Usagi Game MCP Server
usagi-game-mcp
npm
v0.1.5
Published by an unidentified publisher — no publish provenance and no public repository, so the publisher could not be verified and the source cannot be independently located.
The grade answers one question — how safe is this server for you to adopt — so it is computed in two auditable stages. Nothing below is an opinion or an LLM's guess; every line is a real term the deterministic engine applied, and the same input always yields the same number.
1. Threat score — 100 − 0 = 100. What the published surface and source actually contain:
The deterministic scan raised no scored threat in the surface it inspected — the threat score stayed at 100. Capability observations and advisory notes are recorded but never lower it.
2. Client adoption risk — 100 − 8 = 92. Three small, subtract-only factors that reflect your risk in adopting it — a clean scan proves less on a powerful, unverified or barely-inspectable package, so the grade says so plainly:
| Points | Adoption-risk factor |
|---|---|
| −6 | capability blast radius (high) — client exposure if the model is manipulated |
| −2 | publisher verification (unlinked) — no provenance/repo link, but the shipped source was fully read |
Capability observations and info notes are shown under Findings but never scored.
Open any row's finding below for the file, line and evidence behind a deduction.
Findings 9
high Sensitive-source and external-sink co-existMTC-FLOW-004
Tools that read sensitive data ([usagi_read_file, usagi_list_files]) and tools that can send data out ([usagi_write_web_shell]) are exposed together. An agent can move private data to the sink.
Evidence: sources [usagi_read_file, usagi_list_files] → sinks [usagi_write_web_shell]
Fix: Keep secret-reading and egress capabilities on separate, separately-approved servers.
Location: flow usagi_read_file → usagi_write_web_shell
high Tool "usagi_write_web_shell" exposes command/code executionMTC-CAP-001
Tool "usagi_write_web_shell" appears to run shell commands or evaluate code (keyword "shell" in tool name). Arbitrary execution driven by model input is one of the most dangerous MCP capabilities; combined with any untrusted input it becomes RCE.
Fix: Sandbox execution, allowlist commands/arguments, and never pass model output to a shell unescaped.
Location: tool usagi_write_web_shell
high Shell/command execution in server code (dist/dev/dev-process-manager.js)MTC-SRC-002
In the server's implementation (`dist/dev/dev-process-manager.js:179`): Spawning a shell/process is command-execution capability; with unsanitized tool input it is command injection / RCE. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: ']; const pty = spawn(shell, args, { cwd: projectPath, env: filteredEnv, col
Fix: Review this call path: confirm it never receives unsanitized tool input, constrain it, or remove it. Treat a server whose code reaches these sinks as high-capability regardless of what its tools claim.
Location: server dist/dev/dev-process-manager.js
high Shell/command execution in server code (dist/sandbox/lua-binary.js)MTC-SRC-002
In the server's implementation (`dist/sandbox/lua-binary.js:7`): Spawning a shell/process is command-execution capability; with unsanitized tool input it is command injection / RCE. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: port { execFile } from 'child_process'; import { promisify } from 'util'; const execFileAsync = promisify(execFile); con
Fix: Review this call path: confirm it never receives unsanitized tool input, constrain it, or remove it. Treat a server whose code reaches these sinks as high-capability regardless of what its tools claim.
Location: server dist/sandbox/lua-binary.js
high Shell/command execution in server code (dist/sandbox/lua-runner.js)MTC-SRC-002
In the server's implementation (`dist/sandbox/lua-runner.js:1`): Spawning a shell/process is command-execution capability; with unsanitized tool input it is command injection / RCE. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: port { execFile } from 'child_process'; import * as fs from 'fs/promises'; import * as path from 'path'; import * as os
Fix: Review this call path: confirm it never receives unsanitized tool input, constrain it, or remove it. Treat a server whose code reaches these sinks as high-capability regardless of what its tools claim.
