Worked Examples

Worked Examples

The examples/ directory holds complete, CI-validated instances of the CDM. Every example is validated against its schema on each push and pull request (see Validation & Conformance), so the examples can never drift from the schema. They share a fictional procurement: Buyer's "Managed network services — Northern region refresh", awarded to Acme Networks.

File	Object	Stage
examples/need.json	Need	planning
examples/sourcing-event.json	SourcingEvent	tender
examples/policy-evaluation.json	Policy	(governs tender)
examples/award-decision.json	Decision	award
examples/contract.json	Contract	contract
examples/invoice.json	Invoice	implementation
examples/invoice.ubl.xml	UBL projection	implementation

The examples trace a single thread through the lifecycle:

Need (12M EUR)  ──>  SourcingEvent (competitiveFlexible)  ──>  [evaluated under Policy]
   #need-0420            #event-1207                              #policy-eval-mat
                                                                       │
   Decision (award) <── made by synthetic agent under mandate ────────┘
   #decision-8842
        │
        ▼
   Contract (#contract-3310, 12M EUR, 2026–2029, 2 obligations)
        │                                    ▲
        ▼                                    │ settles ob-1 / dischargedBy
   Invoice (Peppol INV-2026-000512, €7,502 payable)  ──>  invoice.ubl.xml
        └── settles ──> Obligation ob-1 (status: met)  [loop closed]

The Invoice settles the SLA obligation ob-1, and ob-1 back-references the Invoice via dischargedBy — the commitment made in the Contract is discharged explicitly, as data. The settles link is SIGNET-original and is omitted on the UBL projection, so invoice.ubl.xml is unchanged.

---

Need

examples/need.json — a €12M demand signal, classified under CPV 72720000 (wide area network services), governed by an ISO 27001 eligibility policy.

{
  "@context": "https://concert.foundation/signet/v0.1/context.jsonld",
  "type": "Need",
  "id": { "scheme": "did", "id": "did:web:buyer.example#need-0420" },
  "title": "Managed network services — Northern region refresh",
  "requestingParty": { "scheme": "did", "id": "did:web:buyer.example#buyer" },
  "budget": { "amount": 12000000, "currency": "EUR" },
  "classification": { "scheme": "cpv", "id": "72720000", "description": "Wide area network services" },
  "rationale": "End-of-life transport equipment refresh across the northern operating region.",
  "governingPolicies": [ { "scheme": "did", "id": "did:web:buyer.example#policy-elig-iso27001" } ]
}

See Process Layer → Need.

---

SourcingEvent

examples/sourcing-event.json — an active competitiveFlexible procedure (UK Procurement Act 2023) with one lot, an eligibility policy and an evaluation policy, and a submission window. Note the criteria are references to Policy objects.

{
  "type": "SourcingEvent",
  "id": { "scheme": "did", "id": "did:web:buyer.example#event-1207" },
  "procuringParty": { "scheme": "did", "id": "did:web:buyer.example#buyer" },
  "procedure": "competitiveFlexible",
  "status": "active",
  "lots": [ { "id": "lot-1", "title": "Core transport", "value": { "amount": 12000000, "currency": "EUR" } } ],
  "eligibilityCriteria": [ { "scheme": "did", "id": "did:web:buyer.example#policy-elig-iso27001" } ],
  "evaluationCriteria": [ { "scheme": "did", "id": "did:web:buyer.example#policy-eval-mat" } ],
  "period": { "startDate": "2026-07-01T00:00:00Z", "endDate": "2026-08-15T17:00:00Z" }
}

See Process Layer → SourcingEvent.

---

Policy

examples/policy-evaluation.json — a Most-Advantageous-Tender scoring model. It carries both an executable Rego expression and a humanReadable statement of the same rule — the mandatory dual requirement.

{
  "type": "Policy",
  "id": { "scheme": "did", "id": "did:web:buyer.example#policy-eval-mat" },
  "policyType": "evaluation",
  "expressionLanguage": "rego",
  "expression": "package signet.eval\nscore := price*0.4 + quality*0.35 + social*0.25",
  "humanReadable": "Most Advantageous Tender: price 40%, quality 35%, social value 25%.",
  "version": "1.0.0",
  "issuedBy": { "scheme": "did", "id": "did:web:buyer.example#buyer" }
}

See Agent Layer → Policy.

---

Decision (award)

examples/award-decision.json — the accountability centrepiece. A synthetic agent (#agent-eval-3) decides the award under a mandate (#mandate-eval-3), from two submission inputs, applying the MAT policy, with a plain-language rationale, a human approval record, and cryptographic provenance.

