Version: Next

@crawlee/basic

Provides a simple framework for parallel crawling of web pages. The URLs to crawl are fed either from a static list of URLs or from a dynamic queue of URLs enabling recursive crawling of websites.

BasicCrawler is a low-level tool that requires the user to implement the page download and data extraction functionality themselves. If we want a crawler that already facilitates this functionality, we should consider using CheerioCrawler, PuppeteerCrawler or PlaywrightCrawler.

BasicCrawler invokes the user-provided requestHandler for each Request object, which represents a single URL to crawl. The Request objects are fed from the RequestList or RequestQueue instances provided by the requestList or requestQueue constructor options, respectively. If neither requestList nor requestQueue options are provided, the crawler will open the default request queue either when the crawler.addRequests() function is called, or if requests parameter (representing the initial requests) of the crawler.run() function is provided.

If both requestList and requestQueue options are used, the instance first processes URLs from the RequestList and automatically enqueues all of them to the RequestQueue before it starts their processing. This ensures that a single URL is not crawled multiple times.

The crawler finishes if there are no more Request objects to crawl.

New requests are only dispatched when there is enough free CPU and memory available, as judged by the crawler's ConcurrencySystem. Concurrency is tuned via the minConcurrency, maxConcurrency and maxRequestsPerMinute options of the BasicCrawler constructor, or, for finer control, by injecting a pre-configured concurrencySystem.

Example usage

import { BasicCrawler, Dataset } from 'crawlee';

// Create a crawler instance
const crawler = new BasicCrawler({
    async requestHandler({ request, sendRequest }) {
        // 'request' contains an instance of the Request class
        // Here we simply fetch the HTML of the page and store it to a dataset
        const { body } = await sendRequest({
            url: request.url,
            method: request.method,
            body: request.payload,
            headers: request.headers,
        });

        await Dataset.pushData({
            url: request.url,
            html: body,
        })
    },
});

// Enqueue the initial requests and run the crawler
await crawler.run([
    'http://www.example.com/page-1',
    'http://www.example.com/page-2',
]);

