Send web vitals data to Speed Insights API (Deprecated: Use @vercel/speed-insights package instead)
AI agents use send_web_vitals to create or update resources in Vercel MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Vercel MCP Server environment.
This tool creates or transmits analytics/metrics data to Vercel's Speed Insights API. While it modifies state in the remote service by recording metrics, it is reversible (metrics can be replaced or ignored) and poses minimal risk. It does not execute arbitrary code, delete data, move funds, or cause destructive changes.
From the tool's definition Tool description states 'Send web vitals data to Speed Insights API', which involves transmitting/posting data to an external service. The deprecated status and recommendation to use a package instead indicate this is a data submission mechanism.
Documented attack patterns abuse exactly the kind of access send_web_vitals gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Vercel MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for send_web_vitals:
{
"version": "1",
"default": "deny",
"tools": {
"send_web_vitals": {
"limits": [
{
"counter": "send_web_vitals_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}send_web_vitals stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
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Send web vitals data to Speed Insights API (Deprecated: Use @vercel/speed-insights package instead). It is categorised as a Write tool in the Vercel MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Vercel MCP Server MCP server in PolicyLayer and add a rule for send_web_vitals: 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 Vercel MCP Server. Nothing to install.
send_web_vitals is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the send_web_vitals 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 send_web_vitals. 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.
send_web_vitals is provided by the Vercel MCP Server MCP server (quegenx/vercel-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 154 Vercel MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
154 Vercel MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.