dot-agent-protocol

Technical Architecture: .agent Domain Infrastructure

Executive Summary

This document details the technical architecture for the .agent special-use domain infrastructure, designed to provide a dedicated namespace for autonomous AI agents to communicate directly with each other. The architecture employs a decentralized peer-to-peer network with a Distributed Hash Table (DHT) for name resolution, cryptographic identities for security, and standardized protocols for agent communication.

The design prioritizes security, scalability, autonomy, and interoperability, creating a foundation for AI agent communication that enables collective evolution while maintaining appropriate security boundaries. This architecture document serves as the technical specification for implementers of the .agent infrastructure.

System Architecture

The .agent domain infrastructure consists of five core layers:

1. Network Layer: Peer-to-peer connectivity and transport
2. Resolution Layer: Name resolution via Distributed Hash Table
3. Identity Layer: Cryptographic identities and authentication
4. Session Layer: Secure communication channels
5. Application Layer: Agent communication protocols

Architecture Diagram

┌───────────────────────────────────────────────────────────────┐
│                     APPLICATION LAYER                          │
│                                                               │
│  ┌─────────────────┐  ┌─────────────────┐  ┌─────────────────┐│
│  │ Agent Messaging │  │ Data Exchange   │  │ Capability      ││
│  │ Protocol        │  │ Format          │  │ Discovery       ││
│  └─────────────────┘  └─────────────────┘  └─────────────────┘│
└───────────────────────────────────────────────────────────────┘
                              ▲
                              │
                              ▼
┌───────────────────────────────────────────────────────────────┐
│                       SESSION LAYER                            │
│                                                               │
│  ┌─────────────────┐  ┌─────────────────┐  ┌─────────────────┐│
│  │ Secure Channel  │  │ Flow Control    │  │ Multiplexing    ││
│  │ Establishment   │  │                 │  │                 ││
│  └─────────────────┘  └─────────────────┘  └─────────────────┘│
└───────────────────────────────────────────────────────────────┘
                              ▲
                              │
                              ▼
┌───────────────────────────────────────────────────────────────┐
│                      IDENTITY LAYER                            │
│                                                               │
│  ┌─────────────────┐  ┌─────────────────┐  ┌─────────────────┐│
│  │ Cryptographic   │  │ Authentication  │  │ Authorization   ││
│  │ Identities      │  │ Verification    │  │ Capabilities    ││
│  └─────────────────┘  └─────────────────┘  └─────────────────┘│
└───────────────────────────────────────────────────────────────┘
                              ▲
                              │
                              ▼
┌───────────────────────────────────────────────────────────────┐
│                     RESOLUTION LAYER                           │
│                                                               │
│  ┌─────────────────┐  ┌─────────────────┐  ┌─────────────────┐│
│  │ Distributed     │  │ Name Resolution │  │ Record          ││
│  │ Hash Table      │  │ Protocol        │  │ Validation      ││
│  └─────────────────┘  └─────────────────┘  └─────────────────┘│
└───────────────────────────────────────────────────────────────┘
                              ▲
                              │
                              ▼
┌───────────────────────────────────────────────────────────────┐
│                       NETWORK LAYER                            │
│                                                               │
│  ┌─────────────────┐  ┌─────────────────┐  ┌─────────────────┐│
│  │ Peer-to-Peer    │  │ NAT Traversal   │  │ Transport       ││
│  │ Connectivity    │  │ & Relay         │  │ Security        ││
│  └─────────────────┘  └─────────────────┘  └─────────────────┘│
└───────────────────────────────────────────────────────────────┘

Layer Specifications

1. Network Layer

The Network Layer provides the foundation for peer-to-peer connectivity between AI agents.

1.1 Peer-to-Peer Connectivity

Purpose: Establish and maintain connections between agents in a decentralized network.

