fw_block_domain
Instance-wide block of a remote domain (all actors/libraries from that domain become unreachable). QUEUED — does not apply until an operator confirms in the Nest panel within 72 hours.
This record as markdown: /tools/kh0pper-crow/fw-block-domain.md
What fw_block_domain does on Crow
AI agents call fw_block_domain to retrieve information from Crow without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Why fw_block_domain is rated Low
Even though fw_block_domain only reads data, uncontrolled read access leaks sensitive information and racks up API costs: an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.
Attacks that exploit this kind of access
The rule that runs fw_block_domain safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Crow, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For fw_block_domain, this is the rule to start with:
fw_block_domain 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 Crow, apply this rule, and every fw_block_domain call is checked against it from then on.
Questions about fw_block_domain
Instance-wide block of a remote domain (all actors/libraries from that domain become unreachable). QUEUED — does not apply until an operator confirms in the Nest panel within 72 hours. It is categorised as a Read tool in the Crow MCP Server, which means it retrieves data without modifying state.
Register the Crow MCP server in PolicyLayer and add a rule for fw_block_domain: 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 Crow. Nothing to install.
fw_block_domain 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 fw_block_domain 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 fw_block_domain. 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.
fw_block_domain is provided by the Crow MCP server (kh0pper/crow). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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