Index

References

Classes

BasicCrawler

Interfaces

Type Aliases

Functions

createBasicRouter

References

Dataset

Re-exports Dataset

DatasetConsumer

Re-exports DatasetConsumer

DatasetContent

Re-exports DatasetContent

DatasetDataOptions

Re-exports DatasetDataOptions

DatasetExportOptions

Re-exports DatasetExportOptions

DatasetExportToOptions

Re-exports DatasetExportToOptions

DatasetIteratorOptions

Re-exports DatasetIteratorOptions

DatasetJournalEntry

Re-exports DatasetJournalEntry

DatasetMapper

Re-exports DatasetMapper

DatasetOptions

Re-exports DatasetOptions

DatasetReducer

Re-exports DatasetReducer

DatasetStats

Re-exports DatasetStats

defaultRoute

Re-exports defaultRoute

DefaultRouteUserData

Re-exports DefaultRouteUserData

DefaultStorageIdentifier

Re-exports DefaultStorageIdentifier

EnqueueLinksOptions

Re-exports EnqueueLinksOptions

EnqueueStrategy

Re-exports EnqueueStrategy

EnqueueStrategyOption

Re-exports EnqueueStrategyOption

EnqueueUrlsOptions

Re-exports EnqueueUrlsOptions

ErrnoException

Re-exports ErrnoException

ErrorSnapshotter

Re-exports ErrorSnapshotter

ErrorTracker

Re-exports ErrorTracker

ErrorTrackerOptions

Re-exports ErrorTrackerOptions

EventLoopLoadSignal

Re-exports EventLoopLoadSignal

EventLoopLoadSignalOptions

Re-exports EventLoopLoadSignalOptions

EventManager

Re-exports EventManager

EventManagerOptions

Re-exports EventManagerOptions

EventStatusMessageData

Re-exports EventStatusMessageData

EventType

Re-exports EventType

EventTypeName

Re-exports EventTypeName

ExplicitStorageIdentifier

Re-exports ExplicitStorageIdentifier

ExtractLinksOptions

Re-exports ExtractLinksOptions

field

Re-exports field

FieldsInput

Re-exports FieldsInput

FieldsOutput

Re-exports FieldsOutput

FinalStatistics

Re-exports FinalStatistics

GetUserDataFromRequest

Re-exports GetUserDataFromRequest

GlobInput

Re-exports GlobInput

GlobObject

Re-exports GlobObject

IConcurrencySystem

Re-exports IConcurrencySystem

IProxyConfiguration

Re-exports IProxyConfiguration

IRequestLoader

Re-exports IRequestLoader

IRequestManager

Re-exports IRequestManager

IStatistics

Re-exports IStatistics

IStorage

Re-exports IStorage

JournaledRequest

Re-exports JournaledRequest

JournalEntry

Re-exports JournalEntry

KeyConsumer

Re-exports KeyConsumer

KeyValueStore

Re-exports KeyValueStore

KeyValueStoreIteratorOptions

Re-exports KeyValueStoreIteratorOptions

KeyValueStoreJournalEntry

Re-exports KeyValueStoreJournalEntry

KeyValueStoreOptions

Re-exports KeyValueStoreOptions

KeyValueStoreRawRecord

Re-exports KeyValueStoreRawRecord

KeyValueStoreStats

Re-exports KeyValueStoreStats

LabeledSource

Re-exports LabeledSource

LoadedRequest

Re-exports LoadedRequest

LoadSignal

Re-exports LoadSignal

LoadSignalInfo

Re-exports LoadSignalInfo

LoadSignalsOptions

Re-exports LoadSignalsOptions

LoadSignalStartContext

Re-exports LoadSignalStartContext

LoadSnapshot

Re-exports LoadSnapshot

LocalEventManager

Re-exports LocalEventManager

LocalEventManagerOptions

Re-exports LocalEventManagerOptions

log

Re-exports log

Log

Re-exports Log

Logger

Re-exports Logger

LoggerJson

Re-exports LoggerJson

LoggerOptions

Re-exports LoggerOptions

LoggerText

Re-exports LoggerText

LogLevel

Re-exports LogLevel

MAX_POOL_SIZE

Re-exports MAX_POOL_SIZE

MemoryLoadSignal

Re-exports MemoryLoadSignal

MemoryLoadSignalOptions

Re-exports MemoryLoadSignalOptions

MemoryStorageBackend

Re-exports MemoryStorageBackend

MemoryStorageOptions

Re-exports MemoryStorageOptions

MissingSessionError

Re-exports MissingSessionError

NavigationSkippedError

Re-exports NavigationSkippedError

NonRetryableError

Re-exports NonRetryableError

parseRetryAfterHeader

Re-exports parseRetryAfterHeader

parseValue

Re-exports parseValue

PERSIST_STATE_KEY

Re-exports PERSIST_STATE_KEY

PersistenceOptions

Re-exports PersistenceOptions

PersistentRateLimitError

Re-exports PersistentRateLimitError

ProxyConfiguration

Re-exports ProxyConfiguration

ProxyConfigurationFunction

Re-exports ProxyConfigurationFunction

