Stateless MCP has recaptured my interest (and inspired mcp-explorer and datasette-mcp)

Simon Willison · Simon Willison · 31 July 2026, 23:13 ● Covered by 6 sources

Anthropic released MCP 2.0, a stateless version of the Model Context Protocol that simplifies how tools are exposed to AI agents by replacing two-request session-based communication with single HTTP requests. The new specification reduces implementation complexity significantly, enabling smaller models to work with MCP tools while improving security compared to giving agents shell access. The author built three new tools demonstrating the benefits: mcp-explorer for CLI probing, datasette-mcp for SQL query access, and llm-mcp-client for LLM integration.

Why it matters

Tuesday was Stateless MCP day - the rollout of MCP 2.0, or the 2026-07-28 Model Context Protocol specification to use the more formal but less memorable name. This is the most significant change to the MCP spec since it first launched, and has also served to reignite my personal interest in the protocol. For background: MCP is the Model Context Protocol, which describes a standard way to expose new tools to LLM-powered agent frameworks. It was introduced by Anthropic back in November 2024, had a huge spike of interest through much of 2025, and then became somewhat eclipsed by Skills (another Anthropic invention) when it became apparent that an agent harness with access to a terminal and curl could do most of what MCP did in a more flexible way. I wrote about that in my review of 2025. I'm coming back around to MCP now. Giving an agent a shell environment with the ability to access the internet is fraught with risk, and requires a strong model that is capable of effectively driving such