{
  "protocol": {
    "name": "CVP",
    "version": "1.0.0-proposed",
    "revision": "2026-09-13",
    "spec_sha256": "f62725968356c92930531cd6085db76e216da06e95be53d636b0d2cf3218b148",
    "spec": "https://www.calculatorx.com/developers/cvp/spec/1.0"
  },
  "document_status": "proposed",
  "calculator": {
    "id": "percentage",
    "version": "1.1.2",
    "title": "Percentage Calculator",
    "formula_family": "percentage",
    "capability_id": "math.percentage",
    "verification_revision": "2026-10-21.percentage-complete-contract-v2"
  },
  "profile": "core",
  "status": "STALE",
  "verification_status": "VERIFIED",
  "production_freshness": "STALE",
  "overall_trust": "VERIFIED_STALE",
  "runner": {
    "name": "cvp-runner",
    "version": "1.0.0"
  },
  "environment": {
    "runtime": "node",
    "runtime_version": "22.20.0",
    "numeric_model": "IEEE-754 binary64",
    "os": "darwin"
  },
  "suite": {
    "id": "percentage",
    "version": "1.1.2",
    "uri": "https://www.calculatorx.com/evidence/math.percentage/1.1.2.json",
    "verification_revision": "2026-10-21.percentage-complete-contract-v2"
  },
  "obligation_set": [
    "CVP-PROV-01",
    "CVP-MODEL-01",
    "CVP-SCOPE-01",
    "CVP-UNIT-01",
    "CVP-REF-01",
    "CVP-GOLD-01",
    "CVP-BND-01",
    "CVP-INV-01",
    "CVP-NUM-01",
    "CVP-COV-01",
    "CVP-CONTRACT-01",
    "CVP-DEP-01",
    "CVP-ART-01",
    "CVP-PROD-01",
    "CVP-DIM-01",
    "CVP-PROP-01",
    "CVP-META-01",
    "CVP-ROUND-01",
    "CVP-XCAL-01",
    "CVP-IFACE-01"
  ],
  "provenance": {
    "mode": "direct",
    "sources": [
      {
        "label": "BIPM — The International System of Units (SI), 9th edition",
        "kind": "other",
        "reference": "Units accepted for use with the SI — percent (symbol %), 1% = 0.01",
        "url": "https://www.bipm.org/en/publications/si-brochure"
      },
      {
        "label": "NIST Special Publication 811 — Guide for the Use of the International System of Units (SI)",
        "kind": "other",
        "reference": "Writing values of quantities — the percent",
        "url": "https://www.nist.gov/pml/special-publication-811"
      },
      {
        "label": "CalculatorX percentage conventions",
        "kind": "other",
        "reference": "Six phrase modes, |old| percent change, non-negative percentage difference"
      },
      {
        "label": "NIST — SI Unit Rules and Style Conventions",
        "kind": "other",
        "reference": "Percent and fractions",
        "url": "https://physics.nist.gov/cuu/Units/checklist.html"
      }
    ]
  },
  "controls": {
    "CVP-PROV-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "Sources present on evidence"
    },
    "CVP-MODEL-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "All seven percentage operations; exact rational formulas of normalized binary64 operands, one ties-even rounding; complete typed secondary results"
    },
    "CVP-SCOPE-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "All seven modes; sampled numeric scales, signed inputs, exact zeros, denominator/domain errors, representable subnormals; nonzero conversion and output under/overflow rejected, including delta and average. Independent CPython Fraction reference; private280-case corpus."
