feat: parse and display warp route fees

[paulbalaji]

Summary

• Parse warp route fees from origin transaction logs by comparing ERC20 Transfer events (total tokens sent to router) vs SentTransferRemote event (net bridged amount)
• Display "Warp fee" and "Total sent" rows in the Warp Transfer Details card when fees are detected
• Only applies to EVM ERC20 token routes; native token routes and non-EVM chains are gracefully skipped

Changes

File	Description
src/features/messages/warpFees/types.ts	WarpFeeBreakdown type
src/features/messages/warpFees/fetchWarpFees.ts	Parse fees from tx receipt logs
src/features/messages/warpFees/useWarpFees.ts	React hook for fee fetching
src/features/messages/warpFees/fetchWarpFees.test.ts	Unit tests
src/features/messages/cards/WarpTransferDetailsCard.tsx	Display fee rows

How it works

1. Fetch origin tx receipt for EVM warp transfers
2. Parse SentTransferRemote(uint32,bytes32,uint256) to get net bridged amount
3. Parse ERC20 Transfer(from,to,value) events from sender → router for total tokens pulled
4. Warp fee = total transferred - sent amount
5. Only display when fee > 0

Test plan

• pnpm run typecheck — clean
• pnpm run lint — clean
• pnpm run test — 3 new tests pass, no regressions
• Manual: navigate to a warp transfer with fees, verify fee rows appear
• Manual: non-warp message shows no fee rows
• Manual: warp transfer with no fees shows no fee rows

🤖 Generated with Claude Code

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Note

Medium Risk
Adds new RPC-backed fee parsing by decoding origin transaction receipts and ERC20/router logs; incorrect assumptions about sender/router/token addresses or decimals could cause missing/incorrect fee display or extra RPC load. Changes are otherwise additive and gated to EVM ERC20 warp routes with graceful null fallbacks.

Overview
Warp transfers now surface bridge fees. The message details view fetches the origin transaction receipt for EVM ERC20 warp routes and computes a fee breakdown by comparing ERC20 Transfer totals into the router vs the router’s SentTransferRemote amount (with decimal/scale normalization).

When a non-zero fee is detected, WarpTransferDetailsCard shows new Warp fee and Total sent rows, backed by a new useWarpFees react-query hook and unit tests for the log parsing/decimal normalization helpers.

Also includes small formatting-only tweaks (imports/line wrapping) and minor CSS hex-case cleanup.

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Project	Deployment	Actions	Updated (UTC)
hyperlane-explorer	Ready	Preview, Comment	Mar 13, 2026 5:53pm

[paulbalaji]

@claude review

[claude]

Claude finished @paulbalaji's task in 1m 43s —— View job

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Review Complete

• Run code review analysis
• Post inline PR comments

Submitted a consolidated PR review with 2 inline suggestions:

1. useWarpFees.ts:17 — Add staleTime: Infinity to avoid redundant RPC refetches (tx receipts are immutable)
2. fetchWarpFees.ts:75 — Consider adding collateralAddressOrDenom to TokenArgsWithWireDecimals type for explicitness

Overall the feature looks solid — good fail-closed design, proper decimal normalization, and clean test coverage. Nothing blocking.

[claude]

Review Summary

Clean, well-structured feature. The fee parsing logic is sound — normalizing SentTransferRemote amounts back to native decimals via getWarpRouteAmountParts/getEffectiveDecimals is the right approach, and the fail-closed design (return null on any anomaly) is appropriate. The cursor bugbot issues from the earlier revision have been addressed.

Two minor items below worth considering; nothing blocking.

Nits

• The formatting-only changes (AppLayout, QuestionMarkIcon, MessageTable, WarpRouteVisualizationCard, Footer, Header, og.tsx, global.css) are fine but could've been a separate commit to keep the feature diff focused.

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