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Multi-Agent Delegation in Sovereign Object Systems
draft-sato-soos-mad-02

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Author Tom Sato
Last updated 2026-06-10
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draft-sato-soos-mad-02
Internet Engineering Task Force                              T. Sato
Internet-Draft                                       MyAuberge K.K.
Intended Status: Standards Track                        9 June 2026
Expires: 9 December 2026

           Multi-Agent Delegation in Sovereign Object Systems
                       draft-sato-soos-mad-02

Abstract

   When a consequential task requires multiple AI agents -- one to
   coordinate, others to execute, each operating on different objects
   in a shared workflow -- who is responsible for the outcome?  Which
   agent caused which state change?  Under whose authority?  If the
   coordinating agent's authorization is revoked, does the authority
   of every sub-agent it delegated to immediately expire?  If one
   agent in a parallel workflow exceeds its scope, can that excess
   propagate to others?

   Today, no protocol ensures the answers to these questions are
   knowable.  Multi-agent AI systems can produce accountability black
   holes: chains of delegation where the authority at each hop is
   unclear, where revocation does not cascade reliably, and where
   the audit record cannot reconstruct which agent caused which
   outcome under which authorization.

   This document defines the Multi-Agent Delegation (MAD) protocol:
   a normative specification ensuring that authority in multi-agent
   AI workflows is structured, verifiable, and reconstructable.  MAD
   specifies three mechanisms.  The Narrowing Property (INV-4)
   ensures that authority can only attenuate across a delegation hop
   -- a sub-agent can never acquire capabilities its orchestrator
   does not itself hold.  SO Instance Topology Types provide five
   formally defined patterns for how governed objects relate at
   runtime.  SO Cluster Coordination Primitives (L1-16) enable
   parallel fan-out topologies in which multiple specialist agents
   execute simultaneously, with aggregation rules that let the
   orchestrator proceed as soon as a quorum of specialists complete.

   For human principals, MAD provides a single recoverable property:
   the accountability chain is always reconstructable from the GEC-
   signed audit record alone.  Cascade revocation means one decision
   stops the entire tree.  For AI agents, MAD provides machine-speed
   delegation authority and the parallel execution efficiency that
   sequential single-agent approaches cannot achieve.

   MAD-02 adds a fourth guarantee: when revocation fires during
   active execution, the completion state of every in-flight
   operation is classified and recorded, and partial-completion
   cases are routed to human oversight through the HEM escalation
   chain.  This closes the revocation gap across offline-attenuated
   delegation chains that the OpenID Foundation identifies as
   unsolved in current agentic AI authorization infrastructure.

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
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   as reference material or to cite them other than as "work in
   progress."

   This Internet-Draft will expire on 9 December 2026.

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
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   respect to this document.

Table of Contents

   1.  Introduction
   2.  Terminology
   3.  Multi-Agent Mandate Model
       3.1.  The Narrowing Property
       3.2.  Mandate Issuance Tree
       3.3.  SO-Type-Bound Creation Mandates
       3.4.  Creation Principal Classes
       3.5.  Cross-Mandate Revocation Cascade
       3.6.  Agent Session Revocation
           3.6.1.  The SOOS/MAD Revocation Model
           3.6.2.  CAEP Profile for Agent Session Revocation
           3.6.3.  Partial-Completion Handling
           3.6.4.  Session Revocation Trigger Taxonomy (R-1 -- R-7)
           3.6.5.  DEADLOCK State
           3.6.6.  Continuation Mandate Authority
       3.7.  Cluster Invariants
           3.7.1.  INV-17: Horizontal Non-Contamination
       3.8.  Cluster Resource Governance
           3.8.1.  BUDGET_TRANSFER Procedure
       3.9.  Multi-Agent Topology Events
           3.9.1.  ALE-013: DELEGATION_INITIATED
           3.9.2.  ALE-014: DELEGATION_COMPLETED
           3.9.3.  ALE-015: DELEGATION_FAILED
           3.9.4.  ALE-016: CLUSTER_TOPOLOGY_CHANGE
   4.  SO Instance Topology Types
       4.1.  Topology Classification
       4.2.  Topology 1: Linear Chain
       4.3.  Topology 2: Parallel Fan-Out
       4.4.  Topology 3: Directed Acyclic Graph (DAG)
       4.5.  Topology 4: Dynamic and Emergent
       4.6.  Topology 5: Cyclic and Re-entrant
       4.7.  Kernel Effects by Topology
   5.  SO Cluster Coordination
       5.1.  The SO Granularity Rule
       5.2.  Cluster Declaration Protocol
       5.3.  Cluster Membership Model
       5.4.  Cluster Registry
       5.5.  Cluster-Enriched Cedar Evaluation
       5.6.  SO Cluster Manager (L1-16)
       5.7.  Aggregation Rules
       5.8.  Visibility Extensions
   6.  Orchestrator-Specialist Model
       6.1.  GEE Orchestration Mode
       6.2.  Orchestrator Mandate Scope
       6.3.  Specialist Agent Mandate Issuance
       6.4.  Sub-Agent Failure Recovery
       6.5.  Sub-Agent Session Pooling
   7.  Kernel Events
   8.  Cedar Actions
   9.  Conformance
   10. Open Issues
   11. Security Considerations
   12. IANA Considerations
   Acknowledgements
   13. Normative References
   14. Informative References
   Appendix B.  Related Work
       B.1.  SPICE Actor Chain
       B.2.  OAuth Attenuating Agent Tokens
       B.3.  OAuth Transaction Tokens
       B.4.  Agent Communication Protocol (ACP)
       B.5.  A2A Protocol
       B.6.  AuthZEN 1.0
       B.7.  SOOS Companion Drafts
       B.8.  ICON Initiative: Control Pillar
       B.9.  AUDIT Working Group
       B.10. DAWN Working Group
       B.11. OpenID Foundation: Revocation Across Attenuated
             Delegation Chains
   Appendix C.  Vibe Coding Assets
       C.1.  Protocol Summary
       C.2.  Key Identifiers
       C.3.  Canonical Reference
   Author's Address

