Public Node API

Public Node API provides features identical to KAS Node API without authentication and authorization. It makes you able to execute JSON-RPC functions without implementing your own node.

Public Node API is a service by Krust and KAS for you to learn how to develop blockchain applications on Klaytn. It provides features identical to KAS Klaytn Node API without authentication and authorization. It lets you execute JSON-RPC functions (query data, send transactions) without implementing your own node. The list of Node APIs supported on KAS can be found in Node API List.

Before Getting Started

The intended users of Public Node API are:

Purpose	Users
Using Non-custodial wallet	e.g., Users of MetaMask, or Kaikas
Education	e.g., Beginners in blockchain or preparing to build blockchain service
Research	e.g., Researchers in blockchain technology

Since Public EN is limited to 5000 RPS, the user experience may be affected during high traffic. It is different from KAS Node API in terms of usability; therefore, it is not recommended to use Public EN at the production level. Instead, you can use KAS. Please refer to the comparison table below for more details.

• Comparison of Public Node API and KAS

Category	Public EN	KAS
Rate limit per a second	All users share 5000 RPS	Each user has an individual rate limit
Daily Request limit	Unlimited	Depends on the KAS Pricing Plan
Productivity	Only Node API	Different APIs including Wallet, KIP, Token History, Metadata etc.
Availability	H/A	H/A
Technical Support	-	KAS Help Center/Jira
Abusing	Action against specific accounts/IP	-

Public Node API is not intended for the usability of production-level applications. Please take into consideration that it is intended for educational and testing purposes. Overuse may lead to disadvantages.

• Public Node API Domain

  Set the domain depending on whether you are on Cypress or Baobab. You can make Klaytn JSON-RPC requests without an authentication header.

  • Cypress(Klaytn Mainnet): https://public-node-api.klaytnapi.com/v1/cypress

  • Baobab(Klaytn Testnet): https://public-node-api.klaytnapi.com/v1/baobab

For more details on Klaytn JSON-RPC API, please refer to Tutorial.

Connecting Non-Custodial Wallet

Below is the information you need to connect Public Node APIs to a non-custodial wallet.

Item	Description
Newtork Name	Klaytn Cypress (Klaytn Mainnet) or Klaytn Baobab (Klaytn Testnet)
RPC URL	Cypress: https://public-node-api.klaytnapi.com/v1/cypress or Baobab: https://public-node-api.klaytnapi.com/v1/baobab
Chain ID	8217 (Cypress) or 1001 (Baobab)
Currency	KLAY
Explorer URL	Cypress: https://scope.klaytn.com/ or Baobab: https://baobab.scope.klaytn.com/

Connecting Kaikas

Kaikas is a cryptocurrency wallet provided by Klaytn. The RPC URLs for Cypress and Baobab are set as default, but you can change the RPC URL using Public Node API following the instructions below.

1. Run Kaikas

Run Kaikas

2. Click Network > Add Network

Click Network Tab and Add Network

3. Enter the Klaytn chain data to connect to EN and Save

Save Network

Connecting MetaMask

1. Run MetaMask

Run MetaMask

2. Click Network > Add Network

Click Network Tab and Add Network

3. Enter the Klaytn chain data to connect to EN and Save

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Checking the Latest Block Number

To retrieve the latest information on your balance, account key type etc. using Node API, you need the number of the latest block. You can do this by making this JSON-RPC request: { "method": "klay_blockNumber", "id": 1 }.

API Request

curl --location --request POST 'https://public-node-api.klaytnapi.com/v1/cypress' \
    --header 'Content-Type: application/json' \
    --data-raw '{"jsonrpc":"2.0","method":"klay_blockNumber","params":[],"id":1}'

For more details on making API requests, please refer to this link.

API Response

If the API request is successful, it returns the following:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x5d39"
}

• Please refer to this link for for more details on Klaytn JSON-RPC API.

• Please refer to this link for more details on APIs.

List of Currently Supported JSON-RPC API Methods

You can execute other methods in the same way explained above. But please note that KAS doesn't support all of the methods. For a comprehensive list of supported Node API methods, please refer to Node API List.