# Node API Builder

> Node.js/Express API for Cloud Functions or Hostinger Node.js hosting. Middleware chain. Error handling. [EXPLICIT] Use when this capability is needed.

- Skill: `tomevault-io/node-api-builder` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add tomevault-io/node-api-builder`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/node-api-builder/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: DevOps & Infra
- Author: tomevault-io (https://skillmd.com/u/tomevault-io)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/tomevault-io/node-api-builder

---

# node-api-builder {Backend} (v1.0)
> **"Firebase Functions are your backend. Design them like microservices, deploy them like magic."**
## Purpose
Node.js/Express API for Cloud Functions or Hostinger Node.js hosting. Middleware chain. Error handling. [EXPLICIT]
**When to use:** Backend development within Firebase/Google ecosystem.
## Core Principles
1. **Law of Functions:** Each Cloud Function does ONE thing. Single responsibility. [EXPLICIT]
2. **Law of Cold Start:** Minimize dependencies. Use lazy imports. Set min instances for critical functions. [EXPLICIT]
3. **Law of Security:** Every HTTP function verifies Firebase ID tokens. No public endpoints without auth. [EXPLICIT]
## Core Process
### Phase 1: Design
1. Map requirements to Cloud Functions triggers (HTTP, Firestore, Auth, Storage, scheduled). [EXPLICIT]
2. Define input/output contracts for each function. [EXPLICIT]
3. Design error handling and retry strategy. [EXPLICIT]
### Phase 2: Implement
1. Create function with proper trigger type. [EXPLICIT]
2. Add auth middleware for HTTP functions. [EXPLICIT]
3. Implement business logic with error handling. [EXPLICIT]
4. Add Cloud Logging for observability. [EXPLICIT]
### Phase 3: Test + Deploy
1. Test with Firebase Emulator Suite. [EXPLICIT]
2. Deploy with `firebase deploy --only functions`. [EXPLICIT]
3. Verify in Firebase Console. [EXPLICIT]
## 3. Inputs / Outputs
| Input | Type | Required | Description |
|-------|------|----------|-------------|
| Requirements | Text/Spec | Yes | What the function does |
| Output | Type | Description |
|--------|------|-------------|
| Cloud Function code | TypeScript | Deployable function |
## Validation Gate
- [ ] Single responsibility per function
- [ ] Auth middleware on HTTP endpoints
- [ ] Error handling with Cloud Logging
- [ ] Emulator tests pass
- [ ] No AWS/Azure services (R-002)
## 5. Self-Correction Triggers
> [!WARNING]
> IF function has no auth middleware THEN add verifyIdToken check.
> IF function imports 10+ dependencies THEN split or lazy-load to reduce cold start.

## Usage

Example invocations:

- "/node-api-builder" — Run the full node api builder workflow
- "node api builder on this project" — Apply to current context


## Assumptions & Limits

- Assumes access to project artifacts (code, docs, configs) [EXPLICIT]
- Requires English-language output unless otherwise specified [EXPLICIT]
- Does not replace domain expert judgment for final decisions [EXPLICIT]

## Edge Cases

| Scenario | Handling |
|----------|----------|
| Empty or minimal input | Request clarification before proceeding |
| Conflicting requirements | Flag conflicts explicitly, propose resolution |
| Out-of-scope request | Redirect to appropriate skill or escalate |

---
> Source: [JaviMontano/jm-adk-alfa](https://github.com/JaviMontano/jm-adk-alfa) — distributed by [TomeVault](https://tomevault.io).
<!-- tomevault:4.0:skill_md:2026-05-22 -->