Is Grok 3 available through the direct xAI API?
No—not as a distinct API model. xAI’s retirement notice says grok-3 was retired effective May 15, 2026 at 12:00 PM PT. Requests using that slug still resolve, but are automatically redirected to grok-4.3. A successful response to grok-3 therefore does not mean Grok 3 is still serving the request. (docs.x.ai)
The notice recommends changing the request’s model field to grok-4.3 explicitly. That makes the model choice clear rather than relying on the redirect. It also avoids mistaking the old slug for the model you are using. (docs.x.ai)
Send a request to the documented replacement
The xAI quickstart shows how to create an account at the xAI Console, add API credits, create an API key, and send a request to the Responses API. Its example uses POST https://api.x.ai/v1/responses, a Bearer-token authorization header, and the model and input fields. The example below uses grok-4.3, the replacement named in the retirement notice. (docs.x.ai)
export XAI_API_KEY="your_api_key"
curl https://api.x.ai/v1/responses \
-H "Authorization: Bearer $XAI_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "grok-4.3",
"input": "Explain what an API is in one sentence."
}'
A successful Responses API result includes a status and an output array containing the model’s response. Check that status is completed; the API reference also lists in_progress and incomplete as possible statuses. (docs.x.ai)
Check before deploying
- Model behavior: xAI documents Grok 4.3 as supporting text and image input, function calling, and structured outputs. Confirm the listed capabilities meet your application’s needs. (
docs.x.ai) - Cost: The retirement notice says requests redirected from
grok-3are billed at Grok 4.3 rates: US$1.25 per 1 million input tokens and US$2.50 per 1 million output tokens. The Grok 4.3 model page lists the same input and output rates. (docs.x.ai) - Limits: Check the xAI Console for the limits applicable to your team and model before estimating capacity. (
docs.x.ai)
Bottom line: Grok 3 is retired on the direct xAI API. Replace grok-3 with grok-4.3 explicitly and validate the replacement’s capabilities, limits, and cost for your workload. (docs.x.ai)