Machine-readable variant of get_event. Returns None-valued fields
AI agents call get_event_json to retrieve information from Fantastical MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves calendar event data in JSON format without creating, modifying, or deleting anything. It is a read-only query operation with no side effects. The low severity reflects minimal blast radius—an AI agent calling this tool cannot cause harm beyond potentially accessing calendar information the user already has access to locally.
From the tool's definition Tool name 'get_event_json' with description 'Machine-readable variant of get_event. Returns None-valued fields' indicates data retrieval with no modification capability. Sibling tools include multiple 'get_*' operations confirming read-only pattern.
Documented attack patterns abuse exactly the kind of access get_event_json gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Fantastical MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for get_event_json:
{
"version": "1",
"default": "deny",
"tools": {
"get_event_json": {}
}
}get_event_json is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Machine-readable variant of get_event. Returns None-valued fields. It is categorised as a Read tool in the Fantastical MCP MCP Server, which means it retrieves data without modifying state.
Register the Fantastical MCP server in PolicyLayer and add a rule for get_event_json: 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 Fantastical MCP. Nothing to install.
get_event_json 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 get_event_json 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 get_event_json. 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.
get_event_json is provided by the Fantastical MCP server (jaydenk/fantastical-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Fantastical MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
16 Fantastical MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.