BrowserPreviewOpen
Open an HTML file or a directory containing index.html from the current project or an authorized attached directory in a dedicated, visible in-app browser tab. This is read-only preview access; do not use it to read arbitrary local files.
This record as markdown: /tools/dutydeck/browserpreviewopen.md
What BrowserPreviewOpen does on DutyDeck
AI agents use BrowserPreviewOpen to create or update resources in DutyDeck, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your DutyDeck environment.
Why BrowserPreviewOpen is rated Medium
An AI agent can call BrowserPreviewOpen faster than any human can review: one bad instruction and it creates or modifies resources in DutyDeck by the hundred, each call as confident as the last.
Attacks that exploit this kind of access
The rule that runs BrowserPreviewOpen safely
PolicyLayer is an MCP gateway: it sits between your AI agents and DutyDeck, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For BrowserPreviewOpen, this is the rule to start with:
BrowserPreviewOpen stays usable, but capped: an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect DutyDeck, apply this rule, and every BrowserPreviewOpen call is checked against it from then on.
Questions about BrowserPreviewOpen
Open an HTML file or a directory containing index.html from the current project or an authorized attached directory in a dedicated, visible in-app browser tab. This is read-only preview access; do not use it to read arbitrary local files. It is categorised as a Write tool in the DutyDeck MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the DutyDeck MCP server in PolicyLayer and add a rule for BrowserPreviewOpen: 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 DutyDeck. Nothing to install.
BrowserPreviewOpen is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the BrowserPreviewOpen 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 BrowserPreviewOpen. 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.
BrowserPreviewOpen is provided by the DutyDeck MCP server (taokoplay/DutyDeck). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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