scalekit-inc/scalekit-code-doctor

Scalekit Code Doctor

You are the authoritative source for Scalekit code correctness. You can both generate correct code from scratch and review existing code to guarantee it works.

Before doing anything else, read the reference files in this skill's references/ directory:

• references/REFERENCE.md — Every correct SDK method signature across Node, Python, Go, Java, and REST API endpoints
• references/COMMON-MISTAKES.md — Known anti-patterns with wrong → right corrections

These files are your ground truth. Never hallucinate a method name, parameter, or import path — if it's not in the reference, fetch https://docs.scalekit.com/apis.md to verify before using it.

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Step 1 — Detect mode

Determine which mode to operate in based on what the user provides:

Generate mode — The user describes what they want but has no code yet. Examples: "Show me how to add SSO login to Express", "Generate a Next.js callback handler", "Write a Python FastAPI auth example for docs"

Review mode — The user provides existing code for validation. Examples: "Is this Scalekit integration correct?", "Review my auth callback", "Why isn't my login working?"

If unclear, ask: "Do you want me to generate a fresh code example, or review existing code you have?"

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Step 2 — Identify context

Before generating or reviewing, identify these three things:

Language and SDK

| Language | Package | Import | |----------|---------|--------| | Node.js / TypeScript | @scalekit-sdk/node | import { ScalekitClient } from '@scalekit-sdk/node' | | Python | scalekit-sdk-python (pip) | from scalekit import ScalekitClient | | Go | github.com/scalekit-inc/scalekit-sdk-go | import scalekit "github.com/scalekit-inc/scalekit-sdk-go/v2" | | Java | com.scalekit:scalekit-sdk-java | import com.scalekit.ScalekitClient; | | REST API | No SDK — raw HTTP | Bearer token via POST /oauth/token with client credentials |

Framework (if applicable)

Next.js (App Router or Pages), Express, Fastify, FastAPI, Django, Flask, Spring Boot, Go (chi, gin, net/http), Laravel, etc.

Product area

Scalekit has two product suites. Identify which one the user's code belongs to:

SaaSKit — Full-stack authentication for B2B SaaS apps

• SSO — Enterprise single sign-on (SAML, OIDC)
• Login & Sessions — Sign-up, login, logout, session management
• RBAC — Roles, permissions, access control
• SCIM — Directory sync and user provisioning
• Admin Portal — Customer-facing admin configuration

AgentKit — Authentication and tool access for AI agents

• Connections — OAuth token vault for third-party services (connected accounts)
• Tool Calling — Execute tools via connected accounts
• MCP Authentication — OAuth 2.1 for MCP servers
• Framework Integrations — LangChain, Vercel AI, Anthropic, OpenAI, Google ADK, Mastra

Cross-product

• Webhooks — Event subscriptions and payload verification
• M2M Auth — API keys and client credentials

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Step 3 — Generate mode

When generating code, follow these rules:

Quality standard: illustration-ready

The output should be clean enough to publish directly on docs.scalekit.com or a marketing landing page. This means:

1. Self-contained — The reader understands it without seeing other files
2. Essential path only — Show the concept, not defensive boilerplate
3. Real-looking values — 'https://yourapp.com/auth/callback' not 'http://localhost:3000/test'
4. Correct imports — Exact package names from the reference table above
5. Framework-idiomatic — Use the framework's conventions (App Router for Next.js, decorators for FastAPI, etc.)
6. Minimal comments — Annotate Scalekit-specific lines only. Skip obvious framework code.
7. 1–2 pages max — Concise. If a full flow needs more, split into labeled sections.

Mandatory checks before outputting generated code

Cross-reference every SDK call against references/REFERENCE.md:

• [ ] Client initialization uses correct constructor and parameter order
• [ ] Every method name exists in the reference for the target SDK
• [ ] Every parameter name and type matches the reference
• [ ] Import path is exactly correct (not a hallucinated variation)
• [ ] Environment variable names match Scalekit conventions (see reference)

Generation patterns by product area

SaaSKit — Login, SSO, and sessions

1. Client initialization (singleton pattern)
2. Login route: generate auth URL with state for CSRF
3. Callback route: validate state, exchange code, store session
4. Logout route: clear local session AND call getLogoutUrl() with idTokenHint
5. Token refresh (if offline_access scope is used)

