{
  "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": "cos",
    "version": "1.0.6",
    "title": "Cosine Calculator",
    "formula_family": "cosine",
    "capability_id": "math.cos",
    "verification_revision": "2026-10-28.meta-metrics-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": "cos",
    "version": "1.0.6",
    "uri": "https://www.calculatorx.com/evidence/math.cos/1.0.6.json",
    "verification_revision": "2026-10-28.meta-metrics-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": "NIST Digital Library of Mathematical Functions, Chapter 4",
        "kind": "other",
        "reference": "Elementary Functions",
        "url": "https://dlmf.nist.gov/4"
      },
      {
        "label": "NIST DLMF §4.14",
        "kind": "other",
        "reference": "Definitions and period of sine and cosine",
        "url": "https://dlmf.nist.gov/4.14"
      },
      {
        "label": "CalculatorX mathematical conventions",
        "kind": "other",
        "reference": "Degree default; listed-identity exact values; inverse is Arccos"
      }
    ]
  },
  "controls": {
    "CVP-PROV-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "Sources present on evidence"
    },
    "CVP-MODEL-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "cos(theta) with signed degree reduction or Math.cos radians; ratio mode adjacent/hypotenuse"
    },
    "CVP-SCOPE-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "99 independent Decimal420/620 and Fraction references; strict aliases/decimal inputs and bounded symbolic recognition; ratio mode; 2ULP fixed-vector budget, not whole-domain guarantee"
    },
    "CVP-UNIT-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "angle in; dimensionless out"
    },
    "CVP-REF-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "O1 model + O3 expected_values/numerical_behavior (mpmath table) + O2 live identities"
    },
    "CVP-GOLD-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "4/4 legacy golden; 103/103 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 + 25/25 oracle-backed error-code (exact_error_match, not ULP)"
    },
    "CVP-NUM-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "≤2 ULP vs O3 applies to the 18 published tabulated vectors (common angles 0°…180° plus 8 seeded random angles in (−50°, 50°)). It is not a guarantee over the entire real line, including huge angles or unlisted neighborhoods of zeros. Legacy Evidence `tol` is not this policy."
    },
    "CVP-COV-01": {
      "result": "PASS",
      "applicability": "required",
      "notes": "4/4 declared partitions (ratio, cos, invalid-domain, xcal) · 4 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 cos; 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=f3abb5d04ebc51171f259234b69628b210f1534445c968974f68a48041bc5e07 · previous live site report said CURRENT · This calculator is not affected · Bound attestation PASS @ 2026-10-28T05:32:35.458Z · Live production status STALE (210 capabilities; 166 remain CURRENT) @ 2026-10-28T10:42:44.885Z · Public schema 1.0.6 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓ · schema_const=1.0.6 · 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 · cvp-reproduce-manifest-agree=pass · calculator-html-cvp-projection=pass · evidence-html-cvp-projection=pass · attested_evidence_sha256=0904162d9842ae579e660eb678ec02f2ca6e852dd03b716905c0a6501acd7dae · verified_at=2026-10-28T09:09:14.984Z · evidence_attested_at=2026-10-28T09:09:14.984Z · last_confirmed_current_at=2026-10-28T09:09:14.984Z · rendered_at=2026-10-28T10:42:45.297Z · binds=cvp_core_sha256 · attestation snapshot core a8dccdccfcd9 ≠ live cvp_core_sha256 176d7e8ae931 (2026-10-28.meta-metrics-v2)",
      "check_result": "PASS",
      "production_state": "STALE",
      "binding_current": false
    },
    "CVP-DIM-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "angle in → dimensionless cosine (unitless core)"
    },
    "CVP-PROP-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "3/3 property"
    },
    "CVP-META-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "3/3 metamorphic"
    },
    "CVP-ROUND-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "4/4 round-trips"
    },
    "CVP-XCAL-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "8/8 cross-calculator · xcal-sin-60 PASS vs math.sin; xcal-sin-0 PASS vs math.sin; xcal-sin-33 PASS vs math.sin; xcal-sin-90 PASS vs math.sin; xcal-arccos-half PASS vs math.arccos; xcal-arccos-zero PASS vs math.arccos; xcal-arccos-neg-half PASS vs math.arccos; xcal-arccos-quarter PASS vs math.arccos; xcal-sin-huge-na N/A (sin²θ+cos²θ=1 is not claimed as a binary64 identity for huge angles (e.g. 1e16°) after degree→radian conversion loses phase bits. Those inputs are outside the O3 table and XCAL vectors.); xcal-tan-na N/A (Tan is listed as a related forward-trig tool. It does not encode sin²θ+cos²θ=1 or cos(arccos x)=x.); xcal-arcsin-na N/A (Arcsin is listed as a related inverse-trig tool. It does not encode sin²θ+cos²θ=1 or cos(arccos x)=x; its inverse identity is sin(arcsin x)=x.)"
