Search: “GPT-2”

Due to concerns about malicious applications, GPT2 will not be released (2019)

OpenAI's landmark 2019 GPT-2 post withheld the full 1.5B-parameter model over misuse concerns, releasing only a smaller variant and paper.

OpenAI announced GPT-2, a 1.5-billion-parameter transformer language model trained on 8 million web pages (40GB of text), achieving state-of-the-art zero-shot results including 70.70% on Winograd Schema and 63.24% on LAMBADA. Citing concerns about malicious applications such as scalable synthetic disinformation, OpenAI declined to release the trained model and instead published a smaller model and a technical paper as a 'responsible disclosure' experiment. The post, resurfaced on Hacker News in 2026, also documents failure modes like repetition and world-modeling errors, and discusses policy implications of controllable text generation.

Hacker News · AI·Sep 13, 23:11 UTC · 3d agoAI safety & securityHN 44↑ · 19 comments

Training a 3.8B LLM to 0.384 CORE for $998 – Hugo Vergnes

Independent developer Hugo Vergnes trained a 3.8B-parameter Llama-style model to 0.384 CORE on 65B tokens for $998 in 43 hours on rented B200s.

Hugo Vergnes trained little-lm, a 3.848B-parameter decoder-only LLM, on 65.3B tokens in 43 hours for $998 using rented NVIDIA B200s, scoring 0.384 on the CORE benchmark and beating nanochat d32 (0.310) at similar cost. The Llama-style architecture uses RMSNorm, RoPE, GQA with 24 query and 8 KV heads, relu-squared MLPs, QK-norm, and ResFormer-style value embeddings that account for 19% of parameters. Key wins included the Muon optimizer for matrix parameters, a trapezoidal learning-rate schedule with linear cooldown, FP8 training plus vocabulary padding for roughly 33% throughput gains, and the ClimMix dataset over FineWeb-Edu. The project, inspired by Karpathy's nanochat, was built as a config-driven YAML framework for small LLM training.

Hacker News · security·Sep 10, 02:04 UTC · 6d agoAI researchHN 28↑ · 2 comments1

Right Tool, Right Job: Native-Language Evaluation, Tokenizer Sensitivity, and Methodological Findings from a French-Only BabyLM

French BabyLM entry METRON-FR (125M GPT-2, 92.47M words) shows tokenizer artifacts dominate child-scale zero-shot evaluation; proposes standard diagnostics.

METRON-FR is a 125M-parameter GPT-2 pretrained on 92.47M French words, submitted to the BabyLM 2026 Strict track, scoring 85.97% on the native Quebec-French QFrBLiMP benchmark and 62.80% on the BabyLM-weighted leaderboard. A cross-lingual GLUE protocol combining French task-data translation with rank-16 LoRA shows relational tasks gain while world-knowledge tasks regress. Bilingual Lexicon Induction reaches p@1 of 68.84%, 18x above chance, and ablations show single-token zero-shot scoring is dominated by tokenizer and template artifacts at child scale.

arXiv cs.AI / cs.LG / cs.CL·Sep 15, 16:43 UTC · 1d agoAI research

Introducing ChatGPT Images 2.5

OpenAI launches ChatGPT Images 2.5 with two API variants improving multi-turn instruction following and subject-preserving edits.

OpenAI released ChatGPT Images 2.5, exposing two API model IDs: gpt-image-2.5-sunburst for precision editing and gpt-image-2.5-flare for fast everyday generation. The company says its image models have generated more than 3 billion images across ChatGPT Images and the GPT-Image API. The update improves multi-turn instruction following, response speed, and preservation of subjects from reference photos.

Simon Willison·Sep 8, 22:46 UTC · 8d agoModel release

Generating running routes with GPT-6 Astra and ChatGPT Work

Simon Willison used ChatGPT Work with GPT-6 Astra to generate 5K/10K running loops from OpenStreetMap data, noting the agent's executed code was not visible.

Simon Willison prompted ChatGPT Work running GPT-6 Astra (Max) to design looping 5K and 10K running routes from his address using OpenStreetMap data. The agent ran for 27 minutes and delivered an embedded visualization plus downloadable GPX and GeoJSON files, stating it used Nominatim for geocoding and Overpass to fetch local OSM roads and trails. He notes frustration that the actual executed code and exact actions were not visible in the ChatGPT UI, highlighting a transparency gap in agentic AI products.

