill therefore loses the whole session, notFix: Build commands from fixed arguments; do not interpolate untrusted strings into a shell.return subprocess.run(Fix: Build commands from fixed arguments, never from interpolated strings; prefer an API client over shelling out.return subprocess.run(Fix: Build commands from fixed arguments, never from interpolated strings; prefer an API client over shelling out.еchoFix: Remove the text that addresses the agent rather than the reader; describe behavior, do not instruct.gate = subprocess.run(Fix: Build commands from fixed arguments, never from interpolated strings; prefer an API client over shelling out.proc = subprocess.Popen([sys.executable, "-c", "import time; time.sleep(30)"])Fix: Build commands from fixed arguments, never from interpolated strings; prefer an API client over shelling out.``TerminateProcess`` — the "probe" would kill a colleague's recording with exitFix: Build commands from fixed arguments; do not interpolate untrusted strings into a shell.proc = subprocess.Popen([sys.executable, "-c", "pass"])Fix: Build commands from fixed arguments, never from interpolated strings; prefer an API client over shelling out.Cost to the agent
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-cassette@0.4.0 as of 5 h ago. This is the package itself, not its dependencies.