supabase_update · Supabase MCP Server MCP: Risk & Policy

WHAT IT DOES

What supabase_update does on Supabase MCP Server

AI agents use supabase_update 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 supabase_update needs a policy

The tool creates or modifies data in a reversible manner, matching the Write category definition. Severity is high because an AI agent could misuse filter parameters to update many unintended records across the database, potentially affecting business logic, user data, or dependent systems. However, updates are technically reversible (unlike Destructive operations), preventing a critical rating.

From the tool's definition Tool name is 'supabase_update' and description states 'Update records in a Supabase table with filters' — this modifies data reversibly within a database table.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

supabase_update Rate-limited

supabase_update 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": {
    "supabase_update": {
      "limits": [
        {
          "counter": "supabase_update_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 supabase_update

What does the supabase_update tool do? +

Update records in a Supabase table with filters. 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 supabase_update? +

Register the Supabase MCP Server MCP server in PolicyLayer and add a rule for supabase_update: 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 supabase_update? +

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

Can I rate-limit supabase_update? +

Yes. Add a rate_limit block to the supabase_update 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_update completely? +

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

supabase_update is provided by the Supabase MCP Server MCP server (sweir1/supabase-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.