Q: How to submit a transaction with the Promise API?

After connecting, use api.tx. . (...).signAndSend(account, callback). Check the tutorials on the docs site for detailed steps, including fee estimation and event handling.

Question 1

How do I connect to a Polkadot node using @polkadot/api?

Accepted Answer

Use ApiPromise.create() or ApiRx.create() with the node's WebSocket endpoint. The documentation provides examples for both interfaces, including error handling and connection management.

Question 2

@polkadot/api vs web3.js for Polkadot development: which is better?

Accepted Answer

@polkadot/api is tailored for Polkadot/Substrate with dynamic types, while web3.js is for Ethereum. For Polkadot chains, @polkadot/api is the standard choice due to its native integration and type safety.

Question 3

How to submit a transaction with the Promise API?

Accepted Answer

After connecting, use api.tx..(...).signAndSend(account, callback). Check the tutorials on the docs site for detailed steps, including fee estimation and event handling.

Question 4

Does @polkadot/api work with server-side Node.js applications?

Accepted Answer

Yes, it's fully compatible with Node.js for backend services, bots, or scripts. The Promise API is commonly used for its simplicity in server environments with long-running connections.

Question 5

What are common issues with dynamic type generation?

Accepted Answer

Issues often stem from outdated node metadata or network errors during fetch. Ensure your node is synced and use api.on('error') to handle connection drops or type mismatches gracefully.

Question 6

How to handle real-time data with RxJS in @polkadot/api?

Accepted Answer

Use the ApiRx interface to create observables, like api.rpc.chain.subscribeNewHeads(). Apply RxJS operators for filtering and processing streams, as shown in the examples for reactive programming.

Question 7

Can I use @polkadot/api in a React app without extra dependencies?

Accepted Answer

Yes, it integrates directly into React, but for state management, you might need custom hooks or community wrappers. The core library is framework-agnostic, so import it and manage connections in useEffect.

Polkadot-JS API

What is Polkadot-JS API?

Overview

Use Cases

Best For

Related Projects

Found a gem we're missing?

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions