Network Working Group T. Reddy Internet-Draft Z. Sarker Intended status: Informational Nokia Expires: 13 April 2027 K. Yao China Mobile 10 October 2026 Agentic AI Use Cases and Requirements draft-agentic-ai-usecases-requirements-03 Abstract This document describes use cases for agentic AI communication systems and derives protocol requirements from those use cases. The requirements are intended to guide IETF standardization work on protocols in the context of agent-to-agent communication, agent-to- tool communication, with focus on dialog management, transport, multimodal communication, communication security, agent identity and authentication. 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/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 13 April 2027. Copyright Notice Copyright (c) 2026 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components Reddy, et al. Expires 13 April 2027 [Page 1] Internet-Draft agentic-ai-ucreq October 2026 extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1. Dialog Context and Task Context . . . . . . . . . . . . . 5 3. Common Protocol Requirements . . . . . . . . . . . . . . . . 5 3.1. Network-Layer Assumptions . . . . . . . . . . . . . . . . 7 4. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4.1. Simple Single-Agent Task . . . . . . . . . . . . . . . . 8 4.1.1. Description . . . . . . . . . . . . . . . . . . . . . 8 4.1.2. Interaction Flow . . . . . . . . . . . . . . . . . . 8 4.1.3. Protocol Requirements . . . . . . . . . . . . . . . . 9 4.2. Orchestrator and Agent Collaboration . . . . . . . . . . 11 4.2.1. Description . . . . . . . . . . . . . . . . . . . . . 11 4.2.2. Interaction Flow . . . . . . . . . . . . . . . . . . 12 4.2.3. Protocol Requirements . . . . . . . . . . . . . . . . 12 4.3. Long-Running Delegated Task with Authorization Checkpoint . . . . . . . . . . . . . . . . . . . . . . . 13 4.3.1. Description . . . . . . . . . . . . . . . . . . . . . 13 4.3.2. Interaction Flow . . . . . . . . . . . . . . . . . . 13 4.3.3. Additional Protocol Requirements . . . . . . . . . . 14 4.4. Peer Collaborative Multi-Agent Problem Solving . . . . . 15 4.4.1. Description . . . . . . . . . . . . . . . . . . . . . 15 4.4.2. Interaction Flow . . . . . . . . . . . . . . . . . . 15 4.4.3. Additional Protocol Requirements . . . . . . . . . . 15 4.5. Cooperative Reasoning and Consensus Formation . . . . . . 18 4.5.1. Description . . . . . . . . . . . . . . . . . . . . . 18 4.5.2. Interaction Flow . . . . . . . . . . . . . . . . . . 18 4.5.3. Additional Protocol Requirements . . . . . . . . . . 19 4.6. Tool, Data, and API Mediation Between Agents . . . . . . 19 4.6.1. Description . . . . . . . . . . . . . . . . . . . . . 20 4.6.2. Interaction Flow . . . . . . . . . . . . . . . . . . 20 4.6.3. Additional Protocol Requirements . . . . . . . . . . 21 5. Relationship to OAuth and WIMSE Work . . . . . . . . . . . . 22 6. Accountability and Auditing . . . . . . . . . . . . . . . . . 22 7. Security Considerations . . . . . . . . . . . . . . . . . . . 22 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 22 Informative References . . . . . . . . . . . . . . . . . . . . . 23 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 23 Reddy, et al. Expires 13 April 2027 [Page 2] Internet-Draft agentic-ai-ucreq October 2026 1. Introduction An AI agent is an autonomous, adaptive intelligent software system that uses AI models to complete a specific objective on behalf of a user or another AI agent. It makes decisions, executes actions, and interacts with other agents through tasks and tools. Unlike traditional software workloads that follow fixed execution paths, an AI agent dynamically determines at run time which actions to take, which tools to invoke, and which agents to collaborate with, based on reasoning over its goals and context. This document presents use cases that illustrate the key interaction patterns of agentic AI communication systems, and derives protocol requirements from those use cases. The requirements are intended to drive development of the agentic dialog management protocol, its transport bindings, and the reference architecture for agentic AI systems. Each use case contributes a distinct slice of requirements, and it is their composition that distinguishes an agentic communication protocol from ordinary application-to-service invocation. The use cases in this document cover interaction patterns for agentic AI communication systems. This document takes into account related use case and problem statement documents including [SCRM], [YAO], [SONG], and [ROSENBERG], and existing protocol work including [A2A] and [MCP]. 