May 2026 Newsletter
Simon Willison's Weblog1d agoCommentarySimon Willison sent the May 2026 edition of his sponsors-only monthly newsletter. Topics include rising AI costs, Anthropic's strong month, and somewhat disappointing model releases. The issue also covers conferences, podcasts, the launch of Datasette Agent, progress on Datasette, tools he is using, and miscellaneous extras. An April issue is available as a public preview.
How we contain Claude across products
Simon Willison's Weblog2d agoCommentaryAnthropic explains how process sandboxes, VMs, filesystem boundaries, and egress controls limit what Claude agents can access. Claude.ai uses gVisor; local Claude Code uses Seatbelt on macOS and Bubblewrap on Linux; Cowork runs in a full VM. Simon Willison highlights the documentation quality, notes a previously missed file-exfiltration path, and plans to revisit Anthropic's open-source srt tool.
Anthropic Releases Claude Opus 4.8 With Integrity Upgrades and Dynamic Workflows
INSIDE 硬塞 AI4d agoReleaseAnthropic released Claude Opus 4.8 as a rapid iteration focused on stronger integrity and reliability for high-risk tasks. The company also previewed Dynamic Workflows, a feature designed to coordinate multiple agents on large-scale jobs such as code migration. The article mentions Mythos entering a countdown toward unblocking, but does not provide detailed availability or product specifics.
Anthropic Series H Valuation Reaches $965B, Backed by Memory Giants★ 78
INSIDE 硬塞 AI4d agoBusinessAnthropic completed a $65 billion Series H round, bringing its valuation to $965 billion and reportedly surpassing OpenAI. The round included strategic investments from memory makers Micron, Samsung, and SK Hynix. The news highlights how frontier AI companies are increasingly tied to hardware and memory supply chains, as investors continue backing foundational model competition.
Anthropic raises $965B Series H, releases Opus 4.8 and Dynamic Workflows/ultracode
Latent Space4d agoBusinessThe visible AINews item centers on Anthropic, claiming a $965B Series H alongside Opus 4.8 and Dynamic Workflows/ultracode releases. The available body text is extremely brief, offering only the editorial line “Total Anthropic victory!” It signals a major Anthropic narrative across capital, Claude models, and developer workflows, but provides no detailed specs, benchmarks, investor terms, or availability information.
Anthropic's run-rate revenue hits $47 billion★ 76
Simon Willison's Weblog4d agoBusinessSimon Willison highlights Anthropic’s latest Series H announcement, where the company says run-rate revenue crossed $47 billion earlier in May. He traces prior disclosures: about $9 billion at the end of 2025, $14 billion in February 2026, and over $30 billion in April. The post also addresses skepticism, arguing that these numbers appeared in fundraising announcements, where knowingly misleading investors would be securities fraud.
Claude Opus 4.8: "a modest but tangible improvement"
Simon Willison's Weblog4d agoReleaseAnthropic shipped Claude Opus 4.8, and Simon Willison highlights the unusually restrained release language: a “modest but tangible improvement.” The model keeps most Opus 4.7 pricing and specs, while evaluations suggest it is more likely to flag uncertainty and less likely to ignore flaws in code it wrote. Developer-relevant changes include mid-conversation system messages and a lower prompt-cache minimum of 1,024 tokens.
llm-anthropic 0.25.1
Simon Willison's Weblog4d agoReleaseSimon Willison released llm-anthropic 0.25.1 with support for the new Claude Opus 4.8 model, exposed as claude-opus-4.8. The release adds a -o fast 1 option for Anthropic fast mode, limited to organizations that have the feature enabled. It also changes default max_tokens behavior so each model now defaults to its maximum output instead of 8,192.
Anthropic releases Opus 4.8 with new Dynamic Workflows tool
TechCrunch AI5d agoReleaseAnthropic has released a new Opus model, Opus 4.8, alongside a tool called Dynamic Workflows. The report says the tool is designed to coordinate swarms of subagents, pointing to a focus on multi-agent orchestration. The source does not provide benchmarks, pricing, API details, availability, or concrete use cases.
