{
      "tool_id": "art-230-compute-hmda-rate-spread",
      "tool_version": "1.0.0",
      "display_name": "Compute HMDA Rate Spread",
      "mcp_name": "compute_hmda_rate_spread",
      "mandate_type": "compliance_mandate",
      "wave": 39,
      "gpu": false,
      "url": "https://ainumbers.co/chaingraph/art-230-compute-hmda-rate-spread.html",
      "description": "Computes the HMDA rate spread (APR minus APOR) per FFIEC methodology and classifies against HMDA reportability thresholds: 1.5 pp (first lien), 3.5 pp (subordinate lien), 6.5 pp (HELOC). Outputs rate_spread_pct, lien classification, is_reportable flag, and HPML indicator (1.5 pp first / 3.5 pp sub, triggers escrow and appraisal requirements under TILA). Table version: FFIEC-RATE-SPREAD-METHODOLOGY-2023.",
      "input_schema_ref": "chaingraph/art-230-compute-hmda-rate-spread.html#manifest",
      "consumes": [],
      "feeds": [
        "art-229-compute-disparity-metrics"
      ],
      "status": "live",
      "conformance_fixtures": true,
      "compute_capability": "server",
      "compute_images": [{"system":"sha256-source","image_id":"sha256:bf8ab4e43a576fd89244c8f1a43a0adb3c8ae4fb433d163a90773584efe86b9b","valid_from":"2026-07-10"},{"system":"risc0","image_id":"sha256:a1a0bc89b5b1febaeda3519f6dbade0fa5ac16beeb143c4e1b01689573567bc6","valid_from":"2026-07-04"}],
      "export_capability": [
        "json"
      ],
      "compute_proof_ready": "ready",
      "compute_proof": {
        "type": "ZkVmReceipt",
        "system": "risc0",
        "receiptFormat": "groth16-bn254",
        "imageId": "sha256:a1a0bc89b5b1febaeda3519f6dbade0fa5ac16beeb143c4e1b01689573567bc6",
        "seal": "IJT9CAbHeDeesTcHVb9z87IG23o5sBCe+d/pUW48aCIWs1xf6DqmERQHtlQA7C9AddNG/6kZ98Td3xSpmM54XwNHJiT0Ah6jRMD6XPq70UhlyVGV2UdTCmo01OB6d/+zC1Uv8M5IWIeFj2bHc3OHbN13S2QJjRkU6WA6/q3V8V0jP9wbmIue5Ch1WEMcaDBpxWXyKzTqg4N9FXWhmzFGrCLQvCaEMKuYdOM2M/G5QQMgiTyJ6yLghaOe7daEKBYpCQE+JBG9tYI1677iy8t1NVEMf2YpdAiwpapeUlk4xYQgBRVha55rOoYaTD5RiFriVBXVWG5uc4oPCig2ffGW0g==",
        "journal": {
          "chaingraph_version": "0.4.0",
          "kernel_digest": "sha256:bf8ab4e43a576fd89244c8f1a43a0adb3c8ae4fb433d163a90773584efe86b9b",
          "output": {
            "apor_pct": 5.5,
            "apor_source_note": "APOR must be sourced from FFIEC weekly table at ffiec.gov/ratespread for the applicable lock date and comparable transaction term.",
            "apr_pct": 7,
            "hmda_report_code": "1.500",
            "is_reportable": true,
            "lien_type": "first",
            "lock_date": "2026-01-15",
            "pii_note": "All inputs are processed locally in your browser. No data is transmitted.",
            "product_type": "closed_end",
            "rate_spread_pct": 1.5,
            "regulatory_basis": "12 CFR §1003.4(a)(12); HMDA 12 USC §2801; FFIEC Rate Spread methodology",
            "reportability_threshold_pct": 1.5,
            "table_source": "12 CFR §1003.4(a)(12) (2018 HMDA Final Rule FR 2015-26607, effective Jan 2018); FFIEC Rate Spread Calculator (ffiec.gov/ratespread); first-lien threshold 1.5pp; subordinate 3.5pp; HELOC first-lien 6.5pp",
            "table_version": "HMDA-FFIEC-RATE-SPREAD-2024-12CFR1003"
          }
        }
      }
    }