2. Terminology *AI Agent*: An autonomous software entity that perceives its environment, maintains internal state, and executes actions to achieve specified goals, potentially including communication with other agents or invocation of external tools. *Agent Identity*: Identity information associated with an AI agent, used for authentication and accountability within agentic communication systems. *Agentic AI Communication System*: A system comprising one or more AI agents that communicate with each other, with users, and with external tools or services to complete tasks. The communication interfaces between these entities are the subject of protocol standardization in this document. Reddy, et al. Expires 13 April 2027 [Page 3] Internet-Draft agentic-ai-ucreq October 2026 *Agent-to-Agent Communication*: Direct or brokered communication between two or more AI agents, where brokered communication involves an intermediary agent or coordination service, as distinguished from communication between an agent and a user or between an agent and a tool. *Capability*: A description of what an agent can perform, including inputs, outputs, constraints, and required conditions. *Coordinator Agent*: An agent that distributes a shared problem or task to a group of peer agents, aggregates their outputs, and iteratively drives them toward a collective result or consensus. *Delegation*: The act of an agent requesting another agent to execute a task on its behalf. *Initiating Agent*: An agent that receives an initial request and delegates subtasks to peer agents. Any peer agent may itself delegate further to other agents without routing through the initiating agent. *Mediator*: An entity that serves as a proxy or mediator for external tools, APIs, databases, or other resources that other agents require but cannot directly access. *Message*: A discrete unit of communication exchanged between agents containing structured data such as a task request, response, progress update, event notification, or control signal. *Modality*: A category of data format used for input or output in agent communication, such as text, audio, image, or video. A dialog may support one or more modalities simultaneously. *Orchestrator Agent*: An agent that acts as a controller, coordinating the activity of other agents by decomposing goals into sub-tasks and delegating those sub-tasks to appropriate agents. *Peer Agent*: An agent that receives delegated subtasks from another agent and may itself delegate further to other agents. *Dialog*: The correlated sequence of interactions between two or more participants (users, agents, and tools) over the course of a task. A dialog may persist across multiple individual message exchanges and network connections. Reddy, et al. Expires 13 April 2027 [Page 4] Internet-Draft agentic-ai-ucreq October 2026 *Dialog Context*: The identifiers and lifecycle state needed to correlate and maintain a dialog. It does not include the content exchanged with AI models, such as conversation memory, retrieved documents, or prompts. *Task Context*: The data that a participant maintains to execute a task, such as conversation history and intermediate results. Task context is not carried by the protocol. *Task*: A unit of work submitted by a user to an agent, or delegated by one agent to another. *Task State*: The current execution status of a task (e.g., pending, in-progress, completed, failed). *Tool*: An external service invoked by an agent to retrieve data or perform operations. A tool is not necessarily an agent and may not participate in agent-to-agent communication. *User*: A human that initiates interaction with an AI agent by submitting a request or task. 2.1. Dialog Context and Task Context Any participant, including an intermediary, can use dialog context to correlate and maintain a dialog without interpreting the task. For example, if the transport connection between two agents is interrupted, the dialog identifier allows the reconnecting agent to re-associate with the existing dialog instead of starting a new dialog and restarting the task. An intermediary uses the dialog identifier to correlate the requests it receives with the requests it forwards. Neither function requires access to the task context. Each participant can use the dialog identifier to retrieve its own task context. 3. Common Protocol Requirements The following baseline requirements apply to both agent-to-agent and agent-to-tool protocol interactions across all use cases and are not repeated per use case. Each per-use-case requirement is tagged with one or more of the following protocol area tags to allow cross-use-case navigation: * *Discovery*: Requirements related to locating, advertising, or selecting agents, tools, or capabilities. Reddy, et al. Expires 13 April 2027 [Page 5] Internet-Draft agentic-ai-ucreq October 2026 * *Dialog*: Requirements related to dialog correlation, lifecycle, continuity, and recovery. * *Transport*: Requirements related to message delivery, streaming, cancellation, and data transfer. * *Security*: Requirements related to confidentiality, integrity, and authorization. * *Authentication*: Requirements related to identity verification and credential delegation. +========+========================================+================+ | REQ-ID | Description | Tag | +========+========================================+================+ | CMN-1 | The protocol is required to support | Discovery, | | | any client application to communicate | Authentication | | | with any agent service. | | +--------+----------------------------------------+----------------+ | CMN-2 | Mutual authentication is required | Authentication | | | between all communicating parties. | | +--------+----------------------------------------+----------------+ | CMN-3 | All protocol traffic is required to be | Security | | | encrypted and integrity-protected in | | | | transit. | | +--------+----------------------------------------+----------------+ | CMN-4 | Structured error responses are | Security | | | required to include an authorization | | | | scope violation type, reported by the | | | | orchestrator or mediator when an agent | | | | attempts an action that exceeds or | | | | contradicts the scope delegated to