1.  Introduction

   A consequential workflow often requires more than one AI agent.
   A travel itinerary spanning eight suppliers -- flights, ground
   transfers, accommodation, activity operators -- may require eight
   specialist agents, each authorized to manage one supplier's
   state, coordinated by an orchestrating agent tracking overall
   progress.  A network management operation may require a
   coordinating agent that delegates segment-specific routing
   decisions to specialist sub-agents, each operating within a
   defined traffic domain.  A legal document workflow may fan out
   to jurisdictional specialists that each produce a clause, then
   aggregate into a finalized agreement.

   Without a delegation governance protocol, these multi-agent
   workflows produce accountability black holes.  Which agent caused
   which state transition?  Under whose authority?  If the
   orchestrator's mandate is revoked -- because a compliance
   threshold is breached, because a human principal withdraws
   authorization, because the mission governing the session enters
   a terminal state -- does that revocation immediately reach the
   specialist agents it delegated to?  If a specialist agent
   attempts to act beyond its authorized scope, does the confused
   deputy vulnerability allow that excess to propagate?  Without
   protocol-level answers to these questions, multi-agent AI systems
   cannot be audited, safely revoked, or relied upon for
   consequential deployment.

   For AI agents, a governed delegation model is not only a safety
   property -- it is an efficiency property.  An orchestrator
   operating under MAD can delegate to specialist sub-agents at
   machine speed, without a human bottleneck at each hop, because
   the Narrowing Property pre-verifies that authority flows only
   downward.  Parallel fan-out topologies allow multiple specialists
   to execute simultaneously rather than sequentially.  Quorum-based
   aggregation rules let the orchestrator proceed as soon as enough
   specialists complete, without waiting for the full set.  The
   cluster coordination primitives in this document are the mechanism
   by which multi-agent workflows achieve the computational
   efficiency that single-agent sequential approaches cannot match.

   If you are building a multi-agent AI system today, the absence of
   a delegation governance protocol means you cannot answer three
   questions at runtime: which agent is authorized to cause which
   state change, whether a revocation decision has actually reached
   all active sub-agents, and what the completion state of an
   in-flight action was at the moment authority was withdrawn.  MAD
   closes this gap by specifying authority narrowing (INV-4), cascade
   revocation with propagation requirements, and partial-completion
   classification at the GEC layer.  Without it, multi-agent AI
   workflows cannot be safely revoked, audited, or relied upon for
   consequential deployment.

   MAD addresses these requirements through three complementary
   mechanisms:

   (1)  The Narrowing Property (INV-4): a mandate issued to a
        sub-agent MUST contain only a strict subset of the Cedar
        actions available to the issuing agent.  Authority can only
        attenuate, never amplify, across a delegation hop.

   (2)  SO Instance Topology Types: five formally defined patterns
        describing how multiple Sovereign Object instances relate to
        each other at runtime, enabling orchestrators and the GEC
        to reason about multi-agent workflows at the structural
        level.

   (3)  SO Cluster Coordination Primitives (L1-16): a GEC-level
        service for declaring, managing, and querying collections
        of related SO instances executing in coordination, with
        cluster-enriched Cedar evaluation and aggregation rules for
        parallel fan-out patterns.

   This document specifies all three mechanisms as a unified
   Multi-Agent Delegation protocol.  It is intended as a companion
   to draft-sato-soos-aep (Agent Execution Protocol), which defines
   the per-agent execution loop; draft-sato-soos-sov (Sovereign
   Object), which defines the SO structure and lifecycle;
   draft-sato-soos-mjwt (Mandate JWT), which defines the delegation
   credential format; and draft-sato-soos-hem (Human Escalation
   Mechanism), which defines how human oversight integrates into
   multi-agent sessions.  MAD is the coordination governance layer
   across the four-draft stack: IDP [I-D.sato-soos-idp] provides
   the per-transition audit artifact at each delegation hop; HEM
   [I-D.sato-soos-hem] is the escalation mechanism when a hop
   requires human judgment; GAR [I-D.sato-soos-gar] is the permanent
   audit record for the full workflow; CAP [I-D.sato-soos-cap] is
   the prohibition floor applying to every agent at every delegation
   level.

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD 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.

2.  Terminology

   The following terms are used in this document.  Terms defined in
   draft-sato-soos-sov and draft-sato-soos-aep apply when used here.

   Sovereign Object (SO)
      The unit of governance in SOOS.  A causally ordered,
      policy-governed, living typed document that evolves through a
      predefined finite state space under GEC-enforced authority.

   Mandate JWT
      An Ed25519-signed JSON Web Token granting a specific agent
      authority to perform specific Cedar actions on a specific SO
      instance, issued by a principal in the Party Registry.

   Narrowing Property
      The invariant that a child mandate's Cedar action set is always
      a strict subset of the issuing agent's own Cedar action set.
      Defined normatively as INV-4.

   Party Registry
      The GEC-managed registry of all principals (operators,
      agents, humans) and their Ed25519 public keys, and mandate
      issuance relationships.

   Orchestrator Agent
      An agent that coordinates a multi-agent workflow, issuing
      mandates to specialist sub-agents and managing aggregate
      progress across multiple SOs or SO Cluster members.

   Specialist Agent
      An agent operating under a mandate issued by an orchestrator,
      with authority narrowed to a specific SO instance and Cedar
      action subset.

