{
  "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": "percent-change",
    "version": "1.2.0",
    "title": "Percentage Change Calculator",
    "formula_family": "percent_change",
    "capability_id": "math.percent_change",
    "verification_revision": "2026-10-29.math-uuce-fields-v1"
  },
  "profile": "core",
  "status": "VERIFIED",
  "verification_status": "VERIFIED",
  "production_freshness": "CURRENT",
  "overall_trust": "VERIFIED",
  "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": "percent-change",
    "version": "1.2.0",
    "uri": "https://www.calculatorx.com/evidence/math.percent_change/1.2.0.json",
    "verification_revision": "2026-10-29.math-uuce-fields-v1"
  },
  "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": "Curran-Everett — Explorations in statistics: the analysis of change",
        "kind": "other",
        "reference": "Relative change as (final − initial) / initial",
        "url": "https://journals.physiology.org/doi/full/10.1152/advan.00018.2015"
      },
      {
        "label": "CalculatorX signed-change convention",
        "kind": "other",
        "reference": "|V₁| denominator, piecewise inverse, and multiple V₁ solutions"
      },
      {
        "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": "% change = (V2−V1)/|V1|×100%"
    },
    "CVP-SCOPE-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "All published p/v1/v2 directions and three-value consistency; complete signed inverse branches, no/unique/two/infinite solutions; exact binary64-rational formulas rounded ties-even, secondary-field range rejection and input-underflow guards; 8-ULP same-sign consistency with strict zero."
    },
    "CVP-UNIT-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "percent"
    },
    "CVP-REF-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "O1 model + O2 expected_values + O2 numerical_behavior"
    },
    "CVP-GOLD-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "6/6 legacy golden; 108/108 oracle-backed numeric"
    },
    "CVP-BND-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "2/2 CVP boundary · 2/2 legacy Evidence boundary"
    },
    "CVP-INV-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "2 Evidence illegal-input + 23/23 oracle-backed error-code (exact_error_match, not ULP)"
    },
    "CVP-NUM-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "diagnostic_raw_leaf_ulp_max (not an acceptance budget)=0; policy declared a priori"
    },
    "CVP-COV-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "5/5 declared partitions (forward, inverse-v2, inverse-v1, invalid-domain, xcal) · 6 legacy golden / 2 CVP boundary unique cases · 2 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 percent-change; 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": "this calculator CURRENT · bound snapshot pass @ 2026-10-29T09:50:17.083Z · live site-wide report stale @ 2026-10-29T09:50:52.037Z (18 other capabilities) · local checks pass · attestation_id=40e7a05dc161e4cce7ce61ca2a18e81e0b12b04c3bbf14a62ec111a05f943e8f · This calculator CURRENT · This calculator is not affected · Bound attestation PASS @ 2026-10-29T09:50:17.083Z · Live production status STALE (18 capabilities; 358 remain CURRENT) @ 2026-10-29T09:50:52.037Z · Public schema 1.2.0 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓ · schema_const=1.2.0 · 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=04247b6c380c165c9aed6d75d9a913ff0febd08ce53bc1aeb7bf561a0dc53e62 · verified_at=2026-10-29T09:10:42.752Z · evidence_attested_at=2026-10-29T09:10:42.752Z · last_confirmed_current_at=2026-10-29T09:50:17.083Z · rendered_at=2026-10-29T09:50:52.726Z · binds=cvp_core_sha256",
      "check_result": "PASS",
      "production_state": "CURRENT",
      "binding_current": true
    },
    "CVP-DIM-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "relative change"
    },
    "CVP-PROP-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "5/5 property"
    },
    "CVP-META-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "1/1 metamorphic"
    },
    "CVP-ROUND-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "4/4 round-trips"
    },
    "CVP-XCAL-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "3/3 cross-calculator · xcal-pc-40-50 PASS vs math.percentage; xcal-pc-neg100-neg50 PASS vs math.percentage; xcal-pc-old0 PASS vs math.percentage; 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.); xcal-compound-na N/A (Compound interest is listed as a related growth tool. It compounds over periods; it does not encode a one-step |V1| percent change.)"