it. | | +--------+----------------------------------------+----------------+ | CMN-5 | Structured error responses are | Transport | | | required, distinguishing at minimum: | | | | authentication failure, authorization | | | | failure, timeout, and internal error. | | +--------+----------------------------------------+----------------+ | CMN-6 | The protocol is required to provide a | Transport | | | means to signal task priority so that | | | | critical-path tasks can be scheduled | | | | ahead of lower-priority ones. | | +--------+----------------------------------------+----------------+ | CMN-7 | The protocol is required to support | Security, | | | cryptographic algorithm agility, | Authentication | | | ensuring that cryptographic algorithms | | | | used for encryption, authentication, | | | | credential verification, and integrity | | Reddy, et al. Expires 13 April 2027 [Page 6] Internet-Draft agentic-ai-ucreq October 2026 | | protection can be negotiated and | | | | updated over time, in accordance with | | | | [RFC7696]. | | +--------+----------------------------------------+----------------+ | CMN-8 | The protocol is required to provide a | Authentication | | | means to verify the agent | | | | authentication credentials validity | | | | used by agents at the time of use. | | +--------+----------------------------------------+----------------+ | CMN-9 | The protocol is required to support | Security | | | signaling that a presented credential | | | | has been revoked or is otherwise | | | | invalid. | | +--------+----------------------------------------+----------------+ | CMN-10 | The protocol is required to support | Security | | | revoking a previously granted | | | | authorization, including propagating | | | | the revocation across a delegation | | | | chain so that affected agents cease to | | | | act under it. | | +--------+----------------------------------------+----------------+ | CMN-11 | The protocol is required to support | Dialog | | | establishment, modification, and | | | | termination of a dialog, distinct from | | | | cancellation of a delegated subtask | | | | within the dialog. Modification | | | | includes changes to the participants, | | | | modalities, or lifetime of the dialog. | | | | The protocol is required to support a | | | | dialog lifetime, after which the | | | | dialog is terminated. | | +--------+----------------------------------------+----------------+ Table 1 3.1. Network-Layer Assumptions The requirements in this document assume that messages that establish, modify, resume, or terminate a dialog are delivered reliably and in order. Data for real-time modalities, such as interactive audio and video, can be delivered without reliability or ordering to meet latency requirements. All the deliveries are congestion controlled. Whether these share a transport connection is determined by the transport bindings. Reddy, et al. Expires 13 April 2027 [Page 7] Internet-Draft agentic-ai-ucreq October 2026 4. Use Cases These interactions differ from ordinary application-to-service invocation in several respects, one being runtime selection of agents and tools by capability. An agent's internal processing, including perception, planning and re-planning, and invocation of its AI model, is not visible on the protocol interface and is out of scope; it motivates the use cases but drives no protocol requirement. Cross- domain operation can apply to any of these use cases. Crossing an administrative boundary adds authentication and authorization requirements, which map to the OAuth and WIMSE work discussed in Section 5, and privacy requirements on dialog context propagated across the boundary, discussed in Section 7. The use cases are independent of deployment model: they apply whether participants are within a single administrative domain or span several, and whether they interact directly or through intermediaries. 4.1. Simple Single-Agent Task 4.1.1. Description A user submits a task to an AI agent via a client application. The agent executes the task by invoking one or more tools and returns results to the user. The tools invoked by the agent may reside in the same or a different administrative domain. The agent protocol is required to support multiple input and output modalities, and the client application and agent are required to be able to negotiate which modalities are active for the dialog. This use case covers the protocol interface between the client application and the agent. The interaction between the user and the client application is out of scope. This use case assumes that the user communicates with the agent via a client application; direct communication between a user and an agent without an intermediary client application is not covered in this use case. This interaction pattern is described in [ROSENBERG] and [SCRM]. 