Author's Description
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....
Key Specifications
Supported Parameters
This model supports the following parameters:
Features
This model supports the following features:
Performance Summary
Union Alpha, a stealth multimodal model created on September 16, 2026, demonstrates exceptional reliability with a 100% success rate across all 8 benchmarks, indicating consistent and usable responses. While no cost data is available, suggesting potential free tier usage, its speed ranking places it in the 6th percentile, indicating generally longer response times compared to other models. The model exhibits perfect accuracy in critical areas such as Hallucinations, General Knowledge, and Ethics, showcasing its ability to acknowledge uncertainty appropriately and provide accurate information across a broad spectrum of topics. It also performs strongly in Email Classification (99.0% accuracy, 92nd percentile) and Reasoning (98.0% accuracy, 90th percentile). Its performance in Mathematics (94.9% accuracy, 79th percentile) and Coding (94.0% accuracy, 83rd percentile) is also robust. The primary area for improvement appears to be Instruction Following, where it achieved 76.0% accuracy (75th percentile). Despite its high accuracy across many benchmarks, Union Alpha consistently ranks in lower percentiles for duration, indicating that its high accuracy often comes with extended processing times.
Model Pricing
Current Pricing
| Feature | Price (per 1M tokens) |
|---|---|
| Prompt | $0 |
| Completion | $0 |
Price History
Available Endpoints
| Provider | Endpoint Name | Context Length | Pricing (Input) | Pricing (Output) |
|---|---|---|---|---|
|
Stealth
|
Stealth | stealth/union-alpha | 262K | $0 / 1M tokens | $0 / 1M tokens |
Benchmark Results
| Benchmark | Category | Reasoning | Strategy | Free | Executions | Accuracy | Cost | Duration |
|---|
Other Models by stealth
|
|
Released | Params | Context |
|
Speed | Ability | Cost |
|---|---|---|---|---|---|---|---|
| Space Bunny Alpha Unavailable | Sep 23, 2026 | — | 1M |
Image input
Video input
Text input
Text output
|
— | — | $ |
| Ox Alpha Unavailable | Aug 20, 2026 | — | 1M |
Image input
Video input
Text input
Text output
|
★★★ | ★★★★★ | $ |