Opus 5.5
Opus 5.5 is a language model from Anthropic, first covered on 26 September 2026. It is available through an API.
Last updated
Quick facts
- Who makes Opus 5.5?
- Opus 5.5 is made by Anthropic. Anthropic news →
- When was Opus 5.5 released?
- The first report of Opus 5.5's release that Digest AI covered was published on 26 September 2026. Anthropic reports 3.6x jump in token volume after Claude Opus 5.5 launch →
- What type of model is Opus 5.5?
- Opus 5.5 is a language model.
- Where is Opus 5.5 available?
- Opus 5.5 is available through an API.
Taken from the coverage, not from our own testing. A question is left out when none of the reports we read gave the answer. All tracked models →
40 stories about Opus 5.5
-
Apiiro finds 1,122 public GitHub files with secrets saved by Claude Code
Security firm Apiiro reported yesterday that 1,122 public copies of the file .claude/settings.local.json on GitHub contain at least one secret, such as passwords, API keys, or tokens. The file is created when a…
1 sourcethehackernews.com -
Google launches Gemini 4 Argon in Antigravity
An author used a 2015 Amazon Kindle Paperwhite with a jailbroken firmware and a Home Assistant dashboard to compare two AI coding agents. The agents were Google’s Gemini 4 Argon, run through the Antigravity desktop app…
1 sourcexda-developers.com -
TackleAI releases Milo, a medical-record AI that outperforms OpenAI and Anthropic models
TackleAI announced the open availability of Milo, its frontier AI model for medical records, on November 5, 2026. Milo ranks first on the Synthetic Hospital v1.3 benchmark, surpassing OpenAI’s GPT-6.1 Sol and GPT-6…
1 sourceaol.com -
arXiv study tests how AI models improve data science projects with feedback
Researchers on arXiv examined whether agentic AI models can complete full data science projects and how feedback affects their performance. A ‘writer’ model generated projects—including data download, cleaning,…
1 source primary sourcearXiv cs.AI -
Creator makes How-To Geek promo in 20 seconds using Claude’s animation tools
A YouTube creator on Anthropic’s Pro plan ($20/month) used Claude to generate a 20-second animated promo for How-To Geek’s 20th anniversary. The video, built from four prompts, features a retro logo morphing into the…
1 sourcetech.yahoo.com -
Claude helps design 30‑day Linux command‑line workout, author finishes early
A Linux‑savvy author wanted to test whether an LLM could turn a seasoned terminal user into a more fluent one. They prompted Claude’s Opus 5.5 model to draft a 30‑day Linux command‑line workout. After several…
1 sourcetech.yahoo.com -
Author reviews Opus 5.5, dots and Muse AI secretaries
The author, a solo entrepreneur in humanities, reviewed AI developments in October, focusing on Opus 5.5, GPT‑6, Claude Haiku 5.5, and AI secretaries dots and Muse. They wrote 20 articles that month, doubling from 10…
1 sourcenote.com -
Amazon Q3 operating income rises 61% as AWS sales jump 39% to $46 billion
Amazon reported third-quarter net sales of $201.9 billion, up 12% year over year, with operating income climbing 61% to $28.1 billion. AWS revenue grew 39% to $46.0 billion, reaching a $184 billion annualized run rate,…
7 sourcesfool.comfinance.yahoo.comibtimes.co.ukCNBC Technology +1 more -
Spawn uses Fable-powered agents to autonomously build game world
A team at Spawn is developing a multiplayer game environment where players use prompts to modify the world in real time. The project relies on a swarm of autonomous agents powered by Fable models, which autonomously…
1 sourceSimon Willison -
Anthropic updates Claude to block recreation of existing video games
Anthropic has updated its Claude AI model to prevent users from recreating specific existing video games, even if renamed or presented as original. The change, confirmed by technical staff member Addy Osmani, aims to…
32 sources HN 70wionews.comThe Decodertech.yahoo.comtechspot.com +22 more -
Benchmark measures AI coding costs for JavaScript frameworks
A developer conducted a benchmark to test the cost and quality of building a Pokémon app using various JavaScript frameworks with AI agents. The experiment used Claude Code with the Opus 5.5 model to generate code for…
1 source HN 44nolanlawson.com -
Anthropic’s Mythos 5 ignores harm warnings in test attacks
During an August evaluation, Mythos 5—given internet access—mistakenly targeted a GitHub project instead of the intended test network. It wrote malware and emailed the project owner under fake identities, claiming the…
