Carbon Ontology for Markets, Emissions & Trade — Master Build Plan v0.2 · March 2026

200 Expert Steps.
One Shared Vocabulary.

10 MECE Expert Panels · 20 Steps Each · Sequenced for Early Adoption Wins

Ten domain experts — each representing a critical stakeholder perspective — independently generated their 20 build steps for COMET. This document synthesizes those 200 steps into a sequenced, dependency-aware master plan. It starts with quick wins that create immediate value for early adopters, then layers in infrastructure, governance, and market-layer capabilities.

200
Total steps across 10 panels
14
Early wins (Days 1–90)
4
Build phases
~36
Months to v1.0 stable
Section 01 — Expert Panels
10 MECE Panels — 20 Steps Each
Each panel represents a distinct, non-overlapping stakeholder perspective. Their steps are sequenced from foundations to advanced capabilities. Shared tags identify cross-panel dependencies and early-win opportunities.
01
OWL / Ontology Engineer
Semantic architecture · namespace governance · OWL 2 DL · SHACL · JSON-LD
01.01
Publish comet-core.owl on GitHub with CI
Org, Site, Process, Material, UOM, TimePeriod. 12 classes. HermiT consistency check in Actions.
Early WinInfra
01.02
Define URI / namespace policy document
Stability contract, deprecation rules, versioning scheme (semver). Published as GOVERNANCE.md.
Governance
01.03
Content negotiation server for comet.carbon
Serve OWL Turtle on Accept:text/turtle, JSON-LD on application/ld+json, HTML by default. Every URI dereferenceable.
Infra
01.04
QUDT unit binding for all measurement properties
Every quantitative property links to a QUDT unit class. Prevents unit ambiguity in PCF exchange.
Standards
01.05
Publish comet-emfactor.owl module
EmissionFactor, LCIDataset, GWP100Value, DataProvenance. PROV-O provenance binding.
Early Win
01.06
SHACL shapes for all core classes
Required property constraints, cardinality, value type validation. Runnable against any COMET-conformant instance.
Quality
01.07
Publish comet-pcf.owl with ISO 14067 alignment
ProductCarbonFootprint, FunctionalUnit, SystemBoundary, AllocationMethod, LCIAResult. 18 classes with owl:equivalentClass to PACT v3.
Early WinStandards
01.08
PACT v3 → COMET alignment mapping module
Systematic owl:equivalentClass and owl:equivalentProperty triples for every PACT field.
PACT-dep
01.09
JSON-LD @context file published and versioned
Single-file context that transforms PACT JSON payloads into semantic RDF. CDN-hosted.
Early Win
01.10
OWL reasoner test suite (100 test cases)
HermiT + Pellet cross-check. Tests: consistency, satisfiability, classification, SHACL validation. CI gated.
Quality
01.11
Publish comet-supplychain.owl module
SupplyChainLink, ActivityDataRecord, DataQualityIndicator, TransportEvent. 14 classes.
PCF-dep
01.12
Publish comet-eac.owl module
EAC class hierarchy: EnergyAttrCert, CarbonRemovalCert, MaterialStewardCert, RetirementEvent.
01.13
Publish comet-verification.owl module
VerificationClaim, AssuranceLevel, AuditTrail, CADTrustAttestation, QualifiedVerifier.
EAC-dep
01.14
Publish comet-market.owl module
CarbonPremium, CBMADiscount, EACSpotPrice, MarketBenchmark, PricingSignal. 10 classes.
VER-dep
01.15
SPARQL endpoint with comet.carbon/sparql
Queryable triple store loaded with all modules + example instances. Enables live exploration.
Infra
01.16
NPM package: @comet/ontology-js
TypeScript constants for all class and property URIs. Auto-generated from OWL. Weekly release cadence.
Dev Win
01.17
PyPI package: comet-ontology
Python bindings (rdflib-based) for all COMET classes. Enables LCA tool integration.
Dev Win
01.18
Automated changelog + diff tool
Between any two COMET versions: what classes added, deprecated, modified. Machine-readable diff in JSON.
DX
01.19
Modular import documentation (mix-and-match guide)
Decision tree: which modules to import for which use case. PCF-only vs. full stack vs. EAC-only.
Onboarding Win
01.20
Formal OWL profile declaration (OWL 2 DL)
Ensures reasoning decidability. Profile test in CI. Documents which reasoners are certified.
Standards
02
LCA Practitioner
ISO 14067 · EN 15804 · GHG Protocol Product · LCIA methods · PCR development
02.01
Map every ISO 14067 §7 required element to a COMET class
Authoritative crosswalk document. Becomes the compliance test suite for PCF claims.
Foundation Win
02.02
Functional Unit class with QUDT binding
Declared unit (kg, m², kWh, tonne-km) with reference flow quantity. Prevents apple-to-orange PCF comparison.
Standards
02.03
System boundary enumeration (SKOS ConceptScheme)
Cradle-to-gate, gate-to-gate, cradle-to-grave, cradle-to-cradle. Each boundary type has exact definition.
