manage_webhooks · Fathom Fyi MCP: Risk & Policy

WHAT IT DOES

What manage_webhooks does on Fathom Fyi

AI agents use manage_webhooks to create or update resources in Fathom Fyi — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Fathom Fyi environment.

WHY IT NEEDS A POLICY

Why manage_webhooks needs a policy

Removing webhooks is a reversible write operation—configurations can be recreated. It does not permanently destroy data, make financial transactions, or execute arbitrary code. However, it modifies system state by altering registered webhook handlers, which could disrupt monitoring or alerting if misused. Medium severity reflects that webhook removal affects system configuration but remains reversible.

From the tool's definition Tool performs modification operations: 'remove one by ID' indicates deletion/modification of webhook configurations. 'List all registered webhooks' is read-only, but the tool's primary function is management (removal) of webhooks.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

manage_webhooks Rate-limited

manage_webhooks 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "manage_webhooks": {
      "limits": [
        {
          "counter": "manage_webhooks_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Fathom Fyi, so you can run agents against it safely.

FAQ

Questions about manage_webhooks

What does the manage_webhooks tool do? +

List all registered webhooks or remove one by ID. Use action. It is categorised as a Write tool in the Fathom Fyi MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on manage_webhooks? +

Register the Fathom Fyi MCP server in PolicyLayer and add a rule for manage_webhooks: 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 Fathom Fyi. Nothing to install.

What risk level is manage_webhooks? +

manage_webhooks is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit manage_webhooks? +

Yes. Add a rate_limit block to the manage_webhooks 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.

How do I block manage_webhooks completely? +

Set action: deny in the PolicyLayer policy for manage_webhooks. 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.

What MCP server provides manage_webhooks? +

manage_webhooks is provided by the Fathom Fyi MCP server (0xhashy/fathom-fyi). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.