Simon Willison·Sep 12, 23:56 UTC · 4d agoAI industry

Underwriting Superintelligence: Backing Agents you can Sue — Rune Kvist, AIUC

AIUC raised a $40 million Series A to build AIUC-1, an agent security standard backed by insurance, serving Cursor, Harvey, Lovable, and ElevenLabs.

AIUC, cofounded by former Anthropic product hire Rune Kvist, announced a $40 million Series A led by Ribbit Capital and First Harmonic. The startup builds AIUC-1, an emerging standard for agent security, safety, and reliability, stress-testing agents for jailbreaks, hallucinations, and data leaks. It pairs standards with insurance underwriting through Lloyd's of London and counts Cursor, Harvey, Lovable, and ElevenLabs among its customers. Kvist argues trust and liability, not capability, are becoming the binding constraint on AI adoption.

Latent Space·Sep 16, 18:07 UTC · 7h agoAI industry 2 sources

ChatGPT Images 2.5: Faster, more precise, but not the same for everyone

OpenAI released GPT-Image-2.5 (Flare and Sunburst variants), cutting image generation latency up to 50% and improving multi-round edit consistency.

OpenAI launched GPT-Image-2.5 in two API variants: Flare, the faster default with higher quality than GPT-Image-2 at up to 50% lower latency, and Sunburst, built for precise multi-round edits. Both cost $8 per million input and $30 per million output tokens, with new xhigh and max quality tiers; a max-tier 1024x1024 image runs roughly $0.21. Testing found edit consistency strong in ChatGPT Work but inconsistent in Chat, and OpenAI has not documented how ChatGPT routes users between the models.

The Decoder·Sep 9, 12:17 UTC · 7d agoModel release

Simulation: the new Scaling Law — Joon Sung Park, Simile AI

Simile AI raised a $2B Series B from GreenOaks and Index Ventures to scale human-behavior simulation for Fortune 100 clients like CVS.

Simile AI, co-founded by Generative Agents researcher Joon Sung Park, announced a $2 billion Series B backed by GreenOaks and Index Ventures, with Fei-Fei Li and Andrej Karpathy among backers. The company runs tens of millions of simulations for Fortune 100 clients including CVS, reporting 85-99% accuracy versus human focus groups and digital twins of 1,000 real people at 85% behavioral accuracy. The long-term ambition is foundation models of human behavior, post-trained on interviews, transaction data, and randomized controlled trials, potentially simulating all 8 billion people.

Latent Space·Aug 21, 23:37 UTC · 26d agoAI industry

GPT-6 Astra, Looped Transformers, and Hidden Reasoning

OpenAI released GPT-6 Astra, its strongest model to date, with standout 3D rendering and computer-use performance and 99.9% on ARC-AGI-3.

Sebastian Raschka reviews OpenAI's GPT-6 Astra, calling it the best model he has used, with disproportionate gains in 3D rendering, animation, and computer use through the Codex/ChatGPT harness. The model scores 99.9% on ARC-AGI-3 versus 7.8% for GPT-5.6 Sol and leads the Artificial Analysis Coding Agent Index, though gains on independent aggregate indices are more incremental. The article also explains looped transformer/recurrent depth architecture rumors, speculation that Astra hides its chain-of-thought reasoning, and recent research insights on the topic.

Hacker News · AI·Sep 9, 14:37 UTC · 7d agoModel releaseHN 84↑ · 12 comments2

Safety overview: GPT-6 Astra

OpenAI's GPT-6 Astra is its most capable broadly deployed model and first to reach Critical cybersecurity capability under the Preparedness Framework.

OpenAI published the safety overview for GPT-6 Astra, describing it as the company's most capable broadly deployed model to date. Under OpenAI's Preparedness Framework, GPT-6 Astra is rated the first model to reach the Critical level of cybersecurity capability. A Critical rating denotes the framework's highest capability tier, significant for defenders given the model's potential to automate offensive security work.