    },
    "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 2/2 (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 2/2 (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": "09fad8f696e8d9ef23a7f01e71ef638ff938fa72490b500a2611009532078554",
    "evidence_digest": "60c22e494c866f45948421619716f7bf8b85bae1716e9d3932e872e1c89d7714",
    "production_sha256": "04247b6c380c165c9aed6d75d9a913ff0febd08ce53bc1aeb7bf561a0dc53e62",
    "attested_catalog_sha256": "0ae84cdda4265706da5640db58e61e30e0a60e16c65f8eaba247dd5f28369b16",
    "production_checks": [
      {
        "id": "math.percent_change:output-const",
        "status": "pass",
        "detail": "output const 1.2.0 vs capability 1.2.0",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-29T09:10:42.752Z"
      },
      {
        "id": "math.percent_change:evidence-sha256",
        "status": "pass",
        "detail": "636667e675bc",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-29T09:10:42.752Z"
      },
      {
        "id": "math.percent_change:semantic-contract",
        "status": "pass",
        "detail": "8/8",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-29T09:10:42.752Z"
      },
      {
        "id": "math.percent_change:capability-html-public-origin-agree",
        "status": "pass",
        "detail": "public 1.2.0 vs origin 1.2.0",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-29T09:10:42.752Z"
      },
      {
        "id": "math.percent_change:cvp-manifest-public-origin-agree",
        "status": "pass",
        "detail": "math.percent_change/1.2.0/2026-10-29.math-uuce-fields-v1/core/60c22e494c86",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-29T09:10:42.752Z",
        "projection_compared": false
      },
      {
        "id": "math.percent_change:cvp-latest-alias-agrees",
        "status": "pass",
        "detail": "math.percent_change/1.2.0/2026-10-29.math-uuce-fields-v1/core/60c22e494c86",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-29T09:10:42.752Z",
        "projection_compared": false
      },
      {
        "id": "math.percent_change:cvp-immutable-manifest-fetch",
        "status": "pass",
        "detail": "public=200 origin=200",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-29T09:10:42.752Z"
      },
      {
        "id": "math.percent_change:cvp-immutable-manifest-sha256",
        "status": "pass",
        "detail": "60c22e494c86",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-29T09:10:42.752Z"
      },
      {
        "id": "math.percent_change:cvp-latest-alias-matches-immutable",
        "status": "pass",
        "detail": "math.percent_change/1.2.0/2026-10-29.math-uuce-fields-v1/core/60c22e494c86",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-29T09:10:42.752Z",
        "projection_compared": false
      },
      {
        "id": "math.percent_change:calculator-html-cvp-projection",
        "status": "pass",
        "detail": "matches Trust display",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-29T09:10:42.752Z"
      },
      {
        "id": "math.percent_change:evidence-html-cvp-projection",
        "status": "pass",
        "detail": "matches Trust display",
        "scope": "last_attestation_snapshot",
        "current": true,
        "attestation_binding_current": true,
        "attested_at": "2026-10-29T09:10:42.752Z"
      }
    ],
    "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": "60c22e494c866f45948421619716f7bf8b85bae1716e9d3932e872e1c89d7714",
          "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": "60c22e494c866f45948421619716f7bf8b85bae1716e9d3932e872e1c89d7714",
          "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": "636667e675bc125203f5ec7735b8ea0014b32598cb8c7f51fddf8923c5cb7773",
          "note": "Published Evidence JSON core — Trust freshness / production bind subject"
        },
        {
          "name": "evidence_catalog_digest",
          "field": "artifacts.attested_catalog_sha256",
          "digest_scope": "capability_catalog",
          "value": "0ae84cdda4265706da5640db58e61e30e0a60e16c65f8eaba247dd5f28369b16",
          "note": "Capability catalog integrity; site-wide, not per-suite fingerprint"
        }
      ]
    },
    "cvp_core_sha256": "60c22e494c866f45948421619716f7bf8b85bae1716e9d3932e872e1c89d7714"
  },
  "dependencies": [
    {
      "name": "percent-change-engine",
      "version": "1.2.0"
    },
    {
      "name": "percent-change-reference-oracle",
      "version": "1.0.0"
    },
    {
      "name": "math.percentage",
      "version": "1.2.0",
      "role": "cross_calculator_peer",
      "capability_id": "math.percentage",
      "evidence_digest": "3c8e981c1c1f04f97ffac3c1bf12514046010ae953da7d480374e7a6c5a8fa6e",
      "evidence": "https://www.calculatorx.com/evidence/math.percentage/1.2.0.cvp.json"
    },
    {
      "name": "node",
      "version": "22.20.0"
    }
  ],
  "attestation": {
    "status": "CURRENT",
    "href": "/.well-known/calculatorx-production-attestation.json",
    "id": "40e7a05dc161e4cce7ce61ca2a18e81e0b12b04c3bbf14a62ec111a05f943e8f",
    "attested_at": "2026-10-29T09:10:42.752Z",
    "last_confirmed_current_at": "2026-10-29T09:50:17.083Z",
