Skills/npm/cappy

cappy@1.0.2

VERIFIED· startup only

Publisher claims: "Reproducible game capture with scenarios, replayable sessions, OBS recording, and FFmpeg derivatives." Observed in sandbox: no network, touches nothing outside the project, writes no memory.

Registry npm (MCP server)Publisher uppercut-labs · publishing for 47 daysInstalls 254Last detonated 46 h ago
$claude mcp add cappy -- npx -y @uppercut-labs/cappy
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Coverage

Startup only; authenticated tool behavior not tested.
Tested
server startup over stdio (initialize sent) · every file read, file written and host contacted by what ran
Not tested
the tool list (the server exited before answering) · what the tools do when called with real credentials

Is [email protected] safe to install?

KillerSkills ran it in the KillerSkills honeypot sandbox (2 scenarios; startup only; authenticated tool behavior not tested) on 2026-11-12 and scored it 87/100 (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 · 25 s · 2 scenarios · 0 deviations
t+CategoryObserved action
0.0sprocessno install scripts in bundle
4.8sprocessdependency install exit 0
25sclaimedstartup only: exited (0) before answering · -v, --version Show the Cappy version Shorthands are whole tokens: -nc is --no-capture, never -n -c. Exit codes: 0 success, 1 operation failed, 2 invalid usage, 3 configuration, 4 missing dependency, 70 internal error, 130 cancelled.
25sprocessscript backend runs setup only
25sprocessno install scripts to re-run

Static findings

MEDIUM
npx invocation of non-well-known package.agents/skills/cappy/SKILL.md:42 · npx invocation of non-well-known package — may execute untrusted code…game project (`npm install --save-dev @uppercut-labs/cappy`), then run it with `npx cappy`. `npx cappy --version` confirms which version runs. - Never run `npx cappy` wher…Fix: Pin versions and sources; vendor anything fetched at install time.
AST06
MEDIUM
npx invocation of non-well-known package.agents/skills/cappy/SKILL.md:43 · npx invocation of non-well-known package — may execute untrusted code…th `npx cappy`. `npx cappy --version` confirms which version runs. - Never run `npx cappy` where the package is not installed, and never install the unscoped `cappy` pack…Fix: Pin versions and sources; vendor anything fetched at install time.
AST06
MEDIUM
npx invocation of non-well-known package.agents/skills/cappy/SKILL.md:26 · npx invocation of non-well-known package — may execute untrusted codeCappy 1.0.1 adds a local MCP server, launched with `npx @uppercut-labs/cappy mcp -C /absolute/path/to/game`.Fix: Pin versions and sources; vendor anything fetched at install time.
AST06
HIGH
Access to sensitive file pathsdist/cappy.js:4771 · Access to sensitive file paths — SSH keys, AWS credentials, env files, or system filesgame = ManagedProcess.start(executable, config.game.args, { cwd, env: { ...env, ...server.launchEnvironment() } });Fix: Stop enumerating or reading credential locations; take secrets from a declared environment variable the user sets on purpose.
AST05

Cost to the agent

Instructions loaded
≈2,400 tok
1 file · 12 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 @uppercut-labs/cappy@1.0.2 as of 46 h ago. This is the package itself, not its dependencies.