> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.0x.org/changelog/2026/5/31/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.0x.org/_mcp/server.

#### New Liquidity Sources

* **Arbitrum:** Added MimSwap.
* **Avalanche:** Added Pharaoh DLMM.
* **Base:** Added AlienBase V2/V3, BaseX, DackieSwap V2, Equalizer, HydrexLegacy, IziSwap, KimV4, NineMMV2/V3, OmniV3, RocketSwap, SharkSwap V2, SoSwap, Synthswap V2/V3, Treble, TrebleV2/V4, and enabled UniswapV4 hooked pools.
* **BSC:** Added BiSwap V3, Ellipsis, MDEX, Nerve, and PancakeSwap Stable.
* **Ethereum:** Added Blackhole, Fraxswap V2, Rubicon, ShibaSwap, SkyLite PSM, Stepn, USDD Lite PSM, and enabled UniswapV4 hooked pools.
* **Linea:** Added Aqua V2, EchoDEX V3, Etherex, IziSwap, Lynex, Nile, Nile V2, PancakeSwap V3, Secta V2/V3, SpartaDex, SushiSwap V3, SyncSwap Classic/Stable, and Uniswap V3.
* **Polygon:** Added Meshswap and PUSD.
* **Scroll:** Added Aqua V2, SyncSwap Classic/Stable, and Wombat.

#### New Features

* **Exact-out support in Swap API**: You can now specify a precise `buyAmount` to receive and the API returns the minimum sell amount required. Responses include `maxSellAmount`, `estimatedNetSellAmount`, and a `route.refund` leg that converts any buy-token surplus back to the sell token. Supports custom `recipient` and `txOrigin` parameters. [See `buyAmount` in API reference](https://docs.0x.org/api-reference/evm-ap-is/swap/allowanceholder-getprice).
* **Concurrent gasless trades now supported**: Gasless `/submit` now allows multiple in-flight trades for the same taker and sell token, as long as the taker's balance covers all pending sells.

> Developer documentation for the 0x API. Embed swaps in your onchain app. Access 10+ million tokens with liquidity from 150+ exchanges with a single API.