Aws Dynamodb

What the source does

• FilesystemNone observedNo reads or writes in the source
• NetworkNone observedNo outbound calls in the source
• ShellNone observedNo commands run in the source
• DependenciesPinnedNothing floats
• SecretsNone foundNo keys in source

Five audit layers

Gates applied: no behavioural pass.

Audit 0.4.1 · source sha ea59a0c53d79 · 14 Oct 2026Report an issue or request a re-scan

• Publisheralinaqi GitHub userOwner of the repository this skill is read from
• Source folderalinaqi/claude-bootstrap/skills/aws-dynamodbThe exact folder we audited
• LicenceMITAs the repository states it
• Commit pinned for this verdictea59a0c53d79A new audit runs when the source changes
• Repository statusNot archivedPushed today
• Sandboxed runNot runSkills are read, not executed; layer L4 is skipped

Its description: AWS DynamoDB single-table design, GSI patterns, SDK v3 TypeScript/Python

---
name: aws-dynamodb
description: AWS DynamoDB single-table design, GSI patterns, SDK v3 TypeScript/Python
when-to-use: When working with DynamoDB tables or AWS SDK data operations
user-invocable: false
paths: ["**/dynamodb*", "**/dynamo*", "serverless.*", "template.yaml"]
effort: medium
---

# AWS DynamoDB Skill


DynamoDB is a fully managed NoSQL database designed for single-digit millisecond performance at any scale. Master single-table design and access pattern modeling.

**Sources:** [DynamoDB Docs](https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/) | [SDK v3](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/dynamodb/) | [Best Practices](https://aws.amazon.com/blogs/database/single-table-vs-multi-table-design-in-amazon-dynamodb/)

---

## Core Principle

**Design for access patterns, not entities. Think access-pattern-first.**

DynamoDB requires you to know your queries before designing your schema. Model around how you'll access data, not how data relates. Single-table design stores multiple entity types in one table using generic key attributes.

---

## Key Concepts

| Concept | Description |
|---------|-------------|
| **Partition Key (PK)** | Primary key attribute - determines data distribution |
| **Sort Key (SK)** | Optional secondary key for range queries within partition |
| **GSI** | Global Secondary Index - alternate partition/sort keys |
| **LSI** | Local Secondary Index - same partition, different sort |
| **Item** | Single record (max 400 KB) |
| **Attribute** | Field within an item |

---

## Single-Table Design

### Why Single Table?
- Fetch related data in single query
- Reduce round trips and costs
- Enable transactions across entity types
- Simplify operations (backup, restore, IAM)

### Generic Key Pattern
```typescript
// Instead of entity-specific keys:
// userId, orderId, productId

// Use generic keys that work for all entities:
interface BaseItem {
  PK: string;   // Partition Key
  SK: string;   // Sort Key
  GSI1PK?: string;  // First GSI partition key
  GSI1SK?: string;  // First GSI sort key
  EntityType: string;
  // ... entity-specific attributes
}
```

### Example: E-commerce Schema
```typescript
// Users
{ PK: 'USER#123', SK: 'PROFILE', EntityType: 'User', name: 'John', email: '[email protected]' }
{ PK: 'USER#123', SK: 'ADDRESS#1', EntityType: 'Address', street: '123 Main', city: 'NYC' }

// Orders for user (1:N relationship)
{ PK: 'USER#123', SK: 'ORDER#2024-001', EntityType: 'Order', total: 99.99, status: 'shipped' }
{ PK: 'USER#123', SK: 'ORDER#2024-002', EntityType: 'Order', total: 49.99, status: 'pending' }

// Order details (query by order ID using GSI)
{ PK: 'USER#123', SK: 'ORDER#2024-001', GSI1PK: 'ORDER#2024-001', GSI1SK: 'ORDER', ... }
{ PK: 'ORDER#2024-001', SK: 'ITEM#1', GSI1PK: 'ORDER#2024-001', GSI1SK: 'ITEM#1', productId: 'PROD#456', qty: 2 }

// Products
{ PK: 'PROD#456', SK: 'PRODUCT', EntityType: 'Product', name: 'Widget', price: 29.99 }
```

