create_sub_uid · Bybit MCP: Risk & Policy

WHAT IT DOES

What create_sub_uid does on Bybit

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

WHY IT NEEDS A POLICY

Why create_sub_uid needs a policy

This tool creates a new sub-user ID, which is a reversible write operation that modifies account structure. It does not delete data (so not Destructive), does not move money directly (so not Financial), and does not execute arbitrary code (so not Execute). However, the ability to create sub-accounts could enable privilege escalation or unauthorized account sprawl if misused by an AI agent, warranting medium severity.

From the tool's definition Tool name 'create_sub_uid' indicates creation of a subordinate user identifier. Description states 'Create a sub UID,' confirming a write operation that creates new account-level resources.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_sub_uid Rate-limited

create_sub_uid 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": {
    "create_sub_uid": {
      "limits": [
        {
          "counter": "create_sub_uid_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 Bybit, so you can run agents against it safely.

FAQ

Questions about create_sub_uid

What does the create_sub_uid tool do? +

Create a sub UID. It is categorised as a Write tool in the Bybit MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_sub_uid? +

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

What risk level is create_sub_uid? +

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

Can I rate-limit create_sub_uid? +

Yes. Add a rate_limit block to the create_sub_uid 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 create_sub_uid completely? +

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

create_sub_uid is provided by the Bybit MCP server (johnnywic/bybit-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.