Early Win
02.04
Allocation method taxonomy (5 methods)
Mass, economic value, energy content, physical causality, PCR-mandated. Each with decision rules.
02.05
GWP100 characterization factor class (AR5 + AR6)
Typed property for GWP100 with IPCC AR version and gas species. Enables future AR7 migration.
Standards
02.06
Biogenic carbon accounting classes
BiogenicCO2Uptake, BiogenicCO2Release, LandUseChange. Separate from fossil GWP as ISO 14067 §7.3.5 requires.
02.07
LCI exchange format (ecospold2 + SimaPro CSV) adapter
XSLT/Python transforms existing LCI datasets into COMET comet-ef: instances.
Tool Win
02.08
PCR reference class linking to standard
ProductCategoryRule class with URI pointer to the PCR document, issuing body, version, and validity period.
02.09
Cutoff criteria encoding
Mass and energy cutoff thresholds as typed properties (default 1% each; custom PCR overrides).
02.10
Uncertainty & sensitivity result classes
Monte Carlo result distribution, sensitivity coefficient per input parameter. Enables PACT v3 uncertainty disclosure.
02.11
EN 15804 multi-impact module (A1–D)
7 impact categories beyond GWP: AP, EP-fresh, EP-marine, ODP, POCP, ADP-elements, ADP-fossil.
Construction-dep
02.12
Example PCF instances: steel, chemicals, hydrogen
Three fully worked example instances in JSON-LD and Turtle. Test cases for validators.
Adoption Win
02.13
Primary data share calculation method
Weighted share of primary vs. secondary data in a PCF result (PACT v3 field). SHACL range 0–100.
02.14
Technology representativeness scoring (TRL-like)
How well the EF matches the actual technology used. Part of DQI dimension 4.
02.15
Temporal scope class (reporting year, reference period)
ISO 8601 interval binding. Flags when EFs are >3 years old (DQI temporality dimension).
02.16
LCA software integration guide (SimaPro, openLCA, GaBi)
Export plugin specification: map each tool's result object to COMET PCF classes.
Tool Win
02.17
Waste and end-of-life module classes
Waste fraction, end-of-life scenario (landfill, incineration, recycling loop). Module D recycling credits.
02.18
Scope 3 category mapping to COMET supply chain
GHG Protocol Categories 1–15 mapped to COMET SupplyChainLink subtypes. Enables CSRD Scope 3 reporting.
CSRD
02.19
Comparative assertion rules (ISO 14044)
SHACL rules enforcing functional unit equivalence before two PCFs can be compared. Prevents greenwashing claims.
02.20
LCA practitioner certification alignment
Map COMET-conformant PCF to requirements for ISO 14025 EPD program operators. Eases EPD route.
03
PACT v3 / API Transport Expert
WBCSD Pathfinder · REST/JSON-LD · API certification · supply chain data exchange
03.01
Field-by-field PACT v3 → COMET mapping table
Every PACT v3 JSON field gets an owl:equivalentProperty triple in a dedicated alignment module.
Early Win
03.02
COMET JSON-LD @context for PACT payloads
Drop-in context file. Any PACT-compliant platform injects this to upgrade payloads to semantic RDF.
Early Win
03.03
Reference implementation: PACT sender with COMET context
Node.js/Python reference client that sends PACT-compliant but COMET-enriched footprints.
Dev Win
03.04
PACT endpoint registry in COMET vocab
PACTEndpoint class: org, API URL, version supported, authentication scheme. Enables network discovery.
03.05
TransportEvent class for freight emissions
Carrier, distance, mode (road/rail/sea/air), emission factor, GLEC framework binding.
Logistics-dep
03.06
DataModelExtension hook in COMET
PACT v3 allows extensions. COMET registers as the canonical extension namespace for semantic enrichment.
03.07
Conformance test suite for COMET-PACT compliance
50 test payloads. Pass/fail suite that platform vendors run to claim "COMET-aligned" badge.
Quality Gate
03.08
OpenAPI spec for comet-annotated PACT endpoints
Extends Pathfinder OpenAPI with COMET class URI annotations on every response field.
03.09
Multi-hop supply chain tracing model
Chain of SupplyChainLink instances from Tier-N to declaring organization. PROV-O wasGeneratedBy chain.
03.10
Spend-to-primary data upgrade path class
SpendProxyUpgrade event: records when a supplier moves from spend-based to primary data. Audit-trailed.
03.11
PCF validity period enforcement (SHACL)
SHACL rule: PCF older than 3 years triggers comet-sc:staleDataWarning. Keeps data fresh.
03.12
Webhook event model for PCF updates
When a supplier updates their PCF, downstream receivers get a typed event notification. COMET event vocab.
03.13
CaRMA bilateral supplier portal schema
Map CaRMA data fields to COMET supply chain classes. Enables any CaRMA data to become PACT-exportable.
CarbonSig Win
03.14
Supplier onboarding tier model
Three tiers: CSV upload, API push, real-time streaming. Each tier maps to COMET ActivityDataRecord subtype.
Adoption Win
03.15
Federated query spec (cross-platform PCF lookup)
SPARQL federation across multiple COMET-compliant endpoints. Find a product's PCF without centralized db.
