coinBaby (Dalla)

A smart finance advisor web app on AWS. Users track transactions across multiple wallets, set budgets and goals, and chat with Penny — an AI assistant powered by Amazon Bedrock (Claude 3.5 Haiku) that answers questions about their spending and habits.

Live: http://coinbaby.click

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Demo + Architecture Explainer

video1132786004.mp4

Architecture

flowchart LR
    Browser -->|"http://coinbaby.click"| CloudFront
    CloudFront --> S3["S3 (React SPA)"]
    Browser -->|"http://EIP:8000"| EC2["EC2 (FastAPI)"]
    EC2 --> RDS["RDS PostgreSQL"]
    EC2 --> Bedrock["Bedrock (Claude 3.5 Haiku)"]
    EC2 --> Cognito
    Push["git push codecommit"] --> CodePipeline
    CodePipeline --> CodeBuild
    CodeBuild -->|backend| ECR
    CodeBuild -->|frontend| S3

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Layer	Service
Frontend	S3 + CloudFront, custom domain via Route 53 + ACM
Backend	EC2 t3.micro, Elastic IP, Docker
Database	RDS PostgreSQL 16 (db.t3.micro)
Auth	Cognito User Pool (auto-confirm via Lambda trigger)
AI	Bedrock — Claude 3.5 Haiku inference profile
CI/CD	CodeCommit → CodePipeline → CodeBuild (build image, deploy via SSM, build frontend)
IaC	Terraform (single terraform apply)

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Features

Authentication

• Sign up and log in with email/password via Amazon Cognito.
• Auto-confirmed on sign-up (Pre Sign-Up Lambda trigger) — no email verification step.

Wallets & Transactions

• Multiple wallets per user; each wallet holds transactions.
• Transaction types: Income, Expense, Investment, Donation.
• Each transaction has tags, description, and a subcategory (defaults provided; users can add custom ones).

Budgets & Goals

• Budgets — spending limits on expense categories; progress tracked automatically.
• Goals — savings/investment targets with progress bars computed from transactions.

Penny (AI Chat)

• Chat assistant on the dashboard powered by Amazon Bedrock (Claude 3.5 Haiku via cross-region inference profile).
• Answers questions about spending, budgets, goals using the user's financial data as context.
• Quick-question templates for common queries.

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User Flow

flowchart LR
    A[Land on app] --> B{Logged in?}
    B -->|No| C[Sign up / Log in]
    C --> D[Authenticated]
    B -->|Yes| D
    D --> E[Dashboard]
    E --> F[Wallets & transactions]
    E --> G[Budgets & goals]
    E --> H[Penny AI chat]
    F --> F1[Create wallet]
    F --> F2[Add transaction]
    F2 --> F2a[Income / Expense / Investment / Donation]
    G --> G1[Set budget limits]
    G --> G2[Create goal]
    H --> H1[Ask question]
    H1 --> H2[AI response]
    F1 --> E
    F2a --> E
    G1 --> E
    G2 --> E
    H2 --> E

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Deploy on AWS

See notes/Deploy-AWS.md for full steps (Terraform, ECR, DB schema, CI/CD pipeline). After deploy the app is available at http://coinbaby.click (or the CloudFront URL if no custom domain is configured). Use http (not https) so the browser allows calls to the HTTP backend without mixed-content blocking.

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Project Context

• Course: CSCI5409 Advanced Topics in Cloud Computing (Winter 2026)
• Deliverable: Mid-term cloud project (20% of grade).
• Requirements: Fully functional cloud application on AWS; at least one service from Compute, Storage, Networking, and Database; Infrastructure as Code (IaC); single-command deployment; original code.

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Tech Stack

• Auth: Amazon Cognito (User Pool + Lambda auto-confirm trigger)
• Compute: EC2 t3.micro (backend Docker container), Lambda (Cognito trigger)
• Storage: S3 (frontend static assets, pipeline artifacts)
• Networking: VPC, CloudFront, Route 53, ACM
• Database: RDS PostgreSQL 16
• AI: Amazon Bedrock (Claude 3.5 Haiku inference profile)
• CI/CD: CodeCommit, CodePipeline, CodeBuild, ECR, SSM Run Command

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