{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://methods.nirs4all.org/dashboard.schema.json",
  "title": "n4m dashboard payload (D-min contract)",
  "description": "Canonical contract for the benchmark/parity dashboard payload emitted by docs/_extras/build_landing.py:build_payload and consumed by the dashboard template + the per-method doc pages. The full SPA (Phase D-SPA) will consume the same contract. Forward-compatible: additional keys are allowed; the fields below are the stable surface.",
  "type": "object",
  "required": ["generated_at", "columns", "rows", "method_scores", "stats"],
  "properties": {
    "generated_at": {"type": "string"},
    "columns": {
      "type": "array",
      "items": {
        "type": "object",
        "required": ["id"],
        "properties": {
          "id": {"type": "string"},
          "label": {"type": "string"},
          "group": {"type": "string"},
          "lang": {"type": "string"},
          "kind": {"type": "string"}
        }
      }
    },
    "rows": {
      "type": "array",
      "items": {
        "type": "object",
        "required": ["algo", "n", "p", "threads", "cells"],
        "properties": {
          "algo": {"type": "string"},
          "n": {"type": "integer"},
          "p": {"type": "integer"},
          "threads": {"type": "integer"},
          "cells": {
            "type": "object",
            "description": "Keyed by column id. Each cell carries optional timing + parity verdicts.",
            "additionalProperties": {
              "type": "object",
              "properties": {
                "ms": {"type": ["number", "null"]},
                "ok": {"type": "boolean"},
                "parity": {"type": "string"},
                "reference_parity": {"type": "string"},
                "binding_parity": {"type": "string"},
                "divergence": {"type": ["number", "null"]},
                "divergence_fmt": {"type": "string"},
                "divergence_basis": {"type": "string"},
                "divergence_quality": {"type": "string"},
                "divergence_metric": {"type": "string"},
                "divergence_note": {"type": "string"}
              }
            }
          }
        }
      }
    },
    "method_scores": {
      "type": "object",
      "description": "Per-method score card aggregated across the method's cells. Keyed by algorithm/dashboard id.",
      "additionalProperties": {
        "type": "object",
        "required": ["reference", "binding", "divergence", "timing"],
        "properties": {
          "reference": {
            "type": "object",
            "description": "Reference-parity verdict counts (n4m vs the method's canonical external reference): exact / divergent / not_available / not_run / drift / error.",
            "additionalProperties": {"type": "integer", "minimum": 0}
          },
          "binding": {
            "type": "object",
            "description": "Binding-parity verdict counts (each binding tier vs the C++ core).",
            "additionalProperties": {"type": "integer", "minimum": 0}
          },
          "divergence": {
            "type": "object",
            "required": ["reference", "binding"],
            "properties": {
              "reference": {"$ref": "#/$defs/divergence_stat"},
              "binding": {"$ref": "#/$defs/divergence_stat"}
            }
          },
          "timing": {
            "$ref": "#/$defs/timing_stat"
          }
        }
      }
    },
    "stats": {
      "type": "object",
      "required": ["algos", "backends", "rows", "cells", "ok"],
      "properties": {
        "algos": {"type": "integer"},
        "backends": {"type": "integer"},
        "rows": {"type": "integer"},
        "cells": {"type": "integer"},
        "ok": {"type": "integer"}
      }
    }
  },
  "$defs": {
    "divergence_stat": {
      "type": "object",
      "required": ["max", "median", "n"],
      "properties": {
        "max": {"type": ["number", "null"]},
        "median": {"type": ["number", "null"]},
        "n": {"type": "integer", "minimum": 0}
      }
    },
    "timing_stat": {
      "type": "object",
      "required": ["min_ms", "median_ms", "max_ms", "n"],
      "properties": {
        "min_ms": {"type": ["number", "null"]},
        "median_ms": {"type": ["number", "null"]},
        "max_ms": {"type": ["number", "null"]},
        "n": {"type": "integer", "minimum": 0}
      }
    }
  }
}