    "site_attestation_current": false,
    "capability_attestation_current": true,
    "bound_snapshot_status": "pass",
    "live_report_status": "stale",
    "bound_attested_at": "2026-10-29T09:50:17.083Z",
    "live_updated_at": "2026-10-29T09:50:52.037Z",
    "bound_snapshot": {
      "status": "pass",
      "attested_at": "2026-10-29T09:50:17.083Z",
      "site_stale_count": 18
    },
    "live_site_status": {
      "href": "/.well-known/calculatorx-production-attestation.json"
    },
    "bound_snapshot_site_stale_count": 18,
    "site_stale_capability_count": 18,
    "evidence_attested_at": "2026-10-29T09:10:42.752Z"
  },
  "domain_review": {
    "status": "ABSENT",
    "spec_version": "1.2.0",
    "external_third_party": false,
    "note": "Named expert review not performed"
  },
  "timestamps": {
    "verified_at": "2026-10-29T09:10:42.752Z",
    "generated_at": "2026-10-29T09:10:42.752Z",
    "rendered_at": "2026-10-29T09:50:52.726Z",
    "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": 108,
      "total": 108,
      "failed": 0
    },
    "boundary": {
      "passed": 2,
      "total": 2,
      "failed": 0
    },
    "invalid": {
      "passed": 25,
      "total": 25,
      "failed": 0,
      "comparison": "exact_error_match"
    },
    "property": {
      "passed": 5,
      "total": 5,
      "failed": 0
    },
    "round_trip": {
      "passed": 4,
      "total": 4,
      "failed": 0
    },
    "metamorphic": {
      "passed": 1,
      "total": 1,
      "failed": 0
    },
    "contract": {
      "passed": 6,
      "total": 6,
      "failed": 0
    },
    "cross_interface": {
      "passed": 7,
      "total": 7,
      "failed": 0
    },
    "cross_calculator": {
      "passed": 3,
      "total": 3,
      "failed": 0
    }
  },
  "numerical": {
    "representation": "Exact signed formulas of normalized binary64 inputs; one ties-even rounding per field",
    "tolerance": {
      "type": "ulp",
      "value": 0,
      "rationale": "Independent CPython Fraction/float expected primary, secondary and complete inverse branch set; exact0ULP arithmetic comparison. Separate triple-input consistency uses8ULP same-sign nonzero with strict zero.",
      "declared_before_evaluation": true
    },
    "max_error_observed": 0,
    "error_metric": "diagnostic_raw_leaf_ulp",
    "comparison_evidence_protocol": "scoped-comparison-v1",
    "max_error_observed_scope": "Raw finite matching numeric leaves across records/hops; diagnostic only. Acceptance is the per-record/hop comparison predicate and its declared scoped policy."
  },
  "coverage": {
    "partitions": [
      {
        "id": "forward",
        "description": "Forward % change from V1, V2",
        "exercised": true,
        "case_count": 56
      },
      {
        "id": "inverse-v2",
        "description": "Solve final V2",
        "exercised": true,
        "case_count": 38
      },
      {
        "id": "inverse-v1",
        "description": "Solve initial V1",
        "exercised": true,
        "case_count": 33
      },
      {
        "id": "invalid-domain",
        "description": "Invalid inputs",
        "exercised": true,
        "case_count": 25
      },
      {
        "id": "xcal",
        "description": "Cross-calculator |old| identity vs Percentage Change mode; Percent error / VAT / Compound interest N/A",
        "exercised": true,
        "case_count": 3
      }
    ]
  },
  "reference": {
    "items": [
      {
        "class": "O1",
        "reference_scope": "model",
        "scope": "model",
        "label": "Signed percent change with |V1| denominator"
      },
      {
        "class": "O2",
        "reference_scope": "expected_values",
        "scope": "expected_values",
        "label": "Independent CPython Fraction complete signed inverse set",
        "engine": {
          "name": "CPython Fraction/float",
          "precision_bits": 53,
          "independent_of_iut": true,
          "same_runtime_as_iut": false
        }
      },
      {
        "class": "O2",
        "reference_scope": "numerical_behavior",
        "scope": "numerical_behavior",
        "label": "Independent CPython Fraction complete signed inverse set",
        "engine": {
          "name": "CPython Fraction/float",
          "precision_bits": 53,
          "independent_of_iut": true,
          "same_runtime_as_iut": false
        }
      }
    ]
  },
  "links": {
    "legacy_evidence": "https://www.calculatorx.com/evidence/math.percent_change/1.2.0.json",
    "evidence_page": "https://www.calculatorx.com/evidence/math.percent_change/1.2.0",
    "calculator": "https://www.calculatorx.com/calc/math/percentage-change",
    "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.percent_change/1.2.0.cvp.json",
    "manifest_immutable": "https://www.calculatorx.com/evidence/math.percent_change/1.2.0/2026-10-29.math-uuce-fields-v1.cvp.json",
    "manifest_core": "https://www.calculatorx.com/evidence/math.percent_change/1.2.0/2026-10-29.math-uuce-fields-v1.60c22e494c86.cvp.json"
  },
  "disclosure": {
    "policy": "calculatorx-public-evidence-v1",
    "full_validation": "private",
    "representation": "summary"
  }
}