Agent DID Specification | IDA — Identity for the AI Age

did:adi:agent Method

The did:adi:agent sub-method extends did:adi for AI agent identifiers. Agent DIDs are registered on the ADI blockchain and include agent-specific metadata in their DID Document.

ABNF Syntax

agent-did = "did:adi:agent:" agent-id
agent-id  = 1*64HEXDIG

Examples

did:adi:agent:7f3a9b2e1c4d5f6a8b0c2d4e6f8a0b2c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f
did:adi:agent:a1b2c3d4e5f67890abcdef1234567890abcdef1234567890abcdef1234567890

Agent DID Document Schema

An agent DID Document extends the standard did:adi document with the agent property block:

{
  "@context": [
    "https://www.w3.org/ns/did/v1",
    "https://w3id.org/security/suites/ed25519-2020/v1",
    "https://ida.infinia.io/ns/did/v1",
    "https://ida.infinia.io/ns/agent/v1"
  ],
  "id": "did:adi:agent:7f3a9b2e1c4d5f6a8b0c2d4e6f8a0b2c...",
  "controller": "did:adi:operator001...",
  "verificationMethod": [
    {
      "id": "did:adi:agent:7f3a...#key-1",
      "type": "Ed25519VerificationKey2020",
      "controller": "did:adi:agent:7f3a...",
      "publicKeyMultibase": "z6Mkw6QUbN4PqGmPVjR..."
    }
  ],
  "authentication": ["did:adi:agent:7f3a...#key-1"],
  "assertionMethod": ["did:adi:agent:7f3a...#key-1"],
  "capabilityInvocation": ["did:adi:agent:7f3a...#key-1"],
  "keyAgreement": [
    {
      "id": "did:adi:agent:7f3a...#key-agreement-1",
      "type": "X25519KeyAgreementKey2020",
      "controller": "did:adi:agent:7f3a...",
      "publicKeyMultibase": "z6LSe2nPYf9r7QmX..."
    }
  ],
  "service": [
    {
      "id": "did:adi:agent:7f3a...#a2a",
      "type": "AgentToAgent",
      "serviceEndpoint": "https://agent.example.com/a2a"
    },
    {
      "id": "did:adi:agent:7f3a...#agent-card",
      "type": "AgentCard",
      "serviceEndpoint": "https://agent.example.com/.well-known/agent.json"
    },
    {
      "id": "did:adi:agent:7f3a...#mcp",
      "type": "MCPServer",
      "serviceEndpoint": "https://agent.example.com/mcp"
    }
  ],
  "agent": {
    "operator": "did:adi:operator001...",
    "name": "Shopping Assistant",
    "description": "AI agent for grocery shopping and price comparison",
    "model": {
      "provider": "OpenAI",
      "name": "gpt-4o",
      "version": "2026-03-01",
      "hash": "sha256:abc123..."
    },
    "capabilities": [
      "shopping",
      "price-comparison",
      "order-placement",
      "receipt-management"
    ],
    "autonomyLevel": "Junior",
    "state": "active",
    "registeredAt": "2026-03-15T09:00:00Z",
    "activatedAt": "2026-03-15T09:05:00Z",
    "trustScore": 74,
    "maxDelegationDepth": 1,
    "compliance": [
      {
        "standard": "EU AI Act",
        "status": "compliant",
        "credentialId": "urn:uuid:compliance-001"
      }
    ]
  },
  "created": "2026-03-15T09:00:00Z",
  "updated": "2026-03-28T10:00:00Z",
  "versionId": 3,
  "deactivated": false
}

Agent Property Block

Required Fields

Field	Type	Description
`operator`	string (DID)	DID of the human/organization who deployed and is accountable for this agent
`name`	string	Human-readable agent name
`model.provider`	string	AI model provider (e.g., OpenAI, Anthropic)
`model.name`	string	Model identifier (e.g., gpt-4o, claude-3-opus)
`capabilities`	string[]	Tags describing what the agent can do
`autonomyLevel`	string	One of: Intern, Junior, Senior, Principal
`state`	string	One of: registered, active, suspended, decommissioned
`registeredAt`	datetime	When the agent DID was created

Optional Fields

Field	Type	Description
`description`	string	Human-readable description
`model.version`	string	Model version string
`model.hash`	string	Hash of the model weights/config for integrity
`activatedAt`	datetime	When the agent received its first delegation
`trustScore`	integer	Current on-chain trust score (0-100)
`maxDelegationDepth`	integer	Max sub-delegation hops allowed
`compliance`	object[]	Compliance attestations

Agent DID Creation

Request

POST /api/v1/agents
Content-Type: application/json
Authorization: Bearer <operator-api-key>
{
  "name": "Shopping Assistant",
  "description": "AI agent for grocery shopping and price comparison",
  "operatorDid": "did:adi:operator001...",
  "model": {
    "provider": "OpenAI",
    "name": "gpt-4o",
    "version": "2026-03-01"
  },
  "capabilities": ["shopping", "price-comparison", "order-placement"],
  "autonomyLevel": "Intern",
  "services": [
    {
      "type": "AgentToAgent",
      "serviceEndpoint": "https://agent.example.com/a2a"
    }
  ]
}

Response

{
  "agentDid": "did:adi:agent:7f3a9b2e1c4d5f6a...",
  "didDocument": { "..." },
  "keys": {
    "authentication": {
      "keyId": "did:adi:agent:7f3a...#key-1",
      "publicKey": "z6Mkw6QUbN4PqGmPVjR...",
      "privateKey": "** STORE IN AGENT RUNTIME - SHOWN ONCE **"
    }
  },
  "agentCard": {
    "url": "https://agent.example.com/.well-known/agent.json"
  },
  "transactionHash": "0xagent..."
}

Differences from Standard DID Documents

Feature	Standard DID	Agent DID
Identifier prefix	`did:adi:`	`did:adi:agent:`
Controller	Self or chosen DID	Operator’s DID (required)
`agent` property	Not present	Required
`capabilityDelegation`	Optional	Requires Principal autonomy
Service types	DIDComm, LinkedDomains	AgentToAgent, AgentCard, MCPServer
Trust score	Not applicable	On-chain via Agent Trust Registry
Lifecycle states	Active/Deactivated	Registered/Active/Suspended/Decommissioned

Validation Rules

An agent DID Document is valid if:

All standard DID Document validation rules pass (see DID Document Schema)
id starts with did:adi:agent:
controller references a valid non-agent DID (the operator)
agent object is present with all required fields
agent.operator matches controller
agent.state is one of the allowed values
agent.autonomyLevel is one of: Intern, Junior, Senior, Principal
agent.capabilities is a non-empty array
If agent.state is decommissioned, deactivated must be true

Agent Decommissioning

When an agent is decommissioned:

POST /api/v1/agents/did:adi:agent:7f3a.../decommission
Authorization: Bearer <operator-api-key>
{
  "reason": "replaced_by_newer_version",
  "confirm": true
}

This triggers:

Agent state set to decommissioned on-chain
All delegation VCs held by this agent are revoked
All capability and compliance VCs are revoked
All active IBCTs are invalidated
Sub-agents delegated by this agent lose their delegations
DID Document is updated with deactivated: true