This record as markdown: /tools/io-github-kivanccakmak-yaver/open-url.md
What open_url does on Yaver
AI agents invoke open_url 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 |
|---|---|---|---|
url | string | Yes | URL to open |
Parameters from the server's own tool schema.
Why open_url is rated High
This tool launches an external application (the default browser) and navigates it to a specified URL. This is an external operation whose effects depend on the URL argument provided. It could be misused to open malicious URLs, trigger browser-based exploits, or cause unintended navigation. It fits the Execute category as it triggers an external operation.
From the tool's definition 'Open a URL in the default browser' — triggers an external browser action
Risk signalsAccepts URL/endpoint input (url)
Attacks that exploit this kind of access
The rule that runs open_url 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 open_url, this is the rule to start with:
open_url 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 open_url call is checked against it from then on.
Questions about open_url
Open a URL in the default browser. 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.
open_url accepts 1 parameter: url. Required: url. 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 open_url: 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.
open_url 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 open_url 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 open_url. 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.
open_url 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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