feat: using websockets events for transaction polling by jpuri · Pull Request #7822 · MetaMask/core

jpuri · 2026-02-03T15:00:28Z

Explanation

Using event AccountActivityService:transactionUpdated to improve transaction polling.

References

Fixes https://github.com/MetaMask/MetaMask-planning/issues/6948

Checklist

I've updated the test suite for new or updated code as appropriate
I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
I've communicated my changes to consumers by updating changelogs for packages I've changed
I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

Note

Medium Risk
Changes core transaction polling behavior by adding an event-driven trigger path, which could affect polling frequency and missed/extra updates if event filtering or subscriptions are incorrect. Scope is contained to the poller/helper layer with thorough unit coverage.

Overview
Adds event-driven polling: TransactionPoller now subscribes to AccountActivityService:transactionUpdated on start() and unsubscribes on stop(), triggering an immediate poll when a confirmed transaction arrives for the selected account on the same chain.

Refactors chain-id conversion: Introduces shared caip2ToHex in utils.ts (with tests) and replaces the inline CAIP-2 conversion logic in IncomingTransactionHelper to use the shared helper.

Updates CHANGELOG.md to document the new event-driven polling behavior.

^{Written by Cursor Bugbot for commit 7db2f62. This will update automatically on new commits. Configure here.}

packages/transaction-controller/src/helpers/TransactionPoller.ts

…ion_polling_improvements

matthewwalsh0 · 2026-02-04T10:55:37Z

packages/transaction-controller/src/helpers/TransactionPoller.ts

    this.#chainId = chainId;
    this.#messenger = messenger;
+
+    const featureFlags = messenger.call('RemoteFeatureFlagController:getState')


We create small util wrappers for all the feature flags to encapsulate their layout in feature-flags.ts, so could we make a isPollingWebSocketsEnabled?

matthewwalsh0 · 2026-02-04T10:56:42Z

packages/transaction-controller/src/helpers/TransactionPoller.ts

+    const featureFlags = messenger.call('RemoteFeatureFlagController:getState')
+      .remoteFeatureFlags as TransactionControllerFeatureFlags;
+
+    this.#useWebsockets =


Is there any risk here that would warrant a feature flag? Since even if it fires, we still check the receipt?

Not really, I agree feature flag here is not required. I added it to be double safe. But yep let me remove this.

PR is updated to remove the flag

matthewwalsh0 · 2026-02-04T11:04:11Z

packages/transaction-controller/src/helpers/TransactionPoller.ts

+      return;
+    }
+
+    if (transaction.status !== 'confirmed') {


Do we also want to continue if failed so we can check the receipt and update the status to failed?

Good point, let me add that.

PR is updated to check for both dropped and failed statuses also.

matthewwalsh0 · 2026-02-04T11:05:24Z

packages/transaction-controller/src/helpers/TransactionPoller.ts

+      return;
+    }
+
+    this.#interval(false, undefined, true).catch(() => {


Is the block number on the transaction object so we can skip the block request?

Unfortunately no, the only data we get is:

export type Transaction = { /** Transaction ID/hash */ id: string; /** Chain identifier in CAIP-2 format (e.g., "eip155:1") */ chain: string; /** Transaction status */ status: string; /** Timestamp when the transaction was processed */ timestamp: number; /** Address that initiated the transaction */ from: string; /** Address that received the transaction */ to: string; };

matthewwalsh0 · 2026-02-04T11:06:12Z

packages/transaction-controller/src/helpers/TransactionPoller.ts

  async #interval(
    isAccelerated: boolean,
    latestBlockNumber?: string,
+    transactionUpdateReceived: boolean = false,


Rather than adding a second boolean argument, could we define a local enum such as PollingTrigger and replace isAccelerated with trigger?

Let me update the PR

PR is updated

matthewwalsh0 · 2026-02-04T11:06:51Z

packages/transaction-controller/src/helpers/TransactionPoller.ts

+      return;
+    }
+
+    if (transaction.status !== 'confirmed') {


Should we also check the from of the transaction to confirm it's an outgoing transaction?

Let me update the PR

PR is updated

I reverted this change as it is failing for some transactions.

matthewwalsh0 · 2026-02-04T11:08:50Z

packages/transaction-controller/src/helpers/TransactionPoller.ts

+      return;
+    }
+
+    this.#interval(false, undefined, true).catch(() => {


We're technically triggering the polling of all pending transactions for the chain, rather than the specific one from the event.

But I think it will be incredibly rare that a user has two simultaneously submitted meaning it's not worth the code complexity to only query specific transactions.

…/MetaMask/core into transaction_polling_improvements

…ion_polling_improvements

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Cursor Bugbot has reviewed your changes and found 1 potential issue.

packages/transaction-controller/src/helpers/TransactionPoller.ts

Using websockets events for transaction polling

a0902d5

jpuri requested a review from a team as a code owner February 3, 2026 15:00

jpuri added the team-confirmations label Feb 3, 2026

jpuri added 2 commits February 3, 2026 20:47

update

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jpuri force-pushed the transaction_polling_improvements branch from 70ae62d to 41a0567 Compare February 3, 2026 15:22

jpuri requested a review from a team as a code owner February 3, 2026 15:22

jpuri enabled auto-merge February 3, 2026 15:25

update

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jpuri force-pushed the transaction_polling_improvements branch from e9cf4eb to 45493b2 Compare February 3, 2026 15:59

jpuri added 2 commits February 3, 2026 21:30

Merge branch 'main' into transaction_polling_improvements

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jpuri added 2 commits February 4, 2026 13:37

Merge branch 'main' of https://github.com/MetaMask/core into transact…

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…ion_polling_improvements

Merge branch 'main' into transaction_polling_improvements

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matthewwalsh0 requested changes Feb 4, 2026

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jpuri added 2 commits February 4, 2026 18:40

Merge branch 'transaction_polling_improvements' of https://github.com…

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…/MetaMask/core into transaction_polling_improvements

Merge branch 'main' of https://github.com/MetaMask/core into transact…

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…ion_polling_improvements

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packages/transaction-controller/src/helpers/TransactionPoller.ts Show resolved Hide resolved

jpuri added 6 commits February 4, 2026 19:11

check from account of transaction received

9c2c04c

remove use of feature flag

dfcef63

cleanup

dc0d255

update

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update

712814d

update

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jpuri requested a review from matthewwalsh0 February 4, 2026 14:39

update

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jpuri commented Feb 3, 2026 •

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