    },
    "CVP-IFACE-01": {
      "result": "PASS",
      "applicability": "applicable",
      "notes": "UI (SSR) · REST · MCP equivalent (MCP uses calc API handler). Success 100/100. Error-path engine·REST·MCP 25/25 (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. Integration: URL → SSR result → Live graph current point (4/4). Hydration/slider/history are URL-canonical contracts, not a live browser session."
    },
    "CVP-ORACLE-01": {
      "result": "PASS",
      "applicability": "higher_assurance",
      "notes": "O3 18/18 tabulated vectors vs IUT · ≤2 ULP vs O3 applies to the 18 published tabulated vectors (common angles 0°…180° plus 8 seeded random angles in (−50°, 50°)). It is not a guarantee over the entire real line, including huge angles or unlisted neighborhoods of zeros."
    },
    "CVP-EXP-01": {
      "result": "SKIP",
      "applicability": "optional",
      "notes": "named expert review not performed"
    }
  },
  "interfaces": {
    "compared": [
      "ui-ssr",
      "rest",
      "mcp",
      "ui-url-result-graph"
    ],
    "result": "PASS",
    "notes": "UI (SSR) · REST · MCP equivalent (MCP uses calc API handler). Success 100/100. Error-path engine·REST·MCP 25/25 (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. Integration: URL → SSR result → Live graph current point (4/4). Hydration/slider/history are URL-canonical contracts, not a live browser session."
  },
  "artifacts": {
    "evidence_bundle_sha256": "5c922c8c3edddbcd0ff36dae3c9f797ac4a95dd62a9044d9872df8645e687336",
    "evidence_digest": "176d7e8ae93172e34c080b827c30c22823472d8cd5c355276039723281ebc06d",
    "production_sha256": "0904162d9842ae579e660eb678ec02f2ca6e852dd03b716905c0a6501acd7dae",
    "attested_catalog_sha256": "163b0d7072a58bed20a0320572211167e1629730bef43c185b5f545ceac7744c",
    "production_checks": [
      {
        "id": "math.cos:output-const",
        "status": "pass",
        "detail": "output const 1.0.6 vs capability 1.0.6",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-28T09:09:14.984Z",
        "attestation_revision": "core"
      },
      {
        "id": "math.cos:evidence-sha256",
        "status": "pass",
        "detail": "5b8b4291bb3e",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-28T09:09:14.984Z",
        "attestation_revision": "core"
      },
      {
        "id": "math.cos:semantic-contract",
        "status": "pass",
        "detail": "6/6",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-28T09:09:14.984Z",
        "attestation_revision": "core"
      },
      {
        "id": "math.cos:capability-html-public-origin-agree",
        "status": "pass",
        "detail": "public 1.0.6 vs origin 1.0.6",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-28T09:09:14.984Z",
        "attestation_revision": "core"
      },
      {
        "id": "math.cos:cvp-manifest-public-origin-agree",
        "status": "pass",
        "detail": "math.cos/1.0.6/2026-10-28.meta-metrics-v2/core/176d7e8ae931",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-28T09:09:14.984Z",
        "attestation_revision": "core",
        "projection_compared": false
      },
      {
        "id": "math.cos:cvp-latest-alias-agrees",
        "status": "pass",
        "detail": "math.cos/1.0.6/2026-10-28.meta-metrics-v2/core/176d7e8ae931",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-28T09:09:14.984Z",
        "attestation_revision": "core",
        "projection_compared": false
      },
      {
        "id": "math.cos:cvp-immutable-manifest-fetch",
        "status": "pass",