4.1.2. Interaction Flow Reddy, et al. Expires 13 April 2027 [Page 8] Internet-Draft agentic-ai-ucreq October 2026 +----------------+ +-----------+ | App/agent |<--------------------> | Agent | +----------------+ Protocol +-----------+ | Protocol | v +---------+ | Tool(s) | +---------+ 4.1.3. Protocol Requirements This use case involves two distinct protocol interfaces. The App/ Agent-to-Agent interface is between the party making the request, which may be a client application or another agent, and the agent that handles it. The Agent-to-Tool interface is between the agent and the tools it invokes. A given requirement does not necessarily apply to both; the Interaction column indicates which interface each applies to. +========+=======================+================+================+ | REQ-ID | Description | Interaction | Tag | +========+=======================+================+================+ | A1-1 | The protocol is | App/Agent-to- | Transport | | | required to support | Agent | | | | incremental streaming | | | | | of agent output, | | | | | allowing partial | | | | | results to be | | | | | delivered to the | | | | | client before the | | | | | agent has completed | | | | | processing. | | | +--------+-----------------------+----------------+----------------+ | A1-2 | The protocol is | App/Agent-to- | Transport | | | required to define a | Agent | | | | task cancellation | | | | | message that the | | | | | client can issue at | | | | | any point during task | | | | | execution. | | | +--------+-----------------------+----------------+----------------+ | A1-3 | The protocol is | Both | Transport | | | required to define | | | | | structured error | | | | | message types that | | | | | distinguish at | | | | | minimum: transport | | | Reddy, et al. Expires 13 April 2027 [Page 9] Internet-Draft agentic-ai-ucreq October 2026 | | failure, tool | | | | | invocation failure, | | | | | and agent processing | | | | | failure. | | | +--------+-----------------------+----------------+----------------+ | A1-4 | The protocol is | App/Agent-to- | Transport | | | required to support | Agent | | | | multiple modalities | | | | | for both input and | | | | | output. | | | +--------+-----------------------+----------------+----------------+ | A1-5 | The protocol is | App/Agent-to- | Discovery, | | | required to support | Agent | Transport | | | modality negotiation | | | | | at dialog | | | | | establishment, | | | | | allowing the client | | | | | and agent to agree on | | | | | which modalities are | | | | | active for the | | | | | dialog. | | | +--------+-----------------------+----------------+----------------+ | A1-6 | The protocol is | App/Agent-to- | Transport | | | required to support | Agent | | | | agent-initiated | | | | | notifications to the | | | | | client during task | | | | | execution. | | | +--------+-----------------------+----------------+----------------+ | A1-7 | The protocol is | Agent-to-Tool | Discovery, | | | required to support | | Transport, | | | concurrent invocation | | Security | | | of multiple tools | | | | | within a single agent | | | | | task, where tools may | | | | | be operated by | | | | | distinct providers | | | | | across different | | | | | administrative | | | | | domains, each with | | | | | independent | | | | | authentication and | | | | | authorization | | | | | requirements. | | | +--------+-----------------------+----------------+----------------+ | A1-8 | The protocol is | Both | Transport | | | required to support | | | | | bulk transfer of | | | Reddy, et al. Expires 13 April 2027 [Page 10] Internet-Draft agentic-ai-ucreq October 2026 | | large data between | | | | | communicating | | | | | parties, applicable | | | | | to both agent-to-tool | | | | | and agent-to-agent | | | | | interactions. | | | +--------+-----------------------+----------------+----------------+ | A1-9 | A delegation | Agent-to-Tool | Authentication | | | mechanism is required | | | | | to be defined by | | | | | which an agent | | | | | presents to a tool | | | | | provider a credential | | | | | attesting the | | | | | authorization for the | | | | | requested tool | | | | | access, without | | | | | exposing the client's | | | | | primary credentials. | | | +--------+-----------------------+----------------+----------------+ | A1-10 | The protocol is | App/Agent-to- | Dialog | | | required to preserve | Agent | | | | the dialog context | | | | | when a participant | | | | | transforms data from | | | | | one modality to | | | | | another, such as | | | | | audio to text. | | | +--------+-----------------------+----------------+----------------+ Table 2 4.2. Orchestrator and Agent Collaboration 4.2.1. Description An orchestrator agent acts as a controller, decomposing a task into subtasks and delegating them asynchronously to one or more other agents. The orchestrator decides which other agents to invoke, sequences the delegation, and aggregates results to continue task execution. Each agent executes the respective subtask independently and reports results back to the orchestrator. It should be noted that AI models are stateless by nature: each inference call processes only what is explicitly provided with a particular context, with no persistent memory between calls. The application layer is responsible for maintaining the context across the calls by carrying conversation history, intermediate results, and Reddy, et al. Expires 13 April 2027 [Page 11] Internet-Draft agentic-ai-ucreq October 2026 task state. Dialog continuity is therefore required to preserve the dialog context across network interruptions, so that a reconnecting agent can re-associate with the dialog and use it to restore its own task context without reconstructing it from scratch. This pattern is described in [ROSENBERG] and reflected in [A2A], and is implemented in deployed multi-agent frameworks including [AUTOGEN], [LANGCHAIN], and [OPENAI-AGENTS]. 