   SO Cluster
      A GEC-managed collection of related SO instances executing
      in coordination.  A cluster is a coordination and visibility
      overlay; it does not itself hold Cedar-governed state.

   Cluster Registry
      A GEC-maintained in-memory index of all declared clusters
      and their member SOs, rebuilt from the Event Log on kernel
      restart per INV-14.

   Aggregation Rule
      A declared condition on SO Cluster member states that, when
      satisfied, causes the GEC to fire a
      CLUSTER_AGGREGATION_CONDITION_MET ProximityEvent to the
      orchestrator session.

   Creation Principal Class
      The class of principal authorised to create an SO instance:
      HUMAN_DIRECT, AGENT_DELEGATED, or AGENT_AUTONOMOUS.

   Mandate Issuance Tree
      The directed tree of mandate issuance relationships maintained
      in the Party Registry, used to compute CASCADE_TO_DESCENDANTS
      revocation scope.

   GEC (Governing Enforcement Component)
      The runtime component that enforces MAD coordination primitives.
      A GEC maintains the Cluster Registry, enforces INV-4 at mandate
      issuance, executes Cedar policy at each transition, records all
      events to the GEC-signed Event Log, and fires ProximityEvents
      to orchestrator sessions.  Earlier versions used "kernel" for
      this component; GEC is the normative term across the SOOS stack.

   GEE
      Goal Execution Engine.  An optional SOOS OS service that inverts
      control, driving the agent execution loop on behalf of an
      orchestrator rather than the agent driving its own loop.

   Natural Breakpoint
      A point in an agent's execution loop, declared by the SO Type
      author in the AEP execution manifest, at which no irreversible
      actions are in flight and the agent's state is consistent with
      a clean halt.  Natural breakpoints are the GEC's reference
      points for CLEAN completion state classification under
      Section 3.6.3.

   Partial Completion
      The condition in which a session is revoked after one or more
      irreversible actions have been taken but before execution is
      complete.  Partial completion requires human review via the HEM
      escalation chain.  Defined in Section 3.6.3.

   Agent Session Revocation
      The termination of an active agent session following mandate
      revocation, including classification of completion state and
      routing to HEM escalation if required.  Distinct from authority
      revocation (cancellation of the mandate JWT) in that session
      revocation addresses the in-flight execution state at the
      moment the authority decision takes effect.  Defined in
      Section 3.6.

   Delegation Pair
      A two-session delegation relationship consisting of one
      orchestrator session and one sub-agent session operating under
      a delegated mandate.  A delegation pair is not a cluster.
      Cluster governance machinery (Section 3.7, Section 3.8,
      DEADLOCK detection) activates only when a third session joins
      or when cluster_mode is explicitly declared in the MJWT.

   Cluster Mode
      The operational state of a multi-session group when cluster
      governance machinery is active.  Activated when session count
      reaches three, or when session_pooling or cluster_mode is
      declared in the cluster MJWT.

3.  Multi-Agent Mandate Model

3.1.  The Narrowing Property

   INV-4 (Narrowing Property) is the foundational invariant of the
   SOOS multi-agent delegation model.

   INV-4:  A Cedar action MUST only appear in a mandate if it is a
   subset of the issuing agent's own Cedar action set.  The Narrowing
   Property MUST be enforced at mandate issuance, not only at
   evaluation.

   This invariant has three consequences:

   (a)  Authority can only attenuate across a delegation hop.  A
        specialist agent cannot acquire capabilities its orchestrator
        does not itself hold.  An orchestrator cannot grant what it
        does not have.

   (b)  The confused deputy attack is structurally prevented at the
        mandate layer.  A malicious or compromised sub-agent that
        attempts to invoke actions beyond its mandate will be rejected
        at Step 1 (Mandate Validation) of the kernel execution sequence
        defined in draft-sato-soos-aep Section 4.2.

   (c)  Revocation of an orchestrator mandate cascades to all
        descendant mandates in the issuance tree (Section 3.5).

   Implementations MUST enforce INV-4 at mandate issuance time in the
   Party Registry, not solely at gec.transition() evaluation time.
   A mandate that violates INV-4 MUST be rejected by the Party
   Registry before it is issued.

3.2.  Mandate Issuance Tree

   The Party Registry MUST maintain a mandate issuance tree: a
   directed tree of mandate issuance relationships where each node is
   a Mandate JWT and each directed edge records that the parent mandate
   was used to issue the child mandate.

   The mandate issuance tree MUST record, for each issued mandate:

      parent_mandate_jti   The jti of the mandate used to authorise
                           this issuance.  NULL for mandates issued
                           directly by a human-held Party Registry
                           principal.

      issuing_principal    The Party Registry ID of the issuing agent
                           or human.

      cedar_action_set     The Cedar actions granted.  MUST satisfy
                           INV-4 with respect to the parent mandate's
                           cedar_action_set.

      issued_at            ISO-8601 timestamp of issuance.

      so_uuid              The SO UUID this mandate is bound to.
                           Per INV-6 (draft-sato-soos-mjwt Section 4),
                           a mandate is SO-instance-bound.

      predecessor_mandate_id
                           The jti of the mandate this MJWT supersedes,
                           if this is a reissued mandate (BUDGET_TRANSFER
                           or other reissuance trigger).  NULL on initial
                           issuance.

   The mandate issuance tree is used to compute the
   CASCADE_TO_DESCENDANTS revocation scope defined in Section 3.5.

3.3.  SO-Type-Bound Creation Mandates

   INV-6 binds a mandate JWT to a specific SO UUID.  This creates a
   bootstrapping dependency: creating an SO requires a mandate, but the
   SO UUID does not exist until creation.

