105 lines
3.6 KiB
Plaintext
105 lines
3.6 KiB
Plaintext
_section: Providers @<providers>
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A **Provider** is an abstraction of a connection to the
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Ethereum network, providing a concise, consistent interface
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to standard Ethereum node functionality.
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The ethers.js library provides several options which should
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cover the vast majority of use-cases, but also includes the
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necessary functions and classes for sub-classing if a more
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custom configuration is necessary.
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Most users should use the [[providers-getDefaultProvider]].
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_subsection: Default Provider @<providers-getDefaultProvider>
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The default provider is the safest, easiest way to begin
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developing on //Ethereum//, and it is also robust enough
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for use in production.
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It creates a [[FallbackProvider]] connected to as many backend
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services as possible. When a request is made, it is sent to
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multiple backends simulatenously. As responses from each backend
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are returned, they are checked that they agree. Once a quorum
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has been reached (i.e. enough of the backends agree), the response
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is provided to your application.
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This ensures that if a backend has become out-of-sync, or if it
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has been compromised that its responses are dropped in favor of
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responses that match the majority.
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_property: ethers.getDefaultProvider([ network, [ options ] ]) => [[Provider]]
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Returns a new Provider, backed by multiple services, connected
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to //network//. Is no //network// is provided, **homestead**
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(i.e. mainnet) is used.
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The //network// may also be a URL to connect to, such as ``http:/\/localhost:8545``
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or ``wss:/\/example.com``.
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The //options// is an object, with the following properties:
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_table: Option Properties
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$Alchemy: [[link-alchemy]] API Token
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$Etherscan: [[link-etherscan]] API Token
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$Infura: [[link-infura]] Project ID or ProjectID and Project Secret
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$Quorum: The number of backends that must agree
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//(default: 2 for mainnet, 1 for testnets)//
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| **Property** | **Description** |
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| //alchemy// | $Alchemy |
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| //etherscan// | $Etherscan |
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| //infura// | $Infura |
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| //quorum// | $Quorum |
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_note: Note: API Keys
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It is highly recommended for production services that to acquire
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and specify an API Key for each sercice.
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The default API Keys used by ethers are shared across all users,
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so services may throttle all services that are using the default
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API Keys during periods of load without realizing it.
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Many services also have monitoring and usage metrics, which are
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only available if an API Key is specified. This allows tracking
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how many requests are being sent and which methods are being
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used the most.
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Some services also provide additional paid features, which are only
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available when specifying an API Key.
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_subsection: Networks
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There are several official common Ethereum networks as well as custom
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networks and other compatible projects.
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Any API that accept a [[providers-Networkish]] can be passed a common name (such as
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``"mainnet"`` or ``"ropsten"``) to use that network definition or may specify
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custom parameters.
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_heading: Custom ENS Contract
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One common reason to specify custom properties for a [[providers-Network]] is to override
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the address of the root ENS registry, either on a common network to intercept
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the [ENS Methods](Provider--ens-methods) or to specify the ENS registry on a
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dev network (on most dev networks you must deploy the ENS contracts manually).
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_code: Example: Override the ENS registry @lang<script>
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const network = {
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name: "dev",
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chianId: 1337,
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ensAddress: customEnsAddress
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};
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_subsection: Provider Documentation
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_toc:
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provider
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jsonrpc-provider
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api-providers
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other
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types
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