Models

Each model has a display name, shown in the dashboard, and an API id. Send the API id as model in the body of POST /v1/systemone. When model is omitted, Drex uses drex-v2.0.

State limit and row limit are in tokens. The state limit covers the state alone. The row limit covers the state plus the longest question. See Limits.

The table documents the model catalog. Availability can differ by environment and API key, including during a staged release. GET /v1/models returns the models available to the API key used for that request, with each model's name (its API id, such as drex-v2.0), description, and release_date. The CLI alternatives are nace models and nace models --json, using the same API key and base URL. Aliases come after the versions, then retired ids. alias_for names the version that answers an alias or a retired id. It is null for a version.

For a finance example and image support, see Drex Max Finance.

Retired modelsCopy Anchor Link

A retired model has no fleet of its own. A request that names it is answered by a newer version at that version's price, and the response model reports the newer version. Stored usage still shows the retired id, its name and its price.

The retired ids above are now served by drex-max-v1.1, using its request limits and $0.03 per million input-token price. Existing clients can keep sending a retired id; new integrations should send the successor. The successor must be available to the caller. Historical usage keeps the original model's name and price.

GET /v1/models lists a retired id after the aliases, with alias_for set to the version that answers it and a description that starts with Retired on.

Versions and the drex-latest aliasCopy Anchor Link

An API id with a version number, such as drex-v2.0, is pinned while that version is active. Retired ids are forwarded as listed above.

drex-latest is an alias. It currently points to drex-v2.0. It moves to a newer version only on a date announced in advance, so a request that sends it can change model and price on that date.

• Send a pinned id to control when you change versions. You move to a new version by changing the id in your code.
• The response model reports the pinned version that answered, never the alias. A request that sends drex-latest today gets drex-v2.0 as model.
• A request is billed at the price of the version in the response model.

Accepted valuesCopy Anchor Link

• A registered id available to your API key is answered by that model.
• drex-latest is answered by the version it points to.
• A retired id is answered by the version listed under Retired models.
• The legacy name nacedm-latest is answered like drex-latest.
• Any other value returns 422 invalid_request_error with path model and a message that starts with unknown model "<value>"; use and suggests public active model ids and aliases in that environment. These suggestions omit retired ids and models offered only through staff preview; GET /v1/models remains the full catalog for your key. See Errors for a full example.
• A registered id that is unavailable to your API key in that environment returns 422 invalid_request_error with path model and a message that starts with model "<id>" is not available yet; use and suggests available alternatives.

Prices are per input token. Output tokens are not billed. See Pricing.

What changed in Drex 2.0Copy Anchor Link

drex-v2.0 is a mixture of experts with 3B active parameters, at $0.03 per million input tokens. It reads states up to 131,072 tokens, and the state plus the longest question up to 262,144. A longer request is refused, as on every model; Drex 2.0 never hands a request to another model.