ProxyConfigurationOptions

Re-exports ProxyConfigurationOptions

purgeDefaultStorages

Re-exports purgeDefaultStorages

PushErrorMessageOptions

Re-exports PushErrorMessageOptions

RecordOptions

Re-exports RecordOptions

RecoverableState

Re-exports RecoverableState

RecoverableStateOptions

Re-exports RecoverableStateOptions

RecoverableStatePersistenceOptions

Re-exports RecoverableStatePersistenceOptions

RegExpInput

Re-exports RegExpInput

RegExpObject

Re-exports RegExpObject

Request

Re-exports Request

RequestHandlerError

Re-exports RequestHandlerError

RequestList

Re-exports RequestList

RequestListOptions

Re-exports RequestListOptions

RequestListSourcesFunction

Re-exports RequestListSourcesFunction

RequestListState

Re-exports RequestListState

RequestManagerOpener

Re-exports RequestManagerOpener

RequestManagerTandem

Re-exports RequestManagerTandem

RequestOptions

Re-exports RequestOptions

RequestQueue

Re-exports RequestQueue

RequestQueueJournalEntry

Re-exports RequestQueueJournalEntry

RequestQueueOperationInfo

Re-exports RequestQueueOperationInfo

RequestQueueOperationOptions

Re-exports RequestQueueOperationOptions

RequestQueueOptions

Re-exports RequestQueueOptions

RequestQueueStats

Re-exports RequestQueueStats

RequestsLike

Re-exports RequestsLike

RequestState

Re-exports RequestState

RequestThrottledError

Re-exports RequestThrottledError

RequestTransform

Re-exports RequestTransform

RequestValidationError

Re-exports RequestValidationError

ResolvedConfigValues

Re-exports ResolvedConfigValues

resolveStorageIdentifier

Re-exports resolveStorageIdentifier

ResponseLike

Re-exports ResponseLike

RestrictedCrawlingContext

Re-exports RestrictedCrawlingContext

RetryRequestError

Re-exports RetryRequestError

RouteOptions

Re-exports RouteOptions

Router

Re-exports Router

RouterHandler

Re-exports RouterHandler

RouterHandlerContext

Re-exports RouterHandlerContext

RouterLabel

Re-exports RouterLabel

RouterRoutes

Re-exports RouterRoutes

RouteSchemas

Re-exports RouteSchemas

RoutesFromSchemas

Re-exports RoutesFromSchemas

SchemaIssue

Re-exports SchemaIssue

serializeValue

Re-exports serializeValue

ServiceConflictError

Re-exports ServiceConflictError

serviceLocator

Re-exports serviceLocator

ServiceLocator

Re-exports ServiceLocator

Session

Re-exports Session

SessionError

Re-exports SessionError

SessionOptions

Re-exports SessionOptions

SessionPool

Re-exports SessionPool

SessionPoolOptions

Re-exports SessionPoolOptions

SessionReuseStrategy

Re-exports SessionReuseStrategy

SitemapRequestLoader

Re-exports SitemapRequestLoader

SitemapRequestLoaderOptions

Re-exports SitemapRequestLoaderOptions

SkippedRequestCallback

Re-exports SkippedRequestCallback

SkippedRequestReason

Re-exports SkippedRequestReason

SnapshotResult

Re-exports SnapshotResult

SnapshotStore

Re-exports SnapshotStore

Source

Re-exports Source

StateConversion

Re-exports StateConversion

StateValidationError

Re-exports StateValidationError

StatisticPersistedState

Re-exports StatisticPersistedState

Statistics

Re-exports Statistics

StatisticsOptions

Re-exports StatisticsOptions

StatisticState

Re-exports StatisticState

StatisticStateExtensionOptions

Re-exports StatisticStateExtensionOptions

StorageBackend

Re-exports StorageBackend

StorageBackendLoadSignal

Re-exports StorageBackendLoadSignal

StorageBackendLoadSignalOptions

Re-exports StorageBackendLoadSignalOptions

StorageIdentifier

Re-exports StorageIdentifier

StorageInstanceManager

Re-exports StorageInstanceManager

StorageOpenOptions

Re-exports StorageOpenOptions

StorageStatsTracker

Re-exports StorageStatsTracker

StorageTransaction

Re-exports StorageTransaction

StorageTransactionOptions

Re-exports StorageTransactionOptions

StorageTransactionState

Re-exports StorageTransactionState

StorageTransactionView

Re-exports StorageTransactionView

StorageWriteMode

Re-exports StorageWriteMode

StorageWritePolicy

Re-exports StorageWritePolicy

supportsDomainThrottling

Re-exports supportsDomainThrottling

SupportsDomainThrottling

