This record as markdown: /tools/io-github-kivanccakmak-yaver/port-scan.md
What port_scan does on Yaver
AI agents invoke port_scan 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 |
|---|---|---|---|
host | string | Yes | |
ports | string | — | Comma-separated ports (default: common ports) |
Parameters from the server's own tool schema.
Why port_scan is rated High
Port scanning sends network probes to external or internal hosts to discover open ports and services. This is an active network operation with side effects (network traffic generated, detectable by target), not a simple read. It can be used to map infrastructure, identify attack surfaces, or violate network policies.
From the tool's definition "Scan common ports on a host" — actively probes network ports on a target host
Risk signalsAccepts URL/endpoint input (host)
Attacks that exploit this kind of access
The rule that runs port_scan 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 port_scan, this is the rule to start with:
port_scan 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 port_scan call is checked against it from then on.
Questions about port_scan
Scan common ports on a host (pure Go, no nmap needed). 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.
port_scan accepts 2 parameters: host, ports. Required: host. 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 port_scan: 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.
port_scan 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 port_scan 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 port_scan. 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.
port_scan 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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