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

# Overview

Orb handles usage-based, seat-based, and hybrid billing. From simple subscriptions to complex enterprise contracts, test pricing changes before deploying, backdate amendments without manual fixes, and process millions of events per second. Built on our query-based architecture for flexibility and scale.

<Tip>
  Explore Orb's [demo environment](https://demo.withorb.com?vertical=cloud_infra) with sample data across common use cases. To get started, [contact sales](https://www.withorb.com/contact-us).
</Tip>

## Any pricing model

<CardGroup cols={2}>
  <Card title="Usage-based pricing" icon="chart-line" href="/product-catalog/price-configuration">
    Bill for API calls, compute, tokens, agents. Common for infrastructure and AI.
  </Card>

  <Card title="Seat-based & hybrid" icon="users" href="/product-catalog/build-catalog">
    Combine seats with usage overages. Common for B2B SaaS platforms.
  </Card>

  <Card title="Prepaid credits" icon="credit-card" href="/product-catalog/prepurchase">
    Support trials, access control, and enterprise commits with credits.
  </Card>

  <Card title="Enterprise contracts" icon="briefcase" href="/enterprise/enterprise-billing">
    Backdate amendments, shared credits, complex multi-year deals.
  </Card>
</CardGroup>

## Learning paths

<CardGroup cols={2}>
  <Card title="Start building" icon="code" href="/quickstart/ingest">
    Complete billing workflow in 30 minutes
  </Card>

  <Card title="Understand why Orb" icon="lightbulb" href="/introduction">
    Learn what makes query-based architecture different
  </Card>
</CardGroup>

## Key features

* **[Simulations](/simulations/introduction)** - Test pricing changes against historical usage before deploying.
* **[Backfills & corrections](/architecture/query-based-billing)** - Late data handled safely. Orb recalculates affected invoices automatically.
* **[Hosted rollups](/events-and-metrics/high-throughput-ingestion)** - Handle 1M+ billing events per second in production deployments.
* **[Real-time visibility](/product-catalog/usage-visibility)** - Track accrued revenue before invoices. Forecast and spot expansion.
* **[Custom SQL metrics](/events-and-metrics/construct-metrics)** - Build complex billing metrics with full SQL control.
* **[Usage alerting](/usage-alerting/overview)** - Trigger alerts at usage thresholds to power product-led growth.
* **[Revenue recognition](/revenue-reporting/revenue-recognition)** - Track recognized and deferred revenue with exports for financial systems.

## Resources

<CardGroup cols={3}>
  <Card title="Core concepts" href="/core-concepts">
    Events, Metrics, Plans, Subscriptions, Invoices
  </Card>

  <Card title="API reference" href="/api-reference">
    Complete docs with SDKs for Python, Node, Ruby, Go
  </Card>

  <Card title="Migration guides" href="/migration-guides/stripe-billing">
    Move from Stripe Billing, Metronome, Chargebee
  </Card>
</CardGroup>