@leash/sdk

v0.4.4

Published

2 months ago

TypeScript SDK for Leash platform - authentication and environment management

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unleash_arvin

leash authentication nextjs react typescript

Leash SDK

TypeScript SDK for the Leash platform. Works with any JavaScript/TypeScript framework — Next.js, Express, Koa, Hono, Fastify, plain Node.js.

Install

npm install @leash/sdk

Entry Points

| Import | Use case | Requires | |--------|----------|----------| | @leash/sdk | React hooks (useLeashAuth, useLeashEnv, LeashProvider) | React | | @leash/sdk/server | Server auth (getLeashUser, isAuthenticated) | Nothing — works with any framework | | @leash/sdk/middleware | Next.js route protection (leashMiddleware) | Next.js | | @leash/sdk/integrations | API client (LeashIntegrations, getIntegrations) | Nothing | | @leash/sdk/integrations/react | React hooks for integrations (useIntegrations, useIntegrationStatus) | React | | @leash/sdk/integrations/mcp | MCP server config helpers | Nothing |

Quick Start

React (Next.js) — client auth

// app/providers.tsx
'use client'
import { LeashProvider } from '@leash/sdk'

export default function Providers({ children }: { children: React.ReactNode }) {
  return <LeashProvider>{children}</LeashProvider>
}

// app/layout.tsx
import Providers from './providers'

export default function RootLayout({ children }: { children: React.ReactNode }) {
  return <html><body><Providers>{children}</Providers></body></html>
}

// app/page.tsx
'use client'
import { useLeashAuth, useLeashEnv } from '@leash/sdk'

export default function Home() {
  const { user, isLoading, error } = useLeashAuth()
  const env = useLeashEnv()

  if (isLoading) return <div>Loading...</div>
  if (error) return <div>{error.message}</div>
  if (!user) return <div>Not authenticated</div>

  return <div>Welcome {user.name} — App: {env.LEASH_APP_ID}</div>
}

Express — server auth

import express from 'express'
import { getLeashUser } from '@leash/sdk/server'

const app = express()

app.get('/me', (req, res) => {
  try {
    const user = getLeashUser(req)
    res.json({ user })
  } catch {
    res.status(401).json({ error: 'Not authenticated' })
  }
})

app.listen(process.env.PORT || 3000)

Next.js API route — server auth

import { getLeashUser } from '@leash/sdk/server'
import { NextRequest, NextResponse } from 'next/server'

export async function GET(req: NextRequest) {
  const user = getLeashUser(req)
  return NextResponse.json({ user })
}

Next.js middleware — route protection

// middleware.ts
import { leashMiddleware } from '@leash/sdk/middleware'

export const middleware = leashMiddleware({
  publicRoutes: ['/login', '/about'],
  redirectTo: '/login'
})

export const config = {
  matcher: ['/((?!_next/static|_next/image|favicon.ico).*)']
}

Integrations — server-side

import { LeashIntegrations } from '@leash/sdk/integrations'

const integrations = new LeashIntegrations({
  apiKey: process.env.LEASH_API_KEY,
})

const messages = await integrations.gmail.listMessages({ maxResults: 5 })
const env = await integrations.getEnv()

Integrations — React hooks

import { useIntegrations, useIntegrationStatus } from '@leash/sdk/integrations/react'

function Dashboard() {
  const integrations = useIntegrations()
  const { isConnected, getConnectUrl } = useIntegrationStatus()

  if (!isConnected('gmail')) {
    return <a href={getConnectUrl('gmail')}>Connect Gmail</a>
  }

  // Use integrations.gmail.listMessages(), etc.
}

Server Auth — Framework Compatibility

getLeashUser(req) works with any request object that carries cookies:

Next.js — req.cookies.get() (NextRequest)
Express — req.cookies (with cookie-parser) or req.headers.cookie
Koa — ctx.cookies or ctx.headers.cookie
Hono — req.headers.cookie
Fastify — req.headers.cookie
Plain Node.js — req.headers.cookie (IncomingMessage)

No framework-specific dependencies. Just reads the leash-auth cookie from wherever it lives.

Environment Variables

Server-side (set in dashboard, injected at deploy)

LEASH_JWT_SECRET — for JWT verification (optional, decodes without it)

Runtime values (auto-injected by platform)

LEASH_USER_ID
LEASH_USER_EMAIL
LEASH_APP_ID
SUPABASE_URL
SUPABASE_KEY

Testing

npm test

Build

npm run build

License

Apache-2.0