gpt-oss-20b
Fireworks AI/🇺🇸 US/chat10% off
GPT-OSS-20B is OpenAI's lightweight open-weight model with 21.5 billion total parameters (3.6 billion active, Mixture-of-Experts). Optimized for lower latency and local or specialized use cases including agentic tasks, chain-of-thought reasoning, and web browsing. Released under Apache 2.0 license.MoreLess
Which id to call
fireworks/gpt-oss-20bThis exact deployment on Fireworks AI, with no routing and no failover. Send it as the model field.
Input /1M
$0.06
$0.07 list
$0.03 cached
Output /1M
$0.27
$0.30 list
4.3x input
Context
131K
66K output
Added
Aug 2025
chat
Capabilities 2/8
Provider rates
What gpt-oss-20b costs
Provider prices per 1M tokens, updated August 25, 2026.moreless
These are the upstream provider rates. Pay as you go adds 5%, or 0% if you bring your own keys, and there is no per-request fee. Prompt caching and routing change what you pay against these rates, not the rates themselves.
This endpoint is discounted. List is $0.07 per 1M input and $0.30 per 1M output, and the rates below are what you pay. The discount applies to every request on this endpoint, with nothing to claim or enter.
Input /1M
$0.06
$0.07 list
Output /1M
$0.27
$0.30 list
Cache write /1M
-
Cache read /1M
$0.03
What a workload costs
- 100K input + 10K output
- $0.0090
- 1M input + 100K output
- $0.0900
- 10M input + 1M output
- $0.90
At the rates above, before caching. A cache read costs $0.03 per 1M, so repeated context lands under these figures.
OpenAI compatible
Call it in three lines
Change the base url, use your Requesty key, set the model to fireworks/gpt-oss-20b. Existing OpenAI SDK code needs no other edit.
123456789101112131415from 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-20b", messages=[ {"role": "user", "content": "Explain quantum computing in one paragraph."}, ], ) print(response.choices[0].message.content)
Reference
Specs and data terms
What the catalog reports for this deployment, and what the provider does with the traffic.
Released 2025-08-05
Benchmark scores
Benchmarks measure the model, not this endpoint, so they are the same wherever these weights are served.
Artificial Analysis Coding Index: a composite of coding evaluations including LiveCodeBench, SciCode and Terminal-Bench.
Graduate-level physics, chemistry & biology questions designed to resist Googling.
Artificial Analysis Intelligence Index: a composite of multiple evaluations measuring overall model capability.
Scores from official model cards, Artificial Analysis and public leaderboards. They measure specific skills and do not capture every aspect of model quality, so test on your own workload.
Same provider
More from Fireworks AI
Newest first, on the same provider and the same key.
Reference
gpt-oss-20b questions
How much does gpt-oss-20b cost?
gpt-oss-20b is priced at $0.06 per million input tokens and $0.27 per million output tokens when accessed via Requesty. Those figures include a 10% discount on this endpoint, off a list rate of $0.07 per million input tokens and $0.30 per million output tokens. Prompt caching is supported, which can cut effective input cost by up to 90% on repeated context. Those are the upstream provider rates: pay as you go adds 5% on top, or 0% if you bring your own provider keys.
What is the context window of gpt-oss-20b?
gpt-oss-20b 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-20b perform on benchmarks?
gpt-oss-20b scores 89.3% on Math Index, 89.3% on AIME 2025, 77.7% 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-20b do?
gpt-oss-20b supports 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-20b 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-20b". The Quickstart above shows Python, JavaScript and cURL snippets.
Can I run gpt-oss-20b through Requesty?
Yes. gpt-oss-20b 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-20b", and requests are routed to the upstream provider with automatic failover. The same key gives you 600+ other models too.
Call gpt-oss-20b through one endpoint
One key for this endpoint and 600+ other models. No markup on provider prices, automatic failover, caching built in.