MCP Apps spec launched — standard format for rich UI from MCP servers

Source type	Community
Confidence	Low
Last verified	2026-03-20
Topics	mcp

Insight: Anthropic officially launched the MCP Apps specification, absorbing the independent MCP UI project and collaborating with OpenAI, Block, VS Code, JetBrains, Antigravity, and AWS. MCP Apps provide a standard format for applications to return rich UI from MCP servers, moving beyond text-only responses. The spec was ratified by all major players, establishing the basis for a rich ecosystem of interoperable applications and open-source support.

Detail: MCP Apps follow OpenAI's earlier ChatGPT Apps trial balloon from Dev Day 2025, but with broader industry backing. The spec also coincides with the emergence of the Recursive Language Model (RLM) pattern — passing files and context by reference and pulling minimum slices (via shell/grep/AST) rather than stuffing everything into context. Daytona is positioning RLMs as "unlimited recursion depth" via per-agent sandboxes.

Sources

• Latent Space — "[AINews] Anthropic launches the MCP Apps open spec, in Claude.ai" (2026-01-27)

Related: existing entry "MCP origin story" in external/mcp.md — COMPLEMENTS