feat(transaction-pay): add TokenPay strategy with Across provider + metrics by pedronfigueiredo · Pull Request #7806 · MetaMask/core

pedronfigueiredo · 2026-02-02T12:46:52Z

Explanation

This PR introduces a TokenPay strategy that routes to provider adapters (Relay + Across), adds an Across provider end‑to‑end, and tracks quote/execution latency and costs. It also enforces current Across limitations (same‑chain swaps, perps deposits, and type‑4 authorization lists) with explicit gating and TODOs.

Key changes

New TokenPay strategy + provider adapter interface/registry.
Across provider:
- Quote requests to /swap/approval (GET or POST with actions).
- Quote normalization for provider fees, source/target network fees, dust, amounts, and duration.
- Actions API support for delegated calls (token transfer + delegation).
- Submit flow for approval + swap txs, requiredTransactionIds tracking, intent completion.
Relay adapter:
- Wraps existing Relay quote + submit logic for TokenPay.
Feature flags:
- TokenPay provider config (Across API base/key/app fees/slippage; Relay quote URL).
Gating and TODOs:
- Reject same‑chain quotes (mUSD conversions) when Across can’t do same‑chain swaps.
- Disable perps deposits (Hypercore) until Across supports USDC‑PERPs.
- Block type‑4/EIP‑7702 authorizationList actions until supported (first‑time Polymarket deposits).
Metrics:
- Across quote latency stored on quote original.metrics.latency.
- Execution latency stored on transactionMeta.metamaskPay.executionLatencyMs.

References

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
Adds a new Across quoting/submission path and changes pay strategy selection/execution to use ordered fallback, which can affect which provider executes and how source transactions are submitted. While guarded by feature flags and tests, it touches transaction submission, metadata updates, and quote normalization logic.

Overview
Adds a new Across MetaMask Pay strategy (quotes + submit) and moves strategy selection to an ordered list with compatibility checks and fallback for both quote retrieval and publish-hook execution.

Introduces Across quote fetching/normalization (including optional “actions” POST for delegation/transfer, gas estimation with buffer/fallback, and strict gating for unsupported cases like same-chain swaps when disallowed, perps deposits, and EIP-7702 authorization lists). Across submission now batches approvals + deposit transactions and records required transaction IDs/intent completion.

Adds metrics and fee model updates: TransactionPayFees gains impact/impactRatio, Relay quotes now compute impact when missing, and execution submit latency is recorded once per flow and persisted to transactionMeta.metamaskPay.executionLatencyMs (preserved across metadata updates). Feature flags now include payStrategies config (Across API base/keys/fees; Relay enabled/quote URL) and default strategy order [Relay, Across]. Also adds new transaction types perpsAcrossDeposit and predictAcrossDeposit and threads onSubmitted latency callbacks through strategies/submission helpers.

^{Written by Cursor Bugbot for commit b6c9ca4. This will update automatically on new commits. Configure here.}

packages/transaction-pay-controller/src/strategy/token-pay/TokenPayStrategy.ts

packages/transaction-pay-controller/src/strategy/across/across-submit.ts

packages/transaction-pay-controller/src/utils/feature-flags.ts

packages/transaction-pay-controller/src/strategy/across/across-submit.ts

packages/transaction-pay-controller/src/strategy/across/across-quotes.ts

matthewwalsh0 · 2026-02-02T16:20:56Z

packages/transaction-pay-controller/src/strategy/relay/RelayProvider.ts

+import { getRelayQuotes } from './relay-quotes';
+import { submitRelayQuotes } from './relay-submit';
+
+export class RelayProvider implements TokenPayProvider<RelayQuote> {


For the sake of modularity and risk, can we refactor Relay in a dedicated PR and leave as is here?

Would let us have a working control in the clients when testing also.

matthewwalsh0 · 2026-02-02T16:21:58Z

packages/transaction-controller/src/types.ts

+  /**
+   * Deposit funds for Across quote.
+   */
+  acrossDeposit = 'acrossDeposit',


We actually have a pending task to make relayDeposit more granular, so perpsRelayDeposit and predictRelayDeposit, so should do the same for Across also.

matthewwalsh0 · 2026-02-02T16:22:14Z

packages/transaction-controller/src/types.ts

  totalFiat?: string;
+
+  /** Total time spent executing the MetaMask Pay flow, in milliseconds. */
+  executionLatencyMs?: number;


Minor, alphabetical.

matthewwalsh0 · 2026-02-02T16:24:36Z

packages/transaction-pay-controller/ARCHITECTURE.md

+
+- `tokenPay.providerOrder` controls priority (default: `[primaryProvider, 'relay', 'across']`).
+- Each provider can be enabled/disabled via `tokenPay.providers.<id>.enabled`.
+- Providers may also implement capability gating in `supports(...)` (e.g., Across rejects same-chain swaps).