        "detail": "public=200 origin=200",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-28T09:09:14.984Z",
        "attestation_revision": "core"
      },
      {
        "id": "math.cos:cvp-immutable-manifest-sha256",
        "status": "pass",
        "detail": "a8dccdccfcd9",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-28T09:09:14.984Z",
        "attestation_revision": "core"
      },
      {
        "id": "math.cos:cvp-latest-alias-matches-immutable",
        "status": "pass",
        "detail": "math.cos/1.0.6/2026-10-28.meta-metrics-v2/core/176d7e8ae931",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-28T09:09:14.984Z",
        "attestation_revision": "core",
        "projection_compared": false
      },
      {
        "id": "math.cos:cvp-reproduce-manifest-agree",
        "status": "pass",
        "detail": "2026-10-27.full-review-v2 · efdad939a92a",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-28T09:09:14.984Z",
        "attestation_revision": "core"
      },
      {
        "id": "math.cos:calculator-html-cvp-projection",
        "status": "pass",
        "detail": "matches Trust display",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-28T09:09:14.984Z",
        "attestation_revision": "core"
      },
      {
        "id": "math.cos:evidence-html-cvp-projection",
        "status": "pass",
        "detail": "matches Trust display",
        "scope": "last_attestation_snapshot",
        "current": false,
        "attestation_binding_current": false,
        "attested_at": "2026-10-28T09:09:14.984Z",
        "attestation_revision": "core"
      }
    ],
    "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": "176d7e8ae93172e34c080b827c30c22823472d8cd5c355276039723281ebc06d",
          "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": "176d7e8ae93172e34c080b827c30c22823472d8cd5c355276039723281ebc06d",
          "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": "5b8b4291bb3eedc44ab93fba5834615964cd24f98c1dd8bf96f5e0485c4612fd",
          "note": "Published Evidence JSON core — Trust freshness / production bind subject"
        },
        {
          "name": "evidence_catalog_digest",
          "field": "artifacts.attested_catalog_sha256",
          "digest_scope": "capability_catalog",
          "value": "163b0d7072a58bed20a0320572211167e1629730bef43c185b5f545ceac7744c",
          "note": "Capability catalog integrity; site-wide, not per-suite fingerprint"
        }
      ]
    },
    "cvp_core_sha256": "176d7e8ae93172e34c080b827c30c22823472d8cd5c355276039723281ebc06d"
  },
  "dependencies": [
    {
      "name": "cos-engine",
      "version": "1.0.6"
    },
    {
      "name": "cos-reference-oracle",
      "version": "1.0.0"
    },
    {
      "name": "cos-o3-mpmath-table",
      "version": "math-mpmath-o3"
    },
    {
      "name": "math.sin",
      "version": "1.0.6",
      "role": "cross_calculator_peer",
      "capability_id": "math.sin",
      "evidence_digest": "3211222bd36434d38d733aeb081295c3073c7564c859ff4afa0a588cbd5ee91a",
      "evidence": "https://www.calculatorx.com/evidence/math.sin/1.0.6.cvp.json"
    },
    {
      "name": "math.arccos",
      "version": "1.0.6",
      "role": "cross_calculator_peer",
      "capability_id": "math.arccos",
      "evidence_digest": "7efb85aee6b91d667c030ee2655375322d4c5b27033b19adf808fc685ae922af",
      "evidence": "https://www.calculatorx.com/evidence/math.arccos/1.0.6.cvp.json"
    },
    {
      "name": "node",
      "version": "22.20.0"
    }
  ],
  "attestation": {
    "status": "STALE",