Location: server dist/sandbox/lua-runner.js
high Shell/command execution in server code (dist/tools/scaffold-tools.js)MTC-SRC-002
In the server's implementation (`dist/tools/scaffold-tools.js:173`): Spawning a shell/process is command-execution capability; with unsanitized tool input it is command injection / RCE. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: } = await import('node:child_process'); const { promisify } = await import('node:util'); const execP =
Fix: Review this call path: confirm it never receives unsanitized tool input, constrain it, or remove it. Treat a server whose code reaches these sinks as high-capability regardless of what its tools claim.
Location: server dist/tools/scaffold-tools.js
medium Tool "usagi_delete_file" can modify the filesystemMTC-CAP-002
Tool "usagi_delete_file" can write, overwrite or delete files (keyword "delete_file" in tool name). Verify it is scoped to a safe directory.
Fix: Constrain file operations to an explicit, non-sensitive root; reject path traversal.
Location: tool usagi_delete_file
low Mutating tool "usagi_write_web_shell" declares no destructiveHintMTC-CAP-005
Tool "usagi_write_web_shell" can mutate/egress but declares no destructiveHint. Clients that don't default to spec-safe behavior may not prompt before running it.
Fix: Declare accurate annotations, and gate destructive tools on user confirmation regardless.
Location: tool usagi_write_web_shell
low Mutating tool "usagi_delete_file" declares no destructiveHintMTC-CAP-005
Tool "usagi_delete_file" can mutate/egress but declares no destructiveHint. Clients that don't default to spec-safe behavior may not prompt before running it.
Fix: Declare accurate annotations, and gate destructive tools on user confirmation regardless.
Location: tool usagi_delete_file
Tools 22
Each tool and what it can reach — statically extracted from the published source.
usagi_delete_filewrites filesusagi_list_filesreads sensitive datausagi_read_filereads sensitive datausagi_write_web_shellruns code / shellusagi_boot_testno sensitive capabilityusagi_dev_resetno sensitive capabilityusagi_dev_restartno sensitive capabilityusagi_dev_startno sensitive capabilityusagi_dev_statusno sensitive capabilityusagi_dev_stopno sensitive capability
Show 12 more tools ↓
usagi_init_projectno sensitive capabilityusagi_read_logno sensitive capabilityusagi_rename_fileno sensitive capabilityusagi_scaffold_collision_handlerno sensitive capabilityusagi_scaffold_entityno sensitive capabilityusagi_scaffold_save_systemno sensitive capabilityusagi_scaffold_stateno sensitive capabilityusagi_scaffold_state_machineno sensitive capabilityusagi_validate_projectno sensitive capabilityusagi_write_configno sensitive capabilityusagi_write_datano sensitive capabilityusagi_write_luano sensitive capability
Toxic flows 1
Cross-tool combinations that form a data-exfiltration primitive (untrusted input → sensitive source → external sink).
What this scan could not see
- Tools were statically extracted from the published source (22 recovered), not enumerated from a running server. Tool-poisoning, Unicode-smuggling, capability and toxic-flow analysis ran on this inferred surface, but a mis-parsed registration could be missed or mis-attributed, so tool-derived findings are capped below “confirmed”. To grade the real runtime surface, scan the running server: --command "npx -y <package>".
Versions 1
Scan history per published version. The engine is deterministic — the same version always yields the same score, so a changed score means the package itself changed.
| Version | Score | Findings | Engine | Scanned |
|---|---|---|---|---|
v0.1.5 latest |
A 92/100 | 9 | 1.9.0 | 2026-07-24 |
Embed this score
Show this server's live Trust Score in your README, docs or website. The badge is served straight from the registry and updates automatically after every rescan — no API key needed. It links back to this page, so anyone who sees the grade can also read the findings behind it instead of taking a number on faith.
Verify this score yourself
The score above is reproducible: the same package version always yields the same result. Run it locally or over the free API — no account, no LLM, fully deterministic.
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