This sounds like a good mechanism, but can we abstract to PayStrategy in general so we can accommodate fiat in future also and any strategy?

That way, we could isolate this into it's own dedicated PR for risk and easier review?

matthewwalsh0 · 2026-02-02T16:26:00Z

packages/transaction-pay-controller/src/constants.ts

 export enum TransactionPayStrategy {
  Bridge = 'bridge',
  Relay = 'relay',
+  TokenPay = 'tokenPay',


I was assuming this would just be an abstract internal class to remove duplication.

Ideally the client could specify multiple preferences in priority order, and we pick the first that is supported or throw?

Thereby combining the new fallback mechanism and getStrategy?

matthewwalsh0 · 2026-02-02T16:35:00Z

packages/transaction-pay-controller/src/strategy/token-pay/TokenPayStrategy.ts

+        continue;
+      }
+
+      if (provider.id === 'across' && !config.providers.across.enabled) {


Is this breaking the abstraction if it knows about the implementations?

matthewwalsh0 · 2026-02-02T16:37:31Z

packages/transaction-pay-controller/src/strategy/across/across-submit.ts

+  return { transactionHash };
+}
+
+async function executeSingleQuote(


I understood the core benefit of the TokenPayStrategy was to remove duplication between the Relay and Across strategies.

But if we're just using it for the fallback logic, would it not be simpler to incorporate that into PayStrategy directly (as mentioned in another comment)?

Then we could create some common token strategy utils to add the origin transactions for example given the duplication?

matthewwalsh0 · 2026-02-02T16:38:24Z

packages/transaction-pay-controller/src/strategy/across/across-submit.ts

+    return Math.ceil(estimatedGas * gasBuffer);
+  } catch (error) {
+    log('Gas estimate failed, using fallback', { error });
+    return 900000;


We have some feature flags for this too, so another benefit of a common util.

matthewwalsh0 · 2026-02-02T16:39:29Z

packages/transaction-pay-controller/src/strategy/across/across-quotes.ts

+  };
+}
+
+function buildDelegationAction(delegation: {


This is all done in the client via a constructor callback, so we can decouple delegations from this controller.

matthewwalsh0 · 2026-02-02T16:41:00Z

packages/transaction-pay-controller/src/strategy/across/across-quotes.ts

+  }
+
+  const relayer = quote.fees?.relayerTotal?.amountUsd ?? '0';
+  const app = quote.fees?.app?.amountUsd ?? '0';


I'm worried this isn't the total price impact for the user, but just the Across specific fee, does this definitely include the total impact of the bridge provider itself?

Have we confirmed for example, that the quote results in the requested fee minus the this fee only?

Good point, I adjusted the provider fee to be the impact just like in the case of relay.

packages/transaction-controller/CHANGELOG.md

packages/transaction-pay-controller/CHANGELOG.md

packages/transaction-pay-controller/src/strategy/relay/relay-quotes.ts

…etrics - Introduce TokenPay strategy with provider adapter interface and registry - Add Across provider (quotes + submit) and Relay adapter wrapper - Implement Across quote normalization (fees, dust, durations, fiat) and actions API payloads for delegated calls - Add feature flags for tokenPay providers and Across API config - Add Across submit flow (approvals + swap tx), intent completion, and confirmation waits - Gate unsupported cases (same-chain, perps deposits) and block type‑4 authorizationList until Across supports it - Add Across quote latency metrics and execution latency recording in metamaskPay metadata - Add/extend unit tests for Across quotes/submit/supports and publish hook metrics

cursor

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

cursor · 2026-02-06T10:08:39Z

packages/transaction-pay-controller/src/strategy/across/across-submit.ts

+    default:
+      return TransactionType.perpsAcrossDeposit;
+  }
+}


Default deposit type mislabels non-perps Across transactions

Medium Severity

getAcrossDepositType defaults to TransactionType.perpsAcrossDeposit for any transaction type other than perpsDeposit or predictDeposit. Since AcrossStrategy.supports() already blocks perpsDeposit, the only transactions reaching Across are predictDeposit and all other types (e.g., regular token transfers via fallback). Non-perps, non-predict transactions get incorrectly labeled as perpsAcrossDeposit, which misrepresents the transaction in analytics, tracking, and any downstream type-checking logic. The transaction-controller CHANGELOG even references a generic acrossDeposit type that was never defined, suggesting a missing general-purpose deposit type.

pedronfigueiredo self-assigned this Feb 2, 2026

pedronfigueiredo requested review from a team as code owners February 2, 2026 12:46

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Default deposit type mislabels non-perps Across transactions

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pedronfigueiredo commented Feb 2, 2026 •

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