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

> ## Agent Instructions
> fal has two developer products. Model APIs run hosted models through an API key. fal Serverless deploys your own Python apps and models on fal GPUs.
> To call a hosted model, start with the [Quick Start](https://fal.ai/docs/documentation/quickstart.md) and the [Model APIs overview](https://fal.ai/docs/documentation/model-apis/overview.md).
> To deploy your own model with fal Serverless, start with these pages:
> - [Introduction to Serverless](https://fal.ai/docs/documentation/serverless/index.md): What fal Serverless is and the three ways to deploy on it.
> - [Installation & Setup](https://fal.ai/docs/documentation/development/getting-started/installation.md): Install the fal CLI with `pip install fal` and authenticate.
> - [Quick Start](https://fal.ai/docs/documentation/development/getting-started/quick-start.md): Build a Hello World app, test it with `fal run`, and ship it with `fal deploy`.
> - [App Lifecycle](https://fal.ai/docs/documentation/development/app-lifecycle.md): How a `fal.App` goes from code to running runners.
> - [Define Your Endpoints](https://fal.ai/docs/documentation/development/endpoints-overview.md): Structure the API endpoints that your app exposes.
> - [Deploy to Production](https://fal.ai/docs/documentation/deployment/deploy-to-production.md): Persistent URLs, authentication modes, and automatic scaling.
> - [Machine Types](https://fal.ai/docs/documentation/deployment/machine-types.md): Available GPU and CPU machine types and how to choose one.
> - [Pricing](https://fal.ai/docs/documentation/serverless/pricing.md): Per-second billing and the runner states that are billed.
> - [Scaling Parameter Reference](https://fal.ai/docs/documentation/deployment/scale-your-application.md): Parameters that control runners, concurrency, and scale to zero.
> - [Optimizing Cold Starts](https://fal.ai/docs/documentation/serverless/optimizations/optimize-cold-starts.md): Causes of cold starts and ways to make them shorter.
> - [Examples](https://fal.ai/docs/examples/index.md): Complete Serverless apps for image, video, audio, 3D, realtime, and multi-GPU workloads.
> - [Migrating to fal](https://fal.ai/docs/documentation/development/migrating-to-fal.md): Guides to move an existing Docker server or an app from another platform to fal.
> fal Serverless deploys need access that the fal team approves for each account. Request access at https://fal.ai/dashboard/serverless-get-started.

# Pricing

> How billing works for fal Serverless.

When you deploy your own applications on fal Serverless, you are billed for the **total time your runners are alive**, measured per-second by machine type.

## Billing by runner state

Every runner transitions through the states below during its lifecycle. You are billed for the states marked **Yes** at the per-second rate for your machine type.

| State | Billed | Description |
| - | - | - |
| **PENDING** | No | Waiting to be scheduled on available hardware |
| **DOCKER\_PULL** | No | Pulling your container image from the registry |
| **SETUP** | Yes | Running your `setup()` method — loading models, initializing resources |
| **IDLE** | Yes | Runner is ready but waiting for requests (includes `keep_alive` time) |
| **RUNNING** | Yes | Actively processing one or more requests |
| **DRAINING** | Yes | Finishing in-flight requests before shutdown |
| **TERMINATING** | Yes | Running your `teardown()` method |
| **TERMINATED** | No | Runner has stopped and resources are released |

5xx errors (HTTP 500+) are also not charged.

See [Runners](/docs/documentation/deployment/runners) for full details on each state and transitions.

## GPU count multiplier

Multi-GPU instances are billed as `gpu_count x duration`. For example, a runner using 2x A100 GPUs for 60 seconds is billed as 120 GPU-seconds.

## Monitoring your usage

<CardGroup cols={2}>
  <Card title="Dashboard Billing" icon="chart-line" href="https://fal.ai/dashboard/billing">
    View your overall spend, invoices, and payment methods.
  </Card>

  <Card title="App Analytics" icon="chart-bar" href="/docs/documentation/serverless/observability/app-analytics">
    See per-app cost breakdown, request counts, and runner utilization.
  </Card>
</CardGroup>