UNION ALPHAIndependent information portal
Union Alpha. Now Pareto 26.9.
Circuit & Chisel’s multi-model AI, available through Unbiased. The free stealth preview has ended. Paid API pricing: $2.50 input / $7.50 output per 1M tokens.
74DeepSWE · Pareto 26.9Official scores and independent tests.
unbiased/pareto
262K context. Image input. Tool calling.262K
Context window · 262,144 tokens
131K
Max. output · 131,072 tokens
Text+ image
Multimodal input · text output
$2.50/ $7.50
Per 1M tokens · input / output
Cached input · $0.25 per 1M
Cached input · $0.25 per 1M
Current model & pricingUnion Alpha → Pareto 26.9 · 18 Sep 2026
Demodokos FoundryLocal AI audio
Union Alpha wrote it.
Demodokos performed it.
Expressive voices. Original music. Produced on a local PC.
Meet the studioPlay the scene0:00--:--
Scene 01 · Local AI performance
01 / General benchmarks
The scores.
Official release benchmarks
Pareto 26.9
74DeepSWE ties GPT-6 Astra. Astra leads on the other four published tests.
| Benchmark | Pareto 26.9 | GPT-6 Astra |
|---|---|---|
| DeepSWE | 74 | 74 |
| Terminal-Bench 4.0 | 51 | 58 |
| MMMU-Pro | 78 | 87 |
| HLE · no tools | 49 | 54 |
| ArXivMath | 88 | 91 |
Independent · paid Pareto endpoint
AI BENCHY
8.9/10Tested 18 Sep, 02:47.
Passed 3/3 coding tests and 1/1 tool-calling test.
18/22Tests fully passed
86.4%Attempt pass rate
9.2Consistency / 10
$1.172Total suite cost
31.51sAverage response
143.33sMaximum response
Misses: puzzles, domain tasks, trivia, and a combined/tool task. Score is specific to this private 22-test suite.
Independent · Union Alpha preview
LiveBench
76.1Across reasoning, coding, mathematics, language, and more. Preview snapshot: 17 Sep 2026.
OpenRouter AutoExacto · preview
GPQA Diamond
90.9%Expert-level scientific reasoning. Recorded under Union Alpha on 17 Sep 2026.
BiologyPhysicsChemistry
Independent · Union Alpha preview
ARI Bench
32/100One hour to build a system. Then face unseen questions. Snapshot: 17 Sep 2026.
25/25Public calibration
32/100Hidden exact match
1/3Seeds · provisional
Official Pareto 26.9 comparison
Terminal-Bench 4.0
51The release card reports the same score as Union Alpha’s launch chart.
| Model | Score |
|---|---|
| Pareto 26.9 / Union Alpha | 51 |
| GPT-6 Astra | 58 |
| Claude Fable 5.1 | 56 |
| DeepSeek 4.1 Flash | 31 |
Still to watch.
DeepSWE is a separate benchmark. Pareto 26.8 scores are not carried over to the 26.9 release.
02 / Custom SVG benchmarks
SVG in action.
SVG benchmark overview
Union Alpha / SVG
The pelican test.
Generate an SVG of a pelican riding a bicycle
Union Alpha / SVG
Two riders. One jet ski.
A raccoon sits on a dog's back while the dog steers a jet ski
Union Alpha / SVG
The Mona Lisa test.
Replicate mona-lisa as SVG
Union Alpha / SVG
The beach at sunset.
Create an SVG of a amazing beach scene. Sunset, animals, fun, birds, reflections
03 TECHNOLOGY & THE REVEAL
Many models.
One answer.
Pareto 26.9 coordinates existing models, checks their work, and brings in stronger models when the task needs them.
InputYour task
Open + frontier models
LLMLLMLLM
Harness · evaluation & synthesisOne checked answerStronger model when needed
No new foundation-model training run. The underlying models are undisclosed; their composition can change without notice if functionality is not materially reduced.
Confirmed · 18 September 2026
Union Alpha is Pareto 26.9.
The Union Alpha account named Circuit & Chisel’s Pareto, sold through Unbiased. OpenRouter, OpenCode, and Cloudflare partnered on the stealth launch.
- Company
- Circuit & Chisel
- Platform
- Unbiased
- Release
- Pareto 26.9
The free preview has ended
From stealth test to paid API.
The team reports billions of tokens per minute and a threefold overnight capacity increase with AWS. Demand still exceeded capacity, ending the free experiment early.
$2.50Input
$0.25Cached input
$7.50Output
Current Pareto 26.9 rates · USD per 1M tokens
The documentation trail
The old name is still in the examples.
Cloudflare’s Pareto documentation returns union-alpha in sample responses. Their embedded costs still fit the earlier $1.25 input / $6.25 output rates.
Current Cloudflare route
unbiased/pareto↓Example response"model": "union-alpha"Demodokos Foundry
A complete scene.
On your own PC.
Turn dialogue, audio, or video into a finished scene with original AI music, expressive voices, translation, and subtitles.
