Purpose and architecture

Open EPM and the MCP client agent have different authorities.

Open EPM server

Publishes the immutable skill, authenticates and authorizes callers, validates application-language programs, sequences effects, persists authoritative business state and returns durable evidence. It operates without Codex or another model runtime on the server.

MCP client agent

Interprets the user's goal, retrieves and verifies instructions, interviews or inspects supplied sources, drafts programs, requests approvals, keeps client workflow state and presents evidence. It cannot bypass server authorization.

Client host

Controls whether prompts, native skills, local files, hooks and scheduled runners are supported. MCP cannot force an arbitrary host to display or install a skill.

The server is the authority for product behavior and business state. A local checkpoint helps the agent resume its workflow but never proves that a remote effect committed.