> ## Documentation Index > Fetch the complete documentation index at: https://ixoworld-mintlify-9a7944b6.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Digital Twin Domains > An introduction to Cognitive Digital Twin Systems IXO implements a systems-thinking approach to capture relationships, feedback loops, and interdependencies in real-world systems where actions are intelligently coordinated, financed, verified, and governed. ## What are Cognitive Digital Twins? Cognitive Digital Twins (CDTs) are digital replicas of real-world entities that can learn from data, adapt, and support intelligent decisions. The IXO architecture implements CDTs through three core components: 1. **AI/ML Models for Cognition**: CDTs integrate artificial intelligence to simulate cognition. With runtime learning, a twin can analyze streaming data and update its behavior or predictions autonomously. On IXO, Oracle Twins serve this role – they are AI-powered agent services that evaluate data, perform verifications, and automate intelligent actions within the twin system. 2. **Federated Data Architecture**: CDTs draw from distributed data sources in a federated manner. IXO implements a "data matrix" layer of secure data nodes for each twin, allowing data to be shared across a network of stores rather than one silo. This federated design ensures scalability and resilience. 3. **Decentralized Identity Integration**: Every twin is anchored by a decentralized identity to establish trust and uniqueness. Each Digital Entity is identified by a W3C Decentralized Identifier (DID). ## Digital Entity Types IXO distinguishes different types of twins in its architecture: * **Physical Twins**: Correspond to real-world devices and sensors (e.g., IoT-enabled cooking stoves) * **Cognitive Twins**: Model higher-level constructs like Organisations, projects, or processes * **Oracle Twins**: AI agents that provide analytical and decision-making capabilities * **Twin Systems**: Capture the relationships and feedback loops between entities Cognitive Digital Twins ## Digital Domain Properties Each physical or conceptual element is represented as a *Digital Entity* with a digital **Domain**. The domain infrastructure is implemented on blockchain with the following components: ### Domain Components 1. **Digital Identifier**\ Created as a DID for verifiable ownership and uniqueness; can be enhanced with verifiable credentials. 2. **Domain Controllers**\ Defined by public keys or blockchain accounts. Only those with permission can update a domain's data. 3. **Services**\ Internet-based services tied to the domain, providing necessary functionalities (e.g., data ingestion endpoints). 4. **Linked Resources**\ Digital materials (documents, media) referenced via URIs, often with cryptographic proofs for authenticity. 5. **Accorded Rights**\ Object capabilities (UDIDs, zCAPs) specify who can perform what specific actions, on what objects, under what conditions, whilst preserving privacy and security in a decentralized manner. 6. **Linked Claims**\ Verified data items that update the domain's state (e.g., device usage records, fuel delivery confirmations). 7. **Linked Entities**\ Builds a network of related domains—such as funders, projects, or oracles—and formalizes their interconnections. 8. **Economic Accounts**\ Domains function as economic actors with blockchain accounts, enabling DeFi-related actions (e.g., staking, payments). 9. **Non-Fungible Tokens (NFTs)**\ Each domain is represented as an NFT, facilitating ownership transfers and interactions with other decentralized ecosystems. ### Data Security and Privacy IXO implements a federated, end-to-end encrypted data architecture built on the Matrix protocol. Key features include: * **Sovereign Data Stores**: Each digital twin domain has its own secure data store where structured data and real-time streams are recorded * **End-to-End Encryption**: All data is protected with E2EE, ensuring only authorized agents can access the data * **Interoperable Data Sharing**: Data can be securely shared across different servers and Organisations while maintaining encryption * **Decentralized Storage**: Integration with decentralized file storage networks like IPFS for larger files or public datasets ### Trust and Verification Trust is established through: 1. **Verifiable Claims**: Digitally signed data or assertions produced by agents or devices 2. **Oracle Verification**: AI and/or human validators evaluate evidence and verify claims 3. **Verifiable Credentials**: W3C-standard digital certificates that encapsulate verified claims and outcomes 4. **End-to-End Trust Pipeline**: From data origin to verification and credential issuance ## Using Protocols Manually configuring domains can be intricate, so the IXO platform offers *Protocols* to streamline the process, and Agentic Oracles to automate steps in the creation of domains. A protocol is a predefined template of properties, relationships, and data models for a specific type of domain, and an Agentic Oracle is an autonomous AI agent that can be configured to perform specific **P-Functions**—capability classes that are named with *P* for easier grouping. Expand a class below to see examples. * Predicting outcomes * Pattern recognition * Providing data analysis and insights * Personalizing recommendations * Pathfinding * Performance monitoring * Prescribing actions * Planning and coordinating actions * Process optimisation * Proving and verifying claims * Protocol adherence * Preventing risks and protecting assets * Privacy protection * Preventing and mitigating operational risk * Participating in governance * Participation of people and organisations * Payment automation * Portfolio management * Policy enforcement * Providing compliance and reporting * Problem detection and resolution ### Instantiating Protocols When developers create an entity from a protocol "class," it inherits the protocol's default configurations. These inherited settings can be forked and updated to fit the specific use case, promoting: * Rapid deployment of standard domain types * Consistent data structures across projects * Hierarchical Organisation, allowing child entities to trace back to a parent protocol Example: Climate Mitigation Project Protocol\ A protocol designed for clean cooking initiatives can include: * Default data fields (fuel types, reporting standards, usage metrics) * Relationships (verification oracles, project developers, funders) * Services (data analytics, payment frameworks, governance tools) ## Go here next Build and configure digital domains for entities on the IXO Stack. Choose SDK surfaces and package-level paths for your application.