blink-backend

MCP Tools

blink_backend_status · blink_backend_deploy · blink_backend_logs

When to Use

• Prefer SDK for auth, db, storage, AI (~95% of cases)
• Use backend for: webhooks, server-side secrets, third-party callbacks, heavy processing
• Never create a backend just for CRUD — use blink.db instead

Getting Started

# Check backend eligibility (Pro/Max/Team)
blink backend status

# Create the entry point
mkdir -p backend
# Write backend/index.ts (see below)

# Deploy
blink backend deploy

# View logs
blink backend logs

Structure

backend/
├── index.ts          ← REQUIRED: export default Hono app
├── routes/
│   ├── stripe.ts
│   └── webhooks.ts
└── lib/
    └── auth.ts

backend/index.ts (Required Entry Point)

import { Hono } from "hono"
import { cors } from "hono/cors"
import { createClient } from "@blinkdotnew/sdk"

const app = new Hono()
app.use("*", cors())

const getBlink = (env: Record<string, string>) =>
  createClient({
    projectId: env.BLINK_PROJECT_ID,
    secretKey: env.BLINK_SECRET_KEY,  // server key, not publishableKey
  })

app.get("/health", (c) => c.json({ ok: true }))

app.post("/api/example", async (c) => {
  const blink = getBlink(c.env as Record<string, string>)
  const body = await c.req.json()
  return c.json({ success: true })
})

export default app

Secrets

Auto-injected (never hardcode): BLINK_PROJECT_ID, BLINK_SECRET_KEY, BLINK_PUBLISHABLE_KEY

User secrets (third-party keys): Add via project settings or CLI, access as c.env.MY_SECRET.

JWT Verification

app.post("/api/protected", async (c) => {
  const blink = getBlink(c.env as Record<string, string>)
  const auth = await blink.auth.verifyToken(c.req.header("Authorization"))
  if (!auth.valid) return c.json({ error: auth.error }, 401)
  return c.json({ userId: auth.userId })
})

Calling from Frontend

// Direct fetch
const res = await fetch("https://{projectId8}.backend.blink.new/api/example", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({ key: "value" }),
})

// Via SDK
const data = await blink.functions.invoke("api/example", { body: { key: "value" } })

projectId8 = last 8 chars of the full project ID.

Deployment Flow

# 1. Check eligibility
blink backend status

# 2. Write backend/index.ts

# 3. Deploy (reads all backend/ files, bundles with esbuild, deploys to CF Workers)
blink backend deploy

# 4. URL is printed: https://{projectId8}.backend.blink.new

Common Errors

Error	Cause	Fix
BACKEND_REQUIRES_PRO	Free/Starter workspace	Upgrade to Pro+
MISSING_ENTRYPOINT	No backend/index.ts	Create with export default app
CORS error	Missing middleware	Add app.use("*", cors())
401 on blink-apis	Wrong key	Use secretKey, not publishableKey

Checklist

• backend/index.ts exports default app
• app.use("*", cors()) present
• Uses secretKey in createClient (not publishableKey)
• Deployed with blink backend deploy
• AbortController timeout on all external fetch() calls