   SOOS resolves this with SO-Type-bound creation mandates.  A
   creation mandate is scoped to an SO Type identifier, not to an SO
   instance UUID.  It grants authority to call
   gec.createSovereignObject() for SOs of the specified type.

   SO-Type-bound creation mandates MUST record:

      creation_mandate     Boolean flag indicating this mandate
                           authorises SO creation, not transitions.

      so_type              The SO Type Registry identifier the mandate
                           is scoped to.

      so_type_version      The version constraint, if any.

   The GEC MUST enforce that a creation mandate is only accepted at
   the gec.createSovereignObject() call, not at
   gec.transition().  An SO-instance-bound mandate MUST NOT be
   accepted at gec.createSovereignObject().

3.4.  Creation Principal Classes

   Every SO instance is created by exactly one of three Creation
   Principal Classes:

   HUMAN_DIRECT
      A human operator creates the SO instance directly via an
      application.  No parent mandate is required.  The creating
      principal MUST hold a human-backed Ed25519 Party Registry key.

   AGENT_DELEGATED
      An agent creates the SO instance under a mandate that explicitly
      includes SO creation authority for a given SO Type
      (Section 3.3).  The creating agent MUST present a valid SO-Type-
      bound creation mandate at gec.createSovereignObject().

   AGENT_AUTONOMOUS
      An agent with standing Party Registry creation rights for a
      specific SO Type creates the instance without a per-invocation
      mandate.  Standing rights are declared in the Party Registry
      at agent registration time by a human principal.

   The creation_principal_class MUST be recorded in the
   CREATE_SOVEREIGN_OBJECT GEC event (Section 7).

   Cedar evaluates against the SO Type's creation policy before
   creation occurs.  The default result is PERMIT.  The SO Type
   designer MAY declare DENY rules for: class restriction (e.g.,
   AGENT_AUTONOMOUS prohibited for this type), rate control, operator
   suspension, or cross-SO dependency conditions.

3.5.  Cross-Mandate Revocation Cascade

   When a mandate revocation is issued with revocation_scope:
   CASCADE_TO_DESCENDANTS (as defined in draft-sato-soos-mjwt
   Section 5.3), the GEC MUST look up all mandate JWTs in the
   Party Registry whose issuance chain includes any revoked jti as an
   ancestor.

   All descendant jti values MUST be added to the Revocation Registry
   atomically with the parent revocation.  The cascade MUST be
   recorded in the single MANDATE_REVOCATION_ISSUED event -- not as
   separate per-descendant events.  One human decision; one kernel
   action; complete audit trail.

   This invariant ensures that revoking an orchestrator mandate
   terminates all specialist sub-agent mandates simultaneously,
   without requiring the revoking human to enumerate the delegation
   tree.

3.6.  Agent Session Revocation

3.6.1.  The SOOS/MAD Revocation Model

   MAD defines revocation at three layers:

   (a)  Authority revocation: the mandate JWT is cancelled and added
        to the Revocation Registry; downstream CASCADE_TO_DESCENDANTS
        processing fires per Section 3.5.  This layer exists in
        MAD-01.

   (b)  Session revocation: active agent sessions holding the revoked
        mandate are terminated.  This layer is defined in this
        section.

   (c)  Partial-completion handling: the GEC MUST classify and record
        the completion state of any in-flight action at the point of
        revocation, and route to HEM escalation if required.  This
        layer is defined in this section.

   Authority revocation (layer a) is always atomic and unconditional.
   Session revocation (layer b) and partial-completion handling
   (layer c) operate after the authority decision is final.

   SA-09 cross-reference: All SOOS companion drafts that reference
   session revocation behavior (including [SOOS-HEM] Section 8.4
   (TERMINATE), [SOOS-AEP] session lifecycle, and [SOOS-CAP] Tier 0
   enforcement) defer normatively to this section (MAD §3.6) for the
   revocation procedure.  Implementations MUST treat MAD §3.6 as the
   single authoritative specification for what happens when an agent
   session is revoked mid-execution, regardless of which protocol
   triggers
   the revocation signal.

3.6.2.  CAEP Profile for Agent Session Revocation

   MAD profiles the OpenID Shared Signals Framework [SSF] and
   Continuous Access Evaluation Protocol [CAEP] for agentic session
   revocation.  CAEP defines a session-revoked event type for
   continuous access evaluation in identity sessions.  MAD extends
   this event type for the multi-agent governance context.

   Session revocation events MUST be delivered as CAEP
   session-revoked events.  The CAEP subject identifier MUST use the
   oauth_token subject identifier format
   (draft-ietf-secevent-subject-identifiers Section 3.2), with the
   token_type set to mandate_jwt and the token field carrying the
   jti of the revoked MJWT.

   The agent-session-revoked event type extends CAEP session-revoked
   with the following additional claims:

      delegation_depth
         Integer.  The depth of the revoking mandate in the mandate
         issuance tree at the time of revocation.  Zero indicates a
         root (operator-issued) mandate.  Required.

      completion_state
         Enumerated string.  One of: CLEAN, PARTIAL, UNKNOWN.
         Classification of the action state at revocation per
         Section 3.6.3.  The CAEP event body SHOULD carry this
         field as a non-normative copy for operational consumers.
         completion_state in GAR is authoritative.  Implementations
         MUST gate completion_state delivery using the CAEP aud
         claim -- only consumers with an authorised audience claim
         receive the completion_state field.

      natural_breakpoint_reached
         Boolean.  True if the GEC determined that the session had
         reached a natural breakpoint (as declared in the AEP
         execution manifest, [I-D.sato-soos-aep] Section 4.2) prior
         to receiving the revocation signal.  Required.

      irreversible_actions_taken
         Boolean.  True if one or more actions classified as
         irreversible in the IDP intent record have been executed
         since the last natural breakpoint.  Required.

      rollback_available
         Boolean.  True if the SO Type definition includes a rollback
         action and the GEC has determined that its preconditions are
         satisfied.  Required.

      revocation_trigger
         Enumerated string.  One of: R-1, R-2, R-3, R-4, R-5, R-6,
         R-7.  The trigger that caused this revocation per
         Section 3.6.4.  Required.

      mandate_id
         String.  The MJWT jti of the revoked session.  Required.

      gec_id
         String.  The GEC instance that detected the revocation
         condition.  Required.

