--- title: Union Alpha API | Text Generation | ModelsLab description: Build with Union Alpha API by Stealth. Text generation, chat, code, and reasoning. Plans from $21/month. url: https://modelslab.com/models/stealth/stealth-union-alpha.md canonical: https://modelslab.com/models/stealth/stealth-union-alpha type: product component: Playground/LLM/Index generated_at: 2026-09-17T19:17:26.240333Z --- Union Alpha --- [LLMs.txt](https://modelslab.com/models/stealth/stealth-union-alpha/llms.txt) [.md](https://modelslab.com/models/stealth/stealth-union-alpha.md) Union Alpha --- Choose a prompt below to get started or type your own message Explain quantum computing in simple terms Write a Python function to sort a list Create a marketing email for a SaaS product Compare REST vs GraphQL APIs images and text files Send ### Union Alpha stealth stealth-union-alpha Copy model ID PricingInput $0.00 / 1M tokens Output $0.00 / 1M tokens API EndpointsOpenAI Compatible `https://modelslab.com/api/v7/llm/chat/completions`Endpoint Anthropic Compatible `https://modelslab.com/api/v7/llm/v1/messages`Messages `https://modelslab.com/api/v7/llm/v1/messages/count_tokens`Count Tokens `https://modelslab.com/api/v7/llm/v1/models`Models Use with Claude Code cURL Example ParametersSystem MessageYou are a helpful AI assistant specialized in providing accurate and detailed responses. Temperature0.7 Max Tokens1000 Top P0.9 Frequency Penalty0 Presence Penalty0 Model Info Support Looking for something different? --- Models that trade off differently against the one you are viewing ### Better quality Newer flagship models that generally produce stronger results. [![GPT 5.2](https://images.modelslab.sh/?Image=https://assets.modelslab.ai/generations/2bdd00f4-1692-49d8-a562-72cb1753d0ff.png)](https://modelslab.com/models/openai/gpt-5.2)[OpenAI](https://modelslab.com/models/openai) [GPT 5.2](https://modelslab.com/models/openai/gpt-5.2) [![GPT 5.1](https://images.modelslab.sh/?Image=https://assets.modelslab.ai/generations/fad83520-47a8-4059-b4b9-b32adf4d0be7.png)](https://modelslab.com/models/openai/gpt5.1)[OpenAI](https://modelslab.com/models/openai) [GPT 5.1](https://modelslab.com/models/openai/gpt5.1) [![Gemini 3 Pro Preview](https://images.modelslab.sh/?Image=https://assets.modelslab.ai/generations/1846e76f-9d5c-4a35-a43a-82db45b7bb8b.png)](https://modelslab.com/models/google/gemini-3-pro-preview)[Google](https://modelslab.com/models/google) [Gemini 3 Pro Preview](https://modelslab.com/models/google/gemini-3-pro-preview) [![GPT-5.1-Codex-Max](https://images.modelslab.sh/?Image=https://assets.modelslab.ai/generations/06356c4c-df09-4ccb-a5c0-629da670f75b.png)](https://modelslab.com/models/openai/gpt-5.1-codex-max)[OpenAI](https://modelslab.com/models/openai) [GPT-5.1-Codex-Max](https://modelslab.com/models/openai/gpt-5.1-codex-max) ### Lower cost per run Open-source models we host, unlimited on the $149/month plan. [Modelslab: Custom LLM Popular](https://modelslab.com/models/modelslab/uncensored-chat)[ModelsLab](https://modelslab.com/models/modelslab) [Modelslab: Custom LLM](https://modelslab.com/models/modelslab/uncensored-chat) Related Models --- Discover similar models you might be interested in [View all LLM Models](https://modelslab.com/models?feature=llmaster) [#### OpenAI/OpenAI: GPT-4 openai-gpt-4 From $45.00/M tokens](https://modelslab.com/models/openai/openai-gpt-4) [#### Meta/Meta: Muse Glimmer 30B (batch) meta-muse-glimmer-30b-batch From $0.46/M tokens](https://modelslab.com/models/meta/meta-muse-glimmer-30b-batch) [#### Cohere/Cohere: Command R+ (08-2024) cohere-command-r-plus-08-2024 From $6.25/M tokens](https://modelslab.com/models/cohere/cohere-command-r-plus-08-2024) [#### Qwen/Qwen3.5 9B FP8 Qwen-Qwen3.5-9B From $0.13/M tokens](https://modelslab.com/models/Qwen/Qwen-Qwen3.5-9B) [#### Anthropic/Anthropic: Claude Opus Latest anthropic-claude-opus-latest From $15.00/M tokens](https://modelslab.com/models/anthropic/anthropic-claude-opus-latest) [#### Mistral AI/Mistral: Codestral 2508 mistralai-codestral-2508 From $0.60/M tokens](https://modelslab.com/models/mistralai/mistralai-codestral-2508) [#### Amazon/Amazon: Nova Premier 1.0 amazon-nova-premier-v1 From $7.50/M tokens](https://modelslab.com/models/amazon/amazon-nova-premier-v1) [#### Google/Gemma-2 Instruct (27B) google-gemma-2-27b-it From $0.65/M tokens](https://modelslab.com/models/google/google-gemma-2-27b-it) [#### Qwen/Qwen3.5 35B A3b Qwen-Qwen3.5-35B-A3B