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

# AuditRails: Tamper-Proof Audit Logging for Compliance

> AuditRails is a tamper-proof audit logging platform with SHA-256 hash chaining, WORM storage, and built-in compliance for SOC 2, HIPAA, GDPR, and 15 more frameworks.

AuditRails gives you cryptographically tamper-proof audit logs with a single SDK call. Every event is SHA-256 hash-chained and written to immutable WORM storage — making it mathematically impossible to alter or delete a log entry without detection. Drop in one of the five official SDKs, and you can be logging compliance-ready audit events in under two minutes.

<CardGroup cols={3}>
  <Card title="Quickstart" icon="rocket" href="/quickstart">
    Log your first audit event in under 2 minutes across any of 5 supported languages.
  </Card>

  <Card title="Core Concepts" icon="lightbulb" href="/concepts">
    Learn about hash chains, WORM storage, projects, and how AuditRails keeps logs tamper-proof.
  </Card>

  <Card title="Authentication" icon="key" href="/authentication">
    Create an API key and start making authenticated requests to the AuditRails API.
  </Card>
</CardGroup>

## How It Works

AuditRails sits between your application and your compliance auditors. You send events through the SDK or REST API; AuditRails hash-chains them, writes them to immutable storage, and makes them searchable — so you always have an unimpeachable record of what happened.

```
Your App → SDK / REST API → Hash Chain → WORM Storage + Real-Time Search
```

<Steps>
  <Step title="Create an account">
    Sign up at [app.auditrails.io/register](https://app.auditrails.io/register). Every plan starts with a 90-day free trial — no credit card required.
  </Step>

  <Step title="Get your API key">
    In the dashboard, go to **API Keys → Create API Key**. Copy the key — it begins with `at_live_` and is shown only once.
  </Step>

  <Step title="Install an SDK">
    Install the SDK for your language: `npm install @auditrails/node`, `pip install auditrails`, `go get github.com/auditrails/auditrails-go`, or use the Maven/Composer packages.
  </Step>

  <Step title="Log your first event">
    Call `audit.log({ action: 'user.login', actorId: 'user_123' })`. The event is hash-chained and stored in WORM storage within seconds.
  </Step>
</Steps>

## Key Features

<CardGroup cols={2}>
  <Card title="Immutable Hash Chains" icon="link">
    Every event is SHA-256 linked to the previous one. Any modification or deletion instantly breaks the chain and is detectable.
  </Card>

  <Card title="WORM Storage" icon="lock">
    Logs are written to S3 Object Lock in COMPLIANCE mode — immutable even against AWS root. Required for SOC 2, HIPAA, and SEC 17a-4.
  </Card>

  <Card title="18 Compliance Frameworks" icon="shield-check">
    Built-in support for SOC 2, HIPAA, ISO 27001, GDPR, PCI DSS, NIS2, DORA, SOX, FedRAMP, EU AI Act, and more. Auto-verification included.
  </Card>

  <Card title="Drop-In SDKs" icon="code">
    Official SDKs for Node.js, Python, Go, Java, and PHP. Fire-and-forget `log()` never blocks your application.
  </Card>

  <Card title="Real-Time Search" icon="magnifying-glass">
    ClickHouse-powered search and filtering across billions of events. Exportable as CSV for external audit review.
  </Card>

  <Card title="GDPR & DSAR Tools" icon="user-shield">
    Built-in data subject access request (DSAR) export and deletion workflows to satisfy GDPR Articles 15 and 17.
  </Card>
</CardGroup>

## Explore the Docs

<CardGroup cols={2}>
  <Card title="Compliance Mapping" icon="clipboard-check" href="/guides/compliance-mapping">
    See exactly how AuditRails maps to SOC 2, HIPAA, ISO 27001, GDPR, PCI DSS, and 13 more frameworks.
  </Card>

  <Card title="API Reference" icon="server" href="/api-reference/overview">
    Full REST API docs with request/response examples for ingestion, querying, and chain verification.
  </Card>

  <Card title="SDK Overview" icon="book" href="/sdks/overview">
    Compare all five official SDKs and pick the right one for your stack.
  </Card>

  <Card title="Hash Chain Verification" icon="shield" href="/guides/hash-chain-verification">
    Understand how cryptographic hash chaining works and how to verify log integrity.
  </Card>
</CardGroup>