NestCode defines a machine-readable digital twin for every building — a permanent NestCode ID, a 0–1000 NestScore™, and 38 open RFCs governing everything from Khata records to AI agent tooling.
// NestCode Twin · RFC-0001 · v0.3 { "nestcode_id": "hin:v1:IN:7e3cf2a148b9d0c4c54fa831", "address": { "unit": "4B", "building": "Tower C, Prestige Park", "locality": "Indiranagar", "city": "Bengaluru", "pincode": "560038", "country": "IN" }, "nestscore": { "total": 812, "band": "excellent", "factors": { "maintenance": { "score": 287, "weight": 0.35 }, "financial": { "score": 228, "weight": 0.25 }, "documents": { "score": 164, "weight": 0.20 }, "assets": { "score": 87, "weight": 0.12 }, "governance": { "score": 46, "weight": 0.08 } } }, "documents": { "count": 9, "verified": 7, "expiring_soon": 1 }, "assets": { "count": 12, "critical_overdue": false }, "schema_version": "0.3", "last_updated": "2026-10-23T14:32:00Z" }
| Weight | Factor | Source RFCs |
|---|---|---|
Maintenance Compliance AMC fulfilment rate, work order SLA adherence, preventive maintenance schedule, asset condition index. The single largest factor — chronic deferred maintenance destroys building value. |
RFC-0002 RFC-0030 |
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Financial Obligations Maintenance charge payment history, utility dues, outstanding penalties, escrow balance, sinking fund contributions. Property-level credit track record. |
RFC-0006 RFC-0014 |
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Document Completeness Sale deed, RERA cert, OC, building plan approval, insurance policies, Khata/Patta, encumbrance certificate. Weighted by expiry proximity and document criticality tier. |
RFC-0004 RFC-0037 RFC-0038 |
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Asset Condition IoT sensor health, last-service age, warranty status, energy efficiency rating. Devices past calibration date penalise this factor automatically. |
RFC-0002 RFC-0003 |
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Governance Compliance Society poll participation, AGM attendance, bylaw adherence, board election engagement. Introduced in NestScore v2.0. |
RFC-0023 RFC-0018 |
| RFC | Title & Description | Category |
|---|---|---|
| RFC-0001 | Home Twin Entity Base entity schema: unit, building, society, geolocation, lifecycle state. Foundation for all other entities. | Core Schema |
| RFC-0002 | Asset & Maintenance Inventory Lifts, pumps, generators, HVAC — AMC records, service history, condition index, failure probability score. | Core Schema |
| RFC-0003 | IoT Device Registry Sensors, controllers, meters. Firmware version, calibration date, last-read telemetry, alert thresholds. | Core Schema |
| RFC-0004 | Document Schema 28 document types: sale deed, title deed, RERA cert, OC, CC, NOC (bank/fire/airport), building plan, insurance, survey, EC, Khata, Patta. | Documents |
| RFC-0005 | Resident & People Directory Residents, owners, tenants, authorised persons. PII isolation: only hashed IDs in the twin; PII lives in consent-gated identity store. | Core Schema |
| RFC-0006 | Financial Aggregates Maintenance charge history, dues ledger, sinking fund balance, escrow, penalty accrual. ISO 20022 message shapes. | Finance |
| RFC-0007 | Property Passport Signed portable credential anchored to NestCode ID. Contains NestScore™ snapshot, key document hashes, and lifecycle state at issuance. | Core Schema |
| RFC-0008 | NestCode ID SHA-256 of NFC-normalised address. Format: hin:v1:{CC}:{32hex}. Self-computable offline. DID subject for RFC-0015. | Identity |
| RFC-0010 | Consent & Data Exchange EdDSA-signed consent tokens, 20-scope vocabulary, 60-second revocation, purpose-bound delegation. GDPR / DPDP compliant. | Privacy |
| RFC-0011 | MCP Tool Registry 10 standard AI tool shapes for property context. One implementation serves Claude, GPT-4o, Gemini, and other MCP-compatible agents. | AI |
| RFC-0012 | Security Model Ed25519 signatures, AES-256-GCM at rest, HKDF key derivation, HMAC audit log chaining. ISO 27001 Annex A mapping. | Security |
| RFC-0014 | Home Financial Protocol & NestScore™ The NestScore™ 0–1000 algorithm: 5 weighted factors, band definitions, ISO 20022 payment integration, escrow standard. | Finance |
| RFC-0015 | Verifiable Credentials did:opentwin DID method, W3C VC 2.0 conformant, SD-JWT selective disclosure, EUDI Wallet compatible. Property certificates as VCs. | Identity |
| RFC-0016 | Home Lifecycle 7 lifecycle states (construction → decommissioned), 12 transition events, HMAC-chained immutable log for regulator access. | History |
| RFC-0017 | NestCode Query Language (NQL) Declarative JSON query language for property data. 11 operators, date variables, cross-entity joins. Reference implementation in TypeScript. | Query |
| RFC-0018 | Community Twin Housing society entity: shared infrastructure, machine-readable bylaws, financial roll-up across all units, bulk consent delegation. | Community |