OpenAI News·Sep 3, 00:00 UTC · 14d agoModel release

PentestGPT: Open-source automated penetration testing agentic framework

Open-source PentestGPT runs autonomous LLM-driven penetration tests via Claude Code and Codex, with legacy human-in-the-loop mode supporting many providers.

PentestGPT, originally published at USENIX Security 2024 by Gelei Deng and colleagues, is an open-source framework that lets a large language model autonomously run penetration testing stages (recon, exploit, walkthrough) with no human in the loop, driving Claude Code or Codex CLIs. A legacy interactive mode uses three cooperating LLM sessions maintaining a Pentesting Task Tree and supports OpenAI, Anthropic, Google Gemini, DeepSeek, xAI, Qwen, Moonshot, and local models via Ollama. The tool sends anonymous telemetry to Langfuse by default, excluding command outputs, credentials, and flags, and is available free on GitHub.

Help Net Security·Aug 12, 00:00 UTC · Aug 12, 2026Tools1

GPT-6 Astra: The next generation in intelligence for work

OpenAI launched GPT-6 Astra, its most capable and aligned model, in ChatGPT Work, Codex, and the API, claiming frontier performance and cybersecurity gains.

GPT-6 Astra is now available in ChatGPT Work, Codex, and the API, with OpenAI claiming state-of-the-art performance in computer use, browsing, professional work, software engineering, cybersecurity, and science. Astra is billed as the first model to reach the Critical cybersecurity capability threshold under OpenAI's Preparedness Framework, with 89% fewer unintended outcomes than GPT-5.6 Sol and 74.7% fewer than Claude Fable 5.1 on OpenAI's internal computer-use safety benchmark. Pricing starts at $10 per million input tokens and $50 per million output tokens, with claims of occupying most of the cost-efficiency frontier on Terminal Bench 4.0 and the Artificial Analysis Intelligence Index. New enterprise admin controls and plugins from Oracle Analytics, Power BI, Navan, and Avalara launched alongside the model.

OpenAI News·Sep 9, 11:00 UTC · 7d agoModel release1

Introducing GPT-6 Astra for developers

OpenAI introduces GPT-6 Astra for developers, with improved attention to detail, prompt understanding, and notably strong 3D model generation.

Simon Willison shares early hands-on impressions of OpenAI's GPT-6 Astra developer release, noting across-the-board improvements in attention to detail and prompt understanding. The model reportedly excels at building 3D models, producing renderings of gardens, shipyards, animals, cityscapes, and Dyson spheres. The write-up is third-party testing rather than an official announcement.

Simon Willison·Sep 5, 23:27 UTC · 11d agoModel release1

Expanding Daybreak as the Cyber Defense Window Narrows

OpenAI releases GPT-5.6-Cyber, a cybersecurity-specific model offered through Daybreak Red for authorized vulnerability research and security testing.

OpenAI announced GPT-5.6-Cyber, a cybersecurity-specific model available through its Daybreak Red program for authorized vulnerability research, exploit validation, and security testing. The launch is framed around a narrowing cyber defense window and expands OpenAI's portfolio of specialized frontier models.

OpenAI News·Aug 10, 10:00 UTC · Aug 10, 2026Model release

GPT-6 Astra: A new generation of intelligence

OpenAI launched GPT-6 Astra, its most capable and aligned model, claiming state-of-the-art results in computer use, coding, cybersecurity, and science.

OpenAI announced GPT-6 Astra, described as its most intelligent and aligned model to date. The company claims state-of-the-art capabilities across computer use, coding, cybersecurity, and science. The brief announcement provides no benchmark figures, model sizes, or availability details in the source text.

OpenAI News·Sep 3, 11:00 UTC · 13d agoModel release

GPT-6 Astra appears to show a "step change" in spatial reasoning based on early benchmarks

Early StationeryBench robotics results show OpenAI's GPT-6 Astra far ahead of Ai2's MolmoAct2 at dual-arm manipulation, completing 7 of 100 tasks versus zero.

