add: Web3 Providers

docs/WalletSupport/8.Providers.md

@@ -0,0 +1,116 @@
+---
+sidebar_label: '8. Provider'
+sidebar_position: 8
+image: /cover-image.png
+description: The Most Powerful Multi-Chain NFT bridge
+---
+
+# Provider
+
+
+## Definition
+
+A Web3 provider is a software component that facilitates communication between a decentralized application (DApp) and the Ethereum blockchain or other blockchain networks. In the context of Web3, which refers to the third generation of the web focused on decentralized and blockchain-based applications, a Web3 provider plays a crucial role in enabling interactions between the front end (user interface) of a DApp and the underlying blockchain. The wallet selected by a user injects a provider or a provider with a signer into a web3 dApp, allowing the application to query the blockchain of interest or sign transactions on behalf of the user once authorized by the user in the wallet.
+
+Key characteristics and functionalities of a Web3 provider include:
+
+1. **Connection to the Blockchain**
+The Web3 provider establishes a connection between the DApp and a blockchain network, allowing the DApp to send and receive data from the blockchain.
+
+2. **User Wallet Interaction**
+It enables the DApp to interact with the user's cryptocurrency wallet. It includes requesting the user's address, signing transactions, and performing other wallet-related operations.
+
+3. **Ethereum JavaScript Provider API**
+A Web3 provider typically implements or adheres to a standard API for interacting with Ethereum from JavaScript. EIP-1193 is an example of an Ethereum Improvement Proposal that aims to standardize the Ethereum JavaScript Provider API.
+
+4. Event Handling
+Providers often emit events to notify the DApp about changes in the user's wallet state or other relevant events. It allows the DApp to react dynamically to user actions.
+
+Web3 providers play a crucial role in ensuring the security of transactions and interactions with the blockchain. They handle tasks such as transaction signing, a critical security measure.
+
+## Provider related standards
+
+### EIP-1193 Ethereum Provider JavaScript API
+
+[EIP-1193](https://eips.ethereum.org/EIPS/eip-1193) is a proposal for an Ethereum Improvement Proposal (EIP) that defines a standard Ethereum JavaScript Provider API. The primary goal of EIP-1193 is to standardize the way Ethereum decentralized applications (DApps) interact with user wallets and Ethereum providers in the browser.
+
+#### Connectivity
+
+A provider can interact with only one chain at a time. The provider is said to be `connected` when such a connection is established. Otherwise, the provider is said to be `disconnected`.
+
+#### Request API
+
+All provider APIs must implement the following interface:
+
+```ts
+interface RequestArguments {
+  readonly method: string;
+  readonly params?: readonly unknown[] | object;
+}
+
+Provider.request(args: RequestArguments): Promise<unknown>;
+```
+
+```ts
+// Most Providers are available as window.ethereum on page load.
+const ethereum = window.ethereum;
+```
+
+**Example requests**:
+
+```ts
+(async() => {
+    const chainId = await ethereum.request({
+        method:'eth_chainId'
+    }).catch(err => {
+        console.error(`Error fetching chainId: ${err.code}: ${err.message}`)
+    })
+})
+```
+
+
+#### Provider Errors
+
+If a Remote Procedure Call (RPC) is rejected, the provider returns a `ProviderRpcError`. All such errors must implement the following interface:
+
+```ts
+interface ProviderRpcError extends Error {
+    // A human-readable string
+    message: string;
+    // An integer number
+    code: number;
+    // Additional info
+    data?: unknown;
+}
+```
+
+|Status Code|Error Name|Problem descriptopn|
+|:-:|:-:|:-|
+|4001|User Rejected Request|The user rejected the request.|
+|4100|Unauthorized|The user has not authorized the requested method and account.|
+|4200|Unsupported Method|The Provider does not support the requested method.|
+|4900|Disconnected|The Provider is disconnected from all chains.|
+|4901| Chain Disconnected|The Provider is disconnected from the requested chain.|
+
+#### Events
+
+JS Provider events follow the [Node.js Class EventEmitter API](https://nodejs.org/api/events.html).
+
+Listening to events happen like this:
+
+```ts
+// Template
+Provider.on('event-name', listener:(<variable>:<type>) => void): Provider;
+
+// Examples:
+Provider.on('connect', listener: (connectInfo: {chainId: string}) => void): Provider;
+Provider.on('disconnect', listener: (error: ProviderRpcError) => void): Provider;
+Provider.on('chainChanged', listener: (chainId: string) => void): Provider;
+Provider.on('accountsChanged', listener: (accounts: string[]) => void): Provider;
+```
+
+Other related EIPs
+- [EIP-1102 Opt-in account exposure](https://eips.ethereum.org/EIPS/eip-1102)
+- [EIP-1474 RPC Call Specification](https://eips.ethereum.org/EIPS/eip-1474)
+- [EIP-1767 GraphQL interface to Ethereum node data](https://eips.ethereum.org/EIPS/eip-1767)
+- [EIP-2255 Wallet Permissions](https://eips.ethereum.org/EIPS/eip-2255)