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Fireworks AI

gpt-oss-120b

GPT-OSS-120B is OpenAI's open-weight large language model with 116 billion total parameters (5.1 billion active, Mixture-of-Experts). Designed for high-performance reasoning, agentic tasks, function calling, and general-purpose applications. Supports configurable reasoning depth and chain-of-thought. Released under Apache 2.0 license.

ReasoningTool callingCaching
CompareDocs

Specifications

Context window131K tokens
Max output66K tokens
API typechat
AddedMay 27, 2026
Model IDfireworks/gpt-oss-120b
Data retentionNo
Used for trainingNo
Provider location🇺🇸 US
Privacy policyFireworks Privacy Policy→

Benchmarks

Released 2025-08-05
Coding Indexcoding
30.4%

Artificial Analysis Coding Index — a composite of coding evaluations including LiveCodeBench, SciCode and Terminal-Bench.

GPQA Diamondreasoning
78.2%

Graduate-level physics, chemistry & biology questions designed to resist Googling.

Intelligence Indexreasoning
23.8%

Artificial Analysis Intelligence Index — a composite of multiple evaluations measuring overall model capability.

Scores are sourced from official model cards, Artificial Analysis, and public leaderboards. Benchmarks measure specific skills and do not capture every aspect of model quality. Always test on your own workload.

Pricing

Input / 1M
$0.15
Output / 1M
$0.60
Cache write
N/A
Cache read / 1M
$0.01
Estimated cost
100K input + 10K output$0.0210
1M input + 100K output$0.21
10M input + 1M output$2.10

Requesty charges exactly what the upstream provider charges, no markup, no per-request fees. Prompt caching and smart routing can reduce effective cost by 30-80%.

Quickstart

Drop-in compatible with the OpenAI SDK. Change the base URL, swap in your Requesty API key, and set the model to fireworks/gpt-oss-120b.

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from openai import OpenAI

client = OpenAI(
    api_key="YOUR_REQUESTY_API_KEY",
    base_url="https://router.requesty.ai/v1",
)

response = client.chat.completions.create(
    model="fireworks/gpt-oss-120b",
    messages=[
        {"role": "user", "content": "Explain quantum computing in one paragraph."},
    ],
)

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

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minimax-m3
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kimi-k2.7-code
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gpt-oss-20b
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Frequently asked questions

How much does gpt-oss-120b cost?
gpt-oss-120b is priced at $0.15 per million input tokens and $0.60 per million output tokens when accessed via Requesty. Prompt caching is supported, which can cut effective input cost by up to 90% on repeated context. Requesty charges exactly what the upstream provider charges, we don't add markup.
What is the context window of gpt-oss-120b?
gpt-oss-120b has a context window of 131K tokens, with a maximum output of 66K tokens per response. That's roughly 175 words of input you can fit in a single prompt.
How does gpt-oss-120b perform on benchmarks?
gpt-oss-120b scores 93.4% on Math Index, 93.4% on AIME 2025, 87.8% on LiveCodeBench. See the full benchmark chart above for results across MMLU Pro, GPQA Diamond, SWE-Bench Verified, HumanEval, MATH, AIME, MMMU, and LiveBench.
What can gpt-oss-120b do?
gpt-oss-120b supports tool calling, extended reasoning, prompt caching. You can call it through any OpenAI-compatible client by pointing base_url to Requesty.
How do I use gpt-oss-120b with the OpenAI SDK?
Install the OpenAI SDK, set base_url to "https://router.requesty.ai/v1", set your API key to your Requesty key, and set the model to "fireworks/gpt-oss-120b". The Quickstart above shows Python, JavaScript and cURL snippets.
Can I run gpt-oss-120b through Requesty?
Yes. gpt-oss-120b runs through Requesty's OpenAI-compatible API, served from Fireworks AI. You do not host the model yourself: point base_url at Requesty, set the model to "fireworks/gpt-oss-120b", and requests are routed to the upstream provider with automatic failover. The same key gives you 400+ other models too.

Access gpt-oss-120b through Requesty

One API key, 400+ models, OpenAI-compatible. No markup on provider prices, automatic failover, and smart caching built-in.

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