    },
    "CVP-UNIT-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "percent / dimensionless"
    },
    "CVP-REF-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "O1 model + O2 expected_values + O2 numerical_behavior"
    },
    "CVP-GOLD-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "12/12 legacy golden; 253/253 oracle-backed numeric"
    },
    "CVP-BND-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "7/7 CVP boundary · 7/7 legacy Evidence boundary"
    },
    "CVP-INV-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "7 Evidence illegal-input + 27/27 oracle-backed error-code (exact_error_match, not ULP)"
    },
    "CVP-NUM-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "max_error_observed_ulp=0; policy declared a priori"
    },
    "CVP-COV-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "9/9 declared partitions (of, is-what, of-what, change, adjust-up, adjust-down, difference, invalid-domain, xcal) · 12 legacy golden / 7 CVP boundary unique cases · 7 Evidence invalid-input (may overlap boundary)"
    },
    "CVP-CONTRACT-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "6/6 CVP contract · release-artifacts-aligned=PASS · schema-output-required-declared=PASS · schema-valid-input-executes=PASS · engine-success-output-validates-schema=PASS · schema-rejects-incomplete-input=PASS · rest-success-payload-validates-schema=PASS"
    },
    "CVP-DEP-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "engine percentage; Node binary64"
    },
    "CVP-ART-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "release_integrity.status=verified · digests: artifact_evidence_sha256=Evidence core (Trust freshness) · cvp_evidence_digest=artifacts.evidence_digest (fingerprint v2) · evidence_bundle_sha256=legacy Evidence JSON bytes · evidence_catalog_digest=attested_catalog_sha256 · production_sha256=bound production report · see artifacts.digest_registry"
    },
    "CVP-PROD-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "Capability production binding: STALE · Site report: stale · STALE (freshness / digest drift after last PASS snapshot) · site report stale · local checks pass · local production checks PASS; capability production binding is not CURRENT — final status must stay STALE, not VERIFIED · attestation_id=cb614f6316a4a99e61eb83d940f937a7c264e05cb52f3e289bd091d67fdff824 · Capability production binding: STALE · Site report: STALE · Public schema 1.1.2 observed · production binding STALE · Semantic contract ✓ · Last attestation PASS · Evidence changed after the last successful production attestation. Re-attestation required. · Public/cache ✓ · Origin ✓ · schema_const=1.1.2 · report output-const=pass · evidence-sha256=pass · semantic-contract=pass · capability-html-public-origin-agree=pass · cvp-manifest-public-origin-agree=pass · cvp-latest-alias-agrees=pass · cvp-immutable-manifest-fetch=pass · cvp-immutable-manifest-sha256=pass · cvp-latest-alias-matches-immutable=pass · calculator-html-cvp-projection=pass · evidence-html-cvp-projection=pass · attested_evidence_sha256=7c83e318abf41b280fd1a6c860fa53b512cf36456702de13f93c9f6aaf70ab30 · verified_at=2026-10-21T10:48:18.266Z · evidence_attested_at=2026-10-21T10:48:18.266Z · last_confirmed_current_at=2026-10-21T10:48:18.266Z · rendered_at=2026-10-21T10:48:18.266Z · binds=cvp_core_sha256 · Capability production binding: STALE · Site report: STALE · Evidence changed after the last successful production attestation. Re-attestation required.",
      "check_result": "PASS",
      "production_state": "STALE",
      "binding_current": false
    },
    "CVP-DIM-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "ratio×100"
    },
    "CVP-PROP-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "2/2 property"
    },
    "CVP-META-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "2/2 metamorphic"
    },
    "CVP-ROUND-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "2/2 round-trips"
    },
    "CVP-XCAL-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "3/3 cross-calculator · xcal-pc-40-50 PASS vs math.percent_change; xcal-pc-neg100-neg50 PASS vs math.percent_change; xcal-pc-old0 PASS vs math.percent_change; xcal-pe-na N/A (Percent error is listed as a related tool. It encodes |experimental−true|/|true|, not Δ%=100×(new−old)/|old|.); xcal-vat-na N/A (VAT is listed as a related finance tool. It does not encode the |old| percent-change identity used by Change mode.); xcal-fractions-na N/A (Fractions is listed as a related conversion tool. It does not encode Δ%=100×(new−old)/|old|.)"
    },
    "CVP-IFACE-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "UI (SSR) · REST · MCP equivalent (MCP uses calc API handler). ui-ssr is query-result HTML, not a live browser session. Error-path engine·REST·MCP 7/7 (status, code, calculation_version). SSR compared on URL-canonical requested calculations; empty query is idle (not an error) and JSON-typed object/array inputs are REST/MCP-only."
