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grok-3-fast-beta API pricing & access

grok-3-fast-beta API pricing: $5.5 per 1M tokens. grok-3-fast-beta. Supports text input and text output. Listed specifications follow public…

grok-3-fast-beta API access

grok-3-fast-beta. Supports text input and text output. Listed specifications follow public vendor documentation. Available features and limits depend on the selected serving channel.

Compare supported API endpoints and capabilities, then access grok-3-fast-beta through the unified API gateway.

Category
text
Context length
131072 tokens
Supported APIs
OpenAI Chat Completions API, OpenAI Responses API, Anthropic Messages API
API endpoints
POST /v1/chat/completions, POST /v1/responses, POST /v1/messages
Input modalities
text
Output modalities
text
Capabilities
function calling, structured output

grok-3-fast-beta API pricing

Base input price
$5.5 per 1M tokens
Base output price
$27.5 per 1M tokens

Base prices are shown in USD before group-specific adjustments. Open the live pricing page for current access-group prices.

About grok-3-fast-beta

grok-3-fast-beta is a retained historical Grok text catalog name. A vendor management-API example lists it among Grok 3 aliases, establishing historical context rather than current availability or a pinned checkpoint.

Fast and Beta do not guarantee platform speed, served version or reasoning mode. Check returned model identity, request structure and tool support and regression-test existing cases; vendor migration behavior is separate from route evidence. Official reference, checked 2026-10-14.

Use cases and prompting

  1. Define extraction fields and missing-data rules and inspect complete response structure and facts.
  2. Retain old requests and expected outputs and test success, refusals, tool errors and streaming completion.
  3. Confirm route schemas for tools or structured output and retain actual tool results; compare performance with fixed samples and measured timing.
  4. See grok-4.3 for a related catalog entry. Confirm the version and mode, and follow the API documentation.

How to call grok-3-fast-beta

grok-3-fast-beta is served through tbuy's unified gateway. Existing OpenAI or Anthropic SDK code keeps working: point base_url at https://modelsok.com and use your tbuy API key.

curl (OpenAI-compatible)

curl https://modelsok.com/v1/chat/completions \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "grok-3-fast-beta", "messages": [{"role": "user", "content": "Hello"}]}'

Python (openai SDK)

from openai import OpenAI

client = OpenAI(base_url="https://modelsok.com/v1", api_key="YOUR_API_KEY")
response = client.chat.completions.create(
    model="grok-3-fast-beta",
    messages=[{"role": "user", "content": "Hello"}],
)
print(response.choices[0].message.content)

Python (anthropic SDK)

from anthropic import Anthropic

client = Anthropic(base_url="https://modelsok.com", api_key="YOUR_API_KEY")
message = client.messages.create(
    model="grok-3-fast-beta",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Hello"}],
)
print(message.content[0].text)

Frequently asked questions about grok-3-fast-beta

What is grok-3-fast-beta?

grok-3-fast-beta. Supports text input and text output. Listed specifications follow public vendor documentation. Available features and limits depend on the selected serving channel.

How do I call grok-3-fast-beta?

Create an API key with access to grok-3-fast-beta, then use the exact model ID and a supported endpoint from the API access section. Request fields depend on the selected endpoint.

How is grok-3-fast-beta priced?

Pricing depends on the selected provider group and the model billing unit. Refer to the current input, output, request, or media prices in the pricing section.

What is the context window of grok-3-fast-beta?

The model catalog lists a context window of 131072 tokens. Check the selected endpoint for request limits.

How should I evaluate grok-3-fast-beta for my project?

Start with the use cases and prompting guidance on this page, then evaluate the model with representative inputs from your project.

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