[rafa-stacks]

Adds sort_by (receipt_time or fee) and order (asc or desc) to GET /extended/v3/mempool/transactions, so pending transactions can be listed by receipt time or total fee in either direction; the default stays newest first. A cursor only pages the sort_by it was returned for, but works in either order.

[codecov]

Codecov Report

❌ Patch coverage is 97.41379% with 3 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/api/routes/v3/mempool.ts	93.93%	2 Missing ⚠️
.../1779800000032_mempool-txs-fee-rate-tx-id-index.ts	95.83%	0 Missing and 1 partial ⚠️

📢 Thoughts on this report? Let us know!

[Copilot]

🟡 Changes recommended

Fee cursors above PostgreSQL’s signed bigint maximum still pass validation and cause HTTP 500 instead of being rejected with HTTP 400.

1 open issue

• Reject fee cursors exceeding PostgreSQL bigint range · New

What changed in this PR

Adds highest-total-fee-first sorting to GET /extended/v3/mempool/transactions, while preserving receipt-time sorting as the default.

Changes:

• Adds sort_by=fee with order-specific cursors and mismatch validation.
• Extends keyset pagination and adds a partial index for fee ordering.
• Tests fee ordering, tie-breaking, pagination, filtering, and invalid parameters.

File	Description
tests/​api/​mempool/​mempool-v3.test.ts	Tests fee sorting and cursor behavior.
src/​datastore/​v3/​pg-store-v3.ts	Supports fee-based ordering and keyset pagination.
src/​api/​schemas/​v3/​params.ts	Defines and documents supported sort orders.
src/​api/​schemas/​v3/​cursors.ts	Adds the fee-prefixed list cursor format.
src/​api/​routes/​v3/​mempool.ts	Accepts sort selection and rejects mismatched cursors.
migrations/​1779800000032_mempool-txs-fee-rate-tx-id-index.ts	Adds a partial fee-and-transaction-ID index for pending transactions.

_{Review effort: Balanced}

[Copilot]

🟢 Approval recommended

The mempool fee-sorting and pagination changes have no active review issues.

No open issues 🎉

1 resolved since last review

• Reject fee cursors exceeding PostgreSQL bigint range

_{Review effort: Balanced}

[Copilot]

🟢 Approval recommended

No active review issues block the mempool sorting and pagination changes.

No open issues 🎉

_{Review effort: Balanced}