https://github.com/manifoldfinance/disco-detect-provider
@disco3/detect-provider
https://github.com/manifoldfinance/disco-detect-provider
eip1191 ethereum web3-provider
Last synced: 1 day ago
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@disco3/detect-provider
- Host: GitHub
- URL: https://github.com/manifoldfinance/disco-detect-provider
- Owner: manifoldfinance
- Created: 2022-08-14T00:32:30.000Z (about 3 years ago)
- Default Branch: master
- Last Pushed: 2022-08-14T00:37:42.000Z (about 3 years ago)
- Last Synced: 2025-10-04T21:45:04.215Z (13 days ago)
- Topics: eip1191, ethereum, web3-provider
- Language: TypeScript
- Homepage:
- Size: 137 KB
- Stars: 1
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# @disco3/detect-provider
> A fork of @metamask/detect-provider with updated types and modern packaging
A tiny utility for detecting the MetaMask Ethereum provider, or any provider injected at
`window.ethereum`.
It has 0 dependencies and works out of the box in any modern browser, for synchronously and
asynchronously injected providers.
## Usage
Providers detected by this package may or may not support
[the Ethereum JavaScript Provider API](https://eips.ethereum.org/EIPS/eip-1193).
### Node.js
```javascript
import detectEthereumProvider from '@disco3/detect-provider';
const provider = await detectEthereumProvider();
if (provider) {
console.log('Ethereum successfully detected!');
// From now on, this should always be true:
// provider === window.ethereum
// Access the decentralized web!
// Legacy providers may only have ethereum.sendAsync
const chainId = await provider.request({
method: 'eth_chainId',
});
} else {
// if the provider is not detected, detectEthereumProvider resolves to null
console.error('Please install MetaMask!', error);
}
```
### HTML
```html
const provider = await detectEthereumProvider()
if (provider) {
// handle provider
} else {
// handle no provider
}
```
### Options
The exported function takes an optional `options` object. If invalid options are provided, an error
will be thrown. All options have default values.
#### `options.mustBeMetaMask`
Type: `boolean`
Default: `false`
Whether `window.ethereum.isMetaMask === true` is required for the returned Promise to resolve.
#### `options.silent`
Type: `boolean`
Default: `false`
Whether error messages should be logged to the console. Does not affect errors thrown due to invalid
options.
#### `options.timeout`
Type: `number`
Default: `3000`
How many milliseconds to wait for asynchronously injected providers.
## Advanced Topics
### Synchronous and Asynchronous Injection
Providers can be either synchronously or asynchronously injected:
- _Synchronously_ injected providers will be available by the time website code starts executing.
- _Asynchronously_ injected providers may not become available until later in the page lifecycle.
The MetaMask _extension_ provider is synchronously injected, while the MetaMask _mobile_ provider is
asynchronously injected.
To notify sites of asynchronous injection, MetaMask dispatches the `ethereum#initialized` event on
`window` immediately after the provider has been set as `window.ethereum`. This package relies on
that event to detect asynchronous injection.
### Overwriting or Modifying `window.ethereum`
The detected provider object returned by this package will strictly equal (`===`) `window.ethereum`
for the entire page lifecycle, unless `window.ethereum` is overwritten. In general, consumers should
never overwrite `window.ethereum` or attempt to modify the provider object.
If, as a dapp developer, you notice that the provider returned by this package does not strictly
equal `window.ethereum`, something is wrong. This may happen, for example, if the user has multiple
wallets installed. After confirming that your code and dependencies are not modifying or overwriting
`window.ethereum`, you should ask the user to ensure that they only have a single provider-injecting
wallet enabled at any one time.