Description

This PR addresses WebSocket subscription issues identified during the rate limiting incident investigation. The fixes reduce subscription message volume by ~75% and prevent subscription leaks.

Root Causes Identified

1. Subscriptions to unregistered DEXs - System subscribed to ALL 8 DEXs from API instead of only the 2 in our allowlist (main + xyz)
2. Duplicate DEX subscriptions from race conditions - Concurrent calls created 2× subscriptions per DEX
3. Candle subscription leaks - Cleanup failed when component unmounted before async subscription resolved

Fixes Implemented

1. Filter DEXs by Allowlist on Mainnet (HIGH PRIORITY)

Files: hyperLiquidConfig.ts, HyperLiquidProvider.ts

• Added MAINNET_HIP3_CONFIG with AutoDiscoverAll: false
• DEX filtering is now dynamic - extracts DEX names from the allowlistMarkets feature flag patterns
• Added extractDexsFromAllowlist() method that parses patterns like xyz:*, xyz:TSLA, or xyz
• Impact: Reduces from 8 DEXs to 2 (main + xyz), ~75% reduction in subscription messages

2. Prevent Duplicate DEX Subscriptions (HIGH PRIORITY)

File: HyperLiquidSubscriptionService.ts

• Added pendingClearinghouseSubscriptions and pendingOpenOrdersSubscriptions Maps
• Refactored ensureClearinghouseStateSubscription() and ensureOpenOrdersSubscription() to check for pending promises
• Concurrent calls now wait for the pending promise instead of creating duplicate subscriptions
• Impact: Prevents 50% redundant subscriptions from race conditions

3. Fix Candle Subscription Cleanup (HIGH PRIORITY)

File: HyperLiquidClientService.ts

• Store subscription promise to enable cleanup even when pending
• Updated cleanup function to wait for pending promise and unsubscribe
• Impact: Prevents WebSocket subscription leaks when component unmounts before subscription resolves

Test Results

Changelog

CHANGELOG entry: null

Related issues

Fixes: Rate limiting incident from WebSocket over-subscription

Related: WebSocket Subscription Investigation Report

Manual testing steps

Feature: WebSocket subscription optimization

  Scenario: User connects to perps and only allowlisted DEXs are subscribed
    Given user has the app installed with perps feature enabled
    And WebSocket logging is enabled in dev mode

    When user navigates to Perps home screen
    Then WebSocket logs show subscriptions only for main and xyz DEXs
    And no subscriptions for flx, vntl, hyna, km, abcd, cash DEXs

  Scenario: User navigates between markets without duplicate subscriptions
    Given user is connected to perps
    And WebSocket logging is enabled

    When user navigates from Home to xyz:XYZ100 market details
    And user returns to Home
    And user navigates back to xyz:XYZ100
    Then WebSocket logs show no duplicate clearinghouseState subscriptions
    And WebSocket logs show no duplicate openOrders subscriptions

  Scenario: User views candle chart and subscriptions are properly cleaned up
    Given user is on a market details screen with chart visible

    When user quickly navigates away from the screen
    And user waits for 2 seconds
    Then candle subscriptions are properly unsubscribed
    And no orphaned candle subscriptions exist

Screenshots/Recordings

Before

WebSocket subscription breakdown (full trading flow):

• clearinghouseState: 16 subscriptions (8 DEXs × 2 duplicates)
• openOrders: 16 subscriptions (8 DEXs × 2 duplicates)
• candle: 4 subscriptions, 0 unsubscriptions (leak)

After

WebSocket subscription breakdown (full trading flow):

• clearinghouseState: 2 subscriptions (main + xyz only)
• openOrders: 2 subscriptions (main + xyz only)
• candle: 2 subscriptions, 2 unsubscriptions (balanced)

Total outgoing messages: 44
Total incoming messages: 402 (down from ~750)

Pre-merge author checklist

• I've followed MetaMask Contributor Docs and MetaMask Mobile Coding Standards.
• I've completed the PR template to the best of my ability
• I've included tests if applicable
• I've documented my code using JSDoc format if applicable
• I've applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

Subscription Breakdown

• clearinghouseState: 2 (main + xyz)
• openOrders: 2 (main + xyz)
• userFills: 1
• webData3: 1
• allMids: 1
• assetCtxs: 2 (xyz only, subscribed/unsubscribed on navigation)
• activeAssetCtx: 2 (xyz:XYZ100, subscribed/unsubscribed on navigation)
• candle: 2 (1h + 15m intervals)
• bbo: 2 (subscribed/unsubscribed during order flow)

Future Optimization Opportunity

Trading operations (order placement, cancellation, modification) currently use HTTP transport:

• ExchangeClient is configured with httpTransport to avoid 429 rate limiting
• InfoClient uses wsTransport for info queries (multiplexed over single WS connection)

Now that subscription volume is reduced by 75%, we could consider moving ExchangeClient to WebSocket transport (see follow-up investigation).