A blockchain API is the layer between a product and the chains it reads or trades on. In 2026 that layer does more than fetch a price. It decodes wallets across dozens of networks, streams order books, and answers AI agents that never open a dashboard. Demand has grown on both sides. According to a16z crypto’s State of Crypto 2025 report, blockchains now process more than 3,400 transactions per second. About 181 million addresses were active onchain each month. On the builder side, 1 in 3 crypto developers already work on multiple chains, per the Electric Capital 2024 Developer Report. One vendor per chain no longer scales.