    "href": "/.well-known/calculatorx-production-attestation.json",
    "id": "f3abb5d04ebc51171f259234b69628b210f1534445c968974f68a48041bc5e07",
    "attested_at": "2026-10-28T09:09:14.984Z",
    "last_confirmed_current_at": "2026-10-28T09:09:14.984Z",
    "site_attestation_current": false,
    "capability_attestation_current": false,
    "bound_snapshot_status": "pass",
    "live_report_status": "stale",
    "bound_attested_at": "2026-10-28T05:32:35.458Z",
    "live_updated_at": "2026-10-28T10:42:44.885Z",
    "bound_snapshot": {
      "status": "pass",
      "attested_at": "2026-10-28T05:32:35.458Z",
      "site_stale_count": 210
    },
    "live_site_status": {
      "href": "/.well-known/calculatorx-production-attestation.json"
    },
    "bound_snapshot_site_stale_count": 210,
    "site_stale_capability_count": 210,
    "evidence_attested_at": "2026-10-28T09:09:14.984Z",
    "stale_reason": "attestation snapshot core a8dccdccfcd9 ≠ live cvp_core_sha256 176d7e8ae931 (2026-10-28.meta-metrics-v2)"
  },
  "domain_review": {
    "status": "ABSENT",
    "spec_version": "1.0.6",
    "external_third_party": false,
    "note": "Named expert review not performed"
  },
  "timestamps": {
    "verified_at": "2026-10-28T09:09:14.984Z",
    "generated_at": "2026-10-28T09:09:14.984Z",
    "rendered_at": "2026-10-28T10:42:45.297Z",
    "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": 103,
      "total": 103,
      "failed": 0
    },
    "boundary": {
      "passed": 2,
      "total": 2,
      "failed": 0
    },
    "invalid": {
      "passed": 27,
      "total": 27,
      "failed": 0,
      "comparison": "exact_error_match"
    },
    "property": {
      "passed": 3,
      "total": 3,
      "failed": 0
    },
    "round_trip": {
      "passed": 4,
      "total": 4,
      "failed": 0
    },
    "metamorphic": {
      "passed": 3,
      "total": 3,
      "failed": 0
    },
    "contract": {
      "passed": 6,
      "total": 6,
      "failed": 0
    },
    "cross_interface": {
      "passed": 125,
      "total": 125,
      "failed": 0
    },
    "cross_calculator": {
      "passed": 8,
      "total": 8,
      "failed": 0
    },
    "ui_integration": {
      "passed": 4,
      "total": 4,
      "failed": 0
    },
    "o3": {
      "passed": 18,
      "total": 18,
      "failed": 0,
      "claim_scope": "≤2 ULP vs O3 applies to the 18 published tabulated vectors (common angles 0°…180° plus 8 seeded random angles in (−50°, 50°)). It is not a guarantee over the entire real line, including huge angles or unlisted neighborhoods of zeros.",
      "max_error_ulp": 0,
      "table_sha256": "efdad939a92a67df1f3995db36c52bb87f428a59fc73568f789c02540f4372ee"
    }
  },
  "numerical": {
    "representation": "IEEE-754 binary64 Math.cos with textbook snap",
    "tolerance": {
      "type": "ulp",
      "value": 2,
      "rationale": "Independent cos with same exact-angle snap table vs IUT; ≤2 ULP on tabulated O3 vectors, declared a priori. Not a whole-domain ULP guarantee.",
      "declared_before_evaluation": true
    },
    "max_error_observed": 1,
    "claim_scope": "≤2 ULP vs O3 applies to the 18 published tabulated vectors (common angles 0°…180° plus 8 seeded random angles in (−50°, 50°)). It is not a guarantee over the entire real line, including huge angles or unlisted neighborhoods of zeros."
  },
  "coverage": {
    "partitions": [
      {
        "id": "ratio",
        "description": "Side ratio mode",
        "exercised": true,
        "case_count": 15
      },
      {
        "id": "cos",
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