    },
    "CVP-ORACLE-01": {
      "result": "SKIP",
      "applicability": "higher_assurance",
      "notes": "O2 present; O3 not required this wave"
    },
    "CVP-EXP-01": {
      "result": "SKIP",
      "applicability": "optional",
      "notes": "named expert review not performed"
    }
  },
  "interfaces": {
    "compared": [
      "ui-ssr",
      "rest",
      "mcp"
    ],
    "result": "PASS",
    "notes": "UI (SSR) · REST · MCP equivalent (MCP uses calc API handler). ui-ssr is query-result HTML, not a live browser session. Error-path engine·REST·MCP 7/7 (status, code, calculation_version). SSR compared on URL-canonical requested calculations; empty query is idle (not an error) and JSON-typed object/array inputs are REST/MCP-only."
  },
  "artifacts": {
    "evidence_bundle_sha256": "850521ddc5782add9e97bcbbdf0ef6dbbe07658bbc7fce28944764defcd46206",
    "evidence_digest": "9cbd3aac385f83b517ed93a52f0ebbf2a360bf18b7ca59a3330a3d91ef27400c",
    "production_sha256": "7c83e318abf41b280fd1a6c860fa53b512cf36456702de13f93c9f6aaf70ab30",
    "attested_catalog_sha256": "9b96a2c8fbf62a8306adee80ae161d6b6eeb7d64addac11a3cc4670eb22d2635",
    "production_checks": [
      {
        "id": "math.percentage:output-const",
        "status": "pass",
        "detail": "output const 1.1.1 vs capability 1.1.1",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-21T10:48:18.266Z"
      },
      {
        "id": "math.percentage:evidence-sha256",
        "status": "pass",
        "detail": "3b56cfdc6586",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-21T10:48:18.266Z"
      },
      {
        "id": "math.percentage:semantic-contract",
        "status": "pass",
        "detail": "19/19",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-21T10:48:18.266Z"
      },
      {
        "id": "math.percentage:capability-html-public-origin-agree",
        "status": "pass",
        "detail": "public 1.1.1 vs origin 1.1.1",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-21T10:48:18.266Z"
      },
      {
        "id": "math.percentage:cvp-manifest-public-origin-agree",
        "status": "pass",
        "detail": "math.percentage/1.1.2/2026-10-21.percentage-complete-contract-v2/core/9cbd3aac385f",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-21T10:48:18.266Z",
        "projection_compared": false
      },
      {
        "id": "math.percentage:cvp-latest-alias-agrees",
        "status": "pass",
        "detail": "math.percentage/1.1.2/2026-10-21.percentage-complete-contract-v2/core/9cbd3aac385f",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-21T10:48:18.266Z",
        "projection_compared": false
      },
      {
        "id": "math.percentage:cvp-immutable-manifest-fetch",
        "status": "pass",
        "detail": "public=200 origin=200",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-21T10:48:18.266Z"
      },
      {
        "id": "math.percentage:cvp-immutable-manifest-sha256",
        "status": "pass",
        "detail": "e1b745d88212",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-21T10:48:18.266Z"
      },
      {
        "id": "math.percentage:cvp-latest-alias-matches-immutable",
        "status": "pass",
        "detail": "math.percentage/1.1.2/2026-10-21.percentage-complete-contract-v2/core/9cbd3aac385f",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-21T10:48:18.266Z",
        "projection_compared": false
      },
      {
        "id": "math.percentage:calculator-html-cvp-projection",
        "status": "pass",
        "detail": "matches Trust display",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-21T10:48:18.266Z"
      },
      {
        "id": "math.percentage:evidence-html-cvp-projection",
        "status": "pass",
        "detail": "matches Trust display",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-21T10:48:18.266Z"
      }
    ],
    "digest_registry": {
      "digest_algorithm": "sha256",
      "canonicalization": "json-sorted-keys-utf8",
      "entries": [
        {
          "name": "cvp_core_sha256",
          "field": "artifacts.cvp_core_sha256",
          "digest_scope": "cvp_verification_fingerprint_v2",