4.2.2. Interaction Flow +---------------------+ +------------+ | Orchestrator Agent |---Task Delegation----->| Agent-1 | | |<--Result Reporting-----| | | | +------------+ | | | | +------------+ | |---Task Delegation----->| Agent-2 | | |<--Result Reporting-----| | +---------------------+ +------------+ 4.2.3. Protocol Requirements +========+=============================================+===========+ | REQ-ID | Description | Tag | +========+=============================================+===========+ | B1-1 | The protocol is required to facilitate task | Transport | | | delegation for an orchestrator to agents | | | | that includes task delegation and | | | | acknowledgement message types. | | +--------+---------------------------------------------+-----------+ | B1-2 | The protocol is required to support | Transport | | | asynchronous delegation, allowing the | | | | orchestrator to delegate to multiple agents | | | | without waiting for each to complete before | | | | proceeding. | | +--------+---------------------------------------------+-----------+ | B1-3 | The protocol is required to define a result | Transport | | | reporting message by which an agent returns | | | | its completed output to the orchestrator. | | +--------+---------------------------------------------+-----------+ | B1-4 | The protocol is required to support | Transport | | | streaming of intermediate results from the | | | | agent to the orchestrator during task | | | | execution. | | +--------+---------------------------------------------+-----------+ | B1-5 | The protocol is required to define a task | Transport | | | cancellation message that the orchestrator | | Reddy, et al. Expires 13 April 2027 [Page 12] Internet-Draft agentic-ai-ucreq October 2026 | | can send to an agent to abort a delegated | | | | subtask. | | +--------+---------------------------------------------+-----------+ | B1-6 | The protocol is required to support | Dialog | | | persistent dialog identifiers that survive | | | | network interruption or change, and is | | | | required to define a dialog resumption | | | | message by which an agent re-attaches to an | | | | interrupted dialog, restoring the prior | | | | dialog context. | | +--------+---------------------------------------------+-----------+ | B1-7 | On resumption, the protocol is required to | Dialog, | | | enable the receiving participant to verify | Security | | | that the party resuming the dialog is the | | | | participant whose exchange was interrupted, | | | | and that the dialog has not been terminated | | | | or its authorization revoked. If either | | | | check fails, the dialog is not resumed and | | | | the failure is signaled. | | +--------+---------------------------------------------+-----------+ Table 3 4.3. Long-Running Delegated Task with Authorization Checkpoint 4.3.1. Description An orchestrator agent delegates a long-running task to other agents. The delegated agent executes the task autonomously and sends progress notifications to the orchestrator. At any certain point one or more delegated agents pause and request explicit authorization from the orchestrator before proceeding further. The orchestrator may relay this authorization request to the invoker (user or agent) or resolve it autonomously based on policy. This pattern is reflected in the In-Task Authorization mechanism defined in [A2A]. 4.3.2. Interaction Flow +---------------------+ +------------+ | Orchestrator Agent |---Task Delegation----->| | | |<--Progress Notif.------| | | |<--Authz Checkpoint-----| Agent(s) | | |---Authz Response------>| | | |<--Result Reporting-----| | +---------------------+ +------------+ Reddy, et al. Expires 13 April 2027 [Page 13] Internet-Draft agentic-ai-ucreq October 2026 4.3.3. Additional Protocol Requirements This use case builds on the requirements defined for Section 4.2 and introduces additional requirements specific to authorization checkpoints in delegated tasks. +========+=========================================+============+ | REQ-ID | Description | Tag | +========+=========================================+============+ | B2-1 | The protocol is required to support | Transport | | | agent-initiated progress notifications | | | | to the delegating agent during task | | | | execution. | | +--------+-----------------------------------------+------------+ | B2-2 | The protocol is required to define an | Transport, | | | authorization checkpoint request, by | Security | | | which an agent pauses task execution | | | | and asks the orchestrator to authorize | | | | a specific action before proceeding. | | | | The request is required to describe the | | | | action to be performed and the effect | | | | it would have, so the orchestrator has | | | | enough information to decide. | | +--------+-----------------------------------------+------------+ | B2-3 | The protocol is required to define the | Transport, | | | responses to an authorization | Security | | | checkpoint request, which include at | | | | minimum approve, deny, and approve with | | | | modified parameters. A denial is | | | | required to be conveyed as an explicit | | | | error response. | | +--------+-----------------------------------------+------------+ | B2-4 | The protocol is required to support a | Transport | | | response timeout, after which the agent | | | | treats the request as unresolved and | | | | halts the affected subtask. | | +--------+-----------------------------------------+------------+ | B2-5 | An authorization checkpoint response is | Transport, | | | required to authorize only the action | Security | | | in the request it answers, including | | | | any approved modification to that | | | | action, and not any different or later | | | | action. | | +--------+-----------------------------------------+------------+ | B2-6 | The protocol is required to support | Transport, | | | authorization requested and granted at | Security | | | the granularity of a specific | | | | operation, so that a sensitive action | | Reddy, et al. Expires 13 April 2027 [Page 14] Internet-Draft agentic-ai-ucreq October 2026 | | is authorized individually rather than | | | | covered by a broad, pre-existing | | | | authorization. | | +--------+-----------------------------------------+------------+ Table 4 4.4. Peer Collaborative Multi-Agent Problem Solving 4.4.1. Description A task requires coordinated problem solving across multiple agents, where no single agent has full authority or capability to complete the task alone. The agent that receives the initial request dynamically delegates subtasks to peer agents based on their advertised capabilities. Any agent may itself delegate further to other agents and use other tools, forming a dynamic collaboration graph. Each agent remains opaque to others, collaborating only through the protocol interface. This use case introduces multi-hop delegation chains that are not present in Section 4.2. Each agent in the chain may delegate further to other agents, and authorization scope is required to be progressively constrained at each hop. This use case is described in [A2A] and [ROSENBERG]. 4.4.2. Interaction Flow +------------------+ | Initiating Agent | +------------------+ | | v v +--------+ +--------+ |Agent-2 | |Agent-3 | +--------+ +--------+ | | v v +--------+ +--------+ |Agent-4 | | Tools | +--------+ +--------+ 4.4.3. Additional Protocol Requirements This use case builds on the requirements defined for Section 4.2 and introduces additional requirements specific to multi-hop delegation chains. Reddy, et al. Expires 13 April 2027 [Page 15] Internet-Draft agentic-ai-ucreq October 2026 +========+=====================================+=================+ | REQ-ID | Description | Tag | +========+=====================================+=================+ | B3-1 | The protocol is required to support | Authentication, | | | multi-hop delegation chains, where | Security | | | an agent that receives a delegated | | | | subtask may itself delegate further | | | | to other agents. At each hop, the | | | | delegating agent is required to | | | | present a credential that does not | | | | exceed the authorization scope of | | | | the credential it received. | | +--------+-------------------------------------+-----------------+ | B3-2 | The protocol is required to | Authentication, | | | preserve the identity of the | Security | | | originating entity across all hops | | | | in the delegation chain, such that | | | | any agent in the chain can | | | | determine the identity of the | | | | entity that originally authorized | | | | the task. | | +--------+-------------------------------------+-----------------+ | B3-3 | The protocol is required to support | Authentication, | | | transferable credentials that carry | Security | | | the original authorization | | | | constraints across all hops in the | | | | delegation chain. Each receiving | | | | agent is required to be able to | | | | cryptographically verify that the | | | | credential presented to it was | | | | issued by the delegating agent and | | | | that the chain of delegation traces | | | | back to the original authorization. | | +--------+-------------------------------------+-----------------+ | B3-4 | The protocol is required to ensure | Authentication, | | | that authorization granted to an | Security | | | agent in a delegation chain, | | | | including for tool invocations, is | | | | derived from the authorization | | | | issued by the initiating agent, and | | | | not from the identity or | | | | authorization scope of any | | | | intermediate agent in the chain. | | +--------+-------------------------------------+-----------------+ | B3-5 | The protocol is required to define | Registration, | | | a capability registration mechanism | Discovery | | | by which agents can publish | | | | metadata describing their | | Reddy, et al. Expires 13 April 2027 [Page 16] Internet-Draft agentic-ai-ucreq October 2026 | | capabilities, supported protocols, | | | | rate limits, authentication | | | | methods, authorization mechanisms, | | | | and authorization scopes to a | | | | discovery service or registry. | | +--------+-------------------------------------+-----------------+ | B3-6 | The protocol is required to define | Discovery | | | a capability discovery mechanism by | | | | which agents can query a discovery | | | | service or registry to discover and | | | | select appropriate peer agents at | | | | runtime without requiring prior | | | | peer-specific configuration. | | +--------+-------------------------------------+-----------------+ | B3-7 | The protocol is required to define | Discovery | | | an agent identifier format that | | | | uniquely represents an agent | | | | identity and is resolvable to the | | | | agent's communication endpoint | | | | using an appropriate discovery | | | | mechanism. | | +--------+-------------------------------------+-----------------+ | B3-8 | The protocol is required to ensure | Discovery, | | | that advertised capabilities are | Security | | | integrity-protected, such that a | | | | discovering agent can verify they | | | | have not been tampered with. | | +--------+-------------------------------------+-----------------+ | B3-9 | The protocol is required to allow a | Dialog, | | | delegating agent to detect that a | Transport | | | delegated agent has become | | | | unavailable and to halt the | | | | affected in-flight subtask. | | +--------+-------------------------------------+-----------------+ | B3-10 | The protocol is required to provide | Authentication, | | | a verifiable provenance record of a | Security | | | request and its response as they | | | | traverse the delegation chain, | | | | attributing each transformation to | | | | the hop that performed it, such | | | | that removal of a hop, or a | | | | modification not attributable to a | | | | signing hop, is detectable. | | +--------+-------------------------------------+-----------------+ | B3-11 | The protocol is required to enable | Authentication, | | | a receiving party to detect and | Security | | | reject a delegation chain that | | | | contains a cycle, such as a chain | | Reddy, et al. Expires 13 April 2027 [Page 17] Internet-Draft agentic-ai-ucreq October 2026 | | in which the receiving party's own | | | | identifier already appears. | | +--------+-------------------------------------+-----------------+ | B3-12 | The protocol is required to enable | Authentication, | | | a receiving party to determine that | Security | | | the authority conveyed to it does | | | | not exceed the authority conveyed | | | | to the hop it received from. | | +--------+-------------------------------------+-----------------+ | B3-13 | The protocol is required to | Dialog | | | propagate the dialog context across | | | | each hop of a delegation chain, so | | | | that participants can correlate | | | | interactions along the chain. | | +--------+-------------------------------------+-----------------+ Table 5 Requirements B3-5 to B3-8 concern discovery, which is outside the scope of the dialog management protocol and is expected to be addressed in coordination with the INT and OPS areas. 4.5. Cooperative Reasoning and Consensus Formation 4.5.1. Description A set of peer agents is tasked with analyzing a shared problem independently and exchanging intermediate reasoning outputs to converge on a collective conclusion. A coordinator agent distributes the problem to all participating agents, collects their reasoning outputs, and drives the convergence process across multiple rounds until a consensus conclusion is reached. Unlike Section 4.4, all agents work on the same problem rather than different subtasks. Two communication topologies are possible. In the first, agents communicate only through the coordinator, which acts as the central hub for all message exchange. In the second, agents may also communicate directly with each other to exchange intermediate reasoning outputs without routing through the coordinator agent. The second topology introduces the same multi-hop authorization requirements defined in Section 4.4. 4.5.2. Interaction Flow The coordinator-mediated topology: Reddy, et al. Expires 13 April 2027 [Page 18] Internet-Draft agentic-ai-ucreq October 2026 +--------------------+ | Coordinator agent | +--------------------+ / | \ v v v +--------+ +--------+ +--------+ |Agent-1 | |Agent-2 | |Agent-3 | +--------+ +--------+ +--------+ The direct agent-to-agent topology: +--------------------+ | Coordinator agent | +--------------------+ / | \ v v v +-------+ +-------+ +-------+ |Agent-1| <-> |Agent-2| <-> |Agent-3| +-------+ +-------+ +-------+ ^ ^ |___________________________| 4.5.3. Additional Protocol Requirements This use case builds on the requirements defined for Section 4.2 and introduces additional requirements specific to group message delivery. +========+=============================================+============+ | REQ-ID | Description | Tag | +========+=============================================+============+ | B4-1 | The protocol is required to support | Transport, | | | one-to-one, one-to-many, and many-to- | Security | | | many message delivery among a defined | | | | group of agents. Group membership is | | | | required to be dynamic, allowing | | | | agents to join or leave the group | | | | during the course of an exchange. | | +--------+---------------------------------------------+------------+ Table 6 4.6. Tool, Data, and API Mediation Between Agents Reddy, et al. Expires 13 April 2027 [Page 19] Internet-Draft agentic-ai-ucreq October 2026 4.6.1. Description In many multi-agent deployments, access to external resources such as APIs, databases, enterprise systems, or hardware interfaces is intentionally mediated through a designated mediator. Other agents request the mediator to perform actions or retrieve data on their behalf, rather than directly invoking external systems. This architecture allows access control, auditing, rate limiting, and schema normalization to be applied uniformly at the mediation layer. The mediator may also serve as an adapter between the agent protocol and non-agent systems or other services that do not natively support agent communication protocols, or between different agent communication protocols such as translating between the agentic protocol suite being developed at the IETF and existing protocols such as [MCP] and [A2A]. In this role, the mediator is responsible for protocol translation and for presenting the appropriate credentials to the target system on behalf of the requesting agent. The mediator may additionally act as a request router, dispatching requests to appropriate agents or tools based on the content and context of the request, without requiring the requesting agent to have prior knowledge of which agent or tool is most appropriate. The mediator may also validate agent requests before invocation, checking whether the action being requested matches the authorization granted to the agent and whether execution would cause unintended or irreversible side effects. Note that mediating can be a function within an orchestrator. This pattern is reflected in the MCP server architecture defined in [MCP] and the agent routing patterns discussed in [A2A]. 