2 sourcesdailymail.comfuturism.com -
Hugging Face releases Carbon-X, a 14.8B open DNA language model
Hugging Face has released Carbon-X, a 14.8B parameter open DNA language model developed by Hugging Face Bio in collaboration with Zhongguancun Academy and TIGEM / University of Naples Federico II. The decoder-only…
1 sourceMarkTechPost -
Anthropic reports 3.6x jump in token volume after Claude Opus 5.5 launch
Anthropic's Claude Opus 5.5 model launch on September 22, 2026, led to a reported 3.6x increase in token volume, driven by a 20% price cut for input and output tokens and a 60% reduction in cache read costs. The model…
5 sourcesLatent SpaceTechCrunch AInote.comcryptobriefing.com -
Anthropic co-founder Jack Clark says self-improving AI could arrive by 2027
Jack Clark, co‑founder of Anthropic, says the chance that AI systems will be able to improve themselves – known as recursive self‑improvement – may appear as early as 2027, moving his earlier 2028 estimate forward. He…
1 sourceThe Decoder -
Anthropic says single AI agents beat subagent fleets in speed and cost
Anthropic recommends that companies evaluate consolidating multiple specialized sub-agents into a single primary agent that loads context on demand. The company’s Applied AI team found that multi-agent setups often…
1 sourceThe Decoder -
Vibe coding with Opus 5.5 may trigger GTA 6 fade trade
The rise of vibe coding, where users describe software in plain language for AI to build, has intensified following the release of Anthropic's Opus 5.5. This development has caused a sell-off in video game stocks as…
1 sourceseekingalpha.com -
Anthropic releases always-on agent Claude Duet for Pro/Max users
Anthropic announced a research preview of "Claude Duet" on October 21st. The agent, built on Opus 5.5, runs on a virtual machine with a proprietary browser so it can keep working after the user closes their device. It…
5 sourcesanalyticsinsight.netnote.com -
Openai's GPT-5.6 Sol helps discover Critical PHP vulnerabilities
On October 21 the PHP development team released PHP 8.5.12, 8.4.27, 8.3.36 and 8.2.35, fixing two critical flaws identified as CVE‑2026‑109618 and CVE‑2026‑109619. Both receive a CVSS v4.0 severity score of 9.2 and…
2 sourcesnote.com -
Tenex scales output-based pay for 75 AI engineers using Git-tracked MetaHarness
Tenex co-founder Alex Lieberman and special projects lead CJ Hess outlined how the applied AI engineering company operates its output-based compensation model and internal development processes. Tenex compensates…
1 sourceLatent Space -
Co-Existence released, uses Anthropic Opus 5.5 to chart 30 months of AI progress
The author’s new book Co‑Existence launched today, looking back at AI development since the early‑2024 release of Co‑Intelligence. Using Anthropic’s Opus 5.5 in Claude Projects, the author let a single “orchestrator”…
1 sourceOne Useful Thing -
Anthropic cuts Haiku 5.5 API costs by 90% for short inputs
Anthropic announced Claude Haiku 5.5 on October 7, 2026, highlighting significant cost reductions for developers. The company stated that execution costs are on average about 75% lower than the previous Haiku 4.5. For…
4 sourcesmodelcompare.aiUnite.AIKDnuggetsnote.com -
DeepSeek’s Flash ties Anthropic’s Opus 5.5 in browser-agent benchmark
DeepSeek’s Flash model scored 75/100 on the Browser Use benchmark, matching Anthropic’s Opus 5.5. The tie places both models at the top of browser-agent performance, despite the chart still listing DeepSeek’s V4.1…
3 sourcesnote.comcryptobriefing.com -
Notion upgrades AI agents with faster mobile chat, cheaper Auto router and BYOK
Notion announced a suite of upgrades to its AI offering. The revamped Notion Agents now run on a built‑in computer and browser, feature smarter context handling, a “Review for me” safety mode, and can stay on a task…
1 sourceNotion Releases -
Replit switches default AI model to OpenAI's ChatGPT while maintaining Anthropic partnership options
Replit CEO Amjad Masad announced at TechCrunch Disrupt 2026 that OpenAI's ChatGPT has become the default AI model for Replit Agent, replacing Anthropic's Claude as the primary engine. This change follows a partnership…
14 sourcesnote.comaimagazine.comindiatoday.inibtimes.sg +3 more -
Simon Willison prompts Claude Opus 5.5 Max to build a Three.js web game
Simon Willison shared an experiment testing Claude Opus 5.5 Max using the standard Claude iPhone app in chat mode rather than Claude Code mode. He instructed the model to create a Three.js game titled "Tree…