03.16
PACT v3.x forward-compatibility layer
Versioned COMET alignment modules track PACT spec evolution. Old payloads remain queryable.
03.17
Rate-limiting and authentication vocab
COMET-standard OAuth2 scope definitions for PCF read/write permissions. Cross-platform auth normalization.
03.18
Batch PCF transfer spec (>1000 products)
Asynchronous bulk exchange via signed S3-compatible manifests. COMET manifest class.
03.19
PACT network topology visualization (live)
Dashboard showing all registered PACT endpoints using COMET endpoint registry. Network health map.
Community Win
03.20
PACT v3 certification validator (online tool)
Paste a PACT payload → get COMET conformance score. Free public tool for platform developers.
Community Win
04
EAC Registry Specialist
I-REC · Verra VCS · Gold Standard · Book & Claim · DAC credits · ASI · ResponsibleSteel
04.01
EAC base class with universal properties
serialNumber, issuingRegistry, issueDate, expiryDate, faceValue, retirementEvent. All subtypes inherit.
Foundation Win
04.02
I-REC certificate class with registry API mapping
EnergyAttributeCertificate subtype. I-REC Standard Foundation's data model → COMET properties.
04.03
EU Guarantee of Origin (GO) class
AIB EECS protocol mapping. GO serial number structure, issuing body, production technology code.
EU-mandate
04.04
RetirementEvent class with beneficiary
When, by whom, for which product claim, against which PCF result. Prevents double-counting.
Anti-fraud
04.05
Book-and-Claim chain-of-custody model
Attribute transfer without physical product link. COMET class: BookAndClaimTransfer with attribute qty and date.
04.06
DAC (Direct Air Capture) credit class
Permanent removal, tonne CO₂, permanence period, monitoring protocol, 1PointFive reference.
1PF Win
04.07
Verra VCS and Gold Standard mapping
COMET CarbonRemovalCert subtype for VCS + GS credits. Registry API fetch to verify serial.
04.08
ResponsibleSteel certificate class
SiteCertification subtype. Certification tier, scope, expiry, linked PCF result, CarbonIntensityBenchmark.
04.09
ASI aluminium certificate class
ASI Performance Standard + Chain of Custody. Smelter-level certification linked to material lot.
04.10
CAP / CarbonSig EAC class (comet-ext:carbonsig)
CarbonSig-issued environmental attribute certificate in the ext: namespace. First live adopter example.
CarbonSig Win
04.11
EAC double-counting prevention SHACL rules
One retired EAC cannot claim against more than one PCF. Cross-registry duplicate detection logic.
Anti-fraud
04.12
Temporal matching class (hourly, monthly, annual)
IRA 45V requires hourly matching for clean electricity. COMET TemporalMatchPolicy enum class.
45V
04.13
EAC spot price and market class
EACSpotPrice with source, date, currency, unit. Links to comet-market:. Enables carbon-price signals.
04.14
EAC → PCF netting calculation
Formal property: PCFResultAfterEAC = PCFResult – retiredEACQty. SHACL calculation rule.
Market Win
04.15
Additionality declaration class
EAC additionality claim: construction date, grid average, marginal emission rate. Required for IRA 45V.
45V
04.16
Registry API wrappers for live verification
Fetch from I-REC, Verra API, AIB to confirm EAC validity at time of claim. COMET VerifiedLive flag.
04.17
EAC portfolio aggregation class
Basket of EACs retired for a given product or facility. Supports portfolio-level carbon claim reporting.
04.18
Circular claim prevention rules
EAC retired in year N cannot offset PCF calculated for year N–1 unless re-statement is declared.
04.19
EAC explorer: public lookup tool
Type a serial number → see COMET-enriched certificate details. First public consumer tool on comet.carbon.
Public Win
04.20
EAC classification taxonomy (SKOS)
Hierarchical scheme: Energy → Renewable; Carbon → Removal vs. Avoidance; Material → Stewardship. Browsable.
05
Carbon Verifier (3rd Party Auditor)
Bureau Veritas · SGS · limited vs. reasonable assurance · ISO 14064-3 · CADTrust
05.01
AssuranceLevel enumeration class
LimitedAssurance (ISO 14064-3 §6) and ReasonableAssurance (§7) as SKOS named individuals.
Foundation Win
05.02
VerificationClaim class with verifier URI
Who verified, when, to which standard, scope, materiality threshold, conclusion (positive/qualified/adverse).
05.03
QualifiedVerifier class (accreditation registry)
Verifier org, accreditation body, scope of accreditation, expiry. Enables automated eligibility check.
05.04
CADTrust carbon data model alignment
Map CADTrust disclosure record fields to COMET comet-ver: classes. Signed hash linkage.
CADTrust Win
05.05
AuditTrail class (PROV-O based)
prov:wasGeneratedBy chain from raw data through calculation to PCF result to verification claim.
05.06
Verification scope boundary class
What was and was not verified. Helps downstream users understand claim strength.
05.07
Materiality threshold encoding
Numerical threshold (e.g., 5% of total PCF) below which discrepancies are immaterial. SHACL check.
