supabase.sql · MCP Fullstack MCP: Risk & Policy

WHAT IT DOES

What supabase.sql does on MCP Fullstack

AI agents invoke supabase.sql 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.sql needs a policy

SQL execution is inherently an Execute-category tool because it runs code against a database whose effects depend on the query arguments. However, this warrants critical severity because: (1) SQL queries can be destructive (DROP TABLE, DELETE), (2) can exfiltrate sensitive data (SELECT from any table), (3) can modify data (UPDATE, INSERT), and (4) an AI agent with unsanitized query construction could cause severe…

From the tool's definition Tool name 'supabase.sql' and description 'Execute SQL query on Supabase' indicate arbitrary SQL query execution capabilities.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

supabase.sql Rate-limited

supabase.sql 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.sql": {
      "limits": [
        {
          "counter": "supabase.sql_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.sql

What does the supabase.sql tool do? +

Execute SQL query on 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.sql? +

Register the MCP Fullstack MCP server in PolicyLayer and add a rule for supabase.sql: 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.sql? +

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

Can I rate-limit supabase.sql? +

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

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

supabase.sql 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.