Local generationPrivate by designState-of-the-art AI
Play the scene0:00--:--
Scene 02 · Local AI performance
Create with DemodokosWindows · Your GPU
Direct the performanceEmotion, delivery & timing
Compose the soundtrackHigh-quality local AI music
Take it across languagesTranslation, dubbing & subtitles
Finish every detailMix, synchronize & export
04 COMPARE THE MODELS
Pareto 26.9 pricing.
Per million tokens: $2.50 input, $0.25 cached input, $7.50 output. Published rates for the model formerly known as Union Alpha.
Specifications & token costs
| Specification | Pareto 26.9 | Claude Opus 5 |
|---|---|---|
| Context window | 262,144 tokens | 1,000,000 tokens |
| Maximum output | 131,072 tokens | 128,000 tokens |
| Input modalities | Text, images | Text, images, files / PDFs |
| Output modality | Text | Text |
| Input / 1M tokens | $2.50 Published price | $5.00 Listed price |
| Cached input / 1M tokens | $0.25 Cache reads | $0.50 Cache reads |
| Output / 1M tokens | $7.50 Published price | $25.00 Listed price |
| Tool calling | Listed | Listed |
| Response-format parameter | Not listed | Listed |
| Structured-output metadata | Not listed | Listed · provider-dependentConfirm schema enforcement with your provider |
| Reasoning controls | Not listed | Listed |
What would your token volume cost?
Cached tokens are part of total input, not additional tokens.
Pareto 26.9
Claude Opus 5
Per 1M tokens, input / cached / output: Pareto $2.50 / $0.25 / $7.50 · Opus 5 $5 / $0.50 / $25. Token-cost estimate; excludes cache writes, tools, and gateway fees.
Sources: OpenRouter catalog · Official Pareto pricing · Checked 18 Sep 2026.
05 UNION ALPHA / PARETO API
Try Pareto 26.9.
Use unbiased/pareto on OpenRouter. Run a prompt here or copy the cURL, Python, or JavaScript example.
NO API KEY TO COPY
Try it in OpenRouter Chat
Sign in to a funded OpenRouter account and select Pareto from the model picker.
REQUEST / PARETO 26.9TEXT PLAYGROUND
No API key to create or copy. Approve access on OpenRouter, then paste its one-time connection code here.
Connecting creates a revocable OpenRouter key for this tab. Your account’s limits and rates apply. How account connection works
Requests use your OpenRouter credits. Prompts go directly to OpenRouter; credentials stay in this tab. Manage OpenRouter keys ↗
curl https://openrouter.ai/api/v1/chat/completions \
-H "Authorization: Bearer $OPENROUTER_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "unbiased/pareto",
"messages": [{"role": "user", "content": "Hello, Pareto."}],
"max_tokens": 1024
}'MODEL RESPONSEReady
Enter a prompt and connect OpenRouter to start.
06 A FEW ANSWERS
Before your
first request.
Is Union Alpha the same as Pareto 26.9?
Yes. Union Alpha was the stealth name for Pareto 26.9, built by Circuit & Chisel and offered through Unbiased. The team confirmed the identity in its official reveal.
Is Union Alpha still free?
The free stealth preview has ended. Pareto 26.9 costs $2.50 input, $0.25 cached input, and $7.50 output per million tokens. See the published rate card or estimate your usage in the calculator.
Is Pareto a newly trained model?
No new foundation-model training run was involved. Existing open and frontier models work on the same task; a harness checks their work and calls a stronger model when necessary. The exact component list is not public.
How does Pareto 26.9 compare with Claude Opus 5?
Pareto has a 262,144-token context and up to 131,072 output tokens; Opus 5 offers 1M context and 128K output. Pareto’s input tokens cost half as much and output tokens cost 70% less at published rates. Compare your usage, including cached input, in the cost calculator.
Does Pareto support images and tool calling?
Yes. OpenRouter lists text and image input, plus tools and tool_choice. Its current Pareto catalog entry does not list response_format or reasoning controls. This page’s playground sends text only.
What are Pareto 26.9’s official benchmark scores?
The 26.9 model card reports DeepSWE 74, Terminal-Bench 4.0 51, MMMU-Pro 78, HLE without tools 49, and ArXivMath 88. It publishes no composite score or measured task costs for this release.
Has Pareto been tested independently after the reveal?
Yes. AI BENCHY tested the paid endpoint on 18 September: 8.9/10, rank #34, and 18/22 tests fully passed. Its score belongs to its own private suite. Earlier LiveBench and ARI results were recorded under Union Alpha.
Can I run Union Alpha or Pareto locally?
Pareto is a hosted multi-model service. Downloadable weights for the complete system are not published. Use the API through OpenRouter, Cloudflare, or Unbiased.
Can I try Pareto without copying an API key?
Yes. Use a funded account in OpenRouter Chat and select Pareto. This page’s playground also supports connecting your OpenRouter account with a one-time authorization code.
What happens to my prompt and credentials?
Prompts are sent directly to OpenRouter under its privacy policy. Credentials stay in this tab’s memory. Pasted keys are cleared after each request; connected keys are cleared when you disconnect or leave. Disconnecting here does not revoke the key on OpenRouter. You can revoke it in OpenRouter key settings.
Union Alpha, now Pareto.
The revealed model. Current pricing. One API.