> ## Documentation Index
> Fetch the complete documentation index at: https://docs.rails.wayex.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Changelog

> Dated API changes, with the migration step for anything that breaks an existing integration.

Changes that affect what you send us or what we send back. Entries are newest first. A **Breaking**
entry needs a code change before you take the release; everything else is additive.

<Note>
  Breaking changes are announced here and applied to both environments. Exercise them in the
  [sandbox](https://api.sandbox.rails.wayex.com) — it runs fully simulated provider rails — before
  updating your production integration.
</Note>

## 2026-07-25

### Breaking · you name the settlement network when buying stablecoin

`POST /v1/treasury/conversion-quotes` now **requires `settlementNetwork` when `sourceAsset` is
`"AUD"`**. Wayex no longer selects a chain for that direction.

The network you name is the chain the purchased stablecoin is delivered onto, so it is the chain
your account then holds the balance on and the chain you can withdraw it on. That is your decision,
not ours, and there is no default and no fallback behind it.

```json theme={null}
{
  "sourceAsset": "AUD",
  "destinationAsset": "USDC",
  "settlementNetwork": "base",
  "sourceAmount": "1000.00",
  "externalReference": "quote-10027"
}
```

**Migration.** Add `settlementNetwork` to every AUD-to-stablecoin quote request. Choose from the
`runtimeCapabilities` entries on `GET /v1/treasury`, and choose a chain your account can actually
withdraw on. Omitting it now fails with `400` `settlement_network_required` on the
`settlementNetwork` parameter.

Two refusals you should treat as "pick a different chain", not as transient errors:

* `400` `unsupported_asset_network` — the asset does not settle on that chain, or Wayex cannot
  receive it there. This is now checked before your account's enabled pairs, so an unwired chain
  fails here rather than with `422` `asset_network_unavailable`. A pair that is wired but not
  enabled for your account still returns the `422`.
* `409` `conversion_route_conflict` — Wayex has a settlement route pinned for that asset and you
  named a different chain. This check is unchanged, but it is now reachable on every AUD-to-stablecoin
  quote, because previously nobody sent the field. If a route is pinned for your account, name
  exactly that chain.

**Not affected: stablecoin to AUD.** That direction is unchanged. `settlementNetwork` stays optional
there, Wayex still routes from the chains your account holds the balance on, and a supplied value is
still only an override. Do not make the field mandatory across both directions in your client.

See [Choosing the settlement network](/treasury/conversions-and-withdrawals#choosing-the-settlement-network).

### Breaking · free-form maps reject a reserved key

`metadata` on customers and counterparties, and `partyContext`, `businessIdentity`, and `glMapping`
on Treasury requests, now refuse the reserved key `@@wxtype` and any `@@wxtype.esc…` variant, with
`400` `invalid_request`. Nothing is written, including on a `PATCH` that would otherwise merge. These
keys were previously accepted.

**Migration.** Only integrations that happen to use that exact key name are affected. Near misses
such as `wxtype`, `@@wxtypes`, and `my@@wxtype` remain ordinary keys. See
[Reserved metadata key](/errors#reserved-metadata-key).

### New hold reason · `withdrawal_network_not_held`

A stablecoin withdrawal on a network your account has no credited deposit and no settled conversion
for is now accepted as `held` with `statusReason` `withdrawal_network_not_held`, instead of
proceeding. The source debit is reserved and nothing is sent until Wayex releases it.

Retrying will not clear it: withdraw on a network you have funded, or convert onto that network
first. The withdrawal preview does not test this restriction, so an unheld network previews cleanly
with `canProceed` true and is held on create — treat the create response as authoritative. See
[Withdrawals on a network you do not hold](/treasury/conversions-and-withdrawals#withdrawals-on-a-network-you-do-not-hold).