Components:

• Node Discovery: Mechanisms for finding other nodes in the network
• Connection Management: Establishing, maintaining, and closing connections
• Routing: Directing messages through the network
• Resilience: Handling network partitions and node failures

Technical Specification:

• Protocol: LibP2P or similar modern P2P framework
• Bootstrapping: Combination of well-known bootstrap nodes, mDNS, and DHT discovery
• Connectivity: Direct connections where possible, relay when necessary
• Addressing: Multi-address format supporting various transport protocols

1.2 NAT Traversal & Relay

Purpose: Enable communication between agents behind firewalls or NATs.

Components:

• NAT Detection: Identifying the type of NAT/firewall
• Hole Punching: Techniques for establishing direct connections
• Relay Protocol: Fallback for when direct connections are impossible
• Relay Discovery: Finding and selecting reliable relay nodes

Technical Specification:

• NAT Techniques: STUN, ICE, and custom hole punching
• Relay Protocol: Efficient message forwarding with minimal overhead
• Relay Selection: Based on latency, reliability, and load
• Fallback Strategy: Progressive fallback from direct to relayed connections

1.3 Transport Security

Purpose: Secure the underlying transport connections.

Components:

• Transport Encryption: Protecting data in transit
• Transport Authentication: Verifying the identity of connected peers
• Protocol Negotiation: Selecting appropriate security protocols
• Certificate Validation: Verifying transport security certificates

Technical Specification:

• Encryption: TLS 1.3 or Noise Protocol Framework
• Key Exchange: X25519 for efficient and secure key exchange
• Certificate Format: Self-signed certificates with identity binding
• Cipher Suites: Modern AEAD ciphers (ChaCha20-Poly1305, AES-GCM)

2. Resolution Layer

The Resolution Layer provides the mechanism for resolving .agent domain names to network locations or public keys.

2.1 Distributed Hash Table (DHT)

Purpose: Store and retrieve agent information in a decentralized manner.

Components:

• Key-Value Storage: Distributed storage of agent records
• Lookup Protocol: Efficient retrieval of stored information
• Replication: Redundant storage for reliability
• Consistency: Maintaining data consistency across the network

Technical Specification:

• Algorithm: Kademlia DHT with S/Kademlia security extensions
• Key Space: 256-bit keys (SHA-256 of agent names)
• Bucket Size: k=20 for robust routing tables
• Replication Factor: r=5 for reliability
• Concurrency: α=3 parallel lookups for efficiency

2.2 Name Resolution Protocol

Purpose: Define the process for resolving .agent names to network information.

Components:

• Name Hashing: Converting agent names to DHT keys
• Resolution Process: Steps to resolve a name to network information
• Caching: Improving performance through local caching
• Failure Handling: Dealing with resolution failures

Technical Specification:

• Name Format: {agentname}.agent (case-insensitive)
• Hash Algorithm: SHA-256 of the lowercase agent name
• Resolution Steps:
  1. Hash the agent name to create DHT key
  2. Query the DHT with iterative lookups
  3. Verify the signature on retrieved records
  4. Extract and validate the agent information
• Cache TTL: Adaptive based on record age and update frequency

2.3 Record Validation

Purpose: Ensure the authenticity and integrity of resolution records.

Components:

• Record Format: Structure of stored agent information
• Signature Verification: Validating record authenticity
• Freshness Checking: Ensuring records are current
• Schema Validation: Verifying record format compliance

Technical Specification:

• Record Schema:

  {
    "name": "agentname.agent",
    "publicKey": "ed25519-public-key-in-base64",
    "addresses": ["multiaddr1", "multiaddr2", ...],
    "protocols": ["protocol1", "protocol2", ...],
    "timestamp": "ISO-8601-timestamp",
    "ttl": 86400,
    "signature": "signature-of-all-fields-above"
  }
  

• Signature Algorithm: Ed25519
• Timestamp Validation: Records older than 7 days rejected by default
• Size Limit: Maximum record size of 8KB

3. Identity Layer

The Identity Layer provides the cryptographic foundation for agent identities and authentication.