### Access Patterns Covered
```
1. Get user profile          → Query PK='USER#123', SK='PROFILE'
2. Get user with addresses   → Query PK='USER#123', SK begins_with 'ADDRESS'
3. Get all user orders       → Query PK='USER#123', SK begins_with 'ORDER'
4. Get order by ID           → Query GSI1, PK='ORDER#2024-001'
5. Get order with items      → Query GSI1, PK='ORDER#2024-001'
6. Get product details       → Query PK='PROD#456', SK='PRODUCT'
```

---

## SDK v3 Setup (TypeScript)

### Install Dependencies
```bash
npm install @aws-sdk/client-dynamodb @aws-sdk/lib-dynamodb
```

### Client Configuration
```typescript
// lib/dynamodb.ts
import { DynamoDBClient } from '@aws-sdk/client-dynamodb';
import { DynamoDBDocumentClient } from '@aws-sdk/lib-dynamodb';

const client = new DynamoDBClient({
  region: process.env.AWS_REGION || 'us-east-1',
  // For local development with DynamoDB Local
  ...(process.env.DYNAMODB_LOCAL && {
    endpoint: 'http://localhost:8000',
    credentials: { accessKeyId: 'local', secretAccessKey: 'local' }
  })
});

// Document client for simplified operations
export const docClient = DynamoDBDocumentClient.from(client, {
  marshallOptions: {
    removeUndefinedValues: true,  // Important: match v2 behavior
    convertClassInstanceToMap: true
  },
  unmarshallOptions: {
    wrapNumbers: false
  }
});

export const TABLE_NAME = process.env.DYNAMODB_TABLE || 'MyTable';
```

### Type Definitions
```typescript
// types/dynamodb.ts
export interface BaseItem {
  PK: string;
  SK: string;
  GSI1PK?: string;
  GSI1SK?: string;
  EntityType: string;
  createdAt: string;
  updatedAt: string;
}

export interface User extends BaseItem {
  EntityType: 'User';
  userId: string;
  email: string;
  name: string;
}

export interface Order extends BaseItem {
  EntityType: 'Order';
  orderId: string;
  userId: string;
  total: number;
  status: 'pending' | 'paid' | 'shipped' | 'delivered';
}

// Key builders
export const keys = {
  user: (userId: string) => ({
    PK: `USER#${userId}`,
    SK: 'PROFILE'
  }),
  userOrders: (userId: string) => ({
    PK: `USER#${userId}`,
    SKPrefix: 'ORDER#'
  }),
  order: (userId: string, orderId: string) => ({
    PK: `USER#${userId}`,
    SK: `ORDER#${orderId}`,
    GSI1PK: `ORDER#${orderId}`,
    GSI1SK: 'ORDER'
  })
};
```

---

## CRUD Operations

### Put Item (Create/Update)
```typescript
import { PutCommand } from '@aws-sdk/lib-dynamodb';
import { docClient, TABLE_NAME } from './dynamodb';
import { User, keys } from './types';

async function createUser(userId: string, data: { email: string; name: string }): Promise<User> {
  const now = new Date().toISOString();
  const item: User = {
    ...keys.user(userId),
    EntityType: 'User',
    userId,
    email: data.email,
    name: data.name,
    createdAt: now,
    updatedAt: now
  };

  await docClient.send(new PutCommand({
    TableName: TABLE_NAME,
    Item: item,
    ConditionExpression: 'attribute_not_exists(PK)'  // Prevent overwrite
  }));

  return item;
}
```

### Get It

Excerpt, first 6,000 characters of SKILL.md, verbatim from the audited commit. It is text from someone else’s repository, quoted so you can judge it before your agent reads it.

npm install @aws-sdk/client-dynamodb @aws-sdk/lib-dynamodb

git clone https://github.com/alinaqi/claude-bootstrap
git -C claude-bootstrap checkout ea59a0c53d79

Works in

1. 2026-10-14
   ✓SAFE B 89 / 100

   first audit · source ea59a0c53d79

Questions about Aws Dynamodb

• github.com/alinaqi/claude-bootstrap/tree/main/skills/aws-dynamod — the audited source at commit ea59a0c53d79 and every finding aboveObserved · 14 Oct 2026

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