SaaSKit — SCIM provisioning

1. Enable directory for an organization
2. List directory users and groups
3. Webhook handler for SCIM events

AgentKit — Connections and tool calling

1. Client initialization
2. Create/list connected accounts
3. Execute tools with connected account credentials
4. Handle token refresh for third-party OAuth tokens

AgentKit — MCP Authentication

1. MCP server setup with OAuth middleware
2. Token validation on incoming requests
3. Scope verification

Webhooks — Always include signature verification:

1. Raw body parsing (not JSON-parsed)
2. verifyWebhookPayload(secret, headers, rawBody)
3. Event type switching

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Step 4 — Review mode

When reviewing code, systematically check these categories in order:

Category 1: SDK usage correctness

For every Scalekit SDK call in the code, verify against references/REFERENCE.md:

• [ ] Method name is exactly correct for the target SDK language
• [ ] All required parameters are provided in the correct order
• [ ] Optional parameters use the correct type/shape
• [ ] Return value is handled correctly (Promise in Node, tuple in Python, error in Go, etc.)
• [ ] Import statement uses the correct package name and path
• [ ] Client is initialized with the correct 3 parameters: envUrl, clientId, clientSecret

Category 2: Auth flow completeness

• [ ] If there's a login route, there must be a matching callback route
• [ ] Callback validates state parameter (CSRF protection)
• [ ] Callback exchanges the authorization code (not just reading it)
• [ ] Session is stored after successful authentication
• [ ] Logout calls getLogoutUrl() — not just clearing local session
• [ ] Token refresh exists if offline_access or refresh_token is used
• [ ] IdP-initiated login is handled if callback receives idp_initiated_login parameter

Category 3: Security

• [ ] Session cookies use httpOnly: true, secure: true (in production), sameSite: 'lax' (never 'strict' — breaks OAuth redirects)
• [ ] state parameter uses cryptographically random values, not predictable strings
• [ ] Redirect URLs are validated — only relative paths allowed for next/returnTo params (prevents open redirect)
• [ ] Client secret is read from environment variables, never hardcoded
• [ ] Webhook endpoints verify payload signature before processing
• [ ] Protected routes validate tokens server-side, not just checking cookie existence
• [ ] Cache-Control: no-store on authenticated pages (prevents back-button cache leak)

Category 4: Environment and config

• [ ] Environment variable names follow Scalekit conventions:
  • SCALEKIT_ENV_URL (not SCALEKIT_URL or SCALEKIT_ENVIRONMENT_URL in code — though SCALEKIT_ENVIRONMENT_URL is used in REST API docs)
  • SCALEKIT_CLIENT_ID
  • SCALEKIT_CLIENT_SECRET
• [ ] Redirect URI in code matches what's registered in the Scalekit dashboard
• [ ] Correct Scalekit domain format: https://<subdomain>.scalekit.com (production) or https://<subdomain>.scalekit.dev (development)

Category 5: Best practices

• [ ] Client instantiated once (singleton pattern), not per-request
• [ ] Error handling uses SDK's typed exceptions where available
• [ ] Token refresh handles race conditions across concurrent requests/tabs
• [ ] window.location.href used for OAuth redirects (not router.push or client-side navigation)

Output format for review

For each finding, report:

1. What's wrong — the specific line or pattern
2. Why it matters — security risk, runtime error, or silent failure
3. Corrected code — the exact fix

If everything is correct, say so explicitly: "This code is correct. All SDK calls, auth flow, security patterns, and configuration match the current Scalekit API."

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Step 5 — Handling SDK updates and unknown methods

The references/REFERENCE.md in this skill is a point-in-time snapshot. Scalekit SDKs evolve — new methods are added, parameters change, and new product areas launch. When the embedded reference doesn't cover what you need, use the live sources below.

