Runs npm test, pnpm test, or yarn test and returns structured output with exit code, stdout, stderr, and duration. Auto-detects package manager via lock files (pnpm-lock.yaml → pnpm, yarn.lock → yarn, otherwise npm). Shorthand for running the test script defined in package.json. Automatically par...
Risk signalsAccepts file system path (path) · High parameter count (11 properties)
Part of the Npm server.
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AI agents call test to retrieve information from Npm without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though test only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
{
"version": "1",
"default": "deny",
"tools": {
"test": {}
}
}See the full Npm policy for all 10 tools.
These attack patterns abuse exactly the kind of access test gives an agent. Each links to the full case and the policy that stops it:
Other read tools across the catalogue. The same approach applies to each: allow, with a rate cap to control cost.
Runs npm test, pnpm test, or yarn test and returns structured output with exit code, stdout, stderr, and duration. Auto-detects package manager via lock files (pnpm-lock.yaml → pnpm, yarn.lock → yarn, otherwise npm). Shorthand for running the test script defined in package.json. Automatically parses test framework output (jest, vitest, mocha, tap) to extract pass/fail/skip counts.. It is categorised as a Read tool in the Npm MCP Server, which means it retrieves data without modifying state.
Register the Npm MCP server in PolicyLayer and add a rule for test: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Npm. Nothing to install.
test is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the test rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for test. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
test is provided by the Npm MCP server (Dave-London/Pare). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 10 Npm tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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