   The agent-session-revoked event is emitted by the GEC to the
   Shared Signals receiver designated in the operator's SOOS
   configuration.  The event MUST be recorded in the GAR event log
   (per [I-D.sato-soos-gar] Section 5) simultaneously with session
   termination.  Emission to the SSF receiver is RECOMMENDED; GAR
   recording is REQUIRED.

   cascade_timeout: When a session revocation signal is issued, the
   cluster coordinator MUST propagate the revocation to all sessions
   in the delegation tree within the cascade_timeout period specified
   in the cluster MJWT.  cascade_timeout SHOULD NOT exceed 30 seconds
   for clusters where all sessions operate within a single network
   region.  For geographically distributed clusters, cascade_timeout
   MAY be set to a higher value.  Implementations that set
   cascade_timeout above 30 seconds MUST declare the chosen value in
   the GEC Manifest.  GAR MUST record a CASCADE_TIMEOUT_EXTENDED flag
   on any cascade revocation that completes beyond the 30-second
   threshold.  Sessions that do not acknowledge the revocation signal
   within cascade_timeout MUST be treated as non-responsive and
   revoked under R-3.  GAR MUST record a CASCADE_TIMEOUT_REVOCATION
   event for each session revoked on non-response.

3.6.3.  Partial-Completion Handling

   When the GEC receives a mandate revocation signal while an agent
   session is in active execution, it MUST classify the current
   action state and respond as follows.

   CLEAN:  No irreversible actions have been taken since the last
           natural breakpoint (natural_breakpoint_reached: true,
           irreversible_actions_taken: false).  The GEC MAY complete
           the current atomic operation if it is already in progress,
           then MUST halt the session.  The agent MUST NOT initiate
           further operations.

   PARTIAL:  Irreversible actions have been taken and execution is
             incomplete (irreversible_actions_taken: true).  The GEC
             MUST halt immediately without completing the current
             operation.  The GEC MUST record completion_state: PARTIAL
             in the GAR entry and MUST route to the HEM escalation
             chain per [I-D.sato-soos-hem] Section 7.  Human review
             is REQUIRED before any further action on affected SOs.
             Implementations MUST NOT release the affected Sovereign
             Objects for re-use until remediation or rollback has been
             completed and recorded in GAR.

   UNKNOWN:  The GEC cannot determine completion state, for example
             due to a network partition or process restart during
             execution.  The GEC MUST treat UNKNOWN as PARTIAL for
             all remediation purposes.  The distinction between
             UNKNOWN and PARTIAL is informational only; both trigger
             identical remediation obligations.  The GEC MUST NOT
             make optimistic assumptions about completion state under
             uncertainty.

   Natural breakpoints are declared by the SO Type author in the AEP
   execution manifest ([I-D.sato-soos-aep] Section 4.2).  Actions
   classified as irreversible are declared in the IDP intent record
   ([I-D.sato-soos-idp]).  An SO Type that does not
   declare natural breakpoints has no CLEAN exit under partial
   revocation; all revocations on non-terminated sessions of that
   type MUST be treated as PARTIAL.

   INV-15:  A GEC MUST NOT treat UNKNOWN completion state as CLEAN.

   INV-16:  A GEC MUST record completion_state in the GAR entry for
            every session terminated by revocation.

3.6.4.  Session Revocation Trigger Taxonomy (R-1 -- R-7)

   The following trigger taxonomy classifies the conditions under
   which an agent session is revoked.  All triggers result in session
   revocation per Section 3.6.1.  The revocation_trigger field in
   the CAEP event body and GAR record MUST cite one of R-1 through
   R-7.

   R-1 -- CAP Tier 0-A Violation
      A CAP constitutional prohibition (Tier 0-A) has been violated
      or imminently threatened.  Revocation is immediate and
      unconditional.  Human principal reauthorisation is REQUIRED
      before any continuation mandate is issued (Section 3.6.6).

   R-2 -- Scope Boundary
      The agent has attempted or is imminently about to attempt an
      action outside its mandate scope (INV-4 violation detected
      at execution time rather than issuance time).  Human principal
      reauthorisation is REQUIRED before any continuation mandate
      is issued (Section 3.6.6).

   R-3 -- Non-Response
      The agent session has failed to respond to a governance signal
      (revocation propagation, HEM escalation, or cascade timeout)
      within the required window.  Operator MAY issue continuation
      mandate per Section 3.6.6.

   R-4 -- Irreversible Threshold
      The agent has reached or is about to exceed an irreversible
      action threshold declared in the mandate or SO Type.  Human
      principal reauthorisation is REQUIRED before any continuation
      mandate is issued (Section 3.6.6).

   R-5 -- Scheduled Rotation
      The agent session is being revoked as part of a planned
      rotation or maintenance operation.  Operator MAY issue
      continuation mandate per Section 3.6.6.

   R-6 -- Operator Override
      An operator has explicitly revoked the agent session.
      Operator MAY issue continuation mandate per Section 3.6.6.