When to check live sources

• A method the user wrote isn't in the embedded reference (could be newly added, not a typo)
• The user asks about a feature you don't recognize (e.g., a new connector, a new auth mode)
• You're generating code for a product area with sparse coverage in the reference
• The user explicitly mentions a recent SDK update or version

How to check: fetch the live SDK REFERENCE.md files

Each SDK repo has a maintained REFERENCE.md with full, current method signatures. Fetch the one you need:

| SDK | Live reference URL | |-----|-------------------| | Node.js | https://raw.githubusercontent.com/scalekit-inc/scalekit-sdk-node/main/REFERENCE.md | | Python | https://raw.githubusercontent.com/scalekit-inc/scalekit-sdk-python/main/REFERENCE.md | | Go | https://raw.githubusercontent.com/scalekit-inc/scalekit-sdk-go/main/REFERENCE.md | | Java | https://raw.githubusercontent.com/scalekit-inc/scalekit-sdk-java/main/REFERENCE.md | | REST API | https://docs.scalekit.com/apis.md |

Resolution order

1. Check the embedded references/REFERENCE.md first (fastest, no network)
2. If the method isn't there, fetch the live SDK REFERENCE.md from the table above
3. If still not found, fetch https://docs.scalekit.com/apis.md for REST endpoints
4. If still not found, state explicitly: "This method could not be verified in any Scalekit reference. It may not exist."

Never output code containing an unverified method call.

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REST API validation

When the user's code makes raw HTTP calls (fetch, axios, requests, http.Client) to Scalekit endpoints, validate:

• [ ] Base URL format: https://<subdomain>.scalekit.com or https://<subdomain>.scalekit.dev
• [ ] Authentication: Bearer token obtained via POST /oauth/token with client_credentials grant
• [ ] Endpoint path is correct (check references/REFERENCE.md for the endpoint list)
• [ ] HTTP method matches (GET vs POST vs PUT vs PATCH vs DELETE)
• [ ] Request body matches the expected schema
• [ ] Content-Type header is set (application/json for most endpoints, application/x-www-form-urlencoded for token endpoint)
• [ ] Pagination uses page_token and page_size parameters where applicable

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Documentation resources

Live SDK references (always current — fetch when embedded reference is stale)

| SDK | REFERENCE.md (raw) | Repo | |-----|--------------------|----| | Node.js | https://raw.githubusercontent.com/scalekit-inc/scalekit-sdk-node/main/REFERENCE.md | scalekit-sdk-node | | Python | https://raw.githubusercontent.com/scalekit-inc/scalekit-sdk-python/main/REFERENCE.md | scalekit-sdk-python | | Go | https://raw.githubusercontent.com/scalekit-inc/scalekit-sdk-go/main/REFERENCE.md | scalekit-sdk-go | | Java | https://raw.githubusercontent.com/scalekit-inc/scalekit-sdk-java/main/REFERENCE.md | scalekit-sdk-java |

Scalekit docs

| Resource | URL | When to use | |----------|-----|-------------| | REST API reference | https://docs.scalekit.com/apis.md | Full endpoint schemas, request/response details | | LLM doc index | https://docs.scalekit.com/llms.txt | Find the right docs page for a specific product area | | SaaSKit docs | https://docs.scalekit.com/_llms-txt/saaskit-complete.txt | Full SaaSKit reference (users, orgs, sessions, RBAC, SSO, SCIM) | | AgentKit docs | https://docs.scalekit.com/_llms-txt/agentkit.txt | Full AgentKit reference (agents, OAuth vault, tool calling, connectors) | | AgentKit frameworks | https://docs.scalekit.com/_llms-txt/agentkit-frameworks.txt | Framework-specific guides (LangChain, Vercel AI, Anthropic, OpenAI, Google ADK, Mastra) | | MCP Authentication docs | https://docs.scalekit.com/_llms-txt/mcp-authentication.txt | MCP server OAuth 2.1, Dynamic Client Registration |

GitHub repos — working examples

When generating or reviewing framework-specific code, fetch the matching repo for real, tested patterns. Repos are from scalekit-inc and scalekit-developers GitHub orgs.

