smart-transactions-controller

@metamask/smart-transactions-controller

Improves success rates for swaps by trialing transactions privately and finding minimum fees.

Installation

yarn add @metamask/smart-transactions-controller

or

npm install @metamask/smart-transactions-controller

Feature Flags

Smart transactions feature flags are managed via RemoteFeatureFlagController (LaunchDarkly). The configuration uses a default remote object for global settings and chain-specific overrides keyed by hex chain ID.

The flag in LaunchDarkly is named smartTransactionsNetworks.

Adding a New Flag

1. Add the field to the schema in src/utils/validators.ts:

   export const SmartTransactionsNetworkConfigSchema = type({
     // ... existing fields
     myNewFlag: optional(boolean()),
   });

   The SmartTransactionsNetworkConfig type is automatically inferred from this schema.

2. Add default value in src/constants.ts under DEFAULT_DISABLED_SMART_TRANSACTIONS_FEATURE_FLAGS:

   These values should be defensive. They are applied when the remote config is invalid or does not exist for a network. It disables smart transaction.

   export const DEFAULT_DISABLED_SMART_TRANSACTIONS_FEATURE_FLAGS = {
     default: {
       // ... existing defaults
       myNewFlag: false,
     },
   };

3. Use in clients via the exported selectors:

   import { selectSmartTransactionsFeatureFlagsForChain } from '@metamask/smart-transactions-controller';
   
   const chainConfig = selectSmartTransactionsFeatureFlagsForChain(
     state,
     '0x1',
   );
   if (chainConfig.myNewFlag) {
     // Feature is enabled
   }

Contributing

This package is part of a monorepo. Instructions for contributing can be found in the monorepo README.