MaterialDNA
MaterialDNA is the identification layer for tracking raw and processed materials across city loops. It provides stable, verifiable identifiers and provenance metadata to support traceability and matching. This is an early concept with no public pilots yet.
Scope & boundaries
In scope
Stable material identifiers, provenance metadata, batch references, and additive compatibility signals.
Out of scope
Live asset tracking, financial settlement, or verified carbon accounting.
Status
Lab-demo concept only — no public pilots or deployments yet.
What we aim to enable
A common, verifiable identity for materials to support traceability, provenance, and matching across local loops.
Identity
Persistent IDs for raw and processed materials
Metadata
Category, quantity, quality, condition, and lifecycle stage
Provenance
Origin city, batch references, and certifications
Interoperability
Shared schemas across city nodes, supporting Offer/Match/Transfer flows
Data model snapshot
Current status
{
"$schema": "http://json-schema.org/draft-07/schema#",
"$id": "https://local-loop-io.github.io/projects/loop-protocol/schemas/v0.2.0/material-dna.schema.json",
"title": "MaterialDNA",
"description": "Material identity and metadata schema — LOOP v0.2.0 (DPP-compatible baseline)",
"type": "object",
"required": [
"@context",
"@type",
"schema_version",
"id",
"category",
"quantity",
"origin_city",
"current_city",
"available_from"
],
"properties": {
"@context": {
"description": "JSON-LD context",
"type": "string",
"enum": [
"https://local-loop-io.github.io/projects/loop-protocol/contexts/loop-v0.1.1.jsonld",
"https://local-loop-io.github.io/projects/loop-protocol/contexts/loop-v0.2.0.jsonld"
]
},
"@type": {
"description": "Object type identifier",
"type": "string",
"const": "MaterialDNA"
},
"schema_version": {
"description": "Schema version for the interop flow. Emitters SHOULD use 0.2.0; receivers SHOULD accept additive minor/patch releases.",
"type": "string",
"pattern": "^0\\.[1-9]\\d*\\.\\d+$",
"examples": [
"0.1.1",
"0.2.0"
]
},
"id": {
"description": "Unique MaterialDNA identifier",
"type": "string",
"pattern": "^[A-Z]{2}-[A-Z]{3}-\\d{4}-[A-Z]+-[A-Z0-9]{6,}$",
"examples": [
"DE-MUC-2025-PLASTIC-B847F3"
]
},
"category": {
"description": "Standardized material category",
"type": "string",
"enum": [
"plastic-pet",
"plastic-hdpe",
"plastic-pvc",
"plastic-ldpe",
"plastic-pp",
"plastic-ps",
"plastic-mixed",
"metal-steel",
"metal-aluminum",
"metal-copper",
"metal-mixed",
"organic-food",
"organic-garden",
"organic-wood",
"glass-clear",
"glass-brown",
"glass-green",
"glass-mixed",
"paper-clean",
"paper-newsprint",
"cardboard",
"paper-mixed",
"textile-cotton",
"textile-wool",
"textile-synthetic",
"textile-mixed",
"ewaste-computers",
"ewaste-phones",
"ewaste-batteries",
"ewaste-mixed"
]
},
"quantity": {
"description": "Amount of material",
"type": "object",
"required": [
"value",
"unit"
],
"properties": {
"value": {
"description": "Numeric quantity",
"type": "number",
"minimum": 0,
"examples": [
1000,
500.5
]
},
"unit": {
"description": "Unit of measurement",
"type": "string",
"enum": [
"kg",
"g",
"t",
"l",
"ml",
"m3",
"piece",
"bundle"
],
"examples": [
"kg"
]
}
}
},
"quality": {
"description": "Quality score (0.0 to 1.0)",
"type": "number",
"minimum": 0,
"maximum": 1,
"examples": [
0.95
]
},
"origin_city": {
"description": "City that registered the material",
"type": "string",
"minLength": 2,
"maxLength": 80,
"examples": [
"Munich"
]
},
"current_city": {
"description": "City currently holding custody of the material",
"type": "string",
"minLength": 2,
"maxLength": 80,
"examples": [
"Munich"
]
},
"location": {
"description": "Geographic location of material",
"type": "object",
"required": [
"lat",
"lon"
],
"properties": {
"lat": {
"description": "Latitude",
"type": "number",
"minimum": -90,
"maximum": 90,
"examples": [
48.1351
]
},
"lon": {
"description": "Longitude",
"type": "number",
"minimum": -180,
"maximum": 180,
"examples": [
11.582
]
},
"address": {
"description": "Human-readable address",
"type": "string",
"examples": [
"Recycling Center Munich, Sachsenstraße 25"
]
}
}
},
"available_from": {
"description": "When material becomes available (ISO 8601)",