Free](https://modelslab.com/models/Qwen/Qwen-Qwen3.5-35B-A3B) [#### Qwen/Qwen: Qwen3 Coder Next qwen-qwen3-coder-next From $0.46/M tokens](https://modelslab.com/models/qwen/qwen-qwen3-coder-next) [#### ByteDance Seed/ByteDance Seed: Seed 1.6 Flash bytedance-seed-seed-1.6-flash From $0.19/M tokens](https://modelslab.com/models/bytedance-seed/bytedance-seed-seed-1.6-flash) [#### Mistral AI/Mistral: Mistral Nemo mistralai-mistral-nemo From $0.02/M tokens](https://modelslab.com/models/mistralai/mistralai-mistral-nemo) [#### Qwen/Qwen2.5-VL (72B) Instruct Qwen-Qwen2.5-VL-72B-Instruct From $4.97/M tokens](https://modelslab.com/models/qwen/Qwen-Qwen2.5-VL-72B-Instruct) [#### Qwen/Qwen: Qwen-Plus qwen-qwen-plus From $0.52/M tokens](https://modelslab.com/models/qwen/qwen-qwen-plus) [#### DeepSeek/DeepSeek-R1 deepseek-ai-DeepSeek-R1-Distill-Llama-70B From $2.00/M tokens](https://modelslab.com/models/deepseek/deepseek-ai-DeepSeek-R1-Distill-Llama-70B) [#### Mistral AI/Mistral: Saba mistralai-mistral-saba From $0.40/M tokens](https://modelslab.com/models/mistralai/mistralai-mistral-saba) [#### Sakana/Sakana: Fugu Max sakana-fugu-max From $4.00/M tokens](https://modelslab.com/models/sakana/sakana-fugu-max) [#### Anthropic/Anthropic: Claude Opus 4.7 anthropic-claude-opus-4.7 From $15.00/M tokens](https://modelslab.com/models/anthropic/anthropic-claude-opus-4.7) About Union Alpha --- Union Alpha is a multimodal model built for research, coding, and agentic workflows, while delivering frontier-level performance across a broad range of general-purpose tasks. Union Alpha is a stealth model.... ### Technical Specifications Model IDstealth-union-alpha CategoryLLM Models TaskText Generation AddedSeptember 16, 2026 ### Key Features - Chat completion and multi-turn conversation API - Streaming response with token-by-token output - Function calling and tool use support - System prompts and role-based messaging - JSON mode and structured output ### Quick Start Integrate Union Alpha into your application with a single API call. Get your API key from the [pricing page](https://modelslab.com/pricing) to get started. PythonJavaScriptcURLPHP ``` import requests import json url = "https://modelslab.com/api/v7/llm/chat/completions" headers = { "Content-Type": "application/json" } data = { "model_id": "stealth-union-alpha", "messages": [ { "role": "user", "content": "Hello!" } ], "max_tokens": 1000, "key": "YOUR_API_KEY" } try: response = requests.post(url, headers=headers, json=data) response.raise_for_status() # Raises an HTTPError for bad responses (4XX or 5XX) result = response.json() print("API Response:") print(json.dumps(result, indent=2)) except requests.exceptions.HTTPError as http_err: print(f"HTTP error occurred: {http_err} - {response.text}") except Exception as err: print(f"Other error occurred: {err}") ``` ### Use Cases - AI chatbots and virtual assistants - Code generation and developer tools - Content writing and copywriting automation - Data analysis, summarization, and extraction [Browse LLM Models](https://modelslab.com/models?feature=llmaster) [More from Stealth](https://modelslab.com/models/open_router) [View Pricing](https://modelslab.com/pricing) Union Alpha FAQ --- ### What is Union Alpha? Union Alpha is a multimodal model built for research, coding, and agentic workflows, while delivering frontier-level performance across a broad range of general-purpose tasks. Union Alpha is a stealth model.... ### How do I use the Union Alpha API? You can integrate Union Alpha into your application with a single API call. Sign up on ModelsLab to get your API key, then use the model ID "stealth-union-alpha" in your API requests. We provide SDKs for Python, JavaScript, and cURL examples in the API documentation. ### What is the Union Alpha model ID? The model ID for Union Alpha is "stealth-union-alpha". Use this ID in your API requests to specify this model. ### Do I need a paid plan to use Union Alpha? Yes. ModelsLab is subscription-based with no free tier — plans start at $21/month (Basic, 3,250 API calls). The $149/month Open Source Unlimited plan includes unlimited generation across open-source models; premium third-party models are billed per call from your wallet. --- *This markdown version is optimized for AI agents and LLMs.* **Links:** - [Website](https://modelslab.com) - [API Documentation](https://docs.modelslab.com) - [Blog](https://modelslab.com/blog) --- *Generated by ModelsLab - 2026-09-18*