Can LLMs Engineer Their Own Agent Harness? ByteDance Seed’s HarnessDev Says Only 34 of 64 Changes Generalize
ByteDance Seed's HarnessDev benchmark finds LLM-built agent harnesses trail human engineering on code and search, with only 34 of 64 revisions generalizing.
Researchers from ByteDance Seed, SUTD, Georgia Tech, M-A-P, and TokenWave.AI introduce HarnessDev, a benchmark that evaluates the runnable agent harness an LLM writes rather than its answers, using Creation and Evolution stages across SWE-bench Pro, Terminal-Bench 2.1, MLE-bench, EQ-Bench3, and BrowseComp (2,207 instances). Six creator models including Opus 4.8, GPT-5.5, Gemini 3.1 Pro, DeepSeek V4 Pro, Qwen 3.7 Max, and Seed 2.0 Pro were tested; Opus 4.8 posted the best average of 67.8 versus an 86.2 human-engineered reference. Self-built harnesses beat references on writing and ML experimentation but lag badly on code and search, and quality proved executor-specific: Opus 4.8 fell from 69.3 to 33.0 on SWE-bench Pro when the executor was switched to Gemini. Evolution gains were small and noisy: of 64 adjacent changes, feedback and held-out scores agreed only 34 times (53.1%), and much generated state and memory code never executed.
Introducing Meta One: A Subscription Service With More Features and AI to Create, Connect, and Stand Out
Meta launches global Meta One subscriptions bundling Instagram, Facebook, WhatsApp Plus with expanded Meta AI and Muse media generation, priced $2.99-$499 monthly.
Meta introduced Meta One, a global subscription service with plans for individuals, creators, and businesses, launching with more than 50 features across Instagram, Facebook, WhatsApp, and Meta AI. Individual bundles Core ($7.99/month) and Premium ($19.99/month) combine the single-product Plus plans with expanded use of compute-intensive AI capabilities, including image/video generation powered by Muse models and Instagram's Restyle. Business tiers range from Essential ($14.99/month) to Expert ($149/month) and Max ($499/month), with expansion planned to Edits, AI glasses, and more.
Omniscience for the Masses: New Threats in the Metaverse's Democratized World Creation
First systematic assessment of 25 metaverse platforms reveals five novel world-creation attacks enabling covert user surveillance on Roblox, Horizon Worlds, and VRChat.
Researchers present the first systematic security and privacy assessment of metaverse world creators, surveying 25 platforms that support user-created worlds. They designed and implemented five novel attacks that abuse standard creator tools to violate spatial, visual, and auditory constraints, enabling covert user surveillance and manipulation without software vulnerabilities or developer-level privileges. Five previously proposed attacks were replicated using only standard world-creation features. The authors conclude that existing platform vetting, runtime protections, and creator policies are insufficient to mitigate malicious world creators.