WATCHER: get a signed callback when a new US IPO appears on the calendar. Arm once, pay once. Optionally pass keyword to only fire when the company name/symbol matches. Fires once per new IPO (deduped by symbol); bounded by maxFires/expiry. Existing entries at arm time are baselined. Calendar via...
AI agents call watchers.ipo to retrieve information from Mcp without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
Even though watchers.ipo 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
WATCHER: get a signed callback when a new US IPO appears on the calendar. Arm once, pay once. Optionally pass keyword to only fire when the company name/symbol matches. Fires once per new IPO (deduped by symbol); bounded by maxFires/expiry. Existing entries at arm time are baselined. Calendar via Finnhub. Signed (verify offline) + retried; recoverable via watchers.status. Returns a watcherId. It is categorised as a Read tool in the Mcp MCP Server, which means it retrieves data without modifying state.
Register the MCP server in PolicyLayer and add a rule for watchers.ipo: 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 Mcp. Nothing to install.
watchers.ipo 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 watchers.ipo 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 watchers.ipo. 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.
watchers.ipo is provided by the MCP server (@2sio/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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