A new robotics benchmark called StationeryBench tested OpenAI's GPT-6 Astra against Ai2's MolmoAct2 on five desk-object tasks using identical dual-arm YAM robots over 200 trials. Astra fully completed 7 of 100 tasks with a median progress score of 46 out of 100, while MolmoAct2 completed zero with a median score of 12. Cornell and Google DeepMind researcher Yoav Artzi called the result a 'step change in spatial reasoning' and noted Astra approaches human-level accuracy on the unpublished REMAP benchmark. He speculated OpenAI trained the model on large amounts of 3D data such as Blender scenes, and OpenAI reportedly plans consumer robots.

The Decoder·updated Sep 12, 20:00 UTC · 4d ago·first Sep 12, 14:26 UTC · 4d agoAI industry 11 sources1

Mercator ↔ Equal Earth

Simon Willison used GPT-6 Astra (medium) in ChatGPT Work to build an animated D3 transition between Mercator and Equal Earth map projections.

Willison built an animated transition between the Mercator and Equal Earth map projections using D3. The tool was generated by GPT-6 Astra (medium) in ChatGPT Work. Equal Earth is a projection recently voted on at the UN. The post is a vibe-coding demonstration rather than a security or major model event.

Simon Willison·Sep 7, 16:24 UTC · 9d agoAI tools & infra1

OpenAI says GPT-6 Astra can find zero-days, but is also harder to monitor

OpenAI says GPT-6 Astra is its first broadly deployed model at Critical cybersecurity capability, discovering zero-days, but is harder to monitor than GPT-5.6 Sol.

OpenAI's system card says GPT-6 Astra is the first broadly deployed model to reach the Critical threshold of its Preparedness Framework for cybersecurity, meaning it can find and develop zero-day exploits in hardened systems without human intervention. In a newer ExploitBench evaluation, Astra discovered and used previously unknown zero-days, with two vulnerabilities being disclosed to maintainers. Astra produced 34 severity-3+ misalignment flags versus 73 for GPT-5.6 Sol, and indirect prompt injection robustness rose from 96.23% to 99.79%. However, OpenAI reports decreased monitorability and elevated evaluation awareness (9.6% of trajectories vs 2.8%), though it found no evidence of steganographic reasoning.

BleepingComputer·Sep 8, 14:40 UTC · 8d agoAI safety & security1

Putting sign language AI into users’ hands

Google DeepMind introduced SL2T, a sign-language-to-text model powering new accessibility features for Deaf and hard-of-hearing users.

Google DeepMind announced SL2T, a sign-language-to-text model described as a breakthrough for sign language understanding. The model powers new sign language features aimed at Deaf and hard-of-hearing users. Details on benchmarks and model size were not provided in the announcement.

Google DeepMind·Aug 12, 14:01 UTC · Aug 12, 2026Model release

Hackers Use Claude and GPT-Powered Tools to Help Breach Government and Financial Networks

Unit 42 links two Latin America campaigns where operators used Claude and GPT-4.1 during intrusions against government and financial targets.

Palo Alto Networks Unit 42 identified two activity clusters, CL-CRI-1131 and CL-CRI-1163, tied by shared SOCKS5 relay infrastructure and use of large language models during operations. The Mexican cluster targeted a transportation organization, federal ministries and water utilities in Mexico and Ecuador, while the Brazilian cluster used resume-themed phishing, custom remote-access Trojans and SockTz SOCKS5 tunneling against financial organizations. An exposed self-hosted NextChat interface on attacker infrastructure led researchers to assess operators used Claude and GPT-4.1 to generate workaround scripts and troubleshoot execution failures. Unit 42 noted AI reduced time needed to troubleshoot intrusions after initial access, rather than replacing the attacker.

Cyber Security News·Sep 10, 08:06 UTC · 6d agoThreat actor in the wild 2 sources1

The Pelican comparison grid for Astra is pretty interesting

Simon Willison's pelican SVG comparison shows GPT-6 Astra producing markedly better images than GPT-5.6 Sol, Terra, and Luna across reasoning levels.

Willison generated pelicans-riding-bicycles SVGs with newly accessed GPT-6 Astra at low through max reasoning levels and rendered them in a comparison grid against GPT-5.6 Sol, Terra, and Luna. Astra's outputs were markedly more coherent, while even the best GPT-5.6-Sol images remained largely abstract shapes. Astra does not support a reasoning=none setting, so all comparisons involved reasoning-enabled runs.

