GPT OSS 20B
OpenAI's open-weight, 20B-parameter reasoning model for low-latency, local, and agentic use cases — customizable, uncensored, and privacy-first on Venice.
Overview
What is GPT OSS 20B
GPT OSS 20B is OpenAI's medium-sized open-weight reasoning model, released in August 2025 with 21B parameters and 3.6B active parameters. Designed for low-latency and local deployment, it supports configurable reasoning effort, full chain-of-thought, tool use, and fine-tuning under the permissive Apache 2.0 license.
Running it privately on Venice
Running GPT OSS 20B on Venice ensures full sovereignty — your prompts never leave your control. With end-to-end encryption and execution in a Trusted Execution Environment (TEE), Venice guarantees zero retention and private inference. You get the full power of an open, uncensored model without surveillance or data leakage.
Assessment
Strengths and limitations
- Open weights under Apache 2.0: no copyleft restrictions, safe for commercial use and fine-tuning.
- Configurable reasoning effort (low/medium/high) for optimal latency and cost trade-offs.
- Full chain-of-thought visibility and agentic capabilities: web search, Python execution, and structured outputs.
- Optimized for local and edge deployment: runs on devices with as little as 16GB memory.
- Strong performance on reasoning, code, and multilingual tasks despite smaller size.
- Not uncensored: follows OpenAI’s safety policies by default, limiting certain use cases.
- Smaller active parameter count may limit depth of reasoning compared to larger models like gpt-oss-120b.
- No vision or multimodal input support: text-only model.
Capabilities
What it supports
- Tool use / function calling
- Vision (image input)
- Reasoning
- Web search
- Code-optimized
- Structured output (JSON schema)
- Audio input
- Video input
- Multiple image inputs
- Log probabilities
Specifications
Datasheet
- Maker
- OpenAI
- Released
- August 5, 2025
- Architecture
- Mixture of Experts (MoE)
- Parameters
- 21B total, 3.6B active
- Open weights
- Yes — Apache 2.0 license
- Context window
- 128K tokens
- Max output
- 32.768K tokens
- Capabilities
- Reasoning, Web search
- Privacy on Venice
- Private — zero retention
- Available on Venice since
- Mar 2026
- License
- Apache 2.0
API
Call it from your code
Venice exposes an OpenAI-compatible API. Point your base URL at Venice and pass the model id.
curl https://api.venice.ai/api/v1/chat/completions \
-H "Authorization: Bearer $VENICE_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "e2ee-gpt-oss-20b-p",
"messages": [{ "role": "user", "content": "Explain quantum tunneling simply." }]
}'Pricing
What it costs on Venice
Billed per token on Venice: $0.05 per 1M input tokens and $0.19 per 1M output tokens.
New Venice accounts include a free daily allowance and 500 welcome credits — no credit card required.
Alternatives
How it compares
| Model | Max context | Open weights | Price (Venice) | Strongest at |
|---|---|---|---|---|
| GPT OSS 20B | 128K tokens | Yes | $0.05 in · $0.19 out / 1M | Local reasoning & tool use |
| Google Gemma 4 31B Instruct | 256K tokens | Yes | $0.12 in · $0.36 out / 1M | Efficient instruction following |
| GLM 5.1 | 200K tokens | Yes | $1.10 in · $4.15 out / 1M | Multilingual reasoning |
| DeepSeek V4 Flash 0731 | 1M tokens | No | $0.17 in · $0.35 out / 1M | High-context throughput |
Open-weight, privacy-first model ideal for on-device and agentic use.
Use cases
What it is good for
- 01On-device AI agents requiring low latency and privacy.
- 02Customizable reasoning pipelines in regulated or offline environments.
- 03Fine-tuned domain-specific assistants for code, math, or research.
- 04Agentic workflows with tool use (web search, code execution) without cloud dependency.
- 05Privacy-first enterprise deployments where data sovereignty is mandatory.
Prompting
Getting better results
Use the 'reasoning_effort' parameter to balance speed and depth — 'low' for quick tasks, 'high' for complex reasoning.
Structure prompts to trigger tool use explicitly: 'Search the web for...' or 'Run Python to calculate...'.
Leverage full chain-of-thought for debugging — inspect intermediate steps in agentic workflows.
Fine-tune for niche domains where proprietary models lack specialization.
Version history
Larger variant with higher reasoning capacity.
Current — optimized for local and low-latency use.
FAQ
Frequently asked questions
GPT OSS 20B is OpenAI's open-weight, 21B-parameter mixture-of-experts language model released in August 2025. It supports configurable reasoning, tool use, and full chain-of-thought, designed for low-latency, local, and agentic deployments under the Apache 2.0 license.
Yes, GPT OSS 20B is open weights and released under the permissive Apache 2.0 license, allowing free use, modification, and commercial deployment. You can download and run it locally from Hugging Face or via Venice’s private API.
On Venice, GPT OSS 20B is billed per token: $0.05 per 1M input tokens and $0.19 per 1M output tokens. There is no subscription — you pay only for what you use.
Yes, GPT OSS 20B natively supports tool use including web search, Python code execution, and structured outputs, making it ideal for agentic workflows and autonomous tasks.
Yes, GPT OSS 20B is fully fine-tunable under the Apache 2.0 license, allowing developers to customize it for specific domains, tasks, or compliance requirements without restrictions.
GPT OSS 20B excels in agentic reasoning and tool use with configurable effort, while Gemma 4 31B offers stronger base instruction following. GPT OSS 20B is better for dynamic workflows; Gemma may suit static, efficient inference tasks.
No, GPT OSS 20B follows OpenAI’s safety policies by default and is not uncensored. However, its open weights allow developers to modify or fine-tune it for less restrictive behavior, subject to their own policies.
GPT OSS 20B supports a 128K-token context window and can generate up to 32.768K tokens in a single output, making it suitable for long-form reasoning and document processing.
Run GPT OSS 20B privately
No prompt logging. No data used for training.