The 1inch classic swap API (Pathfinder v6.1) is a cutting-edge discovery and routing algorithm that offers asset exchanges at the best rates on the market. Pathfinder finds the most efficient paths for a token swap and is able to split between different protocols and even different market depths within one protocol in the shortest possible time.

## Supported Chains

| Supported Chains | Chain ID |
| :--------------- | :------- |
| Ethereum         | 1        |
| Solana           | 501      |
| Base             | 8453     |
| Binance          | 56       |
| zkSync           | 324      |
| Gnosis           | 100      |
| Optimism         | 10       |
| Polygon          | 137      |
| Linea            | 59144    |
| Sonic            | 146      |
| Unichain         | 130      |
| Arbitrum         | 42161    |
| Avalanche        | 43114    |

## Eficiency

The latest version (V 6.1) of Pathfinder algorithm pushes DeFi trading forward by unlocking smarter, more efficient swaps, and bringing a number of concrete advantages to 1inch Swap users:

- Maximized returns: multiple swap paths are combined to secure the best rates, delivering more value from every trade.
- Superior liquidity efficiency: by splitting volumes into finer chunks and blending paths, Pathfinder taps into pools more effectively, skimming the cream from concentrated liquidity for optimal exchanges.
- Unrivaled access: the new Pathfinder facilitates a deeper dive into diverse liquidity pools, distributing volume to capture better rates where it matters most.
- Gas efficiency: by merging paths to achieve better gas cost efficiency, every swap becomes more cost-effective.

## Before V 6.1

<img src='assets/docs-v2/apis/swap/classic-swap/old-pathfinder-swap-route.png' alt="old routing" />

## After V 6.1

<img src='assets/docs-v2/apis/swap/classic-swap/Swap-route-with-new-pathfinder-algorithm.png' alt="new pathfinder routing" />

## API reference

For detailed information about each endpoint, refer to the classic swap API [OpenAPI specs](./methods/v6.1/1/quote/method/get).

## Quickstart

In order to quickly understand how to make an exchange using the protocol, we suggest you use the [Quickstart guide](./quick-start.md).

:::info

For workloads that require higher RPS, expanded quotas, or sustained performance, explore the available paid plans on the [**pricing page**](/pricing).
For organizations with significant trading volumes or advanced requirements, [**complete this application**](/get-enterprise) to explore tailored Enterprise options.

:::