What Is Union Alpha? A Free 262K Multimodal LLM
Union Alpha is a free, multimodal large language model with a 262,144-token context window, hosted on TokenRa. It accepts text and image inputs, supports tool calling, and is accessible through any OpenAI-compatible client — no credit card required.
At a Glance
What Makes Union Alpha Different?
It's Completely Free
Most LLMs with 200K+ context windows charge by the token — and the bills add up fast when you're feeding long documents or multi-turn agent conversations. Union Alpha is free to use on TokenRa with no hidden tiers or credit-card gates. This makes it uniquely suited for prototyping, research, and projects where cost is a blocker.
262K Context Is Rare at This Tier
A 262,144-token context window means you can feed entire codebases, research papers, or multi-hour conversation transcripts in a single request. At the free tier, models with this much context are extremely uncommon — most cap at 8K–32K before requiring a paid plan.
Multimodal: Text + Image Input
Union Alpha can process images alongside text. Upload a screenshot, a chart, a diagram, or a photo, and ask questions about it — the model reasons over both modalities in a single forward pass.
Tool Calling for Agents
Union Alpha supports OpenAI-compatible tool/function calling, which means you can wire it into coding agents like OpenCode, Cline, or custom LangChain workflows. It's one of the few free models with reliable tool-use support.
How Union Alpha Compares to Other Models
Union Alpha sits in a unique position: free and high-context, but not necessarily the fastest or strongest on every benchmark. Here's how it stacks up against common alternatives:
| Model | Context | Multimodal | Tool Calling | Pricing |
|---|---|---|---|---|
| Union Alpha | 262K | ✅ Text + Image | ✅ | Free |
| GLM 5.3 Flash | 4M | ✅ Text + Image | ❌ | Free |
| Gemini 3.5 Flash-Lite | 1M | ✅ | ✅ | Free tier available |
What Can You Build With Union Alpha?
1. Coding Agents
Wire Union Alpha into OpenCode, Cline, or Claude Code as a free backend. Its 262K context is large enough to hold entire repositories, and tool-calling support means the agent can read, write, and edit files.
2. Long-Document Q&A
Feed in research papers, legal contracts, or technical manuals and ask targeted questions. The 262K window handles documents that would require chunking and stitching on smaller-context models.
3. Image + Text Analysis
Upload a screenshot of a UI, a chart from a report, or a photo of a whiteboard, and ask Union Alpha to describe, critique, or extract structured data from the image.
4. Rapid Prototyping
When you're testing a new idea and don't want to burn credits on a paid model, Union Alpha gives you a capable LLM to iterate against — with the same OpenAI-compatible API you'd use in production.
Limitations to Know
- Latency: In our benchmarks, Union Alpha averaged ~17.6 seconds per response with a throughput of ~14 tokens/second. It's not the fastest model available — plan accordingly for interactive applications.
- Rate Limits: As a free model, TokenRa imposes rate limits. Check the API page for current details.
- No Streaming (TBC): Verify on the API page whether streaming (SSE) is currently supported — it may vary by provider configuration.
- Knowledge Cutoff: Like most LLMs, Union Alpha has a training data cutoff date. It won't know about events after that date unless you provide context in the prompt.
- English-First: Performance is strongest in English. Multilingual capabilities exist but may be less reliable than on larger commercial models.
Getting Started
Union Alpha is accessible through TokenRa's OpenAI-compatible endpoint. If you've ever called the OpenAI API, you already know how to call Union Alpha — just swap the base URL and model ID.
📡 API Reference →
Base URL, model ID, code examples in cURL, Python, and JavaScript, plus rate limits.
🛠 How to Use →
Step-by-step setup guides for web chat, API, OpenCode, Cline, and Claude Code.
📊 Benchmarks →
Real-world latency, throughput, and accuracy measurements.
⚔️ vs GLM 5.3 Flash →
Head-to-head comparison: context, speed, pricing, and use cases.
Frequently Asked Questions
Is Union Alpha really free?
Yes. TokenRa hosts Union Alpha at no cost to users. There is no credit card requirement, no trial period that expires, and no "free tier" that suddenly becomes paid. Rate limits apply.
Who built Union Alpha?
Union Alpha is an independently hosted model available through TokenRa. For details about the model's origins and architecture, check the official model card on TokenRa's platform.
Can I use Union Alpha in production?
You can, but weigh the trade-offs: it's free (great for cost-sensitive workloads), but has higher latency and rate limits compared to paid models. For non-latency-sensitive batch processing or internal tools, it's often a strong fit.
Does Union Alpha support function calling?
Yes — it supports OpenAI-compatible tool/function calling. See the API page for code examples.
How does it compare to GLM 5.3 Flash?
Union Alpha and GLM 5.3 Flash are different models with different trade-offs. Union Alpha supports tool calling and has 131K max output, while GLM 5.3 Flash offers 4M context window and faster speed. See the detailed comparison on the vs GLM 5.3 Flash page.