Re-exports SupportsDomainThrottling

SyncStateConversion

Re-exports SyncStateConversion

SystemInfo

Re-exports SystemInfo

TaskLoopOptions

Re-exports TaskLoopOptions

TaskLoopPredicates

Re-exports TaskLoopPredicates

ThrottlingRequestManager

Re-exports ThrottlingRequestManager

ThrottlingRequestManagerOptions

Re-exports ThrottlingRequestManagerOptions

TypedContextAddRequests

Re-exports TypedContextAddRequests

TypedContextEnqueueLinks

Re-exports TypedContextEnqueueLinks

UrlPatternInput

Re-exports UrlPatternInput

UrlPatternObject

Re-exports UrlPatternObject

useState

Re-exports useState

UseStateOptions

Re-exports UseStateOptions

withDirectStorageAccess

Re-exports withDirectStorageAccess

WithRequired

Re-exports WithRequired

withStorageTransaction

Re-exports withStorageTransaction

Type Aliases

ErrorHandler

ErrorHandler<BaseContext, ExtendedContext>: (inputs, error) => Awaitable<void>

An error handler receives the crawling context and the error that was thrown while processing the request.

Unlike the RequestHandler, an error handler may run before the context pipeline has finished building the full context (e.g. when navigation or session setup fails). Therefore only BaseContext is guaranteed to be present, while the extra properties added by the pipeline and extendContext (the difference between BaseContext and ExtendedContext) are only available as a Partial.

Type parameters

BaseContext: CrawlingContext = CrawlingContext
ExtendedContext: BaseContext = BaseContext

Type declaration

- (inputs, error): Awaitable<void>
- Parameters
  - inputs: BaseContext & Partial<ExtendedContext>
  - error: Error
  Returns Awaitable<void>

RequestHandler

RequestHandler<Context>: (inputs) => Awaitable<void>

Type parameters

Context: CrawlingContext = CrawlingContext

Type declaration

- (inputs): Awaitable<void>
- Parameters
  - inputs: Context
  Returns Awaitable<void>

RequireContextPipeline

RequireContextPipeline<DefaultContextType, FinalContextType>: DefaultContextType extends FinalContextType ? {} : { contextPipelineBuilder: () => ContextPipeline<CrawlingContext, FinalContextType> }

Type parameters

DefaultContextType: CrawlingContext
FinalContextType: DefaultContextType

StatusMessageCallback

StatusMessageCallback<Context, Crawler>: (params) => Awaitable<void>

Type parameters

Context: CrawlingContext = BasicCrawlingContext
Crawler: BasicCrawler<any, any, any, any> = BasicCrawler<Context>

Type declaration

- (params): Awaitable<void>
- Parameters
  - params: StatusMessageCallbackParams<Context, Crawler>
  Returns Awaitable<void>

Example usage​

Index

References

Classes

Interfaces

Type Aliases

Functions

References

AddRequestsBatchedOptions

AddRequestsBatchedResult

ApifyLogAdapter

ArgumentValidationError

BaseCrawleeLogger

BLOCKED_STATUS_CODES

CalculatedStatistics

coerceBoolean

coerceNumber

ConcurrencyConsumer

ConcurrencySystem

ConcurrencySystemOptions

ConfigField

Configuration

ConfigurationInput

ConfigurationOptions

ContextMiddleware

ContextPipeline

ContextPipelineCleanupError

ContextPipelineInitializationError

ContextPipelineInterruptedError

CpuLoadSignal

CpuLoadSignalOptions

crawleeConfigFields

CrawleeLogger

CrawleeLoggerOptions

CrawlingContext

CreateSession

createStorageTransaction

CriticalError

Dataset

DatasetConsumer

DatasetContent

DatasetDataOptions

DatasetExportOptions

DatasetExportToOptions

DatasetIteratorOptions

DatasetJournalEntry

DatasetMapper

DatasetOptions

DatasetReducer

DatasetStats

defaultRoute

DefaultRouteUserData

DefaultStorageIdentifier

EnqueueLinksOptions

EnqueueStrategy

EnqueueStrategyOption

EnqueueUrlsOptions

ErrnoException

ErrorSnapshotter

ErrorTracker

ErrorTrackerOptions

EventLoopLoadSignal

EventLoopLoadSignalOptions

EventManager

EventManagerOptions

EventStatusMessageData

EventType

EventTypeName

ExplicitStorageIdentifier

ExtractLinksOptions

field

FieldsInput

FieldsOutput

FinalStatistics

GetUserDataFromRequest

GlobInput

GlobObject

IConcurrencySystem

IProxyConfiguration

IRequestLoader

Example usage