Claude’s new model is more ‘honest’ when it messes up
The Verge AI5d agoReleaseAnthropic is releasing Claude Opus 4.8 and highlighting the model’s “honesty” as a key improvement. The company says it trains its models to avoid unsupported claims, addressing a broader issue where AI systems sometimes jump to conclusions. Based on the provided excerpt, the update is positioned around reliability and uncertainty handling rather than a specific new tool or benchmark result.
Import AI 458: Reckoning with the future; and a singularity story★ 74
Import AI (Jack Clark)7d agoCommentaryThis Import AI issue is a long essay and fiction piece about living through rapid AI progress. Clark uses personal experience and Anthropic’s internal use of Claude to show work shifting toward delegation, verification, observability, and agent management. He then offers speculative 2026-2028 predictions around biology, autonomous companies, robotics, recursive self-improvement, and a positive singularity story focused on healthcare.
Anthropic 營收爆發成長！傳估值直逼 1 兆美元拿下全球最貴 AI 新創寶座★ 85
INSIDE 硬塞 AI10d agoBusinessAI 新創公司 Anthropic 傳出營收迎來爆發性成長，目前正進行新一輪融資，估值直逼 1 兆美元，有望超越 OpenAI 成為全球最貴的 AI 新創。據悉，包含矽谷創投巨頭 Peter Thiel 旗下的 Founders Fund 以及 General Catalyst 等既有投資人均計劃參與此次投資，顯示市場對其技術與商業化前景的高度信心。
Quoting SpaceX S-1★ 90
Simon Willison's Weblog12d agoBusiness根據 SpaceX 最新提交的 S-1 上市招股書，該公司已與 AI 巨頭 Anthropic 簽署雲端服務協議。Anthropic 將自 2026 年 5 月起至 2029 年 5 月，每月支付高達 12.5 億美元以租用 Colossus 與 Colossus II 超級電腦的算力。此外，招股書也證實 xAI 的 Grok 5 目前正於 Colossus II 進行訓練。
[AINews] Anthropic growing 10x/year while everyone else is laying off >10% of their workforce★ 75
Latent Space24d agoBusiness本文探討了當前科技經濟中極具對比的「雙軌分歧」現象。一方面，多數科技企業正經歷超過 10% 的裁員潮與預算緊縮；另一方面，以 Anthropic 為首的頂尖 AI 公司卻以每年 10 倍的速度瘋狂成長。這種資金與人才高度向生成式 AI 領域集中的現象，正劇烈重塑科技產業的就業與發展版圖。
[AINews] Anthropic-SpaceXai's 300MW/$5B/yr deal for Colossus I, ARR growth is 8000% annualized★ 90
Latent Space26d agoBusiness根據 Latent Space 報導，Anthropic 與 xAI 達成一項歷史性的算力租賃協議。Anthropic 將以每年 50 億美元的價格，租用 xAI 旗下 Colossus I 超級電腦叢集高達 300MW 的電力容量。這項交易不僅代表著 AI 算力市場的版圖重組，也讓相關實體的年化經常性收入（ARR）呈現驚人的 8000% 爆發式成長，顯示出前沿模型對算力的極度飢渴。
Claude Opus 4.7 on AI Gateway★ 75
Vercel Changelog47d agoReleaseVercel 宣布其 AI Gateway 正式支援 Anthropic 的最新旗艦模型 Claude 4.7 Opus。開發者現在可以透過 Vercel 的統一 API 網關輕鬆調用此模型，並享有內建的邊緣快取、速率限制、彈性重試以及詳細的用量分析功能。這項更新將大幅降低開發者在構建高效能、高可靠性 AI 應用程式時的基礎設施管理成本。
Model Context Protocol (MCP) explained: An FAQ★ 85
Vercel Changelog312d agoTutorialModel Context Protocol (MCP) 是一個開放標準，旨在解決 AI 應用程式與各種資料源、工具之間連接破碎化的問題。本文以問答（FAQ）形式，深入淺出地解釋 MCP 的核心架構（Client-Host-Server）、運作原理，以及開發者如何利用 Vercel 和 AI SDK 快速構建與部署 MCP 伺服器，實現更強大的 AI Agent 應用。