`: `agentkit`, `full-stack-auth`, `mcp-auth`, `modular-sso`, `modular-scim` — [Full setup guide](https://docs.scalekit.com/dev-kit/build-with-ai/) --- # The Auth Stack for your SaaS

The Auth Stack for your SaaS

Add auth to your B2B SaaS application without building from scratch.

Drop in a modular capability like MCP Auth, Single Sign-On, or SCIM alongside your existing system, or adopt Scalekit as your full identity layer for users, sessions, organizations, and roles.

Building auth from scratch? Start with SaaS User Management. Adding SSO, SCIM, or MCP Auth to an existing system? Use Modular Auth.

2 steps · ~5 minutes · works with any AI coding agent

```bash title="Step 1 — Add the marketplace (Claude REPL)" showLineNumbers=false /plugin marketplace add scalekit-inc/claude-code-authstack ``` ```bash title="Step 2 — Install your auth plugin (Claude REPL)" showLineNumbers=false # options: full-stack-auth, agent-auth, mcp-auth, modular-sso, modular-scim /plugin install full-stack-auth@scalekit-auth-stack ``` Now ask your agent to implement Scalekit auth in natural language. [See example starting prompts →](/agentkit/quickstart/) ```bash title="Step 1 — Install the Scalekit Auth Stack" frame="terminal" showLineNumbers=false curl -fsSL https://raw.githubusercontent.com/scalekit-inc/codex-authstack/main/install.sh | bash ``` Step 2 — Restart Codex, open **Plugin Directory**, select **Scalekit Auth Stack**, and enable your auth plugin. Now ask your agent to implement Scalekit auth in natural language. [See example starting prompts →](/agentkit/quickstart/) ```bash title="Step 1 — Add the marketplace" frame="terminal" showLineNumbers=false copilot plugin marketplace add scalekit-inc/github-copilot-authstack ``` ```bash title="Step 2 — Install your auth plugin" frame="terminal" showLineNumbers=false # options: full-stack-auth, agent-auth, mcp-auth, modular-sso, modular-scim copilot plugin install full-stack-auth@scalekit-auth-stack ``` Now ask your agent to implement Scalekit auth in natural language. [See example starting prompts →](/agentkit/quickstart/) The Scalekit Auth Stack is pending Cursor Marketplace review. Install it locally in Cursor: ```bash title="Step 1 — Install the Scalekit Auth Stack" frame="terminal" showLineNumbers=false curl -fsSL https://raw.githubusercontent.com/scalekit-inc/cursor-authstack/main/install.sh | bash ``` Step 2 — Restart Cursor, open **Settings > Cursor Settings > Plugins**, and enable your auth plugin. Now ask your agent to implement Scalekit auth in natural language. [See example starting prompts →](/agentkit/quickstart/) Works with OpenCode, Windsurf, Cline, Gemini CLI, Codex, and 35+ more agents via the [Vercel Skills CLI](https://vercel.com/docs/agent-resources/skills). ```bash title="Step 1 — Browse available skills" frame="terminal" showLineNumbers=false npx skills add scalekit-inc/skills --list ``` ```bash title="Step 2 — Install a specific skill" frame="terminal" showLineNumbers=false npx skills add scalekit-inc/skills --skill adding-mcp-oauth ``` Now ask your agent to implement Scalekit auth in natural language. [See example starting prompts →](/agentkit/quickstart/)

Need help? Join the developer community or browse the guides.

Modular auth

Add specific auth capabilities like MCP Auth, SSO, or SCIM without replacing your existing system.

Add OAuth 2.1 authorization to your remote MCP server with Dynamic Client Registration and short-lived tokens Let enterprise users sign in through their company's identity provider like Okta, Microsoft Entra, Google, and more Automatically sync users, roles, and groups when IT admins add or remove people in Okta or Microsoft Entra

SaaS user management

Use Scalekit as your full identity layer to manage users, organizations, sessions, roles, and application access.

[Quickstart](/authenticate/fsa/quickstart)

Get production-ready auth running in minutes

Create, update, and delete users with built-in lifecycle APIs Support modern login flows with passkeys, magic links, OTPs, and social logins Model organizations, user memberships, and multi-tenant access for B2B SaaS apps Define roles and permissions for human users and AI agents Add enterprise capabilities like Single Sign-On (SSO) and SCIM provisioning Issue and validate user-scoped and org-level tokens for APIs and services

Extensibility & Controls

Customize identity workflows and apply your business logic.

Receive real-time events for authentication, user lifecycle, and organizations Apply custom logic and policy checks during authentication and authorization flows Customize hosted login and signup pages plus auth emails to match your app Record and inspect authentication events and user access activity for auditing purposes

Developer Resources

SDKs, code samples, and community resources for building with Scalekit.

Drop-in libraries to quickly integrate Scalekit into your application Reference implementations and code examples for common auth flows Ask questions, share feedback, and learn from other Scalekit developers

Security, Compliance & Availability

Designed for production workloads with strict operational and security requirements.

⊕Multi-region data residency
Dedicated regional clusters in the US and EU

⊕Compliance
SOC 2, ISO 27001, GDPR, and CCPA compliant

⊕Uptime
99.99% uptime with failover redundancy

⊕Secure token & secret storage
Vault-backed storage with strong isolation for tokens and credentials

--- ## More Scalekit documentation | Resource | What it contains | When to use it | |----------|-----------------|----------------| | [/llms.txt](/llms.txt) | Structured index with routing hints per product area | Start here — find which documentation set covers your topic before loading full content | | [/llms-full.txt](/llms-full.txt) | Complete documentation for all Scalekit products in one file | Use when you need exhaustive context across multiple products or when the topic spans several areas | | [sitemap-0.xml](https://docs.scalekit.com/sitemap-0.xml) | Full URL list of every documentation page | Use to discover specific page URLs you can fetch for targeted, page-level answers |