{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://www.schemastore.org/okf-0.1.json",
  "title": "OKF Knowledge Graph",
  "description": "JSON graph representation of an Open Knowledge Format (OKF) bundle. Produced by the `okf graph` command.",
  "type": "object",
  "required": ["version", "nodes", "edges"],
  "properties": {
    "$schema": {
      "type": "string",
      "const": "https://www.schemastore.org/okf-0.1.json",
      "description": "JSON Schema identifier for this graph document. Published on SchemaStore."
    },
    "version": {
      "type": "string",
      "const": "0.1",
      "description": "Schema version of this OKF graph format."
    },
    "timestamp": {
      "type": "string",
      "format": "date-time",
      "description": "UTC timestamp when the graph was generated."
    },
    "bundle": {
      "type": "object",
      "description": "Optional object containing custom properties passed via -p when generating the graph. Only present when such properties were provided.",
      "additionalProperties": true
    },
    "nav": {
      "$ref": "#/$defs/navNode",
      "description": "Index-driven navigation tree reflecting SPEC §6 directory indexes (and synthetic listings when index.md is missing). Present only when the graph was produced with --nav / includeNav. Producer contract: root node has kind \"dir\" and id \"\"; kind \"dir\" always includes body; empty group/orphans nodes are never emitted; directories never appear in nodes[]."
    },
    "nodes": {
      "type": "array",
      "description": "List of concept nodes in the knowledge graph.",
      "items": {
        "$ref": "#/$defs/node"
      }
    },
    "edges": {
      "type": "array",
      "description": "Directed edges representing links between concepts.",
      "items": {
        "$ref": "#/$defs/edge"
      }
    }
  },
  "additionalProperties": true,
  "$defs": {
    "node": {
      "type": "object",
      "description": "A knowledge concept node.",
      "required": ["id", "type"],
      "properties": {
        "id": {
          "type": "string",
          "description": "Unique identifier for the concept (path without .md extension)."
        },
        "slug": {
          "type": "string",
          "description": "Short unique slug for the node (e.g. 'f', 'fc', 'fl'). Computed for compact/URL-friendly references (e.g. #fragments). Stable for a given set of concepts."
        },
        "type": {
          "type": "string",
          "description": "The concept type from frontmatter (e.g. 'BigQuery Table', 'Reference')."
        },
        "title": {
          "type": "string",
          "description": "Display title from frontmatter."
        },
        "description": {
          "type": "string",
          "description": "Short description from frontmatter."
        },
        "resource": {
          "type": "string",
          "description": "Canonical URI for the underlying resource, if any."
        },
        "tags": {
          "type": "array",
          "items": {
            "type": "string"
          },
          "description": "Tags from frontmatter."
        },
        "timestamp": {
          "type": "string",
          "format": "date-time",
          "description": "Timestamp from frontmatter."
        },
        "body": {
          "type": "string",
          "description": "Full markdown body (only present when --body / includeBody was used)."
        },
        "label": {
          "type": "string",
          "description": "Optional display label (falls back to derived values)."
        },
        "path": {
          "type": "string",
          "description": "Relative path to the source .md file within the bundle."
        },
        "degree": {
          "type": "integer",
          "minimum": 0,
          "description": "Total number of connected edges (in + out)."
        },
        "in": {
          "type": "integer",
          "minimum": 0,
          "description": "Number of incoming edges."
        },
        "out": {
          "type": "integer",
          "minimum": 0,
          "description": "Number of outgoing edges."
        },
        "weight": {
          "type": "number",
          "minimum": 0,
          "maximum": 1,
          "description": "PageRank weight (0-1)."
        },
        "rank": {
          "type": "integer",
          "minimum": 1,
          "description": "Rank order by weight."
        }
      },
      "additionalProperties": true
    },
    "edge": {
      "type": "object",
      "description": "A directed link from one concept to another.",
      "required": ["source", "target", "id"],
      "properties": {
        "source": {
          "type": "string",
          "description": "Source node id."
        },
        "target": {
          "type": "string",
          "description": "Target node id."
        },
        "id": {
          "type": "string",
          "description": "Short stable identifier for the edge."
        },
        "label": {
          "type": "string",
          "description": "Human-readable label for the edge (often link text or target title)."
        }
      },
      "additionalProperties": true
    },
    "navNode": {
      "type": "object",
      "description": "A node in the index-driven navigation tree. Directories are not concepts (reserved index.md).",
      "required": ["kind"],
      "properties": {
        "kind": {
          "type": "string",
          "enum": ["group", "dir", "concept", "orphans"],
          "description": "group/orphans are non-routeable grouping headers; dir and concept are navigable."
        },
        "id": {
          "type": "string",
          "description": "Concept id, or directory path relative to bundle root (empty string for root). Omitted for group and orphans."
        },
        "label": {
          "type": "string",
          "description": "Display label (index link text, section heading, or derived title)."
        },
        "description": {
          "type": "string",
          "description": "Optional short description from index entry or concept frontmatter."
        },
        "body": {
          "type": "string",
          "description": "Index markdown for kind=dir (authored after optional root frontmatter strip, or synthetic listing). Parallel to node.body."
        },
        "synthetic": {
          "type": "boolean",
          "description": "True when body/children were synthesized because index.md was missing."
        },
        "children": {
          "type": "array",
          "description": "Child nav nodes (groups, dirs, concepts, trailing orphans).",
          "items": {
            "$ref": "#/$defs/navNode"
          }
        }
      },
      "additionalProperties": true
    }
  }
}