"type": "string",
"format": "date-time",
"examples": [
"2025-05-27T10:00:00Z"
]
},
"expires": {
"description": "When material expires or must be collected (ISO 8601)",
"type": "string",
"format": "date-time",
"examples": [
"2025-06-03T10:00:00Z"
]
},
"certifications": {
"description": "List of certifications",
"type": "array",
"items": {
"type": "string",
"examples": [
"food-grade",
"iso-14001",
"organic-eu"
]
}
},
"images": {
"description": "Photos of the material",
"type": "array",
"items": {
"type": "string",
"format": "uri",
"examples": [
"https://example.com/material-photo.jpg"
]
},
"maxItems": 10
},
"contact": {
"description": "Reserved. Personal contact details are not permitted in minimal interop payloads.",
"not": {}
},
"passport": {
"description": "Optional regulatory interoperability metadata for DPP-style integrations (ESPR, UNTP, Battery Passport, PPWR, NKWS aligned).",
"type": "object",
"properties": {
"passport_id": {
"type": "string",
"maxLength": 160
},
"passport_url": {
"type": "string",
"format": "uri"
},
"backup_copy_url": {
"type": "string",
"format": "uri"
},
"passport_status": {
"type": "string",
"enum": [
"not_applicable",
"optional",
"required",
"available",
"restricted"
]
},
"data_carrier_id": {
"type": "string",
"maxLength": 160
},
"issuer": {
"type": "string",
"maxLength": 160
},
"access_scope": {
"type": "string",
"enum": [
"public",
"role-based",
"restricted"
]
},
"supported_regimes": {
"type": "array",
"items": {
"type": "string",
"enum": [
"espr-dpp",
"battery-passport",
"ppwr",
"waste-shipment",
"nkws"
]
}
},
"gtin": {
"description": "GS1 Global Trade Item Number",
"type": "string",
"pattern": "^\\d{8,14}$"
},
"gs1_digital_link": {
"description": "GS1 Digital Link URL",
"type": "string",
"format": "uri"
},
"economic_operator_id": {
"description": "ESPR economic operator identifier",
"type": "string",
"maxLength": 120
},
"economic_operator_name": {
"description": "ESPR economic operator name",
"type": "string",
"maxLength": 200
},
"manufacturer_id": {
"description": "Manufacturer identifier",
"type": "string",
"maxLength": 120
},
"country_of_production": {
"description": "ISO 3166-1 alpha-2 country code of production",
"type": "string",
"pattern": "^[A-Z]{2}$"
},
"conformity_declaration_ref": {
"description": "EU Declaration of Conformity link",
"type": "string",
"format": "uri"
},
"carbon_footprint_kg_co2e": {
"description": "Carbon footprint per declared unit (kg CO2e)",
"type": "number",
"minimum": 0
},
"carbon_footprint_unit": {
"description": "Declared unit for carbon footprint",
"type": "string",
"examples": [
"per_kg",
"per_unit"
]
},
"recycled_content_percent": {
"description": "Percentage of recycled content (ESPR & PPWR)",
"type": "number",
"minimum": 0,
"maximum": 100
},
"recyclable_content_percent": {
"description": "Percentage of recyclable content (UNTP circularity)",
"type": "number",
"minimum": 0,
"maximum": 100
},
"repair_score": {
"description": "Repairability index 0-10 (ESPR)",
"type": "number",
"minimum": 0,
"maximum": 10
},
"durability_score": {
"description": "Durability rating 0-10",
"type": "number",
"minimum": 0,
"maximum": 10
},
"disassembly_instructions": {
"description": "Link to disassembly information",
"type": "string",
"format": "uri"
},
"substances_of_concern": {
"description": "Substances of Concern declarations (ESPR)",
"type": "array",
"items": {
"type": "object",
"required": [
"name"
],
"properties": {
"name": {
"type": "string"
},
"cas_number": {
"type": "string",
"pattern": "^\\d{1,7}-\\d{2}-\\d$"
},
"concentration_ppm": {
"type": "number"
},
"location": {
"type": "string"
}
}
}
},
"hazardous": {
"description": "UNTP hazardous material flag",
"type": "boolean"
},
"material_safety_info_url": {
"description": "Material safety data sheet URL (recommended if hazardous is true)",
"type": "string",
"format": "uri"
},
"verified_ratio": {
"description": "UNTP data verification coverage (0.0 to 1.0)",
"type": "number",
"minimum": 0,
"maximum": 1
},
"verification_evidence_url": {
"description": "Link to verification attestation",
"type": "string",
"format": "uri"
}
},
"additionalProperties": true
},
"classification": {
"description": "Optional classification hints for customs, waste, or product-specific rules.",
