ChatQuota — Know your AWS usage

ChatQuota lets you ask about your AWS account usage and service quotas in plain English. No more digging through the Console.

Built with Next.js, Ant Design, and Tauri.

This project demonstrates how to:

• Build a Java 17 Lambda using AWS SAM
• Deploy infrastructure using AWS CDK
• Expose the function through Amazon API Gateway
• Chat with the API via a Next.js + Ant Design client on GitHub Pages
• Package as a macOS desktop app with Tauri (Rust)

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Prerequisites

• Java 17+
• Node.js 18+
• AWS CLI
• AWS SAM CLI
• AWS CDK CLI
• Rust (for Tauri desktop build)

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Configure AWS

aws configure

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Initialize Lambda (SAM)

Verify Java:

java --version

Create the SAM project:

sam init -r java17

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Build and Test Lambda

Inside sam-app:

# Ensure JAVA_HOME is set (if using Homebrew on macOS)
export JAVA_HOME=/opt/homebrew/opt/openjdk@17
export PATH="$JAVA_HOME/bin:$PATH"
# Use pip-installed SAM (brew version 1.159.1 has Python 3.13 compatibility issue)
export PATH="/Users/aniu/Library/Python/3.9/bin:$PATH"

sam build && sam local invoke HelloWorldFunction --event events/event.json

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Deploy Infrastructure (CDK)

Create CDK app:

mkdir cdk
cd cdk
cdk init app --language typescript

Build:

npm run build

Deploy:

npm run cdk deploy InfraStack

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CI/CD Pipeline

The project uses GitHub Actions for CI/CD (no CodePipeline needed).

Two independent workflows run on push to main:

1. Deploy to AWS (.github/workflows/deploy-aws.yml)

Triggers on changes to sam-app/, sam-app-integ/, cdk/, or the workflow file itself.

1. Builds the SAM Java Lambda (Gradle) and runs unit tests
2. Deploys InfraStack-Beta to AWS
3. Runs Java integration tests against the Beta API
4. Deploys InfraStack-Prod to AWS (only if integ tests pass)

This gives a beta → test → prod pipeline: if the integration tests fail, the workflow stops and Prod is not deployed.

2. Deploy to GitHub Pages (.github/workflows/deploy-pages.yml)

Triggers on changes to chat-app/ or the workflow file itself.

1. Builds the Next.js static site
2. Deploys to GitHub Pages

Stacks

Stack	Purpose	API URL	API Key
InfraStack-Beta	Test environment — deployed first, verified by integ tests	Get from CDK output ApiUrl	Get from CDK output ApiKeyId
InfraStack-Prod	Production environment — deployed only after tests pass	Get from CDK output ApiUrl	Get from CDK output ApiKeyId

Required GitHub Secrets

Secret	Description
AWS_ACCESS_KEY_ID	AWS IAM access key
AWS_SECRET_ACCESS_KEY	AWS IAM secret key

The IAM user needs permissions for:

• CloudFormation (deploy stacks)
• API Gateway (create/update APIs, manage API keys)
• Lambda (create/update functions)
• IAM (create roles/policies)
• S3 (CDK bootstrap bucket)

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Chat Client (chat-app/)

A single Next.js project with two pages:

Route	Page	Description
/	Landing page	Marketing site with DMG download link
/chat	Chat app	Login + chat interface for your API

It can run as:

• GitHub Pages — static site in browser (landing + chat)
• Tauri Desktop App — native macOS app (Rust → DMG, opens directly to chat)

Architecture

Landing Page (/) → Download DMG
Chat App (/chat) → API Gateway (x-api-key auth) → Lambda → AWS Usage Data

Tech Stack

Layer	Technology
UI Framework	Next.js 16 (React 19)
Design System	Ant Design
Desktop	Tauri 2 (Rust)
Deployment	GitHub Actions → GitHub Pages

Local Development

cd chat-app

# Install dependencies
npm install --legacy-peer-deps

# Dev server (hot reload)
npm run dev

# Build static export
npm run build

# Serve locally
cd out && python3 -m http.server 8080
# Open http://localhost:8080

Deploy to GitHub Pages

1. Enable GitHub Pages in repo Settings → Pages → Source: GitHub Actions
2. Push to main — the workflow in .github/workflows/deploy-pages.yml auto-deploys
3. Or manually trigger from Actions → Deploy to GitHub Pages → Run workflow

The deployed site will have:

• https://<user>.github.io/aniu-lambda/ → Landing page
• https://<user>.github.io/aniu-lambda/chat → Chat app

Release a new version

1. Update version in chat-app/config.json
2. Commit and tag:

   git add chat-app/config.json
   git commit -m "chore: bump to v0.0.4"
   git tag v0.0.4 && git push origin v0.0.4

3. GitHub Actions auto-creates a Release with DMG and updates the landing page

Install Desktop App (macOS)

Download ChatQuota.dmg from Releases.
First time opening? Run this in Terminal to bypass Gatekeeper:

xattr -d com.apple.quarantine /Applications/ChatQuota.app

Build Desktop App (Tauri)

cd chat-app

# Development mode (hot reload in native window)
npm run tauri:dev

# Production build → .app + .dmg
npm run tauri:build

Output:

• src-tauri/target/release/bundle/macos/ChatQuota.app
• chat-app/dist/ChatQuota.dmg

How it works

1. Landing Page (/) — Marketing site with features, architecture diagram, and DMG download
2. Login Screen (/chat) — Enter API Gateway URL + API Key (Ant Design Card + Input)
3. GET / health check — Verifies the connection before entering chat
4. Chat Interface — Send messages via POST to API Gateway
5. Settings panel — Sign out or modify API credentials at any time
6. API Gateway validates the x-api-key header via Usage Plan
7. Lambda processes the message and returns a response

Credentials are saved to localStorage for convenience.

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Request Flow

Client (GitHub Pages / Tauri) → API Gateway (API Key auth) → Lambda → Response