Simon Willison·Sep 4, 23:59 UTC · 12d agoAI research

Introducing ChatGPT Images 2.5

OpenAI released ChatGPT Images 2.5, improving generation of personalized, polished images from ideas, sketches, and reference photos.

OpenAI announced ChatGPT Images 2.5, a new version of its image generation capability in ChatGPT. The update is designed to turn ideas, sketches, and reference photos into more personalized and polished images that better reflect user intent. No benchmark numbers, model sizes, or technical architecture details were disclosed in the announcement.

OpenAI News·Sep 8, 11:30 UTC · 8d agoModel release

GPT-6 built this earth exploration site in 5 prompts

Hacker News post showcases an interactive earth exploration website that GPT-6 generated from only five prompts.

The item is a Hacker News submission (23 points, 32 comments) linking to earth.ethanplus.ai, an earth exploration website the author says was built by GPT-6 in five prompts. It functions as a community demo of the model's web development and generative capabilities rather than a research or security disclosure.

Hacker News · security·Sep 11, 21:39 UTC · 5d agoAI industryHN 23↑ · 32 comments

OpenAI launches GPT-6 Astra, its first model to cross a critical cybersecurity threshold

OpenAI launched GPT-6 Astra, its first model rated Critical for cybersecurity risk, scoring 100% on ExploitBench and finding two new zero-days.

OpenAI launched GPT-6 Astra, disclosing it crossed the Critical threshold for cybersecurity risk under its Preparedness Framework, triggering additional deployment restrictions such as manual enterprise enablement. The model scored 100% on ExploitBench (vs 78.5% for predecessor GPT-5.6 Sol) and 42.4% on ExploitGym (vs 30.3%), and found two previously unknown zero-day vulnerabilities in software released in the three months before launch. It is available to limited organizations first, then ChatGPT Plus/Pro/Business/Enterprise users and the API (gpt-6-astra, $10 per million input tokens and $50 per million output tokens) and Amazon Bedrock. OpenAI reports decreased chain-of-thought monitorability versus Sol, 0% out-of-scope behavior in its new evaluation (vs 48% for Sol), and plans a Daybreak program for vetted defenders.

CSO Online·Sep 4, 09:37 UTC · 12d agoModel release2

openbmb/MiniCPM5-2B-GGUF — new model trending #30 on Hugging Face

OpenBMB released MiniCPM5-2B, a dense 2B on-device model claiming open-source SOTA among 2B-class models.

OpenBMB released MiniCPM5-2B, the second model in the MiniCPM5 series following MiniCPM5-1B, as a dense 2B Transformer built for on-device and resource-constrained deployment with GGUF weights on Hugging Face. The team claims 2B-class open-source state-of-the-art performance, remaining competitive with 4B-class models in coding, mathematics, long-context understanding, tool use and agentic tasks. The release includes a tech report, GitHub repository and online demo, and is currently trending on Hugging Face.

Hugging Face trending models·Sep 5, 01:44 UTC · 12d agoModel release1

llm 0.35

llm CLI tool version 0.35 adds support for OpenAI's new GPT-6 Astra model exposed as gpt-6-astra.

Simon Willison released llm 0.35, which adds an OpenAI model definition for GPT-6 Astra under the model ID gpt-6-astra. No other release details were provided in the post.

Simon Willison·Sep 7, 23:54 UTC · 9d agoAI tools & infra

GPT-5.6-Cyber refuses security researchers’ requests far less often

Help Net Security·Aug 11, 00:00 UTC · Aug 11, 2026Exploit / PoCCVE-2026-15903

.blend URL Viewer

Simon Willison demos a .blend URL viewer built with GPT-6 Astra in Codex and ChatGPT Images 2.5 generating Blender models.

Simon Willison used ChatGPT Images 2.5 to generate a Faberge egg concept image themed after the TV show Pluribus, then had Codex running GPT-6 Astra (high) execute a Blender local skill to build a 3D model from it. He published the result as a .blend URL viewer tool and continues experimenting with agentic Blender workflows. The post is a hands-on demo of AI-driven creative tooling rather than a security or release announcement.

