{
  "id": "projection",
  "title": "Projection",
  "version": 0.1,
  "status": "draft",
  "author": "Pete Dainty",
  "updated": "2026-07-05",
  "summary": "A Projection is a representation of the origin, negotiated and rendered for a specific consumer. It is one of many faces of a single source of truth.\n",
  "definition": "A deterministic rendering of canonical origin data into a target format such as HTML, Markdown, JSON, JSON-LD, llms.txt or MCP, chosen by content negotiation rather than assumed. No projection is privileged. All are equal and consistent.\n",
  "rationale": [
    "Different consumers consume different things. A browser wants HTML. A crawler wants JSON-LD. An agent wants a tool manifest. Serve each what it can use.",
    "Projections are generated from one source, so they cannot contradict each other. The machine view and the human view are the same truth, differently shaped.",
    "Cross-posting is projection. An article on heliacon.com is canonical. The same piece elsewhere is a non-canonical projection that points home with rel=canonical."
  ],
  "examples": [
    "origin.md and origin.html are both projections of origin.yaml.",
    "A definition is projected to JSON for an API, to HTML for a person and to an entry in llms.txt for a model.",
    "A cross-posted article is a projection of a corpus entry, carrying a canonical link back to the origin."
  ],
  "antipatterns": [
    "Hand-maintaining the same content in three formats until they drift.",
    "A machine format that says something the human page does not, or the reverse."
  ],
  "related": [
    "origin",
    "invocation",
    "provenance"
  ],
  "projections": [
    "html",
    "markdown",
    "json",
    "jsonld",
    "llms",
    "mcp"
  ]
}