Home

DynamoDbLite

Another weapon from the MSL Armory

An in-process implementation of IAmazonDynamoDB backed by SQLite — for local development, testing, and offline-capable apps. See the AWS DynamoDB Developer Guide for DynamoDB concepts.

Why DynamoDbLite?

• No AWS credentials needed — develop and test without internet connectivity
• Fast testing — in-memory or file-backed SQLite, no network round-trips
• Zero cost — no DynamoDB provisioned capacity charges during development
• Drop-in replacement — implements the IAmazonDynamoDB interface (see API parity for the supported surface)

Feature summary

Category	Status
Table operations	Supported
Item CRUD (Put, Get, Delete, Update)	Supported
Query and scan	Supported
Batch operations (BatchGet, BatchWrite)	Supported
Transactions (TransactWrite, TransactGet)	Supported
Secondary indexes (GSI, LSI)	Supported
TTL	Supported
Tags	Supported
Export / Import	Supported
Endpoints & Limits	Stubbed (hardcoded values)
Backup & Restore	Out of scope
Global Tables	Out of scope
Kinesis Streams	Out of scope
PartiQL	Out of scope
Vector search	Out of scope

See API parity for a detailed compatibility matrix.

Quick start

dotnet add package MSL.DynamoDbLite

using DynamoDbLite;

// File-backed
using var fileClient = new DynamoDbClient(new DynamoDbLiteOptions(
    "Data Source=myapp.db"));

// In-memory (give the Data Source a unique name per logical database)
using var memoryClient = new DynamoDbClient(new DynamoDbLiteOptions(
    $"Data Source=app_{Guid.NewGuid():N};Mode=Memory;Cache=Shared"));

For dependency injection, use the AddDynamoDbLite extension:

using DynamoDbLite;

services.AddDynamoDbLite(o => o.WithConnectionString("Data Source=myapp.db"));

See DI and configuration for the full surface and Getting started for the setup walkthrough including the in-memory test-isolation foot-gun.

Getting started

• Getting started — installation, configuration, first steps
• Tutorial — hands-on walkthrough building a bookmarks store

Reference

• Table operations — CreateTable, DeleteTable, DescribeTable, ListTables, UpdateTable
• Item operations — PutItem, GetItem, DeleteItem, UpdateItem
• Query and scan — KeyConditionExpression, FilterExpression, pagination
• Batch operations — BatchGetItem, BatchWriteItem
• Transactions — TransactWriteItems, TransactGetItems
• Secondary indexes — GSI, LSI, projection types
• TTL — Time to Live configuration and behavior
• Tags and admin — tags, endpoints, limits, export/import
• DI and configuration — AddDynamoDbLite, options builder, validation, exceptions
• Concurrency — writer serialization and tuning the wait under contention
• Performance — WAL, batching, and the file-backed tuning knobs
• API parity — compatibility matrix and behavioral differences
• FAQ — recurring questions and gotchas

Recipes

• DynamoDBContext for tests — POCO mapping with the AWS SDK's DynamoDBContext
• xUnit per-test isolation — per-test factories, class fixtures, file-backed cleanup
• ASP.NET Core integration test fixture — WebApplicationFactory with a DynamoDbLite-backed IAmazonDynamoDB
• Migrating tests off DynamoDB Local — drop the container, keep the test surface

Internals

• Storage architecture — SQLite schema, concurrency, class hierarchy
• Expression engine — tokenizer, parsers, AST, evaluators