DID Document Schema | IDA — Identity for the AI Age

The DID Document is the core data structure in the did:adi method. It describes the subject of the DID, including its public keys, authentication methods, service endpoints, and capabilities.

JSON-LD Context

Every did:adi DID Document uses the following JSON-LD contexts:

1 {
2   "@context": [
3     "https://www.w3.org/ns/did/v1",
4     "https://w3id.org/security/suites/ed25519-2020/v1",
5     "https://w3id.org/security/suites/secp256k1-2019/v1",
6     "https://w3id.org/security/suites/x25519-2020/v1",
7     "https://w3id.org/security/bbs/v1",
8     "https://ida.infinia.io/ns/did/v1"
9   ]
10 }

The IDA-specific context (https://ida.infinia.io/ns/did/v1) adds:

Agent-specific properties (operator, model, capabilities)
ADI blockchain metadata
IBCT capability invocation extensions

Full DID Document Schema

Person / Organization DID Document

1 {
2   "@context": [
3     "https://www.w3.org/ns/did/v1",
4     "https://w3id.org/security/suites/ed25519-2020/v1",
5     "https://w3id.org/security/suites/x25519-2020/v1",
6     "https://w3id.org/security/bbs/v1",
7     "https://ida.infinia.io/ns/did/v1"
8   ],
9   "id": "did:adi:3f7a9b2e1c4d5f6a8b0c2d4e6f8a0b2c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f",
10   "controller": "did:adi:3f7a9b2e1c4d5f6a8b0c2d4e6f8a0b2c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f",
11 
12   "verificationMethod": [
13     {
14       "id": "did:adi:3f7a...#key-1",
15       "type": "Ed25519VerificationKey2020",
16       "controller": "did:adi:3f7a...",
17       "publicKeyMultibase": "z6Mkf5rGMoatrSj1f4CyvuHBeXJELe9RPdzo2PKGNCKVtZxP"
18     },
19     {
20       "id": "did:adi:3f7a...#key-2",
21       "type": "EcdsaSecp256k1VerificationKey2019",
22       "controller": "did:adi:3f7a...",
23       "publicKeyMultibase": "zQ3shokFTS3brHcDQrn82RUDfCZtME..."
24     },
25     {
26       "id": "did:adi:3f7a...#key-agreement-1",
27       "type": "X25519KeyAgreementKey2020",
28       "controller": "did:adi:3f7a...",
29       "publicKeyMultibase": "z6LShs9GGnqk85JBBenbnvGGnm1V8..."
30     },
31     {
32       "id": "did:adi:3f7a...#bbs-key-1",
33       "type": "Bls12381G2Key2020",
34       "controller": "did:adi:3f7a...",
35       "publicKeyBase58": "25EEStQgp9xE3gqAZqYejcNB..."
36     }
37   ],
38 
39   "authentication": [
40     "did:adi:3f7a...#key-1",
41     "did:adi:3f7a...#key-2"
42   ],
43 
44   "assertionMethod": [
45     "did:adi:3f7a...#key-1",
46     "did:adi:3f7a...#bbs-key-1"
47   ],
48 
49   "keyAgreement": [
50     "did:adi:3f7a...#key-agreement-1"
51   ],
52 
53   "capabilityInvocation": [
54     "did:adi:3f7a...#key-1"
55   ],
56 
57   "capabilityDelegation": [
58     "did:adi:3f7a...#key-1"
59   ],
60 
61   "service": [
62     {
63       "id": "did:adi:3f7a...#didcomm",
64       "type": "DIDCommMessaging",
65       "serviceEndpoint": {
66         "uri": "https://agent.example.com/didcomm",
67         "accept": ["didcomm/v2"],
68         "routingKeys": ["did:adi:mediator1#key-1"]
69       }
70     },
71     {
72       "id": "did:adi:3f7a...#linked-domain",
73       "type": "LinkedDomains",
74       "serviceEndpoint": "https://example.com"
75     }
76   ],
77 
78   "created": "2026-03-28T10:00:00Z",
79   "updated": "2026-03-28T10:00:00Z",
80   "versionId": 1,
81   "deactivated": false
82 }

Agent DID Document

Agent DID Documents extend the base schema with agent-specific properties:

1 {
2   "@context": [
3     "https://www.w3.org/ns/did/v1",
4     "https://w3id.org/security/suites/ed25519-2020/v1",
5     "https://ida.infinia.io/ns/did/v1",
6     "https://ida.infinia.io/ns/agent/v1"
7   ],
8   "id": "did:adi:agent:7f3a9b2e1c4d5f6a8b0c2d4e6f8a0b2c...",
9   "controller": "did:adi:3f7a9b2e1c4d...",
10 
11   "verificationMethod": [
12     {
13       "id": "did:adi:agent:7f3a...#key-1",
14       "type": "Ed25519VerificationKey2020",
15       "controller": "did:adi:agent:7f3a...",
16       "publicKeyMultibase": "z6Mkw6QUbN4PqGmPVjR..."
17     }
18   ],
19 
20   "authentication": ["did:adi:agent:7f3a...#key-1"],
21   "assertionMethod": ["did:adi:agent:7f3a...#key-1"],
22   "capabilityInvocation": ["did:adi:agent:7f3a...#key-1"],
23 
24   "service": [
25     {
26       "id": "did:adi:agent:7f3a...#a2a",
27       "type": "AgentToAgent",
28       "serviceEndpoint": "https://agent.example.com/a2a"
29     },
30     {
31       "id": "did:adi:agent:7f3a...#agent-card",
32       "type": "AgentCard",
33       "serviceEndpoint": "https://agent.example.com/.well-known/agent.json"
34     }
35   ],
36 
37   "agent": {
38     "operator": "did:adi:3f7a9b2e1c4d...",
39     "model": {
40       "provider": "OpenAI",
41       "name": "gpt-4o",
42       "version": "2026-03-01"
43     },
44     "capabilities": ["shopping", "price-comparison", "order-placement"],
45     "autonomyLevel": "Junior",
46     "state": "active",
47     "registeredAt": "2026-03-28T10:00:00Z"
48   },
49 
50   "created": "2026-03-28T10:00:00Z",
51   "updated": "2026-03-28T10:00:00Z",
52   "versionId": 1,
53   "deactivated": false
54 }

Property Reference

Core Properties

Property	Type	Required	Description
`@context`	array	Yes	JSON-LD contexts
`id`	string	Yes	The DID string
`controller`	string/array	Yes	DID(s) authorized to make changes
`verificationMethod`	array	Yes	Public keys and their types
`authentication`	array	Yes	Keys for DID Auth
`assertionMethod`	array	No	Keys for signing VCs
`keyAgreement`	array	No	Keys for encryption
`capabilityInvocation`	array	No	Keys for invoking capabilities
`capabilityDelegation`	array	No	Keys for delegating capabilities
`service`	array	No	Service endpoints

Agent Extension Properties

Property	Type	Required	Description
`agent.operator`	string	Yes	DID of the human/org operator
`agent.model.provider`	string	Yes	AI model provider
`agent.model.name`	string	Yes	Model identifier
`agent.model.version`	string	No	Model version
`agent.capabilities`	array	Yes	List of capability tags
`agent.autonomyLevel`	string	Yes	Intern, Junior, Senior, Principal
`agent.state`	string	Yes	registered, active, suspended, decommissioned
`agent.registeredAt`	string	Yes	ISO 8601 registration timestamp

Service Endpoint Types

Type	Description	Example
`DIDCommMessaging`	DIDComm v2 messaging	Agent messaging endpoint
`LinkedDomains`	Domain ownership	Website verification
`AgentToAgent`	A2A protocol endpoint	Agent task handling
`AgentCard`	Agent metadata	`.well-known/agent.json`
`CredentialRegistry`	Credential status	StatusList2021 endpoint

Verification Method Types

Ed25519VerificationKey2020

1 {
2   "id": "did:adi:3f7a...#key-1",
3   "type": "Ed25519VerificationKey2020",
4   "controller": "did:adi:3f7a...",
5   "publicKeyMultibase": "z6Mkf5rGMoatrSj1f4CyvuHBeXJELe9RPdzo2PKGNCKVtZxP"
6 }

Encoding: Multibase (base58-btc, prefix z)
Key size: 32 bytes (256 bits)
Usage: Authentication, assertion, capability invocation/delegation

EcdsaSecp256k1VerificationKey2019

1 {
2   "id": "did:adi:3f7a...#key-2",
3   "type": "EcdsaSecp256k1VerificationKey2019",
4   "controller": "did:adi:3f7a...",
5   "publicKeyMultibase": "zQ3shokFTS3brHcDQrn82RUDfCZtME..."
6 }

Encoding: Multibase (base58-btc, prefix z)
Key size: 33 bytes (compressed, 264 bits)
Usage: Authentication, blockchain-native operations

X25519KeyAgreementKey2020

1 {
2   "id": "did:adi:3f7a...#key-agreement-1",
3   "type": "X25519KeyAgreementKey2020",
4   "controller": "did:adi:3f7a...",
5   "publicKeyMultibase": "z6LShs9GGnqk85JBBenbnvGGnm1V8..."
6 }

Encoding: Multibase (base58-btc, prefix z)
Usage: Diffie-Hellman key agreement for DIDComm encryption

Bls12381G2Key2020

1 {
2   "id": "did:adi:3f7a...#bbs-key-1",
3   "type": "Bls12381G2Key2020",
4   "controller": "did:adi:3f7a...",
5   "publicKeyBase58": "25EEStQgp9xE3gqAZqYejcNB..."
6 }

Encoding: Base58
Usage: BBS+ signatures for selective disclosure

Validation Rules

A did:adi DID Document is valid if and only if:

@context includes "https://www.w3.org/ns/did/v1" as the first entry
id is a valid did:adi identifier per the ABNF grammar
At least one verificationMethod exists
At least one authentication relationship references a valid verification method
All referenced verification method IDs resolve to entries in verificationMethod
controller is a valid DID (same or different from id)
For agent DIDs: agent object is present with all required fields
For agent DIDs: agent.operator references a valid non-agent DID
created and updated are valid ISO 8601 timestamps
versionId is a positive integer