{ "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": "electricity", "version": "1.3.1", "title": "Electricity Bill Calculator", "formula_family": "flat-rate-bill", "capability_id": "electrical.electricity_bill", "verification_revision": "2026-09-13.trust-contract-ssr" }, "profile": "engineering", "status": "VERIFIED", "verification_status": "VERIFIED", "production_freshness": "CURRENT", "overall_trust": "VERIFIED", "runner": { "name": "cvp-runner", "version": "1.0.0" }, "environment": { "runtime": "node", "runtime_version": "22.23.2", "numeric_model": "IEEE-754 binary64", "os": "linux" }, "suite": { "id": "electricity", "version": "1.3.1", "uri": "https://www.calculatorx.com/evidence/electrical.electricity_bill/1.3.1.json", "verification_revision": "2026-09-13.trust-contract-ssr" }, "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-IFACE-01" ], "provenance": { "mode": "direct", "sources": [ { "label": "NIST Guide to the SI (SP 811)", "kind": "other", "reference": "Kilowatt-hour and energy–cost arithmetic", "url": "https://www.nist.gov/pml/special-publication-811" }, { "label": "Utility billing practice (informational)", "kind": "other", "reference": "Bill = usage + standing + fees" }, { "label": "U.S. Energy Information Administration (EIA)", "kind": "other", "reference": "Residential electricity prices per kWh", "url": "https://www.eia.gov/electricity/" } ] }, "reference": { "items": [ { "class": "O1", "reference_scope": "model", "scope": "model", "label": "Flat-rate electricity bill" }, { "class": "O2", "reference_scope": "expected_values", "scope": "expected_values", "label": "Separate-module electricity-bill oracle — same V8 binary64 as IUT", "engine": { "name": "electricity-bill-reference", "precision_bits": 53, "independent_of_iut": true } }, { "class": "O2", "reference_scope": "numerical_behavior", "scope": "numerical_behavior", "label": "Same O2 module backs ≤2 ULP scalar comparison vs IUT", "engine": { "name": "electricity-bill-reference", "precision_bits": 53, "independent_of_iut": true } } ], "notes": "Golden expected values use a separate O2 module (not IUT transcription). O2 shares Node/V8 binary64 with the IUT unless noted otherwise." }, "controls": { "CVP-PROV-01": { "result": "PASS", "applicability": "required", "notes": "Sources present on evidence" }, "CVP-MODEL-01": { "result": "PASS", "applicability": "required", "notes": "energy·rate + standing·days + fee; meter=curr−prev (curr < prev → METER_READING_DECREASED)" }, "CVP-SCOPE-01": { "result": "PASS", "applicability": "required", "notes": "Flat tariff only; no TOU / demand charges; fee is lump-sum only" }, "CVP-UNIT-01": { "result": "PASS", "applicability": "required", "notes": "kWh, currency/kWh, days; displayed currency is 2 decimal places" }, "CVP-REF-01": { "result": "PASS", "applicability": "required", "notes": "O1 model + O2 expected_values + O2 numerical_behavior" }, "CVP-GOLD-01": { "result": "PASS", "applicability": "required", "notes": "10/10 legacy golden; 2/2 oracle-backed numeric" }, "CVP-BND-01": { "result": "PASS", "applicability": "required", "notes": "4/4 CVP boundary · 6/6 legacy Evidence boundary" }, "CVP-INV-01": { "result": "PASS", "applicability": "required", "notes": "4 invalid-domain cases" }, "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": "3/3 declared partitions (kwh, meter, invalid-domain) · 10 legacy golden / 4 CVP boundary unique cases · 4 Evidence invalid-input (may overlap boundary)" }, "CVP-CONTRACT-01": { "result": "PASS", "applicability": "required", "notes": "4/4 CVP contract" }, "CVP-DEP-01": { "result": "PASS", "applicability": "required", "notes": "engine electricity-bill; 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 @ 2026-09-13T11:35:00.166Z · live site-wide report stale @ 2026-09-13T11:35:03.926Z (4 other capabilities) · local checks pass · attestation_id=c4df4bb073bf87955dccfbc9399f558b5ac157599dcc2ffa7f03224ca402fd8f · This calculator CURRENT · This calculator is not affected · Bound attestation PASS @ 2026-09-13T11:35:00.166Z · Current site report STALE (4 capabilities; 152 remain CURRENT) @ 2026-09-13T11:35:03.926Z · Public schema 1.3.1 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓ · schema_const=1.3.1 · 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=d8679f20af3506f0d939fc41f759265265a940cac3effc1332876304e1ad2bc0 · verified_at=2026-09-12T23:32:04.657Z · evidence_attested_at=2026-09-12T23:32:04.657Z · last_confirmed_current_at=2026-09-13T11:35:00.166Z · rendered_at=2026-09-13T11:35:03.961Z · binds=cvp_core_sha256", "check_result": "PASS", "production_state": "CURRENT", "binding_current": true }, "CVP-DIM-01": { "result": "PASS", "applicability": "applicable", "notes": "Bill total" }, "CVP-PROP-01": { "result": "PASS", "applicability": "applicable", "notes": "5/5 property" }, "CVP-META-01": { "result": "SKIP", "applicability": "not_applicable", "notes": "No input→output transformation vectors in pack — control not in obligation set" }, "CVP-ROUND-01": { "result": "SKIP", "applicability": "not_applicable", "notes": "No inverse / round-trip vectors in pack — control not in obligation set" }, "CVP-XCAL-01": { "result": "SKIP", "applicability": "not_applicable", "notes": "No related calculator in the same formula family / no related-identity peers declared — control not in obligation set" }, "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 1/1 (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. Public share URLs use UI ids (kwhInput/rateInput/prevInput/currInput). CVP-IFACE includes those serialized queries, not only canonical engine keys." }, "CVP-ORACLE-01": { "result": "SKIP", "applicability": "higher_assurance", "notes": "O2 present; O3 not required this wave" }, "CVP-EXP-01": { "result": "SKIP", "applicability": "optional", "notes": "expert_reviewed=false" } }, "tests": { "golden": { "passed": 2, "total": 2, "failed": 0, "case_ids": [ "g-kwh", "g-meter" ] }, "boundary": { "passed": 4, "total": 4, "failed": 0, "case_ids": [ "meter-decreased", "missing-rate", "boundary-zero-kwh", "boundary-standing-only" ] }, "invalid": { "passed": 4, "total": 4, "failed": 0, "case_ids": [ "meter-decreased", "missing-rate", "bad-mode", "boundary-bad-mode" ] }, "property": { "passed": 5, "total": 5, "failed": 0, "case_ids": [ "property-flat", "property-standing", "property-meter", "property-linear-kwh", "property-fee" ], "kind": "fixed" }, "round_trip": { "passed": 0, "total": 0, "failed": 0, "case_ids": [] }, "metamorphic": { "passed": 0, "total": 0, "failed": 0, "case_ids": [] }, "contract": { "passed": 4, "total": 4, "failed": 0 }, "cross_interface": { "passed": 4, "total": 4, "failed": 0, "case_ids": [ "iface-kwh", "iface-kwh-share", "iface-meter-share", "iface-meter-decreased-share" ] } }, "coverage": { "partitions": [ { "id": "kwh", "description": "Direct kWh mode", "exercised": true, "case_count": 17 }, { "id": "meter", "description": "Meter delta mode", "exercised": true, "case_count": 2 }, { "id": "invalid-domain", "description": "Invalid inputs", "exercised": true, "case_count": 4 } ] }, "numerical": { "representation": "IEEE-754 binary64", "presentation": { "currency_decimals": 2, "rounding": "display-only", "note": "Engine returns the unrounded binary64 total. UI/SSR round only the displayed currency amount to 2 decimal places. Utility billing may round components separately." }, "tolerance": { "type": "ulp", "value": 2, "rationale": "Flat-rate electricity bill; ≤2 ULP vs separate-module O2 (same V8). Declared a priori. Presentation rounding is not part of the ULP claim.", "declared_before_evaluation": true }, "max_error_observed": 0, "records": [ { "id": "g-kwh", "reference": 63, "actual": 63, "error_ulp": 0, "threshold_ulp": 2, "suite": "golden" }, { "id": "g-meter", "reference": 63, "actual": 63, "error_ulp": 0, "threshold_ulp": 2, "suite": "golden" } ] }, "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 1/1 (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. Public share URLs use UI ids (kwhInput/rateInput/prevInput/currInput). CVP-IFACE includes those serialized queries, not only canonical engine keys." }, "artifacts": { "evidence_bundle_sha256": "b4d36f88f3682cf8f92cb6c4c2a0b17c277d486485f16e0ec0643edd5e6e8e97", "evidence_digest": "5343ac664b2fa973bc719b381959200c271b123fecf60f8622d89f85377d771e", "production_sha256": "d8679f20af3506f0d939fc41f759265265a940cac3effc1332876304e1ad2bc0", "attested_catalog_sha256": "dfd311ad9f2e37be7af2a29197a84f33944dff9549828dd83635a5da35985df4", "production_checks": [ { "id": "electrical.electricity_bill:output-const", "status": "pass", "detail": "output const 1.3.1 vs capability 1.3.1", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-12T23:32:04.657Z" }, { "id": "electrical.electricity_bill:evidence-sha256", "status": "pass", "detail": "cf60ca3e7b54", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-12T23:32:04.657Z" }, { "id": "electrical.electricity_bill:semantic-contract", "status": "pass", "detail": "21/21", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-12T23:32:04.657Z" }, { "id": "electrical.electricity_bill:capability-html-public-origin-agree", "status": "pass", "detail": "public 1.3.1 vs origin 