Stripe Crypto Onramp

Crossmint offers stablecoin APIs aimed at enterprises, including cross-chain flows. Builders use it to add stablecoin payments to an application without building the payment rails.

The Lido Ethereum SDK is the official package for staking and managing stETH and wstETH through the Lido protocol. Builders install it to add staking to an application without writing the Lido contract calls by hand.

The Machine Payments Protocol SDK, published as mppx by the wevm team behind viem and wagmi, is a TypeScript implementation of an agent payments specification. Builders install it to let a service or agent pay and charge programmatically.

Request Network is a protocol and JavaScript library for creating, paying, and tracking crypto invoices and payment requests onchain. Builders install the client library to add invoicing to their own application.

web3-ethereum-defi is a Python library for DeFi integration and data research, with wrappers for Uniswap, Aave, Chainlink, and USDC on top of web3.py. Python builders import it instead of writing those protocol wrappers themselves.

eth-prices is a Rust crate that estimates the price of an Ethereum asset by reading Uniswap V2 and V3 pools and ERC-4626 vaults through an RPC provider, with no exchange rate API involved. Rust builders add it when a price should be derived from onchain liquidity rather than read from an oracle feed.