> ## Documentation Index
> Fetch the complete documentation index at: https://docs.app.useharmonia.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# Storage and messaging platform

> Durable state, asynchronous delivery, and binary asset storage in Harmonia.

## How Harmonia uses it

DynamoDB owns tenant-scoped workflow truth and atomically records stage outbox entries. SQS transports stage triggers but cannot advance state by itself. Versioned Amazon S3 holds uploaded and generated binary assets while DynamoDB retains identity, lineage, and digests.

<CardGroup cols={2}>
  <Card title="DynamoDB" href="/platform/data/dynamodb">Durable records and transactions.</Card>
  <Card title="SQS" href="/platform/data/sqs">At-least-once stage delivery.</Card>
  <Card title="Amazon S3" href="/platform/data/s3">Authorized source and output assets.</Card>
</CardGroup>

## Evidence status

Emulator and contract tests verify local persistence behavior. Cloud resource existence and production data paths require authenticated infrastructure evidence.