This is awesome for the DeFi community. Glad to have a trusted source to aggregate liquidity from. Seems like liquidity aggregation will be commoditized on a long enough time horizon (think in terms of Plaid/Stripe positioning in legacy finance) and 0x is the first one to position themselves at the top of the funnel.
0x API aggregates liquidity from DEX networks such as 0x, Kyber, Uniswap, and Maker's Oasis (among other sources) to give developers an easy way to swap crypto tokens at the best prices.