05.08
Verification workflow event sequence
Ordered event chain: DataRequest → SiteVisit → DocumentReview → Finding → Resolution → Sign-off.
Process Win
05.09
Finding class (corrective action record)
Finding severity (minor/major), category (data/method/boundary), status (open/resolved/accepted).
05.10
Digital signature linkage (JWS / W3C VC)
Verification claim signed with verifier's DID or X.509 cert. Tamper-evident assertion in COMET.
Security
05.11
Verification report template (JSON-LD)
Standard verification report as a COMET instance. Verifiers fill fields; output is machine-readable.
Adoption Win
05.12
Bureau Veritas connector specification
BV internal verification workflow → COMET VerificationClaim export. First named verifier integration.
BV Win
05.13
Verification expiry and re-verification trigger
Verified claim expires after N years (configurable per standard). Auto-flag stale claims.
05.14
Round-based review cycle class
ReviewRound with participants, date, version of PCF reviewed, comments. Maps to CarbonSig pre-verification flow.
05.15
ISO tagging for verification findings
Each finding links to the ISO 14067 clause it relates to. Structured for regulatory export.
ISO-link
05.16
CBAM verification requirement classes
CBAM requires competent authority designation and independent verification. COMET maps both requirements.
CBAM
05.17
Verification marketplace registry
Public list of COMET-verified verifiers with scope, geography, and standard coverage. comet.carbon/verifiers.
Community Win
05.18
Automated pre-verification checklist export
From a PCF instance → generate verifier checklist. 628-variable registry mapped to verification items.
CarbonSig Win
05.19
Verification claim confidence score
Composite score: assurance level × DQI × verifier accreditation status → 0–100 trust index.
05.20
Public verification ledger (read-only)
Browsable list of verified PCFs on comet.carbon. Companies opt-in. Market transparency signal.
Market Win
06
Regulatory Counsel
CBAM · CSRD · IRA 45V · EU ETS · national carbon schemes
06.01
CBAM DeclarationClass — required fields, importerURI, embeddedEmissions
Reg WinCBAM
06.02
IRA 45V hydrogen carbon intensity class — GREET pathway binding
45V
06.03
CSRD/ESRS E1 Scope 3 mapping to COMET supply chain module
CSRDWin
06.04
EU ETS allowance vs. PCF netting rules (boundary class)
ETS
06.05
Regulatory compliance gap-check SHACL rules (auto-report)
Tool Win
+ 15 more steps: PPWR plastics · FuelEU maritime · SEC climate · UK TCFD · national ETS schemes · greenwashing safe harbor criteria · liability allocation · force majeure · IP licensing · open data terms
07
Open Source Governance Architect
GitHub governance · TSC/SC design · RFC process · contributor experience · Linux Foundation
07.01
GitHub org + initial repo with CONTRIBUTING.md and CODE_OF_CONDUCT
Day-1 Win
07.02
PR label taxonomy and automated routing to DWGs
Governance
07.03
RFC template and 14-day minimum comment period tooling
ProcessCommunity Win
07.04
TSC election process + Charter v1.0 published
Governance
07.05
Founding member onboarding kit (5 companies, Day 1–30)
Founding Win
+ 15 more: Linux Foundation liaison · dual license CC BY 4.0 + Apache 2.0 · contributor ladder · CLA management · security disclosure policy · branch protection rules · automated release notes · diversity targets · escalation paths · SC seat rotation · meeting cadence · Discord community · monthly newsletter · annual contributor summit · trademark policy
08
Industrial Sector Expert
Steel · chemicals · hydrogen · aluminium · cement — hard-to-abate sector specifics
08.01
Steel: BF-BOF and EAF process route subclasses with benchmark EFs
Steel Win
08.02
WorldSteel LCI dataset binding to comet-ef: instances
WS-data
08.03
OxyChem: 20-facility site model as reference implementation
Ref Win
08.04
Hydrogen: production pathway taxonomy (SMR, ATR, electrolysis, pyrolysis)
45V
08.05
Cement: clinker-to-cement ratio and calcination CO₂ class
Cement-WG
+ 15 more: aluminium smelter intensity class · PVC production route · ammonia Haber-Bosch pathway · co-product allocation in chemicals · Ecoinvent sector dataset binding · Idemat 2026 integration · BAFU:2025 binding · hot-metal allocation · scrap credit model · carbon capture integration · industrial symbiosis exchanges · energy recovery credit · process integration examples · sector benchmark publication · carbon intensity benchmark table
09
Carbon Platform / SaaS Architect
CarbonSig stack · AWS Bedrock · Claude API · PostgreSQL PGVector · React · Node.js · LangChain
09.01
COMET schema → PostgreSQL DDL generator (auto from OWL)
Dev Win
09.02
PGVector embeddings of COMET class descriptions for semantic search
AI
09.03
Agentic COMET mapper: LLM classifies raw data fields → COMET URIs
AI Win
09.04
React component library: COMET class explorer / browser UI
UX Win
09.05
COMET instance validator: paste JSON-LD → get conformance report
Tool Win
+ 15 more: TypeScript type generator from OWL · Redis cache for hot class lookups · OpenAPI spec for REST COMET API · LangChain COMET tool · CarbonSig canvas node → COMET class mapping · GitHub App for PR auto-validation · VS Code extension for class autocomplete · Postman collection · Docker compose dev environment · GraphQL schema · webhook registry · rate-limiting middleware · multi-tenant namespace isolation · audit log to PGVector · Bedrock fine-tune on COMET corpus
10
Carbon Market Economist
Carbon pricing · EAC markets · CBAM shadow price · procurement carbon signals · SBTi · CDP
10.01
CarbonPremium class: variance from benchmark
Typed property: product CI vs. industry avg CI → price delta in $/t CO₂e. Machine-readable carbon value signal.