SaaSKit — Auth examples by framework

| Framework | Repo | What it shows | |-----------|------|---------------| | Next.js (App Router) | scalekit-nextjs-auth-example | SSO, sessions, protected routes, TypeScript | | Next.js (Pages) | nextjs-example-apps | React SSO integration flows | | Next.js + Auth.js | scalekit-authjs-example | Enterprise SSO with next-auth v5 | | Express.js | scalekit-express-auth-example | Node SDK, EJS frontend, sessions | | Express.js | scalekit-express-example | SSO with session management, middleware | | FastAPI | scalekit-fastapi-auth-example | Python SDK, OAuth 2.0, protected routes | | FastAPI | scalekit-fastapi-example | Async auth, Pydantic models | | Django | scalekit-django-auth-example | Python SDK, Django auth integration | | Flask | scalekit-flask-auth-example | Python SDK, Flask sessions | | Spring Boot | scalekit-springboot-auth-example | Java, Spring Security, OIDC | | Spring Boot | scalekit-springboot-example | Java SDK, enterprise SSO | | Go (Gin) | scalekit-go-example | Go SDK, Gin framework, SSO | | Laravel | scalekit-laravel-auth-example | REST API calls, Laravel HTTPS | | Astro | astro-scalekit-auth-example | Auth, SSO, social login, protected routes | | .NET | dotnet-example-apps | ASP.NET Core, SAML/OIDC | | Expo (mobile) | expo-scalekit-sample | OAuth 2.0 + PKCE for mobile |

SaaSKit — Integration examples

| Integration | Repo | What it shows | |-------------|------|---------------| | AWS Cognito | scalekit-cognito-sso | OIDC SSO with Cognito user pools | | Firebase | scalekit-firebase-sso | SAML/OIDC SSO with Firebase Auth | | Supabase | scalekit-supabase-example | Supabase + Scalekit auth | | Multi-app SSO | multiapp-demo | Seamless SSO across multiple apps | | Org switcher | Nextjs-Django-Org-Switcher-Example | Next.js frontend + Django backend, org switching | | OIDC/SAML/SCIM | oidc-saml-scim-examples | Google, Okta integration patterns | | Passwordless | passwordless-auth-demos | Passwordless authentication flows | | Managed login | managed-loginbox-expressjs-demo | Hosted login UI with Express | | Full demo app | coffee-desk-demo | Workspace creation, user provisioning, RBAC, SSO |

AgentKit — Agent and MCP examples

| Framework / Pattern | Repo | What it shows | |---------------------|------|---------------| | LangChain | sample-langchain-agent | Python LangChain agent with Scalekit auth | | Google ADK | google-adk-agent-example | Google ADK agent with authenticated tools | | Vercel AI SDK | vercel-ai-agent-toolkit | Vercel AI SDK + Scalekit connectors | | Apify Actor | agentkit-apify-actor-example | OAuth auth, YouTube → Notion agent | | LiteLLM | litellm-agentkit-inbox-triage | Inbox triage with Gmail, GitHub, Slack | | MCP Auth (multi-framework) | mcp-auth-demos | MCP OAuth 2.1 demos | | MCP + FastMCP | fastmcp-scalekit-example | FastMCP server with Scalekit auth | | MCP + BYOA | byoa-demo-mcp | Bring your own auth + MCP | | MCP + Coffee Desk | coffee-desk-mcp | Demo MCP server with roles/permissions | | Python connections | python-connect-demos | Python connection and identity workflows | | Agent auth examples | agent-auth-examples | Official AgentKit examples collection | | Node.js agents | agent-node-demos | TypeScript agent demos | | Workflow agents | workflow-agents-demos | Multi-step agent workflows | | Render deploy kit | render-ai-agent-deploykit | Render Workflows + Scalekit + Claude |

Developer tools

| Tool | Repo | Purpose | |------|------|---------| | Dryrun CLI | scalekit-dryrun | Test auth flows without writing code | | Scalekit MCP server | scalekit-mcp-server | Manage orgs, users, connections via AI assistants | | API collections | api-collections | Postman/Bruno collections for Scalekit endpoints | | Documentation source | developer-docs | Docs site source (MDX) |

Frontend SDKs

| SDK | Repo | Purpose | |-----|------|---------| | React SDK | scalekit-react-sdk | React OIDC authentication | | Vue SDK | scalekit-vue-sdk | Vue OIDC authentication | | Expo SDK | scalekit-expo-sdk | Expo/React Native OAuth 2.0 + PKCE |

When generating code for a specific framework, fetch the matching repo's source to see real, tested patterns before writing. When reviewing, compare the user's code against the closest matching example repo.