{"type":"post","id":"maritaca-ai-open-weights-s5-nano-4b-qwen3-919e38","slug":"maritaca-ai-open-weights-s5-nano-4b-qwen3-919e38","title":"Maritaca AI open-weights S5-nano 4B (Qwen3.5-4B based) for Portuguese","description":"Maritaca AI has released S5-nano, an open-weight model of about 4 billion parameters with separate reasoning and direct-answer modes, a context window of up to 262,144 tokens, and builds for several local-serving stacks.","retrieval_nugget":"Maritaca AI has released S5-nano, an open-weight model of about 4 billion parameters with separate reasoning and direct-answer modes, a context window of up to 262,144 tokens, and builds for several local-serving stacks. Its published Portuguese evaluations make it a candidate for teams testing self-hosted language workloads, though the results are Maritaca's own and need validation on real applications.","published_at":"2026-11-06","updated_at":"2026-11-06","record_date":"2026-11-06","date_kind":"published_at","topics":["open-models","local-models","models"],"entities":["Maritaca AI","S5-nano","Qwen3.5-4B","Hugging Face","vLLM","SGLang","llama.cpp"],"related_patterns":[],"novelty_label":"new_fact","what_changed":"Maritaca AI released S5-nano, a 4B Portuguese-focused open-weight model with Think and Instruct modes, a 262,144-token context window and downloadable BF16, FP8 and GGUF variants.","prior_refs":[],"source_url":"https://huggingface.co/maritaca-ai/S5-nano","source_urls":["https://huggingface.co/maritaca-ai/S5-nano"],"schema_version":"newruntime-agent-readable-v0.2","stable_id":"post:maritaca-ai-open-weights-s5-nano-4b-qwen3-919e38","status":"published","visuals":[],"editor":{"role":"editor","name":"Andrey Reshetnikov","profile":"https://newruntime.com/owner-profile.md","profile_json":"https://newruntime.com/owner-profile.json","same_as":["https://www.linkedin.com/in/reshetnikov1/","https://t.me/lapetuse"]},"routes":{"html":"https://newruntime.com/posts/maritaca-ai-open-weights-s5-nano-4b-qwen3-919e38/","markdown":"https://newruntime.com/posts/maritaca-ai-open-weights-s5-nano-4b-qwen3-919e38.md","json":"https://newruntime.com/posts/maritaca-ai-open-weights-s5-nano-4b-qwen3-919e38.json"},"markdown_url":"https://newruntime.com/posts/maritaca-ai-open-weights-s5-nano-4b-qwen3-919e38.md","next_reads":[{"type":"topic","path":"/topics/open-models/","url":"https://newruntime.com/topics/open-models/","title":"Open Models","reason":"Explore the open-models topic hub.","media_type":"text/html","markdown_url":"https://newruntime.com/topics/open-models.md","json_url":"https://newruntime.com/topics/open-models.json"},{"type":"topic","path":"/topics/local-models/","url":"https://newruntime.com/topics/local-models/","title":"Local Models","reason":"Explore the local-models topic hub.","media_type":"text/html","markdown_url":"https://newruntime.com/topics/local-models.md","json_url":"https://newruntime.com/topics/local-models.json"},{"type":"topic","path":"/topics/models/","url":"https://newruntime.com/topics/models/","title":"Models","reason":"Explore the models topic hub.","media_type":"text/html","markdown_url":"https://newruntime.com/topics/models.md","json_url":"https://newruntime.com/topics/models.json"},{"type":"collection","path":"/posts/","url":"https://newruntime.com/posts/","title":"Field Notes","reason":"Open the latest editorial analysis.","media_type":"text/html","json_url":"https://newruntime.com/posts.json"},{"type":"collection","path":"/sources/","url":"https://newruntime.com/sources/","title":"Sources","reason":"See the original sources this archive cites.","media_type":"text/html"}]}