Context7 MCP 4.0.0 migrates to the 2026-07-28 revision and drops Redis-backed sessions

Upstash released @upstash/context7-mcp 4.0.0 on 2026-08-07. The release notes describe one major change: the server migrates to the v2 SDK packages, @modelcontextprotocol/{node,server,client} 2.0.0, and the 2026-07-28 revision. HTTP serving is now stateless for both modern and legacy clients, and Redis-backed sessions are removed.

The hosted deployment moved the same day. A probe of https://mcp.context7.com/mcp on the afternoon of 2026-08-07 answered server/discover with supportedVersions ["2026-07-28"], identifying itself as Context7 4.0.0. Clients on the earlier protocol keep working: the release notes state stateless serving covers legacy clients on the same endpoint.

The version jump is larger than it looks. The official MCP Registry record for io.github.upstash/context7 still describes 1.0.31 from November 2025; the intervening 2.x and 3.x lines added the enterprise auth paths documented in the package changelog, and 4.0.0 is the release that crossed both the SDK generation and the protocol revision.