{
  "type": "Decision",
  "id": { "scheme": "did", "id": "did:web:buyer.example#decision-8842" },
  "decisionType": "award",
  "madeBy": { "scheme": "did", "id": "did:web:buyer.example#agent-eval-3" },
  "underMandate": { "scheme": "did", "id": "did:web:buyer.example#mandate-eval-3" },
  "inputs": [
    { "scheme": "did", "id": "did:web:buyer.example#submission-5521" },
    { "scheme": "did", "id": "did:web:buyer.example#submission-5522" }
  ],
  "policiesApplied": [ { "scheme": "did", "id": "did:web:buyer.example#policy-eval-mat" } ],
  "rationale": "Submission 5521 ranked highest on the published MAT model (price 40%, quality 35%, social value 25%).",
  "outcome": { "awardedSubmission": "did:web:buyer.example#submission-5521" },
  "humanApproval": { "scheme": "did", "id": "did:web:buyer.example#approval-771" },
  "provenance": {
    "generatedBy": { "scheme": "did", "id": "did:web:buyer.example#agent-eval-3" },
    "generatedAt": "2026-06-21T14:08:00Z",
    "usedPolicies": [ { "scheme": "did", "id": "did:web:buyer.example#policy-eval-mat" } ],
    "signature": { "type": "Ed25519Signature2020", "value": "z58…" }
  }
}

This is the single object that distinguishes a SIGNET network from a conventional platform — see Agent Layer → Decision.

---

Contract

examples/contract.json — a €12M, three-year contract derived from the award, between Buyer and Acme Networks, with two embedded Obligations (an SLA and a migration milestone).

{
  "type": "Contract",
  "id": { "scheme": "did", "id": "did:web:buyer.example#contract-3310" },
  "award": { "scheme": "did", "id": "did:web:buyer.example#award-2208" },
  "parties": [
    { "scheme": "did", "id": "did:web:buyer.example#buyer" },
    { "scheme": "did", "id": "did:web:acme-networks.example#acme" }
  ],
  "value": { "amount": 12000000, "currency": "EUR" },
  "period": { "startDate": "2026-09-01T00:00:00Z", "endDate": "2029-08-31T23:59:59Z" },
  "obligations": [
    { "type": "Obligation", "id": "ob-1", "description": "Achieve 99.95% core availability each calendar month.",
      "status": "met", "dischargedBy": [ { "scheme": "peppol", "id": "INV-2026-000512" } ] },
    { "type": "Obligation", "id": "ob-2", "description": "Complete northern transport migration by 2027-06-30.", "dueDate": "2027-06-30T00:00:00Z", "status": "pending" }
  ]
}

See Process Layer → Contract.

---

Invoice

examples/invoice.json — an EN 16931-mapped invoice (Peppol identifier scheme), drawn against the contract and an order. It is arithmetically self-consistent: €6,200 net + €1,302 VAT @ 21% = €7,502 payable, and projects to examples/invoice.ubl.xml (UBL 2.1 / Peppol BIS Billing 3.0).

{
  "type": "Invoice",
  "id": { "scheme": "peppol", "id": "INV-2026-000512" },
  "invoiceTypeCode": "380",
  "issueDate": "2026-10-05T00:00:00Z",
  "currency": "EUR",
  "contract": { "scheme": "did", "id": "did:web:buyer.example#contract-3310" },
  "settles": [ { "scheme": "did", "id": "did:web:buyer.example#contract-3310/ob-1" } ],
  "seller": { "scheme": "gleif:lei", "id": "5299000ACME00NETWRK1" },
  "buyer":  { "scheme": "gleif:lei", "id": "5299000BUYER00000001" },
  "lines": [
    { "id": "1", "itemName": "Core router managed service — monthly", "quantity": 100, "unitOfMeasure": "MON",
      "itemNetPrice": { "amount": 50, "currency": "EUR" }, "netAmount": { "amount": 5000, "currency": "EUR" },
      "vatCategoryCode": "S", "vatRate": 21 },
    { "id": "2", "itemName": "Field engineering — day rate", "quantity": 10, "unitOfMeasure": "DAY",
      "itemNetPrice": { "amount": 120, "currency": "EUR" }, "netAmount": { "amount": 1200, "currency": "EUR" },
      "vatCategoryCode": "S", "vatRate": 21 }
  ],
  "vatBreakdown": [ { "taxableAmount": { "amount": 6200, "currency": "EUR" }, "taxAmount": { "amount": 1302, "currency": "EUR" }, "categoryCode": "S", "rate": 21 } ],
  "taxExclusiveTotal": { "amount": 6200, "currency": "EUR" },
  "taxTotal":          { "amount": 1302, "currency": "EUR" },
  "taxInclusiveTotal": { "amount": 7502, "currency": "EUR" },
  "payableAmount":     { "amount": 7502, "currency": "EUR" },
  "paymentTerms": "Net 30 days from invoice date."
}

See Process Layer → Invoice and EN 16931 & ViDA E-Invoicing for the projection and verification.

Run them yourself

npm install        # ajv + ajv-formats
npm run validate   # validates every example against the schemas
npm run transform  # projects examples/invoice.json -> examples/invoice.ubl.xml
npm run verify-ubl # reconciles every EN 16931 value in the UBL

See Validation & Conformance.