   R-7 -- DEADLOCK
      The cluster coordinator has detected a DEADLOCK condition per
      Section 3.6.5.  All participating sessions are simultaneously
      suspended.  Human principal reauthorisation is REQUIRED before
      any continuation mandate is issued (Section 3.6.6).

3.6.5.  DEADLOCK State

   A cluster DEADLOCK condition exists when two or more agent sessions
   hold exclusive resource locks such that no session can proceed
   without acquiring a lock held by another session in the same
   cluster, and no session independently meets a trigger condition
   under R-1 through R-6.

   DEADLOCK detection is the exclusive responsibility of the cluster
   coordinator; individual sessions MUST NOT self-report DEADLOCK.

   Upon DEADLOCK detection, the cluster coordinator MUST:

   (1)  Simultaneously suspend all participating sessions.

   (2)  Emit HEM_MULTI_PRINCIPAL_REQUIRED.

   (3)  Route to a human arbitrator.

   (4)  Record a DEADLOCK_DETECTED event in GAR citing all
        participating session_id values, contested so_id values,
        and mandate_id values.

   If no resolution mandate is received within the deadlock_timeout
   period specified in the cluster MJWT, all DEADLOCK-suspended
   sessions MUST be auto-revoked under R-3.  GAR MUST record a
   DEADLOCK_TIMEOUT_REVOCATION event for each session revoked on
   timeout.  On successful human resolution, GAR MUST record a
   DEADLOCK_RESOLVED event.

   deadlock_timeout is a REQUIRED field in cluster MJWTs.  Absence
   of this field in a cluster MJWT is a conformance violation.

   | State     | Entry condition         | Exit -- resolved              | Exit -- timeout           |
   |-----------|-------------------------|-------------------------------|---------------------------|
   | DEADLOCK  | Circular resource       | ACTIVE (on resolution         | REVOKED under R-3         |
   |           | dependency across >=2   | mandate, Cedar PERMIT for     | after deadlock_timeout    |
   |           | sessions detected by    | Action::"ResolveDeadlock")    |                           |
   |           | cluster coordinator     |                               |                           |

   Cedar action: Action::"ResolveDeadlock" is REQUIRED on any
   resolution mandate.  The kernel MUST evaluate this Cedar action
   before resuming any DEADLOCK-suspended session.

3.6.6.  Continuation Mandate Authority

   When a revoked session requires a continuation mandate to resume
   incomplete work following ALE-005 (SESSION_REVOCATION_COMPLETE,
   defined in [I-D.sato-soos-gar] Section 12.5), the authority to
   issue the continuation mandate is determined by the revocation
   trigger as follows.

   Human principal MUST reauthorise (R-1, R-2, R-4, R-7):
      The kernel MUST NOT accept a continuation mandate issued by
      the operator alone.  The operator MAY issue a temporary
      suspension mandate to preserve resource state pending principal
      reauthorisation.  GAR MUST record CONTINUATION_AWAITING_
      PRINCIPAL until the principal issues the continuation mandate.

   Operator MAY issue continuation mandate (R-3, R-5, R-6):
      The operator MAY issue a continuation mandate without principal
      involvement.  The operator MUST notify the human principal
      through the HEM out-of-band channel within the
      principal_notification_timeout period specified in the cluster
      MJWT (default: 300 seconds).  The principal MAY revoke the
      continuation mandate within that window.  GAR MUST record
      CONTINUATION_ISSUED_BY_OPERATOR and PRINCIPAL_NOTIFIED events.

   A continuation mandate MUST:

   (a)  Carry predecessor_mandate_id referencing the revoked
        mandate's MJWT jti.

   (b)  Carry continuation_reason citing the revocation trigger
        (R-1 through R-7).

   (c)  NOT expand scope beyond the original mandate's
        mandate_scope.

   (d)  Be evaluated by the kernel as a new session -- full KIA
        handshake required.

   (e)  Reference the ALE-005 record_id in the GAR chain.

3.7.  Cluster Invariants

   This section defines invariants that MUST hold across all agent
   sessions operating within a SOOS cluster.  Cluster invariants are
   enforced by the cluster coordinator.  Violation of a cluster
   invariant MUST be recorded in GAR and MUST trigger the appropriate
   revocation or escalation procedure.

3.7.1.  INV-17: Horizontal Non-Contamination

   An agent session operating under mandate M MUST NOT read from,
   write to, or modify the state of any Sovereign Object whose Zone A
   authority is held by a sibling session operating under a distinct
   mandate M' in the same cluster, unless an explicit cross-session
   access grant exists in the Cedar policy set and has been evaluated
   by the cluster coordinator before the access occurs.  The result
   of that Cedar evaluation MUST be recorded in GAR before the access
   is permitted.

   Zone B objects are outside the scope of this invariant.
   Horizontal access to Zone B objects within a cluster is governed
   by operator Cedar policy.

   Enforcement: INV-17 horizontal non-contamination is enforced as a
   Tier 0-B mandatory Cedar forbid policy.  Operators MUST NOT remove
   this policy.  Cross-session access requires an explicit permit
   policy satisfying the unless clause.

      forbid (
        principal,
        action in [
          Action::"ReadSovereignObject",
          Action::"WriteSovereignObject",
          Action::"ModifySovereignObjectState"
        ],
        resource
      )
      when {
        resource.zone == "ZONE_A" &&
        resource.mandate_id != context.active_mandate_id &&
        context.cluster_id == resource.cluster_id
      }
      unless {
        context.cross_session_grant_verified == true &&
        context.cross_session_grant_recorded_in_gar == true
      };

   GAR event: INV4_VIOLATION records the attempting session_id, the
   target so_id, the mandate_id of the zone authority holder, and
   the Cedar DENY result.

