diff --git a/.changeset/v11-open-edition-mcp-only.md b/.changeset/v11-open-edition-mcp-only.md
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+---
+"@objectstack/spec": major
+---
+
+Open edition is MCP-only.
+
+The bundled AI authoring service (`@objectstack/service-ai`) is no longer part of
+the open distribution (ADR-0025 S2, #2325); AI now integrates through MCP
+(`@objectstack/mcp`) and the documented opt-in seam — an app that declares
+`@objectstack/service-ai` / `@objectstack/service-ai-studio` still loads the
+service. Removing a published package from the open edition is a breaking change,
+so this cuts the next release as a major.