ethers.js/docs.wrm/api/providers/index.wrm

_section: Providers

A **Provider** is an abstraction of a connection to the
Ethereum network, providing a concise, consistent interface
to standard Ethereum node functionality.

The ethers.js library provides several options which should
cover the vast majority of use-cases, but also includes the
necessary functions and classes for sub-classing if a more
custom configuration is necessary.

Most users should be able to simply use the [[providers-getDefaultProvider]].


_subsection: Default Provider @<providers-getDefaultProvider>

The default provider is the safest, easiest way to begin
developing on //Ethereum//, and it is also robust enough
for use in production.

It creates a [[FallbackProvider]] connected to as many backend
services as possible. When a request is made, it is sent to
multiple backends simulatenously. As responses from each backend
are returned, they are checked that they agree. Once a quorum
has been reached (i.e. enough of the backends agree), the response
is provided to your application.

This ensures that if a backend has become out-of-sync, or if it
has been compromised that its responses are dropped in favor of
responses that match the majority.

_property: ethers.getDefaultProvider([ network, [ options ] ]) => [[Provider]]
Returns a new Provider, backed by multiple services, connected
to //network//. Is no //network// is provided, **homestead**
(i.e. mainnet) is used.

The //options// is an object, with the following properties:

_table: Option Properties

$Alchemy:     [[link-alchemy]] API Token
$Etherscan:   [[link-etherscan]] API Token
$Infura:      [[link-infura]] Project ID or ProjectID and Project Secret
$Quroum:      The number of backends that must agree
              //(default: 2 for mainnet, 1 for testnets)//
    
|  **Property**  |  **Description**  |
|    alchemy     | $Alchemt          |
|   etherscan    | $Etherscan        |
|    infura      | $Infura           |
|    quorum      | $Quorum           |

_note: Note: API Keys

It is highly recommended for production services that to acquire
and specify an API Key for each sercice.

The deafult API Keys used by ethers are shared across all users,
so services may throttle all services that are using the default
API Keys during periods of load without realizing it.

Many services also have monitoring and usage metrics, which are
only available if an API Key is specifie. This allows tracking
how many requests are being sent and which methods are being
used the most.

Some services also provide additional paid features, whichare only
available when specifying an API Key.


_subsection: Provider Documentation

_toc:
    provider
    jsonrpc-provider
    api-providers
    other
    types