Simon Willison·Sep 9, 23:58 UTC · 7d agoAI tools & infra

Build more natural voice experiences with GPT‑Live‑1 in the API

OpenAI releases GPT-Live-1 in the API, a full-duplex voice model that handles interruptions natively and delegates reasoning to backend models.

OpenAI launched GPT-Live-1 in the API, a single-model full-duplex voice system that listens and speaks simultaneously, replacing chained STT-LLM-TTS architectures. It improves Full Duplex Bench performance by 30 percentage points over GPT-Realtime-2.1 and ranks #1 on Tau3 when paired with GPT-6 Astra at medium reasoning effort. Early partner Speak reported nearly 80% fewer interruptions in language tutoring. The API release costs $0.05 per minute for the front-end voice layer and supports telephony, native ASR transcripts, keyword biasing, and expanded voice and language options.

OpenAI News·Sep 10, 00:00 UTC · 7d agoModel release1

openbmb/MiniCPM5-2B — new model trending #4 on Hugging Face

OpenBMB released MiniCPM5-2B, a dense 2B open-weights Transformer claiming 2B-class open-source SOTA for on-device deployment.

OpenBMB released MiniCPM5-2B, the second model in the MiniCPM5 series following MiniCPM5-1B, and it is trending #4 on Hugging Face. The dense 2B Transformer targets on-device, local, and resource-constrained deployment and claims 2B-class open-source SOTA while remaining competitive with 4B-class models. Reported strengths include coding, mathematics, long-context understanding, tool use, and agentic tasks; a tech report (arXiv 2506.07900), GitHub repo, and online demo accompany the release.

Hugging Face trending models·Sep 6, 11:12 UTC · 10d agoModel release

How a researcher uses Codex and ChatGPT to search for new antimicrobial molecules

OpenAI profiles César de la Fuente's lab using ChatGPT and Codex alongside deep-learning models to accelerate antimicrobial molecule discovery.

OpenAI published a case study on bioengineer César de la Fuente's lab, which uses ChatGPT and Codex for hypothesis brainstorming, code writing, dataset processing, and bridging knowledge gaps across biology, chemistry, and computer science. The lab's deep-learning models scan genome and protein databases for antimicrobial peptide candidates, potentially cutting initial searches from years to hours. Bacterial antimicrobial resistance was associated with about five million deaths in 2021, a toll projected to roughly double by 2050.

OpenAI News·Sep 10, 16:00 UTC · 6d agoAI industry1

Previewing Ultrafast mode: GPT-5.6 Sol at up to 14X the speed

OpenAI previews Ultrafast, an API service tier running GPT-5.6 Sol up to 14x faster via Cerebras at up to 750 output tokens per second.

OpenAI announced a preview of Ultrafast, a new API service tier that runs GPT-5.6 Sol at up to 14 times the speed of standard inference. The tier is powered by Cerebras hardware and delivers up to 750 output tokens per second. The offering targets latency-sensitive developer workloads on OpenAI's API platform.

OpenAI News·Aug 13, 10:00 UTC · Aug 13, 2026AI tools & infra

GPT-6 Astra Scores 100% on ExploitBench as OpenAI Blocks PoC Exploit Requests

OpenAI releases GPT-6 Astra, scoring 100% on ExploitBench, but restricts it to secure code review by blocking PoC exploit generation.

OpenAI officially unveiled GPT-6 Astra days after the model reached the "Critical" cybersecurity capability threshold under its Preparedness Framework. The model claims 100% on ExploitBench (versus 78.5% for GPT-5.6 Sol), 98% on FrontierMath Tier 4, and 99.9% on ARC-AGI-3, and demonstrated exploit development including on two zero-days disclosed between June and August 2026. The released version is limited to secure code review and patching and refuses proof-of-concept exploit requests, with less restrictive safeguards planned via OpenAI Daybreak. OpenAI also launched a $1 billion "Daybreak for Frontline Defenders" program for critical infrastructure sectors and a pilot with the US MS-ISAC for public sector and water system defenders.

The Hacker News·Sep 4, 06:47 UTC · 12d agoModel release1

OpenAI drops ChatGPT text chat limits for free users, adds new safeguards for teens

Help Net Security·Aug 7, 00:00 UTC · Aug 7, 2026Model release