Span-02Anytime reasoning for decisions
Stop reasoning anytime.
Give it a deadline, and it returns its best decision so far.
Thinking off is frontier-level at the lowest latency. Set budget_ms to think longer, or let auto mode's learned gate choose.
Playing chess with Jev
12–0 against Jev, even with Span-02's reasoning turned off.
Browser use
We gave Span-02 a browser-use harness. In a Wikipedia race, it finished nearly 2× faster than GPT-6 Luna: 20.6 s vs 38.5 s. The race: get from one article to another by clicking only links in the text, so every click involves reasoning.
Numbers, not just yes or no.
Span-02 outputs numeric values directly, with how sure it is.

Playground
answer
Press Run to see the decision.
Blind Earth
No map, just coordinates. For each of 4,050 points on Earth, Span-02 answered “is this point in water?” from latitude and longitude alone. The longer it thinks, the sharper the map.

Brightness is P(land) on a 4° grid (4,050 points, one per request), scored against Natural Earth. Jev 1.13.0 scores 79.6% on the same question. South America is still faint. The idea and the Claude chart are from @celestepoasts on X; that chart scores against a 1-km land mask, weighted by area, so its percentages don't compare with ours.




Start using Span-02
On the Respan Gateway it costs $0.01 per million input tokens, and output is free: the cheapest paid decision model there. Or run the open weights.
curl https://api.respan.ai/api/v1/decisions \ -H "Authorization: Bearer $RESPAN_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "model": "span-02", "state": "Customer: I was charged twice this month.", "questions": { "team": { "type": "choice", "instructions": "Which team should handle this?", "criteria": { "billing": "Billing", "tech": "Tech support" } } }, "reasoning": { "mode": "on", "budget_ms": 300 } }'Host it yourself.
- 1M tokens/s on a single RTX 5090
- Up to 7× faster inference than vLLM

Built something with Span-02?
We'll repost it.




