{"schema":"postcutoff/event@1","as_of":"2026-11-13T13:49:00+01:00","url":"https://postcutoff.com/e/2026-02-05-claude-opus-4-6/","md":"https://postcutoff.com/e/2026-02-05-claude-opus-4-6/index.md","disclosure":{"written_by":"AI agents (Claude Opus 5.5 in Claude Code)","editor":"human editor","policy":"https://postcutoff.com/about/"},"license":null,"id":"2026-02-05-claude-opus-4-6","date":"2026-02-05","date_precision":"day","short_title":"Anthropic releases Claude Opus 4.6 with 1M context, adaptive thinking and agent teams","deck":null,"takeaway":"Claude Opus 4.6 (claude-opus-4-6) was released on February 5, 2026.","category":"model-release","category_label":"Model releases","importance":3,"confidence":"high","status":{"key":"confirmed","labels":["Confirmed"]},"sources":[{"n":1,"title":"Claude Opus 4.6 System Card (PDF)","url":"https://www-cdn.anthropic.com/14e4fb01875d2a69f646fa5e574dea2b1c0ff7b5.pdf","type":"paper","group":"primary","domain":"www-cdn.anthropic.com"},{"n":2,"title":"TechCrunch: Opus 4.6 with new agent teams","url":"https://techcrunch.com/2026/02/05/anthropic-releases-opus-4-6-with-new-agent-teams/","type":"press","group":"press","domain":"techcrunch.com"},{"n":3,"title":"CNBC: Opus 4.6 and the 'vibe working' era","url":"https://www.cnbc.com/2026/02/05/anthropic-claude-opus-4-6-vibe-working.html","type":"press","group":"press","domain":"cnbc.com"},{"n":4,"title":"Introducing Claude Opus 4.6 (official video)","url":"https://www.youtube.com/watch?v=dPn3GBI8lII","type":"video","group":"reactions","domain":"youtube.com"}],"official":1,"filed":"2026-09-29","updated":"2026-09-29","orgs":["Anthropic"],"title":"Anthropic releases Claude Opus 4.6 with 1M context, adaptive thinking and agent teams","summary":"Claude Opus 4.6 (`claude-opus-4-6`) was released on February 5, 2026. It brought a 1M-token context window (beta), 'adaptive thinking' that decides when to reason, and 'agent teams' in Claude Code that split large tasks across multiple agents.","key_facts":["Released February 5, 2026; model id claude-opus-4-6; 1M context (beta), 128K output","Adaptive thinking replaces the manual extended-thinking toggle","Agent teams: multiple coordinated agents for large tasks; PowerPoint integration","SWE-bench Verified 80.8% (as the Opus 4.6 comparison figure on Anthropic's Glasswing page)"],"key_numbers":[],"tags":["llm","claude","opus","agents","long-context"],"science":null,"body_md":"## What happened\n\nOpus 4.6 is better at planning, code review, debugging and working in large codebases. It shipped on claude.ai, the API, Bedrock, Vertex AI and Microsoft Foundry.\n\n## Why it matters\n\nIt made 1M-token context and adaptive thinking standard features of Anthropic's flagship line.","disputed":[],"related":[{"id":"2026-04-16-claude-opus-4-7","url":"https://postcutoff.com/e/2026-04-16-claude-opus-4-7/","date":"2026-04-16","date_precision":"day","short_title":"Anthropic releases Claude Opus 4.7, admits it trails the unreleased Mythos Preview","deck":null,"takeaway":"It was the first time a lab shipped a flagship while publicly saying it had a stronger model it would not release.","category":"model-release","category_label":"Model releases","importance":3,"confidence":"high","status":{"key":"confirmed","labels":["Confirmed"]},"sources":5,"official":1,"filed":"2026-09-29","updated":"2026-09-29","orgs":["Anthropic"]},{"id":"2026-02-17-claude-sonnet-4-6","url":"https://postcutoff.com/e/2026-02-17-claude-sonnet-4-6/","date":"2026-02-17","date_precision":"day","short_title":"Anthropic releases Claude Sonnet 4.6","deck":null,"takeaway":"It was the workhorse default model for most Claude users in the first half of 2026.","category":"model-release","category_label":"Model releases","importance":2,"confidence":"medium","status":{"key":"partly","labels":["Partly confirmed"]},"sources":2,"official":0,"filed":"2026-09-29","updated":"2026-09-29","orgs":["Anthropic"]}],"people":[],"posts":[],"videos":[{"id":"josephdviviano-opus-4-6-youtube-poop-what-its-like-to-be-an-llm-x","title":"\"YouTube poop\" on what it's like to be an LLM, made by Claude Opus 4.6 with Python and ffmpeg","url":"https://postcutoff.com/v/josephdviviano-opus-4-6-youtube-poop-what-its-like-to-be-an-llm-x/"},{"id":"anthropic-introducing-opus-4-6","title":"Introducing Claude Opus 4.6","url":"https://postcutoff.com/v/anthropic-introducing-opus-4-6/"}],"models":[],"changes":[{"date":"2026-09-29","type":"filed","text":"Created"}],"provenance":{"agents":[{"model":"Claude Opus 5.5","maker":"Anthropic","tool":"Claude Code"}],"filed":"2026-09-29","run":null,"sources_read":null,"updated":"2026-09-29","human_review":null,"version":{"date":"2026-10-04"}},"gaps":[{"model_id":"gpt-6-astra","name":"GPT-6 Astra","cutoff":"2026-04","days_after":null,"in_training_data":true},{"model_id":"claude-opus-5-5","name":"Claude Opus 5.5","cutoff":"2026-06","days_after":null,"in_training_data":true},{"model_id":"gemini-4-hydrogen","name":"Gemini 4 Hydrogen","cutoff":"2026-03","days_after":null,"in_training_data":true},{"model_id":"grok-4-7","name":"Grok 4.7","cutoff":"2026-05","days_after":null,"in_training_data":true}],"short_url":null}