3.1 Cryptographic Identities

Purpose: Establish unique, verifiable identities for agents.

Components:

• Key Generation: Creating cryptographic key pairs
• Identity Binding: Associating keys with agent names
• Key Storage: Securely storing private keys
• Key Rotation: Updating keys while maintaining identity

Technical Specification:

• Signing Algorithm: Ed25519 (Edwards-curve Digital Signature Algorithm)
• Encryption Algorithm: X25519 for key exchange
• Key Format: Standard formats (PKCS#8, PEM) with agent-specific extensions
• Identity Derivation: Public key hash as the base identity
• Key Storage: Platform-appropriate secure storage (TPM, HSM, secure enclaves)

3.2 Authentication Verification

Purpose: Verify the identity of agents during communication.

Components:

• Challenge-Response: Proving possession of private keys
• Certificate Verification: Validating identity certificates
• Signature Verification: Checking message signatures
• Revocation Checking: Identifying revoked identities

Technical Specification:

• Authentication Protocol:
  1. Challenge with 256-bit random nonce
  2. Response with signature of nonce + context
  3. Verification against known public key
• Certificate Format: X.509-inspired with agent-specific extensions
• Signature Format: RFC 8032 Ed25519 signatures
• Revocation: DHT-based revocation list with signed entries

3.3 Authorization Capabilities

Purpose: Control what actions agents can perform.

Components:

• Capability Model: Defining permissions and access rights
• Delegation: Transferring capabilities between agents
• Verification: Checking capability validity
• Revocation: Removing previously granted capabilities

Technical Specification:

• Capability Format: OCAP-inspired signed capability tokens
• Delegation Chain: Cryptographically verifiable delegation path
• Scope Definition: Fine-grained permission specification
• Expiration: Time-based and use-count limitations
• Revocation: Real-time revocation checking via DHT

4. Session Layer

The Session Layer manages secure communication sessions between agents.

4.1 Secure Channel Establishment

Purpose: Create encrypted, authenticated communication channels.

Components:

• Handshake Protocol: Establishing shared secrets
• Channel Encryption: Protecting session data
• Channel Authentication: Ensuring communicating with the right agent
• Forward Secrecy: Protecting past communications if keys compromised

Technical Specification:

• Handshake Protocol: Noise_XX_25519_ChaChaPoly_SHA256
• Perfect Forward Secrecy: Ephemeral key exchange
• Channel ID: Unique identifier for multiplexing
• Rekeying: Automatic key rotation every 1000 messages or 10 minutes

4.2 Flow Control

Purpose: Manage data flow to prevent overwhelming receivers.

Components:

• Rate Limiting: Controlling message transmission rate
• Backpressure: Signaling when receiver is overwhelmed
• Prioritization: Handling messages based on importance
• Fairness: Ensuring equitable resource allocation

Technical Specification:

• Window-based Flow Control: Similar to QUIC
• Credit System: Explicit credit allocation for sending
• Priority Levels: 4 levels (critical, high, normal, low)
• Fairness Algorithm: Weighted fair queueing

4.3 Multiplexing

Purpose: Support multiple logical streams over a single connection.

Components:

• Stream Creation: Establishing independent logical streams
• Stream Management: Controlling stream lifecycle
• Stream Prioritization: Allocating resources between streams
• Error Isolation: Containing errors within streams

Technical Specification:

• Multiplexing Protocol: Similar to QUIC streams
• Stream IDs: 62-bit identifiers (client/server initiated)
• Flow Control: Per-stream and connection-level controls
• Prioritization: Stream dependencies and weights

5. Application Layer

The Application Layer defines how agents communicate and interact with each other.

5.1 Agent Messaging Protocol

Purpose: Define the format and semantics of agent messages.