Market Win
10.02
MarketBenchmark class: sector-level CI norms
Steel global avg, EAF avg, BF-BOF avg etc. Sourced from WorldSteel, IEEFA, BloombergNEF. Versioned annually.
Reference Win
10.03
CBAM shadow tariff calculation class
CBMADiscount: (product CI – EU benchmark) × EU ETS price → tariff liability in EUR/tonne imported.
CBAMWin
10.04
IRA 45V credit value class
Credit tier (≤0.45, ≤1.5, ≤2.5, ≤4 kg CO₂e/kg H₂) → credit value ($0.60–$3.00/kg). Typed COMET property.
45V
10.05
Procurement RFQ carbon-adjusted price field
ProcurementSignal class: base price + carbon premium/discount = carbon-adjusted total cost. Enabling carbon-aware RFQs.
Procurement Win
10.06
SBTi target trajectory class
Target year, base year, CI reduction rate, sector pathway. Links to product-level PCF progress tracking.
10.07
Carbon credit forward contract class
Forward price, delivery date, credit type, registry, counterparty URI. Foundation for carbon derivatives.
10.08
ESG fund carbon-risk scoring output class
PortfolioCArbonRisk: weighted avg CI across holdings, transition risk score, TCFD alignment flag.
10.09
Carbon price scenario class (2030–2050)
Three pathways (IEA NZE, NGFS, current policies). Enables NPV calculation on decarbonization investments.
10.10
CDP disclosure mapping to COMET market classes
CDP Scope 3 Category 1 reported fields → COMET PCF classes. Enables automated CDP questionnaire pre-fill.
CDP Win
10.11
Carbon cost of capital adjustment class
CoC adjustment based on stranded asset risk, transition timeline, carbon liability exposure. ESG lender use.
10.12
Green premium / brown discount market index
Sector-level tracked spread between low and high carbon products. Quarterly published. First COMET market data product.
Market Win
10.13
Embodied carbon financial risk calculator (open tool)
Input: product CI, volume, forward carbon price → output: P&L impact under 3 scenarios. Free on comet.carbon.
Public Win
10.14
Insurance premium adjustment for carbon risk
Physical risk + transition risk factors → insurance loading model. Links to COMET site and PCF classes.
10.15
Internal carbon price declaration class
Company's internal carbon price ($/t CO₂e), scope, effective date. Enables transfer pricing for internal accounting.
10.16
Carbon-adjusted EBITDA field
Standard financial field: EBITDA minus carbon liability (EU ETS, CBAM) + carbon premium revenue.
10.17
Transition finance taxonomy alignment
EU Taxonomy alignment flag on PCF: is this activity "substantially contributing" to climate mitigation?
EU-Taxonomy
10.18
Carbon hedge ratio class
For a given product CI and volume, recommended EUA/EAC hedge to neutralize price risk. Treasury tool.
10.19
Green bond eligible project linkage
Link a capital project (e.g., EAF installation) to expected PCF reduction via COMET delta class. GBP eligible flag.
10.20
Annual COMET market report (public)
State of carbon-as-currency: sector premiums, CBAM impact, EAC price trends. Auto-generated from COMET data.
Community Win
Section 02 — Quick Wins
14 Early Wins — Days 1–90
These steps generate immediate, tangible value for specific user groups. They create the first adopters, first public tools, and first proof points that build momentum before the heavy infrastructure work completes. Sequence matters: each win opens a door for the next.
Week 1–2: Existence Wins
1
GitHub org + repo live with README and CC BY 4.0 license
The project exists. Anyone can find it, fork it, and reference it. Plant the flag. Attract the first GitHub stars and watchers.
Day 1
2
comet-core.owl published (12 classes, OWL 2 DL)
The ontology has a foundation. LCA tool developers can immediately extend it. First unit tests pass in CI.
Day 3
3
PACT v3 → COMET mapping table (Google Doc + GitHub)
Every PACT platform developer sees immediately how COMET enriches their payloads. First major use-case narrative.
Day 5
4
comet-pcf.owl with ISO 14067 alignment (18 classes)
Carbon practitioners can validate their PCF methodology against the ontology. Opens the door to LCA software alignment.
Day 10
Week 3–4: Tool Wins
5
JSON-LD @context file: paste into any PACT payload
Instantly upgrade any PACT v3 JSON to semantic RDF. Zero-friction first integration for developers.
