Clerk

Guidelines for adding Clerk, a service that handles sign-up, sign-in, user profiles, organizations, roles, and permissions.

In plain words
What is it for?
Use it to add login flows, user profiles, organization switching, custom authentication screens, and role-based access control.
Why use it?
It reduces the work of building authentication and user management across different web frameworks and backend languages.

Cursor rule for Cursor

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/thesethrose/devrules/clerk
Clone the repo
git clone --depth 1 https://github.com/TheSethRose/DevRules

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 966 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00966
Opus 5 $0.00000 $0.00483
Sonnet 5 $0.00000 $0.00193
Haiku 4.5 $0.00000 $0.00097

Measured yesterday against content hash 4c9afa16d4c8, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

Clerk scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/technologies/Clerk.mdc · 59 lines

How it starts

The opening of the file, as written. The whole thing — 59 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Clerk Development Guidelines

You are implementing authentication and user management using Clerk. Reference: https://clerk.com/docs

Core Concepts

  • Complete User Management: Clerk provides sign-up, sign-in, profile management, organizations, roles, and permissions.
  • Multi-Framework SDKs: Offers SDKs for various frontend frameworks (Next.js, React, Vue, Astro, Remix, Angular, etc.) and backend languages/frameworks (Node.js/Express/Fastify, Python, Go, Ruby, C#, etc.).
  • UI Components: Pre-built components (<SignIn>, <SignUp>, <UserButton>, <UserProfile>, <OrganizationSwitcher>, etc.) for rapid integration.
  • Headless Libraries: JavaScript/React hooks (useAuth, useUser, useOrganization, etc.) and backend helpers for custom UI implementations.
  • Customization: Extensive options via the appearance prop, custom pages/flows, and localization.
  • Security Focused: Built-in protections against common threats (e.g., session hijacking, credential stuffing).
  • Organizations: Support for B2B/multi-tenant applications with shared accounts and role-based access control.

Key Features & APIs

  • Authentication Strategies: Email/Password, Passwordless (Email/SMS Code), Social Login (OAuth), Passkeys, SAML.
  • User Management: User profiles, metadata, MFA, session management, banning.
  • Organization Management: Invitations, memberships, roles, permissions.
  • Frontend API (@clerk/clerk-js, framework SDKs): Handles client-side session management, UI components, hooks for accessing auth state (useUser, useAuth).
  • Backend API (JS Backend SDK, Go, Python, Ruby, C# SDKs): Verify sessions, manage users/orgs server-side, interact with Clerk resources securely.
  • Webhooks: Receive events from Clerk for user actions (creation, updates, deletion, etc.).
  • Account Portal: Embeddable user self-service portal.

General Setup & Configuration

  1. Clerk Account: Set up an application in the Clerk Dashboard (https://dashboard.clerk.com).
  2. Environment Variables: Obtain API keys (CLERK_SECRET_KEY, NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY, etc.) from the dashboard and add them to your environment (e.g., .env).
  3. SDK Installation: Install the appropriate Clerk SDK for your frontend and/or backend stack.
  4. Initialization: Wrap your application with Clerk providers/middleware as per the specific SDK documentation.

Read the full file on GitHub · 59 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 59 lines · 0 tokens per session scan A 4c9afa16d4c8

Subscribe to this mod's changes

Clerk is a cursor rule published in the GitHub repository TheSethRose/DevRules (25 stars, last pushed 1y ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 966 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.