confirm_cost · Supabase MCP Server MCP: Risk & Policy

WHAT IT DOES

What confirm_cost does on Supabase MCP Server

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

WHY IT NEEDS A POLICY

Why confirm_cost needs a policy

An AI agent can call confirm_cost faster than any human can review — one bad instruction and it creates or modifies resources in Supabase MCP Server by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

confirm_cost Rate-limited

confirm_cost 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": {
    "confirm_cost": {
      "limits": [
        {
          "counter": "confirm_cost_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 Supabase MCP Server, so you can run agents against it safely.

FAQ

Questions about confirm_cost

What does the confirm_cost tool do? +

Confirms the user's understanding of new project or branch costs. This is required to create a new project or branch. It is categorised as a Write tool in the Supabase MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on confirm_cost? +

Register the Supabase MCP Server MCP server in PolicyLayer and add a rule for confirm_cost: 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 Supabase MCP Server. Nothing to install.

What risk level is confirm_cost? +

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

Can I rate-limit confirm_cost? +

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

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

confirm_cost is provided by the Supabase MCP Server MCP server (pipethedev/supabase-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.