PHP SDK v0.8.0 ships 2026-07-28 support, including the stateless lifecycle and multi round-trip requests

The official PHP SDK for the Model Context Protocol released v0.8.0 on 2026-08-25, bringing the 2026-07-28 specification to PHP servers and clients. The release is titled "2026-07-28 Support incl. Stateless HTTP Transport", and its notes describe the HTTP transport rework as the headline change while keeping older revisions of the specification alive and, in the maintainers' words, mostly compatible in userland code.

The merged work reads as a checklist of the revision's defining pieces: the modern SEP-2575 lifecycle in which a server holds no protocol-level session, validation of the standard MCP request headers from SEP-2243, the multi round-trip request flow (SEP-2322) that replaced server-initiated requests, the extensions framework SEP-2133 defines, and the SEP-2577 deprecations of Roots, Sampling and Logging. The release also implements protocol version negotiation, gates structuredContent on the negotiated revision, and closes MCP Apps gaps with extension-negotiation checks.

The PHP SDK remains pre-1.0, and the official SDK listing carries it at Tier 3 alongside Swift and Kotlin, with TypeScript, Python, C#, Go and Rust at Tier 1 and Java and Ruby at Tier 2. The release lands four weeks after the revision shipped.