A DEX aggregator's whole job: find the route that turns token A into token B with the least loss. Drag the trade-size slider and watch the route split across liquidity pools in 3D — then see why the fee quote before signing matters.
Most AMM pools obey x · y = k. Swapping Δx of token A returns Δy = y − k/(x+Δx). The bigger your trade relative to pool reserves, the worse your rate — that curve is why price impact accelerates non-linearly.
Impact grows with the square of trade share per pool, roughly. Splitting 100k across three pools with 40/35/25 weights incurs far less total slippage than dumping it into the deepest pool. Aggregators solve this allocation as an optimization problem per quote.
A honest quote itemizes: pool fee (0.3% typical), batcher/network fee (fixed, per-order on Cardano's eUTxO model), and aggregator margin if any. If a wallet or bot can't show these pre-signature via API, you're trading blind.
With a free routing API and an MCP server, any wallet, dashboard or AI agent can request a route, display the exact fee breakdown, and hand the user a ready-to-sign transaction — without every builder re-implementing an aggregator from scratch.