You can add, update, or remove fees on a locked trade through the Molecule v2 Fees API. You do not need to unlock the trade first, and you do not need override_lock on the fee request.

What lock does and does not cover

A lock stops most trade edits in the app (amend, void, split, transfer, and similar). In the app UI, fees on a locked trade stay read-only. To change fees by hand in the app, unlock the trade first. See How to Lock/Unlock Trades and How to Enter Fee Information.

The v2 Fees API is different. If your API user can already correct fees on unlocked trades, the same fee endpoints work when the trade is locked. List fees with GET /api/v2/fees?trade_id=X. For create, update, and delete, use the same v2 Fees API calls you already use on an unlocked trade. Do not invent other paths.

override_lock and Edit Trade Status

override_lock is for trade updates (amend and similar), not for adding, updating, or removing fees.

Edit Trade Status is the permission used to lock and unlock a trade (and for override_lock on trade updates). It is not what fee create/update/delete checks. Fee calls use the same permission you already need to change fees on an unlocked trade.

Lock and unlock via API is a separate trade action: PATCH /api/v2/trades/lock (bulk). You do not call that to change fees.

Related articles: How to Lock/Unlock Trades; An Exchange Trade Came In Wrong: Fixing Book, Trader, Fees, and Specs; How to Enter Fee Information; Getting Started with Molecule API.