          "value": "9cbd3aac385f83b517ed93a52f0ebbf2a360bf18b7ca59a3330a3d91ef27400c",
          "note": "Immutable verification core; excludes attestation/live-status and Evidence contract counts"
        },
        {
          "name": "cvp_evidence_digest",
          "field": "artifacts.evidence_digest",
          "digest_scope": "cvp_verification_fingerprint_v2",
          "value": "9cbd3aac385f83b517ed93a52f0ebbf2a360bf18b7ca59a3330a3d91ef27400c",
          "note": "Alias of cvp_core_sha256 (historical field name)"
        },
        {
          "name": "artifact_evidence_sha256",
          "field": "release_integrity.digests.evidence_core_sha256",
          "digest_scope": "evidence_artifact_core",
          "value": "e479df2a911dca38072803af60aec01ab083259b5f2098ac2491c810f4a888c4",
          "note": "Published Evidence JSON core — Trust freshness / production bind subject"
        },
        {
          "name": "evidence_catalog_digest",
          "field": "artifacts.attested_catalog_sha256",
          "digest_scope": "capability_catalog",
          "value": "9b96a2c8fbf62a8306adee80ae161d6b6eeb7d64addac11a3cc4670eb22d2635",
          "note": "Capability catalog integrity; site-wide, not per-suite fingerprint"
        }
      ]
    },
    "cvp_core_sha256": "9cbd3aac385f83b517ed93a52f0ebbf2a360bf18b7ca59a3330a3d91ef27400c"
  },
  "dependencies": [
    {
      "name": "percentage-engine",
      "version": "1.1.2"
    },
    {
      "name": "percentage-reference-oracle",
      "version": "1.0.0"
    },
    {
      "name": "math.percent_change",
      "version": "1.1.0",
      "role": "cross_calculator_peer",
      "capability_id": "math.percent_change",
      "evidence_digest": "a7b9f7091c43c5bcbbe43d4be80b6d8bf8da4dc19f2e908b2b261cd959c5b968",
      "evidence": "https://www.calculatorx.com/evidence/math.percent_change/1.1.0.cvp.json"
    },
    {
      "name": "node",
      "version": "22.20.0"
    }
  ],
  "attestation": {
    "status": "STALE",
    "href": "/.well-known/calculatorx-production-attestation.json",
    "id": "cb614f6316a4a99e61eb83d940f937a7c264e05cb52f3e289bd091d67fdff824",
    "attested_at": "2026-10-21T10:48:18.266Z",
    "last_confirmed_current_at": "2026-10-21T10:48:18.266Z",
    "site_attestation_current": false,
    "capability_attestation_current": false,
    "bound_snapshot_status": "pass",
    "live_report_status": "stale",
    "bound_attested_at": "2026-10-21T08:56:09.611Z",
    "live_updated_at": "2026-10-21T10:40:40.492Z",
    "bound_snapshot": {
      "status": "pass",
      "attested_at": "2026-10-21T08:56:09.611Z",
      "site_stale_count": 1
    },
    "live_site_status": {
      "href": "/.well-known/calculatorx-production-attestation.json"
    },
    "bound_snapshot_site_stale_count": 1,
    "site_stale_capability_count": 1,
    "stale_reason": "Capability production binding: STALE · Site report: STALE · Evidence changed after the last successful production attestation. Re-attestation required.",
    "evidence_attested_at": "2026-10-21T10:48:18.266Z"
  },
  "domain_review": {
    "status": "ABSENT",
    "spec_version": "1.1.2",
    "external_third_party": false,
    "note": "Named expert review not performed"
  },
  "timestamps": {
    "verified_at": "2026-10-21T10:48:18.266Z",
    "generated_at": "2026-10-21T10:48:18.266Z",
    "rendered_at": "2026-10-21T10:48:18.266Z",
    "notes": "verified_at/generated_at mark the first publication of this cvp_core_sha256 (artifacts.evidence_digest alias) for suite verification. evidence_attested_at/attested_at is the first production bind of that core digest. last_confirmed_current_at is the latest site-wide report that still confirms CURRENT. rendered_at is this JSON serialization and is not part of cvp_core_sha256 / evidence_digest. Production attestation binds cvp_core_sha256 (binds evidence_digest). Causal order: verified_at ≤ evidence_attested_at ≤ last_confirmed_current_at. attestation.bound_snapshot.site_stale_count is the site-wide stale capability count at Manifest bind time — not a live value. Fetch attestation.live_site_status.href for the current site report."
