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 payment-routing strategy and Across submission path that constructs and submits approval/swap transactions and updates transaction metadata; bugs here could lead to failed payments or incorrect tracking. Feature-flag gating reduces blast radius, but the new provider integration touches transaction creation, gas estimation, and state updates.

Overview
Adds a new TokenPay strategy that routes MetaMask Pay quote/execution through provider adapters (currently Relay and a new Across provider), with provider ordering/enabling controlled via confirmations_pay.tokenPay feature flags.

Introduces an end-to-end Across integration: fetches /swap/approval quotes (GET/POST with optional action payloads), normalizes fees/amounts/dust and records quote latency, then submits approval+swap transactions (batched when needed) while tracking requiredTransactionIds and marking intent completion.

Adds MetaMask Pay execution latency tracking by writing metamaskPay.executionLatencyMs during publish-hook execution, preserves existing metamaskPay fields when updating quote-derived metadata, and extends transaction-controller types with TransactionType.acrossDeposit and the new metadata field.

^{Written by Cursor Bugbot for commit 047509a. 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

…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 2 potential issues.

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.

pedronfigueiredo self-assigned this Feb 2, 2026

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

pedronfigueiredo added the team-confirmations label Feb 2, 2026

cursor bot reviewed Feb 2, 2026

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pedronfigueiredo force-pushed the pnf/cor-across-strategy branch from 5428c48 to 6e9ba0c Compare February 2, 2026 13:13

pedronfigueiredo force-pushed the pnf/cor-across-strategy branch from 6e9ba0c to 047509a Compare February 2, 2026 15:16

cursor bot reviewed Feb 2, 2026

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

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

matthewwalsh0 requested changes Feb 2, 2026

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pedronfigueiredo commented Feb 2, 2026 •

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