supabase_insert · VibeServe MCP: Risk & Policy

WHAT IT DOES

What supabase_insert does on VibeServe

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

WHY IT NEEDS A POLICY

Why supabase_insert needs a policy

This tool modifies state by inserting data into a persistent database (Supabase). While reversible, it could corrupt application state if an AI agent inserts malformed, duplicate, or sensitive data into the wrong table, affecting production systems. The blast radius depends on table schemas and downstream dependencies, warranting 'medium' severity.

From the tool's definition Tool description states 'Insert a row into a Supabase table' — this creates new data in a database without deleting or overwriting existing records. It is a write operation that is reversible (the inserted row can be deleted).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

supabase_insert Rate-limited

supabase_insert 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_insert": {
      "limits": [
        {
          "counter": "supabase_insert_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 VibeServe, so you can run agents against it safely.

FAQ

Questions about supabase_insert

What does the supabase_insert tool do? +

Insert a row into a Supabase table. It is categorised as a Write tool in the VibeServe 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_insert? +

Register the VibeServe MCP server in PolicyLayer and add a rule for supabase_insert: 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 VibeServe. Nothing to install.

What risk level is supabase_insert? +

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

Can I rate-limit supabase_insert? +

Yes. Add a rate_limit block to the supabase_insert 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_insert completely? +

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

supabase_insert is provided by the VibeServe MCP server (ncsound919/vibeserve). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.