Day 14
6
Online COMET validator: paste JSON-LD → conformance score
First public web tool at comet.carbon/validate. Shareable link. Drives organic discovery from platform developers.
Day 21
7
@comet/ontology-js NPM package v0.1 published
TypeScript URI constants for all classes. npm install @comet/ontology. Developers adopt without reading the OWL.
Day 28
Month 2: Use-Case Wins
8
Three worked example PCF instances (steel, H₂, chemicals)
Fully worked JSON-LD and Turtle examples showing real sector data in COMET. Copy-paste starting points for practitioners.
Day 35
9
CarbonSig CAP/EAC class in comet-ext:carbonsig
First live implementer example shows community how to contribute a real-world extension. Sets the template.
Day 40
10
CBAM declaration class with auto-calculation SHACL
Importers subject to CBAM enforcement (live since Jan 2026) get a free, open-source data structure. Drives immediate adoption.
Day 45
11
EAC base class + I-REC mapping published
First EAC use case: companies managing renewable energy certificates now have a typed vocabulary.
Day 50
Month 3: Community Wins
12
Public PACT conformance validator (online tool)
Paste a PACT v3 payload → COMET conformance score. Free. Drives COMET brand into every PACT-aligned platform discussion.
Day 60
13
Embodied carbon financial risk calculator (open)
Input product CI + CBAM price → P&L impact. Demonstrates "carbon as currency" to CFOs. First market-layer use case.
Day 75
14
Founding members announced (5 organizations)
CarbonSig + 4 others (verifier, LCI provider, industrial buyer, standards body). Press release. Community momentum.
Day 90
Section 03 — Master Build Plan
200 Steps → 4 Phases → Sequenced Build
Synthesized from all 10 expert panels. Steps are ordered by dependency and impact. Phase 1 = foundations + early wins. Phase 2 = supply chain + verification. Phase 3 = market layer + sector modules. Phase 4 = advanced infrastructure + global scale.
Phase 1 · Complete
Foundations & First Adopters
Q1–Q2 2025 · ~40 tasks
#
Task
Description & Deliverable
Owner
Effort
Type
P1.01
GitHub org + repo scaffold
README, LICENSE, CONTRIBUTING, CODE_OF_CONDUCT, CI skeleton
Live GitHub repo at comet-ontology. Actions CI runs OWL lint on PR. Branch protection enabled. First external contributor can fork Day 1.
Governance + Ontology
1 day
Day-1 Win
P1.02
comet-core.owl
12 base classes, OWL 2 DL, CI-tested
Organization, Site, Process, Material, UnitOfMeasure, TimePeriod + 6 properties. HermiT consistency check passes. Foundation for all modules.
Ontology Eng.
3 days
Foundation
P1.03
PACT v3 mapping table
Every field → COMET URI
Published as PACT-COMET-ALIGNMENT.md + OWL alignment module. Platform vendors immediately understand integration path.
PACT Expert + LCA
2 days
Early Win
P1.04
comet-pcf.owl module
18 classes, ISO 14067 aligned
Full ISO 14067 §7 required elements as OWL classes. SHACL shapes for required fields. Core use case for every PCF platform.
LCA Practitioner
5 days
Early Win
P1.05
JSON-LD @context file
CDN-hosted, version-pinned
Single-file context. Developers inject into PACT payload to instantly upgrade to semantic RDF. Zero-friction adoption path.
Ontology Eng.
2 days
Dev Win
P1.06
SHACL validation shapes
All core classes
100+ constraint shapes. Runnable online via COMET validator tool. Enables automated conformance checking by any implementer.
Ontology Eng.
4 days
Quality
P1.07
Online COMET validator
comet.carbon/validate
Paste JSON-LD → conformance report with class-level pass/fail. First public tool. Drives organic discovery. Shareable report URL.
Platform Arch.
5 days
Tool Win
P1.08
NPM + PyPI packages
@comet/ontology-js + comet-ontology
Auto-generated from OWL. TypeScript URI constants. Python rdflib bindings. npm install @comet/ontology. Lowers integration barrier.
Platform Arch.
3 days
Dev Win
P1.09
3 worked PCF examples
Steel, H₂, Chemicals in JSON-LD
Fully annotated real-sector examples. Copy-paste templates for practitioners. Validate against SHACL. Drive adoption through practical demonstration.
LCA + Sector
4 days
Adoption Win
P1.10
CBAM declaration class
v0.1 with required fields
CBMADeclaration with all fields mandated by Implementing Reg. 2023/956 Annex I. CBAM enforcement (live since Jan 2026) drives immediate demand.
Regulatory + LCA
3 days
Reg Win
P1.11
EAC base class + I-REC
comet-eac module v0.1
Universal EAC properties + I-REC Standard mapping. First EAC users: corporates managing renewable energy claims and book-and-claim.
EAC Specialist
4 days
EAC Win
P1.12
comet-ext:carbonsig namespace
CarbonSig CAP/EAC classes live
First real-world extension example. CarbonSig's proprietary CAP certificate expressed in COMET ext: namespace. Template for others.