1.3.1", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-12T23:32:04.657Z" }, { "id": "electrical.electricity_bill:cvp-manifest-public-origin-agree", "status": "pass", "detail": "electrical.electricity_bill/1.3.1/2026-09-13.trust-contract-ssr/engineering/5343ac664b2f", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-12T23:32:04.657Z", "projection_compared": false }, { "id": "electrical.electricity_bill:cvp-latest-alias-agrees", "status": "pass", "detail": "electrical.electricity_bill/1.3.1/2026-09-13.trust-contract-ssr/engineering/5343ac664b2f", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-12T23:32:04.657Z", "projection_compared": false }, { "id": "electrical.electricity_bill:cvp-immutable-manifest-fetch", "status": "pass", "detail": "public=200 origin=200", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-12T23:32:04.657Z" }, { "id": "electrical.electricity_bill:cvp-immutable-manifest-sha256", "status": "pass", "detail": "5343ac664b2f", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-12T23:32:04.657Z" }, { "id": "electrical.electricity_bill:cvp-latest-alias-matches-immutable", "status": "pass", "detail": "electrical.electricity_bill/1.3.1/2026-09-13.trust-contract-ssr/engineering/5343ac664b2f", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-12T23:32:04.657Z", "projection_compared": false }, { "id": "electrical.electricity_bill:calculator-html-cvp-projection", "status": "pass", "detail": "matches Trust display", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-12T23:32:04.657Z" }, { "id": "electrical.electricity_bill:evidence-html-cvp-projection", "status": "pass", "detail": "matches Trust display", "scope": "last_attestation_snapshot", "current": true, "attestation_binding_current": true, "attested_at": "2026-09-12T23:32:04.657Z" } ], "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": "5343ac664b2fa973bc719b381959200c271b123fecf60f8622d89f85377d771e", "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": "5343ac664b2fa973bc719b381959200c271b123fecf60f8622d89f85377d771e", "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": "cf60ca3e7b548695bbc836416ea0012d623fa24ba3c659ea03e1c7bb949f3bb0", "note": "Published Evidence JSON core — Trust freshness / production bind subject" }, { "name": "evidence_catalog_digest", "field": "artifacts.attested_catalog_sha256", "digest_scope": "capability_catalog", "value": "dfd311ad9f2e37be7af2a29197a84f33944dff9549828dd83635a5da35985df4", "note": "Capability catalog integrity; site-wide, not per-suite fingerprint" } ] }, "cvp_core_sha256": "5343ac664b2fa973bc719b381959200c271b123fecf60f8622d89f85377d771e" }, "dependencies": [ { "name": "electricity-bill-engine", "version": "1.3.1" }, { "name": "electricity-bill-reference-oracle", "version": "1.0.0" }, { "name": "node", "version": "22.23.2" } ], "attestation": { "status": "CURRENT", "href": "/.well-known/calculatorx-production-attestation.json", "id": "c4df4bb073bf87955dccfbc9399f558b5ac157599dcc2ffa7f03224ca402fd8f", "attested_at": "2026-09-12T23:32:04.657Z", "last_confirmed_current_at": "2026-09-13T11:35:00.166Z", "site_attestation_current": false, "capability_attestation_current": true, "bound_snapshot_status": "pass", "live_report_status": "stale", "bound_attested_at": "2026-09-13T11:35:00.166Z", "live_updated_at": "2026-09-13T11:35:03.926Z", "bound_snapshot": { "status": "pass", "attested_at": "2026-09-13T11:35:00.166Z", "site_stale_count": 4 }, "live_site_status": { "href": "/.well-known/calculatorx-production-attestation.json" }, "bound_snapshot_site_stale_count": 4, "site_stale_capability_count": 4, "evidence_attested_at": "2026-09-12T23:32:04.657Z" }, "domain_review": { "status": "ABSENT", "spec_version": "1.3.1", "external_third_party": false }, "internal_review": { "status": "PASS", "reviewer_role": "electrical-engineer", "reviewed_by": "CalculatorX electrical review", "spec_version": "1.3.1", "independence": "internal", "external_third_party": false }, "timestamps": { "verified_at": "2026-09-12T23:32:04.657Z", "generated_at": "2026-09-12T23:32:04.657Z", "rendered_at": "2026-09-13T11:35:03.961Z", "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." }, "links": { "legacy_evidence": "https://www.calculatorx.com/evidence/electrical.electricity_bill/1.3.1.json", "evidence_page": "https://www.calculatorx.com/evidence/electrical.electricity_bill/1.3.1", "calculator": "https://www.calculatorx.com/calc/electric/electricity", "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/electrical.electricity_bill/1.3.1.cvp.json", "manifest_immutable": "https://www.calculatorx.com/evidence/electrical.electricity_bill/1.3.1/2026-09-13.trust-contract-ssr.cvp.json", "manifest_core": "https://www.calculatorx.com/evidence/electrical.electricity_bill/1.3.1/2026-09-13.trust-contract-ssr.5343ac664b2f.cvp.json" } }