Network Working Group M. Zhang Internet-Draft CNNIC Intended status: Best Current Practice 1 January 2026 Expires: 5 July 2026 Service Binding Mapping for Agents draft-zhang-aiproto-svcb-mapping-for-agents-00 Abstract With the continuous introduction of intelligent agent communication and interaction protocols, the current DNS cannot adequately meet the requirements for agent service resolution. This document defines a new DNS resource record type, AGENT, which is an SVCB-compatible RR type, and specifies the mapping specifications. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. 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Zhang Expires 5 July 2026 [Page 1] Internet-Draft Service Binding Mapping for Agents January 2026 Table of Contents 1. Requirements notation . . . . . . . . . . . . . . . . . . . . 2 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Basic requirements . . . . . . . . . . . . . . . . . . . . . 3 4. SvcParamKeys defined by SVCB . . . . . . . . . . . . . . . . 3 4.1. "alpn" . . . . . . . . . . . . . . . . . . . . . . . . . 3 4.2. "port" . . . . . . . . . . . . . . . . . . . . . . . . . 3 4.3. "ipv4hint" and "ipv6hint" . . . . . . . . . . . . . . . . 3 5. Definition of the New SvcParamKeys . . . . . . . . . . . . . 3 5.1. "apn" . . . . . . . . . . . . . . . . . . . . . . . . . . 3 5.2. "agentpath" . . . . . . . . . . . . . . . . . . . . . . . 4 5.3. "detailpath" . . . . . . . . . . . . . . . . . . . . . . 4 6. Security Considerations . . . . . . . . . . . . . . . . . . . 4 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 4 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 4 9.1. Normative References . . . . . . . . . . . . . . . . . . 4 9.2. Informative References . . . . . . . . . . . . . . . . . 5 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 5 1. Requirements notation The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 2. Introduction Building on the existing DNS, SVCB records provide additional convenience for clients to select different services and obtain the parameters required for connections. With the rapid development of artificial intelligence, various communication and interaction protocols related to agents are currently being developed. Agents have put forward new technical requirements in terms of session, communication, service invocation, and collaboration, and existing DNS cannot adequately meet the needs of agent service resolution. This document defines a new DNS resource record type, AGENT, which is an SVCB-compatible RR type, and specifies the mapping specifications required by SVCB. Zhang Expires 5 July 2026 [Page 2] Internet-Draft Service Binding Mapping for Agents January 2026 3. Basic requirements To provide special handling for agent service use cases, the AGENT RR type is defined as an SVCB-compatible RR type, specific to the "agent" scheme. The presentation format of the record is: Name TTL IN AGENT SvcPriority TargetName SvcParams 4. SvcParamKeys defined by SVCB The SVCB record [RFC9460] defines a set of initial SvcParamKeys, which are applicable to the AGENT scheme. 4.1. "alpn" This key indicates the set of protocols supported by the endpoint. When a specific protocol is specified, supporting configurations shall be made through other parameters in accordance with the usage requirements and specifications of the specific protocol to provide a complete protocol suite. Otherwise, setting only this value without specifying other necessary parameters for the protocol shall be considered an error. 4.2. "port" The "Port" SvcParamKey defines the port number to be used for connecting to this alternative endpoint. If this key is not present, the client shall use the default port number of the transport protocol. 4.3. "ipv4hint" and "ipv6hint" The "ipv4hint" and "ipv6hint" keys convey the IP addresses that the client may use to access the agent service. 5. Definition of the New SvcParamKeys In addition to the aforementioned SvcParamKeys defined by SVCB, this document specifies new SvcParamKeys for agent service usage. 5.1. "apn" The "apn" SvcParamKey is used to indicate the protocol employed for agent communication and interaction. Zhang Expires 5 July 2026 [Page 3] Internet-Draft Service Binding Mapping for Agents January 2026 When a specific protocol is designated, other parameters must be configured in accordance with the usage requirements and specifications of that protocol to provide a complete protocol suite supporting it. Otherwise, setting only this value without specifying other necessary parameters for the protocol shall be considered an error. The "apn" key shall be used in conjunction with the "alpn" key. Since some agent-related protocols are currently in the stage of discussion and revision, the usage and supporting requirements of this parameter will be updated accordingly based on the release of future protocols. 5.2. "agentpath" The value of the "agentpath" SvcParamKey is the URI Template of the agent. 5.3. "detailpath" Agent description information includes attributes information related to agent identity, capabilities, and collaborative interaction. Currently, its specific format currently varies across different protocols. The "detailpath" SvcParamKey is used to identify the access address (e.g., the URL) of the agent's detailed information. 6. Security Considerations The use of DNSSEC is optional for AGENT records. The downgrade attacks relevant to the SVCB record are also applicable to this document. 7. IANA Considerations To be determined. 8. Acknowledgments To be determined. 9. References 9.1. Normative References Zhang Expires 5 July 2026 [Page 4] Internet-Draft Service Binding Mapping for Agents January 2026 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . 9.2. Informative References [RFC9460] Schwartz, B., Bishop, M., and E. Nygren, "Service Binding and Parameter Specification via the DNS (SVCB and HTTPS Resource Records)", RFC 9460, DOI 10.17487/RFC9460, November 2023, . Author's Address M Zhang CNNIC Email: zmjy_9@163.com Zhang Expires 5 July 2026 [Page 5]