| RFC-0019 | Anti-Fraud & Duplicate NestCode ID Resolution 3 conflict classes (address ambiguity, fraudulent twin, split parcel), arbiter protocol, challenge/response with geocode proof. | Trust |
| RFC-0020 | Webhook Event Subscription HMAC-SHA256 signed push events, 14-event catalog, exponential backoff retry, at-least-once delivery, event replay by cursor. | Events |
| RFC-0021 | Rental & Tenancy Protocol Lease lifecycle (draft → active → terminated), tenant PII isolation, portable rental credit score, KYC evidence linking. | Tenancy |
| RFC-0022 | Smart City Aggregate API Municipality-facing API with differential privacy (ε=0.1) and k-anonymity ≥50. Area-level NestScore distribution, maintenance benchmarks. | Urban |
| RFC-0023 | Society Governance Protocol Polls, resolutions, AGMs, board elections, quorum tracking. Results HMAC-chained, verifiable by court or regulator. | Governance |
| RFC-0024 | Facility & Amenity Booking Pool, gym, clubhouse slot management. Capacity limits, cancellation windows, maintenance blackout periods, AI booking via MCP. | Facilities |
| RFC-0025 | Gate Pass Protocol Visitor auth, pre-approved EdDSA-signed QR, contractor passes, delivery codes. AES-256-GCM offline cache (20-min TTL). | Access |
| RFC-0026 | Parcel & Delivery Management Carrier integration, last-mile custody chain, locker schema, OTP-verified collection, return-to-sender flow. | Ops |
| RFC-0027 | Emergency & Safety Protocol SOS with response tracking, evacuation headcount schema, first-responder data feed (floor plan + live occupancy), sensor triggers. | Safety |
| RFC-0028 | Vehicle Registry & Parking Resident and visitor vehicles, parking slot assignment, EV charging sessions (kWh + billing), enforcement log, carbon credit links. | Mobility |
| RFC-0029 | Helpdesk & Complaint Lifecycle Complaint entity, SLA breach tracking, work order linking, resolution evidence hashes, satisfaction score. | Ops |
| RFC-0030 | Predictive Maintenance & NestBrain ML-driven maintenance schedule, failure-probability model output, community benchmarks, AI-generated ops digest. Python + TS parity. | ML / Ops |
| RFC-0031 | Staff & Workforce Protocol Shift schedules, BGV credential (W3C VC with bar council or police ref), incident assignments, access control linkage. | Workforce |
| RFC-0032 | Community Marketplace Resident-to-resident listings, service exchange, event RSVPs, seller verified via twin identity, no PII in listing. | Community |
| RFC-0033 | Pet Registry Registered pets with microchip ID, vaccination records, area/lift access permissions, vet visit log. Linked to resident unit twin. | Registry |
| RFC-0034 | Property Handover Protocol Builder-to-society transition: snag list with photo evidence hashes, defect liability period tracking, OC linkage, common-area inventory. | Handover |
| RFC-0035 | Utility Metering Per-unit energy, water, and gas metering. Smart meter integration protocol, reading reconciliation, carbon credit schema. | Energy |
| RFC-0036 | Notification & Subscription Schema Standardised taxonomy for 40+ property event types. AI agent subscription via RFC-0011. Delivery: push, webhook, and MCP stream. | Events |
| RFC-0037 | Legal & Encumbrance Registry Title chain of ownership, encumbrance certificate (EC), mortgage/charge lien, power of attorney, advocate-attested documents (bar council ID + digital signature), notarisation. | Legal |
| RFC-0038 | Municipal Records & Revenue Khata (Karnataka), Pattas (Tamil Nadu), property tax assessment ID, NA order, zone classification, FSI/FAR entitlement, change of land use (CLU), building completion certificate. | Municipal |
SHA-256 of the geocoding-normalised address. Format: hin:v1:{CC}:{hex[0:32]}. Anyone with the address can verify any NestCode ID without contacting a server or creating an account.
Designed for T1 (SQL column in any property system) → T2 (printed on title deeds) → T3 (W3C Verified Issuer programme with governments).
hin:v1:IN:{32hex} — stored in the property record, printed on documents.POST /opentwin/nestcode-id/resolve for production-grade server-side computation.| Level | Name | Minimum requirements | Cost | Unlocks |
|---|---|---|---|---|
| L1 | Self-Attested | RFC-0001–0007 conformant. Run open-source conformance suite. Self-declare on GitHub. | Free | NestCode™ Compatible badge |
| L2 | Peer-Reviewed | RFC-0008, RFC-0010, RFC-0012 conformant. Review by two existing L2+ members. Public registry listing. | Free + peer time | Public registry entry |
| L3 | Audited | All core RFCs + NestScore™ implementation. Third-party audit required. Annual re-certification. | Audit fee | Bank + insurer integrations |
| L4 | Governance Steward | L3 status + at least one merged RFC contribution. RFC vote participation. | L3 + membership | Co-author future RFCs |