4.6.2. Interaction Flow Reddy, et al. Expires 13 April 2027 [Page 20] Internet-Draft agentic-ai-ucreq October 2026 +--------------+ | Agent | +--------------+ | v +--------------+ | Mediator | +--------------+ / | \ v v v +--------+ +---------+ +--------+ | Agent-1 | | Tool | | Agent-2 | +--------+ +---------+ +--------+ 4.6.3. Additional Protocol Requirements +========+============================================+============+ | REQ-ID | Description | Tag | +========+============================================+============+ | B5-1 | The protocol is required to define error | Transport, | | | response types for request validation | Security | | | failure (rejected due to potential | | | | unintended or irreversible side effects) | | | | and protocol translation failure (rejected | | | | on unsuccessful translation of a request | | | | or response between supported protocols), | | | | distinct from authorization failure. | | +--------+--------------------------------------------+------------+ | B5-2 | The protocol is required to support | Dialog | | | continuation of a dialog through a | | | | different mediator when the mediator in | | | | use fails. | | +--------+--------------------------------------------+------------+ | B5-3 | The protocol is required to enable a | Dialog | | | mediator that translates between agent | | | | communication protocols to carry the | | | | dialog context across the translation, so | | | | that participants on each side can | | | | correlate the dialog. | | +--------+--------------------------------------------+------------+ Table 7 Reddy, et al. Expires 13 April 2027 [Page 21] Internet-Draft agentic-ai-ucreq October 2026 5. Relationship to OAuth and WIMSE Work Several requirements in this document concern authorization, delegation, and agent identity (CMN-4, CMN-8, CMN-9, CMN-10, B1-7, B2-2 to B2-6, B3-1 to B3-4, B3-10, B3-11, B3-12). These are expected to be addressed in the OAuth and WIMSE Working Groups. 6. Accountability and Auditing Accountability and auditing of agent actions are out of scope for this document. Audit and provenance representation is addressed by existing work, including W3C provenance (PROV) and Trace Context. Dialog identifiers can be used to correlate audit records across the participants in a dialog. Editor's note: Add a reference to IETF audit work once it progresses. 7. Security Considerations Security considerations are addressed throughout this document via the Identity, Authentication, and Delegation requirements defined for each use case. Agent identity information is considered to be sensitive, particularly in multi-domain deployments. Use of persistent identifiers across dialogs and domains can enable tracking and correlation of agent activity. Protocol designers need to consider mechanisms such as pseudonymous or temporary identifiers to reduce linkability, while preserving the ability to audit and enforce accountability where required. The trade-offs between privacy, accountability, and traceability need to be considered in the design of agent identity mechanisms. Agent unavailability (B3-9) halts the affected subtask but does not imply revocation, since it may be a transient failure rather than compromise. 8. IANA Considerations This document has no IANA actions. Acknowledgements Thanks to Borislava Gajic, Julien Maisonneuve, Parisa Foroughi, Laurent Ciavaglia, Nathalie Romo Moreno, Peter Leis, Linda Dunbar, Mikhail Sergeev, Iman Schrock, Sumit Ahuja and Sina Khatibi for the discussions and comments. Reddy, et al. Expires 13 April 2027 [Page 22] Internet-Draft agentic-ai-ucreq October 2026 Informative References [A2A] "Agent2Agent Protocol Specification", n.d., . [AUTOGEN] "AutoGen: A Framework for Multi-Agent Conversation", n.d., . [LANGCHAIN] "LangChain Agent Framework", n.d., . [MCP] "Model Context Protocol Specification", n.d., . [OPENAI-AGENTS] "OpenAI Agents SDK", n.d., . [RFC7696] "Guidelines for Cryptographic Algorithm Agility and Selecting Mandatory-to-Implement Algorithms", n.d., . [ROSENBERG] "Framework, Use Cases and Requirements for AI Agent Protocols", n.d., . [SCRM] "Agentic AI Use Cases", n.d., . [SONG] "Problem Statement and Requirements for Dynamic Multi- agent Secured Collaboration", n.d., . [YAO] "Problem Space Analysis of AI Agent Protocols in IETF", n.d., . Authors' Addresses Reddy, et al. Expires 13 April 2027 [Page 23] Internet-Draft agentic-ai-ucreq October 2026 Tirumaleswar Reddy Nokia Bangalore Karnataka India Email: kondtir@gmail.com Zaheduzzaman Sarker Nokia Sweden Email: zaheduzzaman.sarker@nokia.com Kehan Yao China Mobile Email: yaokehan@chinamobile.com Reddy, et al. Expires 13 April 2027 [Page 24]