Extract JSON-schema data from JSON-LD, Microdata, OpenGraph, or CSS. Use multiple:true for listings, mode=
AI agents call extract_data to retrieve information from OpenChrome without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries and retrieves structured data from web page markup using standard web data formats. It has no side effects, cannot modify state, execute code, delete data, or move money. The 'multiple:true' parameter indicates batch retrieval rather than any state-changing operation. This is a straightforward Read category tool with low blast radius if misused by an agent.
From the tool's definition Tool name is 'extract_data' and description states it 'Extract[s] JSON-schema data from JSON-LD, Microdata, OpenGraph, or CSS' — a pure retrieval operation with no modification, deletion, or execution capabilities.
Documented attack patterns abuse exactly the kind of access extract_data gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and OpenChrome, and nothing reaches the server without passing your rules. This is the rule we recommend for extract_data:
{
"version": "1",
"default": "deny",
"tools": {
"extract_data": {}
}
}extract_data is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Extract JSON-schema data from JSON-LD, Microdata, OpenGraph, or CSS. Use multiple:true for listings, mode=. It is categorised as a Read tool in the OpenChrome MCP Server, which means it retrieves data without modifying state.
Register the OpenChrome MCP server in PolicyLayer and add a rule for extract_data: 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 OpenChrome. Nothing to install.
extract_data 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 extract_data 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 extract_data. 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.
extract_data is provided by the OpenChrome MCP server (shaun0927/openchrome). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 106 OpenChrome tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
106 OpenChrome tools catalogued and risk-classified — across an index of 42,500+ MCP servers.