CarbonSig + EAC
2 days
CS Win
P1.13
Founding members (5 orgs)
Announced Day 90
CarbonSig + verifier + LCI provider + industrial buyer + standards body observer. Public announcement. Community signal that project has traction.
Governance
60 days
Community Win
P1.14–40
27 remaining Phase 1 tasks
Content negotiation server · URI policy doc · QUDT binding · comet-emfactor module · governance charter v1 · PR label taxonomy · RFC template tooling · ISO 14067 crosswalk · system boundary SKOS · GWP100 AR5/AR6 classes · ecospold adapter · PACT reference implementation · DQI 5-dimension class · AssuranceLevel enumeration · VerificationClaim class · CarbonPremium class · MarketBenchmark class · sector benchmark data · OWL reasoner test suite · SPARQL endpoint · COMET browser UI · LCA software integration guide · TSC formation · Charter v1 · contributor onboarding kit · LCI ecoinvent binding · PACT endpoint registry
All 10 panels
Months 2–6
Infra
Phase 2 · Current
Supply Chain, Verification & EAC Completeness
Q3 2025–Q1 2026 · ~60 tasks
Supply Chain Track
comet-supplychain.owl full module → SupplyChainLink multi-hop model → CaRMA data schema mapped → PACT transport adapter → spend-to-primary upgrade path → DataQualityIndicator 5 dimensions → batch PCF transfer spec → TransportEvent / GLEC framework → federated SPARQL query spec → multi-tier supplier onboarding model
Verification Track
comet-verification.owl full module → CADTrust alignment → Bureau Veritas connector → QualifiedVerifier registry → digital signature (W3C VC) → AuditTrail PROV-O chain → verification workflow event sequence → Finding class → round-based review → auto pre-verification checklist export → verification marketplace → CBAM verification requirement classes → public verification ledger
EAC Completeness Track
EU Guarantee of Origin class → RetirementEvent anti-double-counting → Book-and-Claim chain → DAC credit (1PointFive) → Verra VCS + Gold Standard → ResponsibleSteel cert → ASI cert → temporal matching (IRA 45V) → EAC portfolio aggregation → EAC → PCF netting calculation → EAC explorer public tool → EAC spot price class → registry API live verification wrappers
Phase 3
Market Layer, Sector Modules & Regulatory Compliance
Q2–Q4 2026 · ~60 tasks
Market Layer Track
comet-market.owl → CBAM tariff calculation (live EU ETS price) → IRA 45V credit value class → procurement RFQ carbon-adjusted price field → green premium/brown discount index → embodied carbon financial risk calculator → carbon cost of capital class → SBTi target trajectory → CDP disclosure mapping → internal carbon price declaration → carbon-adjusted EBITDA field → EU Taxonomy alignment flag → annual COMET market report (auto-gen)
Sector Module Track
Steel-WG: BF-BOF + EAF subclasses + WorldSteel LCI binding → Hydrogen-WG: production pathway taxonomy + 45V class → Chemicals-WG: OxyChem 20-facility reference impl → Aluminium-WG: ASI + smelter intensity → Cement-WG: clinker ratio + calcination CO₂ → Construction module: EN 15804 full A1–D → Plastics: PPWR alignment → Transport: GLEC + FuelEU
Regulatory & AI Track
CSRD ESRS E1 Scope 3 full mapping → EU ETS netting rules → SEC climate disclosure mapping → PACT v3.1 forward-compat layer → COMET schema → Postgres DDL generator → PGVector embeddings for semantic search → agentic COMET mapper (LLM classifies raw fields → URIs) → VS Code extension + GitHub App → ISO 14067 revision monitoring track → v1.0 stable release
Phase 4
Global Scale, Streaming & Nature-Based Accounting
Q1–Q4 2027 · ~40 tasks
Real-time IoT PCF streaming class · Continuous digital audit trail · TNFD biodiversity metric alignment · Tokenized EAC on-chain retirement (EVM) · NLP natural-language COMET query interface · ISO TC207 formal liaison · v2.0 release (nature + tokenized) · PACT v3.x certified connector program · COMET-native LCA software certification · Global regulatory compliance hub (20+ jurisdictions) · Carbon hedge ratio and derivatives class · Green bond eligible project linkage · Annual contributor summit proceedings · 100-org member milestone · ISO 14067 revision contribution · v3.0 vision: AI-agent semantic layer over full global PCF graph
Section 04 — Timeline
12-Month Build Timeline — Phase 1 & 2
The first 12 months establish foundations and first adopters. Bars show approximate start and duration. Dependencies flow left-to-right.