  },
  "tests": {
    "golden": {
      "passed": 253,
      "total": 253,
      "failed": 0
    },
    "boundary": {
      "passed": 7,
      "total": 7,
      "failed": 0
    },
    "invalid": {
      "passed": 34,
      "total": 34,
      "failed": 0,
      "comparison": "exact_error_match"
    },
    "property": {
      "passed": 2,
      "total": 2,
      "failed": 0
    },
    "round_trip": {
      "passed": 2,
      "total": 2,
      "failed": 0
    },
    "metamorphic": {
      "passed": 2,
      "total": 2,
      "failed": 0
    },
    "contract": {
      "passed": 6,
      "total": 6,
      "failed": 0
    },
    "cross_interface": {
      "passed": 14,
      "total": 14,
      "failed": 0
    },
    "cross_calculator": {
      "passed": 3,
      "total": 3,
      "failed": 0
    }
  },
  "numerical": {
    "representation": "Binary64 inputs, exact rational percentage expression, one ties-to-even output rounding",
    "tolerance": {
      "type": "ulp",
      "value": 0,
      "rationale": "CPython Fraction/float independently rounds the exact formula of normalized binary64 inputs. Exact equality, including zero and sign; no relative floor.",
      "declared_before_evaluation": true
    },
    "max_error_observed": 0
  },
  "coverage": {
    "partitions": [
      {
        "id": "of",
        "description": "What is P% of X",
        "exercised": true,
        "case_count": 45
      },
      {
        "id": "is-what",
        "description": "X is what % of Y",
        "exercised": true,
        "case_count": 38
      },
      {
        "id": "of-what",
        "description": "X is P% of what",
        "exercised": true,
        "case_count": 37
      },
      {
        "id": "change",
        "description": "Percent change old→new",
        "exercised": true,
        "case_count": 40
      },
      {
        "id": "adjust-up",
        "description": "Increase X by P%",
        "exercised": true,
        "case_count": 39
      },
      {
        "id": "adjust-down",
        "description": "Decrease X by P%",
        "exercised": true,
        "case_count": 39
      },
      {
        "id": "difference",
        "description": "Percent difference",
        "exercised": true,
        "case_count": 36
      },
      {
        "id": "invalid-domain",
        "description": "Invalid inputs",
        "exercised": true,
        "case_count": 34
      },
      {
        "id": "xcal",
        "description": "Cross-calculator |old| percent change vs Percentage Change; Percent error / VAT / Fractions N/A",
        "exercised": true,
        "case_count": 3
      }
    ]
  },
  "reference": {
    "items": [
      {
        "class": "O1",
        "reference_scope": "model",
        "scope": "model",
        "label": "Percent as 0.01 with phrase algebra"
      },
      {
        "class": "O2",
        "reference_scope": "expected_values",
        "scope": "expected_values",
        "label": "Independent CPython Fraction percentage algebra",
        "engine": {
          "name": "CPython Fraction and float",
          "precision_bits": 53,
          "independent_of_iut": true
        }
      },
      {
        "class": "O2",
        "reference_scope": "numerical_behavior",
        "scope": "numerical_behavior",
        "label": "Independent CPython Fraction percentage algebra",
        "engine": {
          "name": "CPython Fraction and float",
          "precision_bits": 53,
          "independent_of_iut": true
        }
      }
    ]
  },
  "links": {
    "legacy_evidence": "https://www.calculatorx.com/evidence/math.percentage/1.1.2.json",
    "evidence_page": "https://www.calculatorx.com/evidence/math.percentage/1.1.2",
    "calculator": "https://www.calculatorx.com/calc/math/percentage",
    "schema": "https://www.calculatorx.com/developers/cvp/schema/cvp-evidence-1.0.json",
    "protocol": "https://www.calculatorx.com/developers/cvp/spec/1.0",
    "manifest": "https://www.calculatorx.com/evidence/math.percentage/1.1.2.cvp.json",
    "manifest_immutable": "https://www.calculatorx.com/evidence/math.percentage/1.1.2/2026-10-21.percentage-complete-contract-v2.cvp.json",
    "manifest_core": "https://www.calculatorx.com/evidence/math.percentage/1.1.2/2026-10-21.percentage-complete-contract-v2.9cbd3aac385f.cvp.json"
  },
  "disclosure": {
    "policy": "calculatorx-public-evidence-v1",
    "full_validation": "private",
    "representation": "summary"
  }
}