supabase_upload_file · Supabase MCP Server MCP

WHAT IT DOES

What supabase_upload_file does on Supabase MCP Server

AI agents use supabase_upload_file 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_upload_file needs a policy

This tool creates or modifies data (files) in Supabase storage, which is reversible via deletion. The high severity reflects that in a production environment, unrestricted file uploads could lead to storage quota exhaustion, overwriting of critical files, or injection of malicious content that could be served to users.

From the tool's definition Tool name 'supabase_upload_file' and description 'Upload a file to Supabase storage' indicate file creation/modification operations within a production database system.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

supabase_upload_file Rate-limited

supabase_upload_file 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_upload_file": {
      "limits": [
        {
          "counter": "supabase_upload_file_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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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_upload_file

What does the supabase_upload_file tool do? +

Upload a file to Supabase storage. 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_upload_file? +

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

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

Can I rate-limit supabase_upload_file? +

Yes. Add a rate_limit block to the supabase_upload_file 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_upload_file completely? +

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

supabase_upload_file 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.