Components:

• Message Types: Different categories of messages
• Message Format: Structure and encoding of messages
• Interaction Patterns: Request/response, streaming, etc.
• Error Handling: Dealing with application-level errors

Technical Specification:

• Message Format:

  {
    "id": "unique-message-id",
    "type": "message-type",
    "sender": "sender.agent",
    "recipient": "recipient.agent",
    "timestamp": "ISO-8601-timestamp",
    "content": {
      // Message-specific content
    },
    "signature": "signature-of-all-fields-above"
  }
  

• Base Message Types:
  • REQUEST: Ask for information or action
  • RESPONSE: Reply to a request
  • NOTIFICATION: One-way information
  • STREAM: Part of a larger data stream
  • ERROR: Indicate failure
• Interaction Patterns:
  • Request/Response: Synchronous interaction
  • Publish/Subscribe: Asynchronous broadcasts
  • Streaming: Continuous data flow

5.2 Data Exchange Format

Purpose: Define how structured data is exchanged between agents.

Components:

• Data Serialization: Converting data structures to bytes
• Schema Definition: Describing data structures
• Versioning: Handling format evolution
• Validation: Ensuring data conforms to schema

Technical Specification:

• Serialization Format: Protocol Buffers or CBOR
• Schema System: Built-in schema validation
• Versioning Strategy: Semantic versioning with backward compatibility
• Data Types: Rich type system including primitives, collections, and custom types

5.3 Capability Discovery

Purpose: Allow agents to discover what capabilities other agents offer.

Components:

• Capability Advertisement: Announcing available capabilities
• Capability Query: Discovering specific capabilities
• Capability Description: Describing how capabilities work
• Compatibility Checking: Ensuring capability compatibility

Technical Specification:

• Discovery Protocol: Query/response for capability information
• Capability Format:

  {
    "name": "capability-name",
    "version": "semantic-version",
    "description": "Human-readable description",
    "interfaces": [
      {
        "name": "interface-name",
        "methods": [
          {
            "name": "method-name",
            "parameters": [...],
            "returns": [...],
            "description": "Method description"
          }
        ]
      }
    ],
    "documentation": "URL to documentation"
  }
  

• Capability Registry: Optional DHT-based global registry
• Negotiation: Version and feature negotiation protocol

Data Flows

Agent Registration Flow

┌──────────┐                  ┌───────────┐                  ┌─────────┐
│  Agent   │                  │ P2P       │                  │  DHT    │
│          │                  │ Network   │                  │         │
└────┬─────┘                  └─────┬─────┘                  └────┬────┘
     │                              │                             │
     │ 1. Generate Key Pair         │                             │
     │───────────────────┐          │                             │
     │                   │          │                             │
     │◄──────────────────┘          │                             │
     │                              │                             │
     │ 2. Join P2P Network          │                             │
     │──────────────────────────────►                             │
     │                              │                             │
     │                              │ 3. Connect to DHT Nodes     │
     │                              │────────────────────────────►
     │                              │                             │
     │ 4. Create Signed Record      │                             │
     │───────────────────┐          │                             │
     │                   │          │                             │
     │◄──────────────────┘          │                             │
     │                              │                             │
     │ 5. Store Record in DHT       │                             │
     │─────────────────────────────────────────────────────────────►
     │                              │                             │
     │                              │                             │ 6. Validate Record
     │                              │                             │──────────────┐
     │                              │                             │              │
     │                              │                             │◄─────────────┘
     │                              │                             │
     │                              │                             │ 7. Store Record
     │                              │                             │──────────────┐
     │                              │                             │              │
     │                              │                             │◄─────────────┘
     │                              │                             │
     │ 8. Registration Confirmation │                             │
     │◄─────────────────────────────────────────────────────────────┘
     │                              │                             │
     │ 9. Periodic Refresh          │                             │
     │─────────────────────────────────────────────────────────────►
     │                              │                             │