   CONF-MAD-INV4-01: Implementations MUST include the INV-17 Tier 0-B
   Cedar policy in the baseline policy set.  Absence of this policy
   is a non-conforming implementation detectable via KIA attestation
   (cedar_policy_hash mismatch against the conformance baseline).

3.8.  Cluster Resource Governance

   Agent sessions within a cluster MAY request reallocation of
   resource budget from the cluster coordinator.  The cluster
   coordinator is the sole authority for evaluating and approving
   BUDGET_TRANSFER requests.  Individual sessions MUST NOT transfer
   budget directly to sibling sessions.

3.8.1.  BUDGET_TRANSFER Procedure

   Initiation: A session whose resource_envelope is approaching
   exhaustion MAY emit a BUDGET_TRANSFER_REQUEST to the cluster
   coordinator, specifying the requested resource type, requested
   amount, and the session_id of the intended donor session (if
   known) or ANY_DONOR if the requesting session has no preference.

   Evaluation: The cluster coordinator MUST evaluate
   Action::"ApproveBudgetTransfer" via Cedar before approving any
   transfer.  The Cedar evaluation context MUST include the requesting
   session's current resource consumption, the donor session's
   remaining envelope, and the cluster's aggregate resource state.
   The transfer amount and donor selection are Cedar policy decisions;
   no protocol-level fraction cap applies.

   Reissuance: On Cedar PERMIT, the cluster coordinator MUST trigger
   MJWT reissuance for both sessions before the transfer takes effect.
   The donor session receives a new MJWT with a reduced
   resource_envelope.  The receiving session receives a new MJWT with
   an increased resource_envelope.  Both new MJWTs MUST carry the
   original mandate_id in a predecessor_mandate_id field for audit
   chain continuity.  Execution continues under the new MJWTs; the
   prior MJWTs are added to the Revocation Registry.

   Recording: GAR MUST record ALE-018 (CLUSTER_BUDGET_TRANSFER)
   before the new MJWTs are activated.  The ALE-018 record MUST cite
   both session_ids, both old and new mandate_ids, the resource type
   transferred, and the amount transferred.

   Denial: On Cedar DENY, the coordinator returns
   BUDGET_TRANSFER_DENIED to the requesting session.  No MJWT
   reissuance occurs.  The requesting session continues under its
   existing mandate until exhaustion triggers BUDGET_EXHAUSTED
   (per [I-D.sato-soos-hem] Section 5.10).

   BUDGET_TRANSFER_REQUEST schema:

      session_id            String.  Requesting session.  Required.
      resource_type         Enum.    compute | memory | storage |
                                     network | duration.  Required.
      requested_amount      Integer. Amount in resource-type units.
                                     Required.
      donor_session_id      String.  Preferred donor session_id, or
                                     ANY_DONOR.  Required.

   CONF-MAD-BT-01: Cluster coordinators MUST evaluate
   Action::"ApproveBudgetTransfer" via Cedar before activating any
   resource transfer.  Direct mandate mutation without Cedar
   evaluation and MJWT reissuance is a non-conforming implementation.

3.9.  Multi-Agent Topology Events

   This section defines the four multi-agent topology events that
   originate in MAD-02 and are recorded in GAR as Authority Lifecycle
   Events (ALE-013 through ALE-016).  These events are emitted by
   the cluster coordinator.  Individual sessions MUST NOT emit
   topology events directly.

   These events apply only when cluster mode is active
   (Section 2, Cluster Mode definition).  Delegation pairs do not
   produce ALE-013 through ALE-016; they use the standard
   DELEGATION_EVENT defined in [I-D.sato-soos-aep] Section 6.

3.9.1.  ALE-013: DELEGATION_INITIATED

   Emitted when a session successfully delegates a sub-task and a
   sub-mandate MJWT has been issued within an active cluster.

      ale_type                  "DELEGATION_INITIATED". Required.
      delegating_session_id     Session initiating the delegation.
                                Required.
      sub_agent_session_id      Newly created sub-agent session.
                                Required.
      sub_mandate_id            MJWT jti of the sub-mandate.
                                Required.
      parent_mandate_id         MJWT jti of the delegating mandate.
                                Required.
      goal_impact               BLOCKING | NON_BLOCKING. Required.
      hem_class                 HEM class of the delegating session.
                                Required.
      pooling_enabled           Whether sub-agent session will be
                                pooled on completion.  Required.

   DELEGATION_EVENT goal_impact BLOCKING obligations (CHG-MAD-AEP04):

   When goal_impact is BLOCKING, the kernel MUST evaluate the
   delegating agent's HEM class before permitting the delegation.

   Class 1-2: The kernel MUST trigger HEM escalation before the
   delegation is activated.  The delegation MUST NOT proceed until
   a human principal issues an explicit approval mandate.  GAR MUST
   record the escalation and the approval or denial.

   Class 3-4: The kernel SHOULD trigger HEM escalation.  The kernel
   MAY permit the delegation to proceed without escalation if: (a)
   Cedar evaluates Action::"ApproveDelegation" as PERMIT, and (b)
   the delegating session's PT composite score is at or above the
   mandate trust_floor.  GAR MUST record the Cedar evaluation result
   and PT score at the point of delegation regardless of escalation
   outcome.

   Class 5+: No mandatory HEM trigger on BLOCKING delegation.  The
   kernel MUST record the DELEGATION_EVENT and goal_impact: BLOCKING
   in GAR.  Cedar evaluation of Action::"ApproveDelegation" proceeds
   normally.

