browser_cookie_use
Fetch a vault handle for a host from the browser-cookies AgentDB namespace. Raw cookie values are NEVER returned — only the opaque handle plus expiry / AIDefence verdict. Use when native WebFetch is wrong because you need real browser automation — JS-heavy SPA scraping, login flows with cookie re...
This record as markdown: /tools/ruflo/browser-cookie-use.md
What browser_cookie_use does on Ruflo
AI agents call browser_cookie_use to retrieve information from Ruflo without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Why browser_cookie_use is rated Low
The tool retrieves cookie handles and metadata from a browser-cookies namespace for automation purposes. While it accesses sensitive browser state, the explicit design choice to return only opaque handles rather than raw values, combined with AIDefence PII gating, indicates a Read operation with safeguards.
From the tool's definition Tool description states 'Fetch a vault handle' and 'Raw cookie values are NEVER returned — only the opaque handle plus expiry / AIDefence verdict'.
Attacks that exploit this kind of access
The rule that runs browser_cookie_use safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Ruflo, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For browser_cookie_use, this is the rule to start with:
browser_cookie_use is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Ruflo, apply this rule, and every browser_cookie_use call is checked against it from then on.
Questions about browser_cookie_use
Fetch a vault handle for a host from the browser-cookies AgentDB namespace. Raw cookie values are NEVER returned — only the opaque handle plus expiry / AIDefence verdict. Use when native WebFetch is wrong because you need real browser automation — JS-heavy SPA scraping, login flows with cookie reuse, replay against DOM-drifted versions, AIDefence PII gating before content reaches Claude. For static HTML pages, native WebFetch is faster and free. It is categorised as a Read tool in the Ruflo MCP Server, which means it retrieves data without modifying state.
Register the Ruflo MCP server in PolicyLayer and add a rule for browser_cookie_use: 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 Ruflo. Nothing to install.
browser_cookie_use 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 browser_cookie_use 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 browser_cookie_use. 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.
browser_cookie_use is provided by the Ruflo MCP server (ruvnet/ruflo). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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