Is MCP Good Yet?
This technical update discusses the latest revisions to the Model Context Protocol (MCP), focusing on protocol versioning, elicitation capabilities, and client-server communication. It highlights ongoing challenges with implementing task-based extensions and standardized elicitation workflows.
Why it matters
As MCP becomes a standard for AI agent interoperability, these technical updates dictate how developers build and integrate AI tools.
Codex, Cursor, Claude Code, Grok, and OpenCode. Partial means opt-in, a subset, or experimental. Click a cell for the source.
Protocol revision 2026-07-28. No initialize handshake, no session id. Each request carries version and capabilities.
Opt-in mcp_2026_07_28. Default remains 2025-06-18. Stdio also needs CODEX_MCP_PROTOCOL_VERSION.
No public 2026-07-28 claim. Forum reports still show pre-stateless protocol versions.
v2 runtime (SDK 2.x) adds 2026-07-28 and is default on Anthropic-hosted CLI/VS Code/SDK. Bedrock, Vertex, Foundry, and some flags stay on v1. Stdio 2026 needs MCP_PROTOCOL_NEGOTIATION=auto.
Grok Build pins the wire to 2025-11-25 so an rmcp bump cannot silently move it.
SDK v2 client migration reverted 2026-07-28. Stock still uses the initialize handshake.
A server can pause a tool call and ask the user for a form or an out-of-band URL.
elicitation/create surfaces as mcpServer/elicitation/request. Form, URL, and openai/form. Opt-in 2026-07-28 MRTR InputRequiredResult currently errors (issue 40657).
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