Backend from Scratch

This is the smallest useful backend shape for W7S.

Repo structure

my-app/
  backend/
    src/
      health.ts
      notes.ts
  db/
    app/
      migrations/
        0001_init.sql
  w7s.json

Define routes

Create w7s.json:

[
  {
    "type": "webhook",
    "path": "/health",
    "method": "GET",
    "handler": "./backend/src/health.ts",
    "auth": "none"
  },
  {
    "type": "webhook",
    "path": "/notes",
    "method": "ANY",
    "handler": "./backend/src/notes.ts",
    "auth": "none"
  }
]

Add a health handler

export default async function handle() {
  const deployMeta =
    (globalThis as { __W7S_DEPLOY_META?: Record<string, unknown> }).__W7S_DEPLOY_META ?? {};

  return {
    status: 200,
    body: {
      ok: true,
      service: "my-app",
      branch: deployMeta.branch ?? null,
      commit: deployMeta.commitHash ?? null,
    },
  };
}

Add a database migration

Create db/app/migrations/0001_init.sql:

create table if not exists notes (
  id integer primary key autoincrement,
  title text not null,
  body text,
  created_at_ms integer not null
);

Add a note handler

Use Drizzle rather than raw SQL in request handlers.

import { desc } from "drizzle-orm";
import { db, schema } from "./db/client";

export default async function handle(payload: {
  method?: string;
  body?: unknown;
}) {
  const method = String(payload?.method ?? "GET").toUpperCase();

  if (method === "GET") {
    const rows = await db
      .select()
      .from(schema.notes)
      .orderBy(desc(schema.notes.createdAtMs))
      .limit(20);

    return { status: 200, body: { ok: true, items: rows } };
  }

  if (method === "POST") {
    const input = (payload.body ?? {}) as { title?: string; body?: string };
    if (!input.title?.trim()) {
      return { status: 400, body: { ok: false, error: "Missing title." } };
    }

    await db.insert(schema.notes).values({
      title: input.title.trim(),
      body: input.body?.trim() || null,
      createdAtMs: Date.now(),
    });

    return { status: 201, body: { ok: true } };
  }

  return { status: 405, body: { ok: false, error: "Method not allowed." } };
}

Deploy workflow

Minimal backend-only deploy workflow:

name: Deploy Backend

on:
  push:
    branches: [main]
    paths:
      - "backend/**"
      - "db/**"
      - "w7s.json"
  workflow_dispatch:

jobs:
  deploy:
    runs-on: ubuntu-latest
    permissions:
      contents: read
    steps:
      - uses: actions/checkout@v4
      - run: zip -qr repo.zip . -x ".git/*" -x ".github/*"
      - run: |
          OWNER_SLUG="$(echo "${{ github.repository_owner }}" | tr '[:upper:]' '[:lower:]')"
          REPO_SLUG="$(basename "${{ github.repository }}")"
          curl --fail --show-error \
            -X POST "https://${OWNER_SLUG}.w7s.cloud/${REPO_SLUG}/_deploy?artifact=source&scope=backend" \
            -H "Authorization: Bearer ${{ github.token }}" \
            -H "x-github-repository: ${{ github.repository }}" \
            -H "x-github-sha: ${{ github.sha }}" \
            -H "x-github-branch: ${{ github.ref_name }}" \
            -H "content-type: application/zip" \
            --data-binary "@repo.zip"

Result

After deploy:

• GET /health confirms the deploy is live
• migrations are already applied
• GET /notes and POST /notes operate on the repo-scoped database

For the DB layer, continue with Database and Drizzle.