setup_better_auth · Better Auth MCP Server MCP

WHAT IT DOES

What setup_better_auth does on Better Auth MCP Server

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

WHY IT NEEDS A POLICY

Why setup_better_auth needs a policy

This tool writes/creates new authentication infrastructure and modifies project configuration files. While not destructive (changes are theoretically reversible by uninstalling), it is a Write action because it creates and modifies project state. The severity is high because misconfiguration of authentication systems can create security vulnerabilities affecting all users of the application.

From the tool's definition Tool name 'setup_better_auth' and description 'Install and configure Better-Auth in the project' indicate creation and modification of authentication configuration and system state.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

setup_better_auth Rate-limited

setup_better_auth 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": {
    "setup_better_auth": {
      "limits": [
        {
          "counter": "setup_better_auth_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 Better Auth MCP Server, so you can run agents against it safely.

FAQ

Questions about setup_better_auth

What does the setup_better_auth tool do? +

Install and configure Better-Auth in the project. It is categorised as a Write tool in the Better Auth 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 setup_better_auth? +

Register the Better Auth MCP Server MCP server in PolicyLayer and add a rule for setup_better_auth: 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 Better Auth MCP Server. Nothing to install.

What risk level is setup_better_auth? +

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

Can I rate-limit setup_better_auth? +

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

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

setup_better_auth is provided by the Better Auth MCP Server MCP server (lexiconalex/better-auth-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.