What is a Web3 API? A Beginner's Guide (2024)

Today, developers face many challenges while building in web3. Most of these challenges stem from either the nascency of the technology or its rapidly evolving nature. 

Also, web3 development requires developers to use several tools, from blockchain networks to smart contracts, oracles, etc. Most of these tools are not natively designed to work together. The lack of compatibility and standardization of developer tooling is a massive headache for developers.

This is where web3 APIs (application programming interfaces) play a crucial role in simplifying the development process. 

In this blog, we will explain how web3 APIs work, their functions, and how they make developers’ lives easier.

What is a Web3 API?

Web3 APIs, or application programming interfaces, are protocols and tools that define how different web3 components — oracles, smart contracts, blockchain networks, and more — communicate with each other.

They function as bridges between applications and blockchain networks, facilitating various interactions and operations. 

From reading blockchain data and managing smart contracts to handling user wallets and transactions, Web3 APIs simplify the development process. 

Since they abstract the complex operations, developers can focus more on the application's features, logic, and user experience.

Functions of Web3 API

Web3 APIs are the backbones of blockchain applications, facilitating their development and functionality.

Diving deeper, here are some key functions of web3 APIs:

Smart contract deployments 

Web3 APIs abstract away the intricacies of contract deployment. They compile contract code written in high-level programming languages like Solidity into bytecode — the lower-level code that can be executed by the Ethereum virtual machine (EVM).

Next, these APIs also help generate the ABI — Application binary interface (ABI), which makes it easier for developers to understand and interact with the contract. 

This allows developers to initiate contract creation transactions with concise code, while the API handles gas estimation, nonce management, and network interactions. Additionally, developers can configure parameters, initialize the contract states, and ensure security, all with streamlined code with web3 APIs. 

This simplifies the deployment process, allowing developers to focus on contract logic.

Backend wallet management 

Wallets serve as the bridge between users and the dapps, forming a layer of user authentication, security, and authorization on the backend. Their management is crucial.

Web3 APIs can enable the creation of local wallets, secure storage of private keys, and execution of transactions (e.g., transfers and smart contract interactions). 

Security measures like storing private keys securely with AWS KMS (Key management service) or Google Cloud KMS wallet are possible with Web3 APIs. They also help in identity and access management, especially in defining user permissions for wallet operations.

Gasless transactions

Gasless transactions can significantly ease the lives of developers by simplifying user onboarding. Developers can mimic web2-like user journeys to create a more comfortable user experience for new web3 users. 

Web3 APIs introduce mechanisms like meta-transactions or gas stations to sponsor gas fees on behalf of users. These mechanisms help developers build gasless dapps with fluid interactions and functionalities without the deterrent of gas fees.

Smart contract interface 

Web3 APIs provide a developer-friendly interface for interacting with smart contracts. They are essential for automating processes and agreements in a trustless environment. The API facilitates reading data from and writing data to these contracts, enabling applications to execute contract functions and retrieve state information.

This simplifies dapp development, enabling complex operations — such as token transfers or DeFi interactions — to take place without a lot of technical stress needed.

User wallet authentication 

Wallet authentication is a key aspect of user management in dapps. This covers both security and decentralization in the process of user verification and authentication. 

Web3 APIs play a crucial role here; they facilitate this authentication by making on-chain requests to verify the authenticity of the signed message against the user's public wallet address. This verification confirms that the signature was indeed made by the holder of the private key associated with that wallet.

Thereby, they ensure that the user is the legitimate owner of the wallet, and link the user's on-chain activities with their dapp identity.

Smart wallets integration

Smart contract wallets are non-custodial Web3 wallets that leverage smart contract logic for enhanced functionality. They introduce powerful features like recoverable wallets, signless transactions, and batched transactions, unavailable in traditional wallets like MetaMask. 

In essence, they provide all the standard wallet features but with heightened security and advanced customization options, promising a superior Web3 user experience.

Integrating these wallets into applications enhances user experience by providing more functionality and control. This integration is crucial for applications that aim to offer advanced blockchain features, like automated trading, multi-signature transactions, or programmable withdrawals, directly within the user interface.

Major components of a Web3 API

Here are five major components of an API:

Endpoints: URLs defining where API services can be accessed. Each endpoint corresponds to a specific function or resource within the API.

Methods: HTTP verbs like GET, POST, PUT, and DELETE, indicate the action (retrieve, send, update, delete data) to be performed on an endpoint.

Query parameters: These are optional key-value pairs that appear in the URL of a GET request. They are used to filter or customize the response returned by the server.

Request/Response Format: The structure of data sent to and received from the API, typically in JSON or XML, including headers and data content.

Authentication/Authorization: Security measures for verifying user identity (authentication) and access rights (authorization), often using API keys or tokens.

These components are generally agnostic of which technology stack they’re working with — web2 or web3. Now, where does the web3 element come in?

Let’s understand that with an example of how a web3 API works.

How does a Web3 API work?

Here is a short example of how a web3 API works:

Imagine using a crypto wallet app on your phone to view an NFT (Non-Fungible Token) collection. The following is what happens in the background:

Step 1: API Call initiation

When a user requests to view their NFT collection, the app constructs an HTTP GET request targeting the blockchain API's endpoint responsible for NFT queries. 

This request includes the user's wallet address as a query parameter.

Step 2: Endpoint interaction 

The endpoint typically interfaces with the blockchain network's node, which accesses the underlying smart contracts. These contracts manage NFT ownership, usually adhering to standards like ERC-721 or ERC-1155.

Step 3: Blockchain query 

The API processes the request by executing a read operation on the blockchain. It queries the smart contracts using the provided wallet address to fetch the list of NFTs owned by the user. This involves reading the token IDs and associated metadata URLs from the blockchain.

Step 4: Data retrieval and formatting

Once the API obtains the token data, it retrieves the corresponding metadata, often hosted off-chain (like on IPFS). The API then serializes this data into a JSON format, structuring it for easy consumption by the app.

Step 5: Response handling 

The API sends the serialized JSON response back to the app. This response includes an array of objects, each representing an NFT with fields like token ID, image URL, title, and other metadata.

Step 6: Client-side rendering

The app parses the JSON response and dynamically renders the UI to display the NFT collection. 

Step 7: Error and state management 

The app includes error handling for scenarios like network failures, invalid wallet addresses, or empty collections. It also manages the state to ensure UI consistency during asynchronous operations.

If you take a look, web3 APIs abstract the complexities of direct blockchain interactions and provide a streamlined, efficient way to retrieve and display NFT data. 

The future of web3 development

Developer experience in web3 needs a major overhaul with better tooling, developer infrastructure, and standardization. While these ensure better reliability for developers, APIs provide simplicity by abstracting away complexity and reducing the learning curve for developers in web3.

Moreover, the impact of APIs extends beyond developer convenience. It makes dapps and other applications smoother to use and more reliable, ultimately improving the end-user experience. 

A notable solution for web3 APIs is Thirdweb Engine, an open-source server specifically designed to facilitate the development and scalability of Web3 applications. It functions as a robust HTTP server that enables interaction with any smart contract on Ethereum virtual machine (EVM) compatible blockchains.

Engine also includes built-in support for various essential components like RPCs, storage solutions, bundlers, and paymasters.

If you have any questions, join 40,000+ other builders in our Discord community — or reach out to the team directly for more info on how to get started with web3 development using Thirdweb Engine. 

And if you want to build a web3 dapp, get started with thirdweb’s web3 tools & SDKs — they’re free!