# Mistral Large 4, Claude Haiku 5.5 and a wave of decision models

> Week of 5 October 2026: Mistral launches Large 4, Anthropic ships Haiku 5.5, FLUX 3 arrives, and OpenAI, Microsoft and Liquid release decision models.

Published 13 Oct 2026. Coverage: 5 Oct 2026 to 11 Oct 2026. By Ali Asif.

## Items

1. **Mistral Large 4** (Mistral AI, Frontier): A 1.05-trillion-parameter mixture-of-experts model with 49B active parameters, a vision encoder and a 1M-token window, in public preview. [Primary source](https://docs.mistral.ai/models/mistral-large-4-0)
2. **Claude Haiku 5.5** (Anthropic, Frontier): The small Claude is cheaper at $0.10 in and $0.50 out per million tokens under 100K, and gets effort controls and adaptive thinking for the first time. [Primary source](https://www.anthropic.com/claude-haiku-5-5)
3. **FLUX 3 Image** (Black Forest Labs, Image, video, world): One endpoint for text-to-image and editing, with up to ten reference images, layout boxes in the prompt and output up to 4K. [Primary source](https://bfl.ai/models/flux-3-image)
4. **Nano Banana 2.1** (Google DeepMind, Image, video, world): Google's image generation and conversational editing model is generally available, with up to 14 reference images and search grounding. [Primary source](https://ai.google.dev/gemini-api/docs/models/gemini-nano-banana-2.1)
5. **GPT-6 Luna Decisions** (OpenAI, Agents and coding): A Decisions API in public beta where you send input and typed questions and get calibrated probabilities back, billed on input tokens only at $0.10 per million. [Primary source](https://developers.openai.com/api/docs/guides/decisions)
6. **Microsoft-Decision-1** (Microsoft, Agents and coding): A Qwen3.5-9B model post-trained for decision scoring that writes no text and returns a probability for yes/no, choice and score questions. [Primary source](https://learn.microsoft.com/en-us/azure/foundry/foundry-models/how-to/use-foundry-models-microsoft-decision)
7. **d1-3B** (Liquid AI, Open weights): An open 3.12B decision model that Liquid reports at 8 milliseconds per decision on an RTX 4090. [Primary source](https://huggingface.co/LiquidAI/d1-3B)
8. **Voxtral Mini 4B Realtime Arabic** (Mistral AI, Open weights): An open streaming speech-to-text model for Modern Standard Arabic and Gulf, Levantine, Nile Valley and Maghrebi dialects, built to handle code-switching. [Primary source](https://huggingface.co/mistralai/Voxtral-Mini-4B-Realtime-Arabic)
9. **EmbeddingGemma 2** (Google DeepMind, Open weights): A 740M open embedding model that maps text, code, images, video and audio into one vector space, across more than 100 languages. [Primary source](https://blog.google/innovation-and-ai/technology/developers-tools/embeddinggemma-2/)
10. **Mellum2.1 Thinking** (JetBrains, Agents and coding): A 12B open coding model with 2.5B active parameters whose repository-level reinforcement learning lifts SWE-bench Verified from 2.0 to 47.0. [Primary source](https://huggingface.co/JetBrains/Mellum2.1-12B-A2.5B-Thinking)

Two flagships and a new category in the same week. The category surprised me most.

## Mistral Large 4

Mistral launched Large 4 in public preview on 6 October. It is a mixture-of-experts model with 1.05 trillion total parameters, 49B active, a 1.6B vision encoder and a 1M-token context window, taking text and images. The docs list structured outputs, function calling, document question answering, batching and built-in agent tools. For a European lab to land in the trillion-parameter range is the headline, and I'd check the license terms before building on it.

## Claude Haiku 5.5

Anthropic released Haiku 5.5 on 7 October, calling it its cheapest, fastest and most capable small model. It is built for high-volume work: summaries, classification, routing, subagents and live support. It is the first Haiku with effort controls and adaptive thinking. Pricing is $0.10 per million input tokens and $0.50 output for prompts up to 100K tokens, and $0.50 and $2.50 above that.

## Decision models

Over six days a new kind of model showed up in several places. Instead of generating text, a decision model takes input plus typed questions (yes/no, a choice, a score) and returns calibrated probabilities in one pass. OpenAI shipped a Decisions API in public beta on 6 October, powered by GPT-6 Luna, billed on input tokens only. Microsoft announced Microsoft-Decision-1 on 9 October, generally available in Foundry. Liquid AI opened d1-3B on 7 October, reporting 8 ms per decision on a consumer GPU. Perplexity and Meta released theirs the same week, and Cloudflare had opened Clef a few days earlier. I haven't read those closely.

## Images and embeddings

Black Forest Labs released FLUX 3 Image on 5 October, and Google made Nano Banana 2.1 generally available the next day. Google also opened EmbeddingGemma 2, a 740M model that puts text, code, images, video and audio in one 768-dimension space.

## Arabic and code

Mistral released Voxtral Mini 4B Realtime Arabic on 9 October, an open streaming speech model for Modern Standard Arabic and several dialects, tuned for switching languages inside one conversation. JetBrains released Mellum2.1 Thinking on 8 October, a 12B open coding model that reports a jump on SWE-bench Verified from 2.0 to 47.0 under the same setup.

## What I'd watch next

Whether decision models become a standard API shape across vendors, and whether anyone publishes an Arabic benchmark for them.

## My take

The Arabic Voxtral model is the one I'll test first. A small open model that understands Gulf dialect and switches to English mid-sentence is exactly what a Saudi site team sounds like on a call. The decision-model cluster is the pattern of the week: three big vendors, plus Perplexity and Cloudflare, all converged on models that return only a probability. For procurement work, where the output is approve, reject or score, that is a cleaner fit than a chatbot.

## Sources

- https://docs.mistral.ai/models/mistral-large-4-0
- https://www.anthropic.com/claude-haiku-5-5
- https://bfl.ai/models/flux-3-image
- https://ai.google.dev/gemini-api/docs/models/gemini-nano-banana-2.1
- https://developers.openai.com/api/docs/guides/decisions
- https://learn.microsoft.com/en-us/azure/foundry/foundry-models/how-to/use-foundry-models-microsoft-decision
- https://huggingface.co/LiquidAI/d1-3B
- https://huggingface.co/mistralai/Voxtral-Mini-4B-Realtime-Arabic
- https://blog.google/innovation-and-ai/technology/developers-tools/embeddinggemma-2/
- https://huggingface.co/JetBrains/Mellum2.1-12B-A2.5B-Thinking

Canonical: https://heyaliasif.com/ai/2026-10-05-week-in-ai