{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://declawd.com/contracts/declawd.synthid-profile-v1.schema.json",
  "title": "Declawd public SynthID teaching profile",
  "type": "object",
  "additionalProperties": false,
  "required": ["schema", "purpose", "reference", "parameters", "hash", "sampling_table", "scoring"],
  "properties": {
    "schema": {"const": "declawd.synthid-profile/v1"},
    "purpose": {"const": "educational reproduction of a public reference profile; not a production detector"},
    "reference": {
      "type": "object",
      "additionalProperties": false,
      "required": ["software", "version", "commit", "licence", "transfer_limitation"],
      "properties": {
        "software": {"const": "google-deepmind/synthid-text"},
        "version": {"const": "0.2.1"},
        "commit": {"const": "8f2e2316904ea7291ac96e30eb394c453dcc577b"},
        "licence": {"const": "Apache-2.0"},
        "transfer_limitation": {"const": "The reference repository says its hashing differs from Gemini production and its detectors do not transfer. No compatibility with Anthropic is claimed."}
      }
    },
    "parameters": {
      "type": "object",
      "additionalProperties": false,
      "required": ["ngram_len", "keys", "context_history_size"],
      "properties": {
        "ngram_len": {"const": 5},
        "keys": {
          "const": [
            654, 400, 836, 123, 340, 443, 597, 160, 57, 29,
            590, 639, 13, 715, 468, 990, 966, 226, 324, 585,
            118, 504, 421, 521, 129, 669, 732, 225, 90, 960
          ]
        },
        "context_history_size": {"const": 1024}
      }
    },
    "hash": {
      "type": "object",
      "additionalProperties": false,
      "required": ["integer", "initial", "recurrence", "table_index"],
      "properties": {
        "integer": {"const": "signed twos-complement i64 with wrapping after every operation"},
        "initial": {"const": 1},
        "recurrence": {"const": "h = (h + datum) * 6364136223846793005 + 1"},
        "table_index": {"const": "Euclidean remainder modulo 65536"}
      }
    },
    "sampling_table": {
      "type": "object",
      "additionalProperties": false,
      "required": ["size_bits", "seed", "generator", "device", "packing", "path", "byte_length", "sha256", "runtime_policy"],
      "properties": {
        "size_bits": {"const": 65536},
        "seed": {"const": 0},
        "generator": {"const": "torch 2.4.0 torch.randint(low=0, high=2)"},
        "device": {"const": "cpu"},
        "packing": {"const": "LSB0"},
        "path": {"const": "fixtures/synthid/sampling-table-v1.bin"},
        "byte_length": {"const": 8192},
        "sha256": {"const": "4b2efa3fbbaa5f77facce45f2c2af38ba36436b2b2b81f950005fa8af266fd3c"},
        "runtime_policy": {"const": "consume committed bitset; never regenerate at runtime"}
      }
    },
    "scoring": {
      "type": "object",
      "additionalProperties": false,
      "required": ["raw_denominator", "weighted_weights", "weighted_weight_sum", "weighted_denominator", "fractions", "decimal"],
      "properties": {
        "raw_denominator": {"const": "30 * valid_context_count"},
        "weighted_weights": {
          "const": [
            290, 281, 272, 263, 254, 245, 236, 227, 218, 209,
            200, 191, 182, 173, 164, 155, 146, 137, 128, 119,
            110, 101, 92, 83, 74, 65, 56, 47, 38, 29
          ]
        },
        "weighted_weight_sum": {"const": 4785},
        "weighted_denominator": {"const": "4785 * valid_context_count"},
        "fractions": {"const": "unreduced"},
        "decimal": {"const": "12 fractional places, integer round-half-to-even"}
      }
    }
  }
}