Polkadot{.js}

Polkadot.js is a scaffolding browser extension that injects a Polkadot API Signer into a page, alongside associated accounts, enabling use by different DApps. The extension manages accounts and enables the signing of transactions with those accounts.

The collection of tools interfaces with the Polkadot blockchain in a granular way. The Polkadot-JS UI is a hosted application that loads in a user's browser. The UI possesses a standard DNS hosted version and a decentralized IPFS version that is less frequently updated. They are called Polkadot-JS Apps, or the Apps UI.

The Polkadot-JS extension was not created for users to interact with on-chain functions as they would find via a wallet app. It does not inject providers for use by DApps or perform wallet functions like sending funds. The extension serves as a key-store and acts as an account manager for Substrate-based accounts.