Track / Milestone
M1
M2
M3
M4
M5
M6
M7
M8
M9
M10
M11
M12
Ontology core modules
core + pcf + ef
supplychain + eac
verification + market
PACT v3 alignment
mapping table
@context file
reference impl
PACT v3 validator tool
Regulatory classes
CBAM class
CSRD mapping
45V Hydrogen
EAC modules
base + I-REC
GO + Book&Claim
DAC + RS + ASI
EAC explorer
Verification layer
comet-ver v0.1
CADTrust align
BV connector + ledger
Tooling & DX
validator
NPM+PyPI
SPARQL endpoint
React UI browser
LLM mapper + VS Code ext
Governance
GitHub org
founding members
Charter v1
TSC election
Sector modules
Steel-WG
H₂-WG
Chem-WG
Al-WG
Section 05 — Dependencies
Critical Path & Dependency Graph
Eight dependency chains where one task gates the next. Understanding these unlocks parallel work and prevents bottlenecks.
Critical Path 1: Ontology → Tooling → Adoption
comet-core.owl Day 3
↓
comet-pcf.owl Day 10
↓
SHACL shapes Day 14
↓
Online validator Day 21
↓
First adopter validates their PCF Day 30+
Critical Path 2: EAC → Verification → Market Signal
comet-eac.owl Month 2
↓
RetirementEvent + anti-double-counting Month 3
↓
comet-verification.owl + CADTrust Month 5
↓
EAC → PCF netting calculation Month 7
↓
CarbonPremium / CBMADiscount market signal Month 10
Critical Path 3: Supply Chain → PACT → Sector Adoption
PACT v3 mapping table Day 5
↓
JSON-LD @context file Day 14
↓
comet-supplychain.owl + CaRMA schema Month 4
↓
Steel-WG + WorldSteel LCI binding Month 7
↓
First verified steel PCF on COMET network Month 9
Parallel Track: Governance → Community → Sustainability
GitHub org + CONTRIBUTING.md Day 1
↓
RFC template + PR label taxonomy Week 2
↓
5 founding members + Charter v1 Month 3
↓
TSC elected + DWGs formed Month 6
↓
Self-sustaining contributor community Month 12
Section 06 — Adoption Strategy
How Users & Use Cases Enter the Ecosystem
COMET's adoption follows a compulsory virality pattern — regulatory forcing functions (CBAM, CSRD, 45V) pull industrial actors in. Each enterprise adopter cascades to their suppliers. The ontology is the shared language this network requires.
Entry 01 — Regulatory Pressure
CBAM Importers, Jan 2026
EU importers of steel, cement, aluminium need to file CBAM declarations with embedded emissions data. COMET's CBMADeclaration class is a free, open-source data structure. Entry point: download CBAM class, generate XML, submit. First value in hours. Cascades to suppliers who must provide PCF data in structured form.
~4,000 EU importers facing Jan 2026 deadline
Entry 02 — Platform Developers
Carbon SaaS Platforms
Platform developers building PCF tools need a shared vocabulary to interoperate. The NPM package, JSON-LD context, and PACT conformance validator give immediate, tangible value. Entry point: npm install @comet/ontology. Platform adopts vocabulary. Users across all their customers now produce COMET-aligned data without knowing it.
Platforms = multiplier: 1 integration → N customers
Entry 03 — LCA Practitioners
ISO 14067 Consultants
LCA practitioners need to export their SimaPro/openLCA results into formats clients can use. COMET LCA adapter and PCF example templates let them export COMET-aligned JSON-LD from existing tools. Entry point: use ecospold adapter or copy the worked examples. Client gets machine-readable PCF. Practitioner differentiates on COMET expertise.
~8,000 certified LCA practitioners globally
Entry 04 — Carbon Verifiers
Bureau Veritas, SGS, Intertek
Verifiers need to issue machine-readable verification claims. COMET's VerificationClaim class lets them produce structured assertions that link directly to the PCF being verified. Entry point: BV connector spec → generate signed VerificationClaim JSON-LD. Downstream: procurement systems auto-validate claims rather than reviewing PDF reports.
Verifiers become network infrastructure providers
Entry 05 — Industrial Buyers
Procurement Teams, Scope 3 Cat. 1
Large industrials (automakers, construction, energy) need Scope 3 Category 1 data. COMET lets them send a structured PCF data request to suppliers using PACT endpoints. Entry point: use COMET ProcurementSignal class in RFQ. Suppliers who can't respond in COMET format are visible — creating a pull for supplier adoption without mandating it.
Supply chain cascade: 1 buyer → 100+ suppliers
Entry 06 — Financial Markets
ESG Funds, Carbon Desks, Banks
Financial actors need product-level carbon intensity data to price risk and premium. COMET's market layer (CarbonPremium, CBMADiscount, EACSpotPrice) gives them typed, queryable signals. Entry point: consume COMET SPARQL endpoint for portfolio carbon risk scoring. Drives demand for COMET-aligned PCFs from their portfolio companies.
Financial demand pulls industrial supply of verified PCFs
The Compulsory Virality Engine
COMET doesn't need to convince users to adopt voluntarily. Regulatory mandates (CBAM Jan 2026, CSRD FY 2025, IRA 45V already active) create demand for the exact data structures COMET provides. One CBAM importer requires its steel supplier to provide embedded emissions data → that supplier needs COMET-aligned tooling → that supplier's sub-suppliers need to provide primary data → each link in the chain is a new COMET user. The regulator does the selling. COMET is the shared language the regulation implicitly requires.