pkg_install
Install a package via any package manager (npm, pip, cargo, go, brew, gem, apt, dart).
This record as markdown: /tools/io-github-kivanccakmak-yaver/pkg-install.md
What pkg_install does on Yaver
AI agents invoke pkg_install to trigger actions in Yaver. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.
| Parameter | Type | Required | Description |
|---|---|---|---|
global | boolean | — | Install globally (npm -g) |
manager | string | Yes | npm, pip, cargo, go, brew, gem, apt, dart |
package | string | Yes |
Parameters from the server's own tool schema.
Why pkg_install is rated High
Installing packages executes external commands on the host system via package managers, modifying the system environment and potentially introducing arbitrary third-party code. This is an Execute-category action with high severity because a misused or malicious package installation can compromise the development environment, introduce malware, or alter system dependencies irreversibly in practice.
From the tool's definition Install a package via any package manager (npm, pip, cargo, go, brew, gem, apt, dart)
Attacks that exploit this kind of access
The rule that runs pkg_install safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Yaver, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For pkg_install, this is the rule to start with:
pkg_install stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Yaver, apply this rule, and every pkg_install call is checked against it from then on.
Questions about pkg_install
Install a package via any package manager (npm, pip, cargo, go, brew, gem, apt, dart). It is categorised as a Execute tool in the Yaver MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
pkg_install accepts 3 parameters: global, manager, package. Required: manager, package. The full parameter table on this page comes from the server's own tool schema.
Register the Yaver MCP server in PolicyLayer and add a rule for pkg_install: 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 Yaver. Nothing to install.
pkg_install is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the pkg_install 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 pkg_install. 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.
pkg_install is provided by the Yaver MCP server (yaver-cli). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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