v3/languages changelog

Changes and planned updates to the v3/languages endpoints during the beta period.

These endpoints are in BETA. We will try to announce breaking changes here before they land, but cannot guarantee advance notice. Do not use these endpoints in production.

Changes since the initial beta release

This section will list dated changes to the API since the initial beta release.

22 April 2026

Breaking: renamed required_on_source / required_on_target — the feature dependency flags on /v3/languages/products have been renamed:

Old name	New name
required_on_source	needs_source_support
required_on_target	needs_target_support

Semantics are unchanged. Update any code that reads these fields.

Breaking: removed endpoints from /v3/languages/products — the endpoints array has been removed from each product object. The applicable endpoints are still described in the documentation for each product.

New: auto_detection feature — a new auto_detection feature has been added across multiple products to indicate whether a language can be auto-detected as the source. This is a source-only feature (needs_source_support: true, needs_target_support: false).

17 April 2026

Removed: /v3/languages/exceptions — this endpoint has been removed. We no longer have any language pairs where feature support differs from what can be predicted from the individual language objects, so the endpoint had no data to return. Remove any calls to this endpoint; the per-language features arrays from GET /v3/languages are sufficient to determine feature support for all pairs.

19 March 2026

Initial beta release.

Planned changes

The following changes are planned before general availability. They are not yet live.

---

New: language status field

Language objects will include a status field indicating availability:

{
  "lang": "xyz",
  "name": "Example Language",
  "usable_as_source": true,
  "usable_as_target": true,
  "features": [],
  "status": "stable"
}

Possible values: "stable", "beta", "early_access".

---

Breaking: features array replaced by dictionary

The features property on languages will change from a list of strings to an object (dictionary). Each key is a feature name; the value is an object with at least a status field.

Instead of:

{
  "lang": "de",
  "name": "German",
  ...
  "features": [
    "formality",
    "tag_handling"
  ]
}

the following schema will be used:

{
  "lang": "de",
  "name": "German",
  ...
  "features": {
    "formality": {"status": "stable"},
    "tag_handling": {"status": "stable"}
  }
}

Feature objects may include additional fields beyond status in a future update. To check whether a feature is supported for a language, check that the key exists in the features object.

---

New: include query parameter

GET /v3/languages will accept a new include query parameter. By default (no parameter), only generally available languages and features are returned. The parameter accepts the following values:

Value	Effect
beta	Includes languages and features in beta, in addition to stable
early_access	Includes languages and features in early access and beta, in addition to stable
external	Includes features that rely on external providers (orthogonal to stability level)

Values are composable via repeated parameters: ?include=beta&include=external.

This parameter also controls whether beta and external features appear in the features dictionary — see the features schema change above.

---

Breaking: rename product to resource

resource is a clearer name for what this is describing.

This involves the following changes:

• move the GET /v3/languages/products endpoint to GET /v3/languages/resources
• rename the GET /v3/languages query parameter product to resource

---

Breaking: rename custom_instructions feature to style_rules

The custom_instructions feature value on translate_text will be renamed to style_rules:

Current value	New value
custom_instructions	style_rules

Update any code that checks for "custom_instructions" in a language’s features array.

---

New: expanded Voice features

The voice product will expose a richer set of features in /v3/languages/products and per-language features arrays, details are still being worked out.

---

Possible additions

These are under consideration and may or may not land before GA.

• native_name field on language objects — the language’s name in that language (e.g. "Deutsch" for German).

---

Current beta state

For the current API contract, see the overview and the auto-generated reference pages linked there.