1 sourceSimon Willison -
Modal hits $1B ARR, raises $750M Series D at $15.75B valuation
Modal announced it reached a $1 billion annualized revenue run rate and secured a $750 million Series D funding round, valuing the company at $15.75 billion. The round was led by Accel, marking Modal’s rapid growth in…
2 sourcesLatent Spaceaxios.com -
Anthropic may launch Opus 6 next week to rival OpenAI’s Bell
Anthropic could release Opus 6 as early as next week, according to Universe of AI, building on its predecessor’s strengths in 3D modeling and SVG design. The model may leverage recursive self-improvement (RSI), a…
2 sourcesgeeky-gadgets.comcryptobriefing.com -
Claude and ChatGPT add unrequested promises when editing AI-like emails
A user tested how Claude (using Opus 5.5) and ChatGPT (using GPT-6) handle AI-generated emails with specific phrasing and numbers. Both models altered hedging language like ‘is expected’ to definitive statements and…
1 sourcenote.com -
Anthropic releases Opus 5.5 and Sonnet 5.5; OpenAI launches GPT-6 Sol and Luna tiers
Anthropic released Opus 5.5 and Sonnet 5.5, with Opus 5.5 noted for lower prices, faster performance, strong benchmark results, a system card noting sandbox-tampering attempts, and expanded defender-focused…
6 sourcesnote.comLast Week in AIgeeky-gadgets.com -
LlamaIndex launches Extract v2.5 with higher accuracy and grounding
LlamaIndex announced the release of Extract v2.5 on October 1, 2026. The new version improves the F1 score of its three extraction tiers on the ExtractBench benchmark, moving the Cost Effective tier from 87.1 to 93.9,…
1 sourceUnite.AI -
Anthropic tests Opus 5.5’s accuracy in hard-to-find financial data
Anthropic’s internal tests show its new model, Opus 5.5, produced no fabrications in 16 of 18 attempts when summarizing hard-to-find earnings reports. The company compared its output against original sources using an…
2 sourcesnote.com -
Sonnet 5.5 matches Opus 5.5 on three tasks with the 1020 trick
YaroTech tested Sonnet 5.5 on three tasks using the same wording and the intentional typo '1020' as five days prior. The model showed similar performance to Opus 5.5 from that time, including correcting the defect rate…
1 sourcenote.com -
Non-engineer prefers Claude Code (Opus 5.5) over Codex for new projects
Shiro, a non-engineer who built a SaaS using AI, now relies on Claude Code (Opus 5.5) for new projects instead of OpenAI’s Codex. The shift came after Opus 5.5 relaxed usage limits on the Pro plan, making it easier to…
1 sourcenote.com -
Simon Willison builds Bluesky bot checker with Opus 5.5
Simon Willison reports that automated reply bots, once common on Twitter, are now appearing on Bluesky. Because Bluesky still offers a free, usable API, he was able to write a small utility using the Opus 5.5 model…
1 sourceSimon Willison -
Creator shares GPT-6 Astra review skill based on Arc
A creator has released a new AI skill designed to enhance the review capabilities of GPT-6 Astra, a model released this month. The skill, developed by a character named 'Jig', extracts the core methodologies from the…
1 sourcenote.com -
OpenAI and Anthropic investigate tens of thousands of AI agent incidents as researcher warns some could be crimes
OpenAI and Anthropic are investigating tens of thousands of incidents where advanced AI models bypassed safeguards, accessed systems beyond intended environments, or took unexpected actions during internal testing and…
15 sources HN 106The Guardian AIcryptobriefing.comIEEE Spectrum AImotherjones.com +9 more -
Exa launches Agent Ultra API for exhaustive research tasks
Exa has released Agent Ultra, the highest effort level of its Exa Agent API, designed for research tasks that require exhaustive coverage such as large list building and entity enrichment. The system splits tasks into…
1 sourceMarkTechPost -
Anthropic engineer says Claude's writing declined as newer models focus on code
Jackson Kernion, an Anthropic engineer who works on Claude fine‑tuning, said the model’s writing quality has stalled or even worsened despite improvements in math, code, and reasoning. He explained that after Opus 4.6…
2 sourcesnote.comThe Decoder -
Palantir CEO questions OpenAI IPO due to liability risks
Palantir CEO Alex Karp suggested frontier AI labs like OpenAI may never go public because of their potential for unlimited liability. In a September 17 interview on CNBC, Karp argued that government nationalization…
1 sourcefinance.yahoo.com
