{
      "tool_id": "art-339-compute-gross-to-net",
      "tool_version": "1.0.0",
      "display_name": "Gross-to-Net Payroll Calculator (FICA)",
      "mcp_name": "compute_gross_to_net",
      "mandate_type": "compliance_mandate",
      "wave": 60,
      "gpu": false,
      "url": "https://ainumbers.co/chaingraph/art-339-compute-gross-to-net.html",
      "description": "Gross-to-net payroll calculation: FICA (Social Security 6.2% up to the 2025 $176,100 wage base, Medicare 1.45% uncapped, Additional Medicare Tax 0.9% on cumulative wages over $200,000 per IRC 3101(b)(2)), pretax deduction ordering (401(k)/HSA/Section 125 reduce both FICA and federal-taxable wages), and net pay. federal_withholding_per_period is a declared input, normally fed from art-338-compute-federal-withholding's output, since kernels cannot import one another. Federal only, not tax advice, state withholding and state payroll taxes out of scope. Consumes art-338-compute-federal-withholding. Not compute_federal_withholding itself, which only computes the federal income tax withholding line.",
      "input_schema_ref": "chaingraph/art-339-compute-gross-to-net.html#manifest",
      "consumes": [
        "art-338-compute-federal-withholding"
      ],
      "feeds": [],
      "status": "live",
      "conformance_fixtures": true,
      "compute_capability": "server",
      "compute_images": [{"system":"sha256-source","image_id":"sha256:949b39c2c3461b1855d81d48fe4f12b764bd6dca603183b7909b69d7b0dde81a","valid_from":"2026-07-10"},{"system":"risc0","image_id":"sha256:a1a0bc89b5b1febaeda3519f6dbade0fa5ac16beeb143c4e1b01689573567bc6","valid_from":"2026-07-17"}],
      "export_capability": [
        "json"
      ],
      "compute_proof_ready": "ready",
      "compute_proof": {
        "type": "ZkVmReceipt",
        "system": "risc0",
        "receiptFormat": "groth16-bn254",
        "imageId": "sha256:a1a0bc89b5b1febaeda3519f6dbade0fa5ac16beeb143c4e1b01689573567bc6",
        "seal": "LOps2hfJhoXoTJ430cgjDMysczmJTkdI6tbsKzApCQgCchYwsCh0qBVoE5HdnlEBMskRzqLXs0HfCz5/tFa0VByezs03Og0/bGO64m/+duPF5V7bKmKePwelxaZ8maVQKObf3+bSnJlS6rFj/wdA5KsRJ3mXaIN0t5jFkGcLlc8PTk2XYKDSmyD+6NXWqSYKy75T0eX3lJrrmhVyburYSwoHsT2ASnLIRl3Yi4XrM6aJHvQKK2OsCZC1eTXS1RqNFi7NpSBD2xjnZbeBXSc5mSPXug4GKaSNhJFheCfbjLoIo12D2JGf0ZvF/s2v5Ms1UhOU+3sKXHEdrRF5QnupiA==",
        "journal": {
          "chaingraph_version": "0.4.0",
          "kernel_digest": "sha256:949b39c2c3461b1855d81d48fe4f12b764bd6dca603183b7909b69d7b0dde81a",
          "output": {
            "additional_medicare_tax": 0,
            "additional_medicare_threshold": 200000,
            "additional_medicare_wages_this_period": 0,
            "constants_version": "2025",
            "federal_withholding_per_period": 300,
            "fica_tax_total": 214.2,
            "fica_wages_this_period": 2800,
            "medicare_tax": 40.6,
            "net_pay": 2235.8,
            "note": "Federal FICA and net pay only; not tax advice. State/local withholding and state disability/unemployment employee contributions out of scope. federal_withholding_per_period is a declared input (e.g. from compute_federal_withholding), not recomputed here.",
            "post_tax_other_deductions": 50,
            "pretax_reduces_fica_and_fit": 200,
            "regulatory_basis": "IRC 3101/3121 (FICA); SSA 2025 Contribution and Benefit Base ($176,100 OASDI wage base); IRC 3101(b)(2) Additional Medicare Tax ($200,000 employer-withholding threshold).",
            "social_security_tax": 173.6,
            "ss_taxable_wages_this_period": 2800,
            "ss_wage_base": 176100,
            "ytd_fica_wages_after_period": 12800
          }
        }
      }
    }