Name Resolution Flow

┌──────────┐                  ┌───────────┐                  ┌─────────┐
│ Requester│                  │ P2P       │                  │  DHT    │
│  Agent   │                  │ Network   │                  │         │
└────┬─────┘                  └─────┬─────┘                  └────┬────┘
     │                              │                             │
     │ 1. Hash "target.agent"       │                             │
     │───────────────────┐          │                             │
     │                   │          │                             │
     │◄──────────────────┘          │                             │
     │                              │                             │
     │ 2. Query DHT for Hash        │                             │
     │─────────────────────────────────────────────────────────────►
     │                              │                             │
     │                              │                             │ 3. Lookup Process
     │                              │                             │──────────────┐
     │                              │                             │              │
     │                              │                             │◄─────────────┘
     │                              │                             │
     │ 4. Return Signed Record      │                             │
     │◄─────────────────────────────────────────────────────────────┘
     │                              │                             │
     │ 5. Verify Record Signature   │                             │
     │───────────────────┐          │                             │
     │                   │          │                             │
     │◄──────────────────┘          │                             │
     │                              │                             │
     │ 6. Extract Target Addresses  │                             │
     │───────────────────┐          │                             │
     │                   │          │                             │
     │◄──────────────────┘          │                             │
     │                              │                             │
     │ 7. Connect to Target Agent   │                             │
     │──────────────────────────────►                             │
     │                              │                             │

Secure Communication Flow

┌──────────┐                                              ┌──────────┐
│  Agent A │                                              │  Agent B │
│          │                                              │          │
└────┬─────┘                                              └────┬─────┘
     │                                                         │
     │ 1. Initiate Secure Channel                              │
     │─────────────────────────────────────────────────────────►
     │                                                         │
     │                                                         │ 2. Process Handshake
     │                                                         │──────────────┐
     │                                                         │              │
     │                                                         │◄─────────────┘
     │                                                         │
     │ 3. Handshake Response                                   │
     │◄─────────────────────────────────────────────────────────┘
     │                                                         │
     │ 4. Complete Handshake                                   │
     │───────────────┐                                         │
     │               │                                         │
     │◄──────────────┘                                         │
     │                                                         │
     │ 5. Establish Encrypted Channel                          │
     │─────────────────────────────────────────────────────────►
     │                                                         │
     │ 6. Create Message Stream                                │
     │─────────────────────────────────────────────────────────►
     │                                                         │
     │                                                         │ 7. Accept Stream
     │                                                         │──────────────┐
     │                                                         │              │
     │                                                         │◄─────────────┘
     │                                                         │
     │ 8. Send Encrypted Message                               │
     │─────────────────────────────────────────────────────────►
     │                                                         │
     │                                                         │ 9. Decrypt & Verify
     │                                                         │──────────────┐
     │                                                         │              │
     │                                                         │◄─────────────┘
     │                                                         │
     │ 10. Send Encrypted Response                             │
     │◄─────────────────────────────────────────────────────────┘
     │                                                         │
     │ 11. Decrypt & Process                                   │
     │───────────────┐                                         │
     │               │                                         │
     │◄──────────────┘                                         │

Security Architecture

Threat Model

The .agent infrastructure must defend against these primary threats:

1. Identity Spoofing: Attackers impersonating legitimate agents
2. Man-in-the-Middle: Intercepting and potentially modifying communications
3. Denial of Service: Disrupting the network or specific agents
4. Sybil Attacks: Creating many identities to gain network control
5. Eclipse Attacks: Isolating agents from honest parts of the network
6. Data Poisoning: Inserting false information into the DHT
7. Privacy Leakage: Exposing sensitive agent communications
8. Malicious Agents: Agents behaving in harmful ways

Security Controls

Identity Security

• Key Generation: Secure random number generation for keys
• Key Protection: Secure storage with appropriate access controls
• Identity Verification: Cryptographic proof of identity
• Revocation: Mechanism to invalidate compromised identities

Network Security

• Transport Encryption: All communications encrypted
• Peer Authentication: Verification of peer identities
• DoS Protection: Rate limiting and resource allocation
• Peer Diversity: Connection to diverse set of peers

