AI agents use gitlab_add_webhook to create or update resources in GitLab MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your GitLab MCP Server environment.
Adding a webhook creates a new outbound HTTP integration that sends GitLab events to an external URL. This is a Write operation (creates a new resource), but carries high severity because a malicious agent could point the webhook at an attacker-controlled server to exfiltrate sensitive repository events, CI/CD data, tokens, and more.
From the tool's definition "Add a new webhook to a project"
Documented attack patterns abuse exactly the kind of access gitlab_add_webhook gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and GitLab MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for gitlab_add_webhook:
{
"version": "1",
"default": "deny",
"tools": {
"gitlab_add_webhook": {
"limits": [
{
"counter": "gitlab_add_webhook_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}gitlab_add_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.
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Add a new webhook to a project. It is categorised as a Write tool in the GitLab MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the GitLab MCP Server MCP server in PolicyLayer and add a rule for gitlab_add_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 GitLab MCP Server. Nothing to install.
gitlab_add_webhook 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 gitlab_add_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.
Set action: deny in the PolicyLayer policy for gitlab_add_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.
gitlab_add_webhook is provided by the GitLab MCP Server MCP server (rifqi96/mcp-gitlab). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from GitLab MCP Server, 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.
42 GitLab MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.