Models
The models Drex serves, their API ids, prices, and token limits.
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-v1.5.
| Model | API id | Released | Price per 1M input tokens | State limit | Row limit | Notes |
|---|---|---|---|---|---|---|
| Drex 1.0 | drex-v1.0 | 2026-09-24 | $0.04 | 32,768 | 32,768 | |
| Drex 1.5 | drex-v1.5 | 2026-09-28 | $0.05 | 131,072 | 139,264 | drex-latest |
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.
GET /v1/models returns the same models for an API key, with each model's name, description, and release_date. 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.
Retired models
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.
| Model | API id | Retired | Served by |
|---|---|---|---|
| Drex 1.1 | drex-v1.1 | 2026-09-28 | Drex 1.5 (drex-v1.5) |
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 alias
An API id with a version number, such as drex-v1.0, is pinned. A pinned id is always answered by that version at that version's price.
drex-latest is an alias. It currently points to drex-v1.5. 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. On 2026-09-27 it moved from drex-v1.0 to drex-v1.1. On 2026-09-28 it moved from drex-v1.1 to drex-v1.5.
- 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
modelreports the pinned version that answered, never the alias. A request that sendsdrex-latesttoday getsdrex-v1.5asmodel. - A request is billed at the price of the version in the response
model.
Accepted values
- A registered id from the table is answered by that model.
drex-latestis answered by the version it points to.- A retired id is answered by the version listed under Retired models.
- Any other name that starts with
drex-ornacedm-is answered bydrex-v1.5. - Any other value returns
422 invalid_request_errorwith pathmodeland messageunknown model "<value>". See Errors. - A registered id that is not enabled yet returns
422 invalid_request_errorwith pathmodeland messagemodel "<id>" is not available yet.
Both messages end with ; use and the ids that are available, versions first and then aliases, for example ; use "drex-v1.0", "drex-v1.5" or "drex-latest". Retired ids are not suggested.
Prices are per input token. Output tokens are not billed. See Pricing.
What changed in Drex 1.5
drex-v1.5 reads states up to 131,072 tokens, up from 32,768. Requests whose state is over 8,192 tokens go to its long pool, so it no longer hands them to drex-v1.0. See Limits.