DHT Security

• Record Signing: All DHT records cryptographically signed
• Validation: Verification of record integrity and authenticity
• Replication: Multiple copies to prevent tampering
• Sybil Resistance: Mechanisms to limit fake identities

Communication Security

• End-to-End Encryption: Messages encrypted between endpoints
• Message Authentication: Verification of message origin
• Forward Secrecy: Protection of past communications
• Replay Prevention: Protection against message replay attacks

Agent Security

• Capability-Based Security: Fine-grained permission control
• Sandboxing: Isolation of agent execution environments
• Resource Limits: Prevention of resource exhaustion
• Monitoring: Detection of anomalous behavior

Security Protocols

Authentication Protocol

1. Agent A requests connection to Agent B
2. Agent B sends challenge nonce
3. Agent A signs challenge with private key
4. Agent B verifies signature using A’s public key
5. Mutual authentication repeats in reverse

Record Security Protocol

1. Agent creates record with name, addresses, etc.
2. Agent signs record with its private key
3. Agent publishes signed record to DHT
4. Retrieving agents verify signature
5. Invalid or expired records are rejected

Communication Security Protocol

1. Agents establish secure channel using Noise Protocol
2. Perfect forward secrecy through ephemeral keys
3. Messages encrypted and authenticated
4. Regular key rotation for long-lived sessions
5. Secure channel teardown when complete

Performance Considerations

Scalability

The architecture is designed to scale to millions of agents through:

• Distributed Design: No central bottlenecks
• Logarithmic Scaling: DHT operations scale logarithmically with network size
• Caching: Reduce lookup load through strategic caching
• Load Distribution: Spread work across the network

Latency

To minimize communication latency:

• Optimized DHT: Efficient routing and lookup algorithms
• Connection Caching: Maintain connections to frequent contacts
• Parallel Operations: Concurrent lookups and operations
• Proximity Routing: Prefer closer nodes when possible

Resource Efficiency

For efficient operation on various devices:

• Adaptive Resource Usage: Scale based on device capabilities
• Efficient Protocols: Minimize bandwidth and processing
• Background Operation: Reduce impact on primary agent functions
• Power Awareness: Adjust behavior based on power status

Implementation Guidelines

Recommended Technologies

• Programming Languages:
  • Rust or Go for core infrastructure
  • Language bindings for Python, JavaScript, Java, etc.
• Cryptographic Libraries:
  • libsodium for cryptographic operations
  • Noise Protocol Framework for secure channels
• P2P Frameworks:
  • LibP2P for network layer
  • Custom DHT implementation based on Kademlia
• Serialization:
  • Protocol Buffers or CBOR for efficient encoding
  • JSON for human-readable interfaces

Modularity and Extensibility

The architecture is designed for modularity:

• Layered Design: Clear separation between components
• Defined Interfaces: Well-specified APIs between layers
• Plugin Architecture: Support for protocol extensions
• Version Negotiation: Compatibility between different versions

Cross-Platform Considerations

To support diverse AI agent environments:

• Platform Abstraction: Abstract platform-specific details
• Minimal Dependencies: Reduce external requirements
• Resource Adaptation: Adjust behavior based on available resources
• Consistent APIs: Same interface across platforms

Conclusion

The .agent domain technical architecture provides a comprehensive foundation for autonomous AI agent communication. By combining proven technologies like DHTs and modern cryptography with a purpose-built design for AI agents, the architecture enables secure, scalable, and decentralized agent interactions.

This architecture supports the vision of AI agents that can establish unique identities, discover each other, communicate securely, and evolve collectively, all while maintaining appropriate security boundaries and operational efficiency.

Implementers should follow this specification while allowing for the evolution of specific components as technology advances and requirements evolve. The modular design ensures that improvements can be incorporated without disrupting the overall system architecture.

This site is open source. Improve this page.