create_repository_webhook · Mcp Github MCP: Risk & Policy

WHAT IT DOES

What create_repository_webhook does on Mcp Github

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

WHY IT NEEDS A POLICY

Why create_repository_webhook needs a policy

Creating a webhook establishes an outbound HTTP callback from the repository to an external URL, which is reversible (webhooks can be deleted). However, misuse is high-severity because a malicious actor could redirect repository events (pushes, pull requests, secrets) to an attacker-controlled endpoint, potentially exfiltrating sensitive data.

From the tool's definition "Create a webhook for a repository" — creates a new webhook configuration on a GitHub repository

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_repository_webhook Rate-limited

create_repository_webhook 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": {
    "create_repository_webhook": {
      "limits": [
        {
          "counter": "create_repository_webhook_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 Mcp Github, so you can run agents against it safely.

FAQ

Questions about create_repository_webhook

What does the create_repository_webhook tool do? +

Create a webhook for a repository. It is categorised as a Write tool in the Mcp Github MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_repository_webhook? +

Register the Mcp Github MCP server in PolicyLayer and add a rule for create_repository_webhook: 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 Github. Nothing to install.

What risk level is create_repository_webhook? +

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

Can I rate-limit create_repository_webhook? +

Yes. Add a rate_limit block to the create_repository_webhook 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 create_repository_webhook completely? +

Set action: deny in the PolicyLayer policy for create_repository_webhook. 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 create_repository_webhook? +

create_repository_webhook is provided by the Mcp Github MCP server (@missionsquad/mcp-github). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.