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

# What is Fast Protocol?

> An overview of Fast Protocol, the incentive-aligned mev distribution system built on mev-commit.

Fast Protocol is an order flow auction (OFA) system built on top of [mev-commit](/v1.2.x/concepts/mev-commit-intro/what-is-mev-commit) that captures, routes, and redistributes mev across all participants in a transparent and incentive-aligned way.

## How It Works

When users send transactions through [FAST RPC](/v1.2.x/get-started/fastrpc), the system:

1. **Auctions and simulates backruns** for each transaction
2. **Realizes mev** through backrun bundles
3. **Secures commitments** from builders via mev-commit
4. **Distributes value** — validators receive a share based on opt-in status, and the remainder flows into mev distribution contracts that fund user rewards

## Who Benefits

* **Users** receive top-of-market mev refunds — at least 90% of the mev their transactions generate, and in mev-rich periods even more than 100%
* **Validators** earn strictly more when opting in, and materially more than in other OFA systems
* **Builders** maintain sustainable margins while delivering transactions
* **The protocol** becomes more valuable as usage increases, creating a positive feedback loop

## Why It's Unique

The system is designed so that no competing OFA can sustainably provide higher user mev refunds. If Fast Protocol offered less than 90% user refunds, users would switch to alternatives. If a competitor tried offering more, its builders or validators would become unprofitable. Fast Protocol optimally balances incentives so that all participants remain profitable.

<CardGroup cols={2}>
  <Card title="Fast Protocol Economics" icon="chart-line" href="/v1.2.x/concepts/fast-protocol" horizontal>
    Full economic model, fee parameters, and equilibrium analysis.
  </Card>

  <Card title="What are Fast Swaps?" icon="arrows-rotate" href="/v1.2.x/knowledge-base/what-are-fast-swaps" horizontal>
    The swap interface built on Fast Protocol.
  </Card>
</CardGroup>