AMM vs UniswapX Routing

The Uniswap API can return routes from Uniswap AMM liquidity, UniswapX liquidity, or both depending on the request inputs and route availability. This guide explains how routing works and which request fields control route selection.

How Uniswap AMM Routing Works

AMM routing refers to swap paths that use onchain AMM liquidity. It is one of the default routing options used by the Uniswap API when computing quotes.

In the Uniswap API, AMM routes:

• Rely on onchain liquidity only (for example, Uniswap v2, Uniswap v3, and Uniswap v4 pools, depending on chain availability)
• Return AMM quotes when supported liquidity exists
• Do not involve solvers
• May use split routes, multi-hop routes, or both to improve output

How UniswapX Routing Works

UniswapX is an intent-based swap system where solvers compete to fill a swap. Solvers are third parties that can use proprietary routing strategies and token inventories to fill intents. For a broader overview, see UniswapX Filling Overview.

In the Uniswap API, UniswapX routes behave as follows:

• A /quote response may include a UniswapX route when the swap is eligible and a solver can fill it
• The API response returns a UniswapX path rather than AMM split-route details
• The solver submits the onchain order fill, and the swapper signs the required approval or order signature

How the Uniswap API Chooses Between Uniswap AMM and UniswapX

The Uniswap API selects routing based on the request configuration and live route availability.

Routing preferences

Set routing behavior with the routingPreference field. Supported values are BEST_PRICE and FASTEST. Legacy values are deprecated.

• Use BEST_PRICE to search for the most efficient route based on current inputs, either across all protocols or within the protocols you specify
• Use FASTEST to prioritize quote response speed, either across all protocols or within the protocols you specify

FASTEST controls quote response speed, not settlement complexity. When routingPreference is FASTEST, UniswapX routes are not considered.

For field-level details, see the POST /quote API reference.

Protocol restrictions

The protocols field is applied when routingPreference is BEST_PRICE.

• If protocols is omitted, the API considers both Uniswap AMM and UniswapX protocols and returns the most efficient route based on current inputs
• If protocols contains only V2, V3, or V4, routing is restricted to Uniswap AMM routes
• If protocols includes UNISWAPX_V2 (or other supported UniswapX values), UniswapX routes are also considered

UniswapX availability

If UniswapX is unavailable for a request, the API falls back to Uniswap AMM routing when allowed by your protocols selection.

UniswapX quotes may be unavailable when solvers cannot or choose not to fill a swap, or when notional size is below chain-specific thresholds.

Chain coverage

Solver activity varies across chains, so UniswapX route frequency can differ by network. UniswapX is available only on selected chains, and constraints can vary by chain.

See Supported Chains for current coverage and constraints.

Routing Best Practices for Uniswap API Integrators

• Always inspect /quote responses: Do not assume route type in advance. Use the route returned by the API response.
• Avoid unnecessary protocol restrictions: If your goal is broad route coverage, leave protocols unset.
• Plan for Uniswap AMM fallback: Even when UniswapX is enabled, solver availability can vary.
• Make route behavior visible to users: If your product exposes route type, clarify that route availability changes by chain and market conditions.

Common Integration Issues and Solutions

UniswapX support enabled but no quotes on some chains

If you support both Uniswap AMM and UniswapX, set routingPreference to BEST_PRICE (or omit it, which defaults to BEST_PRICE) and omit protocols to maximize available liquidity sources.

If you specify UNISWAPX_V2 in protocols, include at least one AMM protocol (V2, V3, or V4) as fallback.

Quote differs from app.uniswap.org

Depending on your /quote request fields, the API may return a different route than the Uniswap web app for the same pair at a given moment.

The web app typically considers all available protocols unless the user changes routing options. A BEST_PRICE request performs a fresh route search based on current inputs and market conditions, so the result can differ from prior quotes.

Small trades return only Uniswap AMM routes

This is expected in some cases. On some chains, UniswapX quotes are subject to minimum notional thresholds, and solver participation may vary by trade size and market conditions.

For route behavior and configuration details, see Swap Routing and the POST /quote API reference.