supabase.rest · MCP Fullstack MCP: Risk & Policy

WHAT IT DOES

What supabase.rest does on MCP Fullstack

AI agents invoke supabase.rest to trigger actions in MCP Fullstack. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why supabase.rest needs a policy

Making a REST API call to Supabase can encompass a wide range of operations — reads, writes, deletes, or RPC calls — depending on the HTTP method and endpoint used. Since the description is generic and doesn't restrict the operation type, this tool could be used to execute arbitrary REST operations including destructive ones (DELETE) or data modifications (POST/PATCH/PUT).

From the tool's definition "Make REST API call to Supabase"

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

supabase.rest Rate-limited

supabase.rest stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "supabase.rest": {
      "limits": [
        {
          "counter": "supabase.rest_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-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 Fullstack, so you can run agents against it safely.

FAQ

Questions about supabase.rest

What does the supabase.rest tool do? +

Make REST API call to Supabase. It is categorised as a Execute tool in the MCP Fullstack MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on supabase.rest? +

Register the MCP Fullstack MCP server in PolicyLayer and add a rule for supabase.rest: 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 Fullstack. Nothing to install.

What risk level is supabase.rest? +

supabase.rest is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit supabase.rest? +

Yes. Add a rate_limit block to the supabase.rest 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 supabase.rest completely? +

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

supabase.rest is provided by the MCP Fullstack MCP server (jacobfv/mcp-fullstack). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.