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subscribeEvents

Subscribe to events with the given filter and parameters.

Creates a subscription to listen for real-time events from the Flow blockchain. This function configures the subscription parameters for filtering specific events based on type, addresses, contracts, and other criteria.

Events are emitted by Cadence code during transaction execution and provide insights into what happened. Subscriptions allow you to listen for these events in real-time without polling.

Import​

You can import the entire package and access the function:


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import * as sdk from "@onflow/sdk"
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sdk.subscribeEvents(options)

Or import directly the specific function:


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import { subscribeEvents } from "@onflow/sdk"
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subscribeEvents(options)

Usage​


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import * as fcl from "@onflow/fcl";
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// Subscribe to FlowToken transfer events
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const subscription = await fcl.send([
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fcl.subscribeEvents({
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eventTypes: [
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"A.1654653399040a61.FlowToken.TokensWithdrawn",
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"A.1654653399040a61.FlowToken.TokensDeposited"
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],
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startHeight: 1000000, // Start from specific block height
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heartbeatInterval: 3000 // 3 second heartbeat
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})
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]);
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// Subscribe to events from specific contracts
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const contractSubscription = await fcl.send([
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fcl.subscribeEvents({
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contracts: ["FlowToken", "FungibleToken"],
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addresses: ["0x1654653399040a61"]
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})
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]);
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// Handle the subscription data elsewhere using fcl.subscribe()

Parameters​

options​

Returns​

InteractionBuilderFn


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export type InteractionBuilderFn = (
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ix: Interaction
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) => Interaction | Promise<Interaction>

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