"type": "object",
"properties": {
"ewc_code": {
"type": "string",
"pattern": "^\\d{2}(\\s\\d{2}){2}$"
},
"hs_code": {
"type": "string",
"pattern": "^\\d{6,10}$"
},
"cn_code": {
"type": "string",
"pattern": "^\\d{8}$"
},
"battery_category": {
"type": "string",
"enum": [
"portable",
"lmt",
"sli",
"industrial",
"ev"
]
},
"prodcom_code": {
"description": "EU PRODCOM classification code",
"type": "string",
"pattern": "^\\d{8}$"
},
"taric_code": {
"description": "EU TARIC classification code",
"type": "string",
"pattern": "^\\d{10}$"
},
"nace_code": {
"description": "NACE economic activity code",
"type": "string",
"pattern": "^[A-Z]\\d{2}(\\.\\d{1,2})?$"
},
"scip_id": {
"description": "ECHA SCIP database reference",
"type": "string"
},
"waste_framework_code": {
"description": "EU Waste Framework Directive code",
"type": "string"
}
},
"additionalProperties": true
},
"traceability": {
"description": "Optional chain-of-custody, retention, and evidence references.",
"type": "object",
"properties": {
"batch_id": {
"description": "Machine-readable batch identifier for chain-of-custody traceability and regulatory evidence.",
"type": "string",
"maxLength": 120
},
"serial_number": {
"type": "string",
"maxLength": 160
},
"lot_number": {
"type": "string",
"maxLength": 120
},
"source_operator_id": {
"type": "string",
"maxLength": 120
},
"facility_id": {
"type": "string",
"maxLength": 120
},
"retention_until": {
"type": "string",
"format": "date-time"
},
"document_refs": {
"type": "array",
"items": {
"type": "string",
"format": "uri"
},
"maxItems": 20
},
"due_diligence_ref": {
"type": "string",
"maxLength": 160
},
"epcis_event_refs": {
"description": "ISO 19987 (EPCIS) event references for supply chain traceability",
"type": "array",
"items": {
"type": "object",
"required": [
"event_type",
"event_id"
],
"properties": {
"event_type": {
"type": "string",
"enum": [
"observation",
"aggregation",
"transaction",
"transformation"
]
},
"event_id": {
"type": "string"
},
"event_url": {
"type": "string",
"format": "uri"
},
"hash_digest": {
"description": "Integrity hash (UNTP SecureLink)",
"type": "string"
},
"hash_method": {
"type": "string",
"enum": [
"SHA-256",
"SHA-384",
"SHA-512"
]
}
}
}
},
"chain_of_custody_url": {
"description": "Full chain-of-custody evidence URL",
"type": "string",
"format": "uri"
},
"w3c_vc_credential_id": {
"description": "W3C Verifiable Credential ID (if wrapped in VC)",
"type": "string",
"format": "uri"
},
"w3c_vc_issuer": {
"description": "W3C VC issuer DID/URL",
"type": "string",
"format": "uri"
}
},
"additionalProperties": true
},
"metadata": {
"description": "Additional metadata",
"type": "object",
"properties": {
"source": {
"type": "string",
"examples": [
"consumer-collection",
"industrial",
"commercial"
]
},
"batch_number": {
"description": "Human-readable batch label for internal tracking. For regulatory traceability, prefer traceability.batch_id.",
"type": "string",
"examples": [
"2025-W22-01"
]
},
"notes": {
"type": "string",
"maxLength": 500,
"examples": [
"Clean, sorted PET bottles"
]
}
},
"additionalProperties": true
},
"conformity_claims": {
"description": "UNTP-aligned conformity claims for regulatory and standards compliance.",
"type": "array",
"items": {
"type": "object",
"required": [
"claim_id"
],
"properties": {
"claim_id": {
"description": "Unique claim identifier",
"type": "string"
},
"description": {
"type": "string"
},
"reference_standard": {
"description": "Standard name or number",
"type": "string"
},
"reference_regulation": {
"description": "EU regulation reference",
"type": "string"
},
"conformity_topic": {
"type": "string",
"enum": [
"environment",
"social",
"governance",
"safety",
"quality"
]
},
"declared_value": {
"type": "object",
"properties": {
"metric": {
"type": "string"
},
"value": {
"type": "number"
},
"unit": {
"type": "string"
},
"accuracy": {
"type": "number"
}
}
},
"conformance": {
"description": "Whether the claim is met",
"type": "boolean"
},
"assessment_date": {
"type": "string",
"format": "date-time"
},
"conformity_evidence_url": {
"description": "Link to attestation or evidence",
"type": "string",
"format": "uri"
}
}
}
}
},
"additionalProperties": true
}