Fireworks OpenAI gpt-oss-20b (Global)

Welcome to the gpt-oss series, OpenAI's open-weight models designed for powerful reasoning, agentic tasks, and versatile developer use cases. gpt-oss-20b is used for lower latency, and local or specialized use-cases.

Provider: All OpenAI models | Fireworks AI

API Endpoint

https://api.fireworks.ai/inference/v1/chat/completions

Quick Start (Python)

Install: pip install openai

from openai import OpenAI

client = OpenAI(
    api_key="your-fireworks-api-key",
    base_url="https://api.fireworks.ai/inference/v1",
)

response = client.chat.completions.create(
    model="accounts/fireworks/models/gpt-oss-20b",
    messages=[
        {"role": "user", "content": "Hello, how are you?"},
    ],
    max_tokens=1024,
    temperature=0.7,
)

print(response.choices[0].message.content)

Additional examples: Basic invoke, Streaming

Supported Parameters

Parameter	Type	Description
max_tokens	integer	Maximum tokens to generate. (≥1)
temperature	float	Controls randomness. (0–2) Default: 0.7.
top_p	float	Nucleus sampling threshold. (0–1) Default: 1.
stream	boolean	Stream response chunks as they are generated. Default: false.
stop	string	Stop sequence or array of stop sequences.

Feature Guides

Serverless Inference

Pay per token for public open models without managing GPU deployments.

Documentation

OpenAI Compatibility

Use OpenAI-compatible client libraries by changing the API base URL.

Documentation