LLM models
Grok 4.3
On this page
Grok 4.3 — frontier reasoning and generation through one API.
| modelId | grok-4-3 |
| Modality | text |
| Pricing | See this model on the Pricing page for the current per-call price (with your markup). |
Operations
| Operation | modelId | Endpoint | Required input |
|---|---|---|---|
| Default | grok-4-3 | POST /api/v1/generate | prompt |
| Poll task | — | GET /api/v1/task/{id}?model=grok-4-3 | — |
Input parameters
| Field | Type | Required | Values / example |
|---|---|---|---|
| prompt | string | Yes | Text value (example: Explain, in three vivid sentences, why some deep-sea creatures glow in the dark.) |
| structured_outputs | boolean | No | Generate structured outputs (true/false) (example: false) |
| reasoning_effort | string | No | Control reasoning depth: Low for faster responses, High for deeper analysis (options: Low | Medium | High | XHigh) (example: Medium) |
| stream | boolean | No | Send true to receive the reply as an event stream (Content-Type: text/event-stream). Omit it and you get a single JSON response — streaming is opt-in on this endpoint. (true/false) (example: true) |
| images | string[] | No | Up to 4 images per message — JPEG, PNG, GIF or WebP, 5 MB each. Send each one as a data: URL or an https URL. Images are billed as input tokens. (image URL) |
| system | string | No | System instruction for the model. Defaults to "You are Grok 4.3, developed by Grok." when omitted. |
| messages | array | No | A conversation instead of a single prompt: an array of { "role", "content" } objects, where role is user, assistant or system. Send the whole conversation — we do not limit how many messages it has, and we do not drop old ones; the model's context window is the limit. Send prompt or messages, not both. Do not flatten a conversation into one prompt with "User:" / "Assistant:" labels — the model reads that as a single message, and a model using web search then searches for the whole block instead of your question. |
Example request
bash
curl -X POST https://you.bot/api/v1/generate \
-H "Authorization: Bearer $YOUBOT_API_KEY" \
-H "Content-Type: application/json" \
-d '{"modelId":"grok-4-3","input":{"prompt":"Explain, in three vivid sentences, why some deep-sea creatures glow in the dark.","structured_outputs":false,"reasoning_effort":"Medium","stream":true,"images":["data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAIAAAD91JpzAAAAFklEQVR4nGP8z4AATAxIHFQeMg8OAgB1yQIDpk8YwwAAAABJRU5ErkJggg=="]}}'