Anthropic AI Updates: May 18, 2026

1. Anthropic acquires Stainless to own the SDK and MCP toolchain that powers Claude agents

Anthropic. Anthropic acquired Stainless, the 2022-founded company behind every official Anthropic SDK and a generator that turns OpenAPI specs into typed clients across TypeScript, Python, Go, Java, and Kotlin. Head of Platform Engineering Katelyn Lesse framed the deal around the agentic shift, arguing that “agents are only as useful as what they can connect to” and that owning the SDK and connector pipeline tightens Claude’s reach into external data and tools. The Stainless team joins Anthropic to keep working on SDK generation and MCP server tooling, with the stated goal of improving developer experience and how agents connect to the rest of the world. Source

2. Anthropic to brief G20 finance ministries and the FSB on Claude Mythos cyber findings

Anthropic. Anthropic agreed to present findings from its Claude Mythos Preview model to leading finance ministries, central banks, and the Financial Stability Board, after FSB chair and Bank of England Governor Andrew Bailey requested the briefing. The company has previously said Mythos has surfaced thousands of high-severity vulnerabilities across major operating systems and browsers, and the FSB is preparing a report on AI use in the financial system that is due next month. Mythos access is currently limited to roughly 40 organizations including Amazon, Microsoft, and JPMorgan Chase, with the White House asking Anthropic to hold further distribution, against an IMF backdrop warning that advanced models could turn cyber risks into a “macro-financial shock.” Source