Grok 4.20 reasoning variant (0309 snapshot) - chain-of-thought reasoning with a 1M-token context window. Reasoning tokens are billed additively on top of completion tokens.
Test this model instantly in the Console Playground โ no code required
Copy usage instructions for Claude, ChatGPT, or other AI
| Token Type | Credits | USD Equivalent |
|---|---|---|
| Input Tokens | 2,323 | $1.55 |
| Output Tokens | 4,645 | $3.10 |
| Cached Tokens | 371.6 | $0.25 |
* 1,500 credits โ $1 (actual charges may vary based on usage)
curl -X POST "https://api.core.today/llm/grok/v1/chat/completions" \
-H "Content-Type: application/json" \
-H "Authorization: Bearer cdt_your_api_key" \
-d '{
"model": "grok-4.20-0309-reasoning",
"messages": [
{
"role": "user",
"content": "Summarize the attached report in 5 bullets."
}
],
"max_tokens": 1024
}'| Parameter | Type | Required | Default | Description |
|---|---|---|---|---|
model | string | Yes | - | Model ID, e.g. "grok-4.20-0309-reasoning". |
messages | array | Yes | - | Chat messages in OpenAI format (system/user/assistant roles). |
temperature | number | No | 0.7 | Sampling temperature (0-2). |
max_tokens | integer | No | 2048 | Maximum completion tokens. |
stream | boolean | No | false | Stream the response as server-sent events. |
OpenAI-compatible chat completion request
curl -X POST "https://api.core.today/llm/grok/v1/chat/completions" \
-H "Content-Type: application/json" \
-H "Authorization: Bearer cdt_your_api_key" \
-d '{
"model": "grok-4.20-0309-reasoning",
"messages": [
{
"role": "user",
"content": "Summarize the attached report in 5 bullets."
}
],
"max_tokens": 1024
}'POST /llm/grok/v1/chat/completions