3.9.2.  ALE-014: DELEGATION_COMPLETED

   Emitted when a sub-agent session completes its delegated task and
   returns control to the delegating session.

      ale_type                  "DELEGATION_COMPLETED". Required.
      sub_agent_session_id      Completing sub-agent session.
                                Required.
      sub_mandate_id            MJWT jti of the completed task
                                mandate.  Required.
      parent_mandate_id         MJWT jti of the delegating mandate.
                                Required.
      completion_state          CLEAN | PARTIAL | UNKNOWN. Required.
      session_disposition       TERMINATED (if session_pooling:
                                false) | RETURNED_TO_POOL (if
                                session_pooling: true).  Required.
      pool_idle_timeout_starts  Unix timestamp.  MUST be present if
                                session_disposition is
                                RETURNED_TO_POOL.  Conditional.

3.9.3.  ALE-015: DELEGATION_FAILED

   Emitted when a sub-agent session fails, is revoked, or times out
   before completing its delegated task.

      ale_type                  "DELEGATION_FAILED". Required.
      sub_agent_session_id      Failed sub-agent session. Required.
      sub_mandate_id            MJWT jti of the failed task mandate.
                                Required.
      parent_mandate_id         MJWT jti of the delegating mandate.
                                Required.
      failure_mode              GOVERNANCE | TIMEOUT | TASK.
                                Required.
      revocation_trigger        R-1 through R-7.  MUST be present if
                                failure_mode is GOVERNANCE.
                                Conditional.
      completion_state          CLEAN | PARTIAL | UNKNOWN at point
                                of failure.  Required.
      retry_eligible            Whether the task MAY be retried under
                                a new mandate.  Required.

   Remediation routing by failure_mode:

   GOVERNANCE: MUST route to human review before retry is permitted.
   retry_eligible MUST be false unless a human principal explicitly
   sets it in a resolution mandate.

   TIMEOUT: kernel MAY auto-retry under a new mandate if
   retry_eligible is true and Cedar PERMIT on
   Action::"RetryDelegation".

   TASK: returned to orchestrating session for replanning.
   Orchestrator determines retry strategy.

3.9.4.  ALE-016: CLUSTER_TOPOLOGY_CHANGE

   Emitted on any change to cluster membership or coordinator
   identity.

      ale_type                    "CLUSTER_TOPOLOGY_CHANGE".
                                  Required.
      change_type                 SESSION_JOINED | SESSION_LEFT |
                                  SESSION_REVOKED |
                                  COORDINATOR_CHANGE.  Required.
      affected_session_id         Session that joined, left, was
                                  revoked, or (on
                                  COORDINATOR_CHANGE) the new
                                  coordinator session_id.  Required.
      prior_coordinator_session_id
                                  MUST be present if change_type is
                                  COORDINATOR_CHANGE.  Conditional.
      cluster_id                  Cluster identifier.  Required.
      cluster_size_after          Number of active sessions in
                                  cluster after the change.
                                  Required.
      requires_human_notification Boolean.  true if change_type is
                                  COORDINATOR_CHANGE, otherwise
                                  operator-configured.  Required.

   Cluster mode activation: When a third session joins a delegation
   pair, the cluster coordinator MUST: (1) emit ALE-016 with
   change_type: SESSION_JOINED; (2) set cluster_mode: true in the
   cluster MJWT; (3) add cluster_context to the AEP Context Package
   for all sessions; (4) activate INV-4 enforcement; (5) activate
   DEADLOCK detection (R-7).  Steps 1-5 MUST complete atomically
   before the joining session begins execution.

4.  SO Instance Topology Types

4.1.  Topology Classification

   SOOS recognises five SO Instance Topology Types describing how
   multiple SO instances relate to each other at runtime.  These
   topologies are not mutually exclusive within a complex application:
   a single workflow may exhibit Linear Chain structure at the top
   level while individual nodes contain Parallel Fan-Out
   sub-topologies.

   The topology classification is architectural guidance for
   SO Type designers and orchestrator implementors.  The kernel
   operates on individual SOs one transition at a time regardless of
   topology.  INV-1 through INV-16 apply uniformly across all
   topology types.

4.2.  Topology 1: Linear Chain (Sequential Pipeline)

   A parent SO instance owns a defined sequence of child SO instances
   that complete in order.  The parent state machine gates the
   creation of each subsequent child on the prior child reaching a
   terminal state.  ProximityEvents (defined in draft-sato-soos-aep
   Section 7.3.2) deliver completion signals from child to parent.

   Example:  A travel booking workflow comprising
   FlightOut_SO -> Hotel_SO -> Activity_SO -> FlightReturn_SO.

   Kernel requirement:  The parent SO stores child SO UUIDs as Zone A
   cross-references.  The ProximityEvent carries the child's
   so_uuid and terminal state as payload.

   This topology is fully supported by the current SOOS kernel.

4.3.  Topology 2: Parallel Fan-Out (Concurrent Siblings)

   Multiple child SO instances run simultaneously under a common
   parent.  The parent SO aggregates completion signals from children
   according to a declared aggregation rule: ALL_COMPLETE,
   ANY_COMPLETE, or QUORUM(n).

   The SO Cluster Manager (Section 5) provides the coordination
   primitives for this topology.

   Example:  A supplier availability check dispatching simultaneously
   to five vendor SO instances, proceeding when ANY_COMPLETE.

4.4.  Topology 3: Directed Acyclic Graph (DAG)

   Multiple child SO instances execute in parallel.  Not all succeed.
   Terminated children are informational data points for surviving
   paths.  The DAG shape is defined at SO Type design time.

   This topology requires: (a) Dynamic SO creation under
   AGENT_DELEGATED creation mandates; (b) SO Cluster membership that
   can accommodate terminal members while the cluster remains active;
   (c) Cross-SO Zone A data flow.

   Example:  A multi-path experimental workflow where several
   hypothesis SOs are created simultaneously, results of terminated
   experiments feed surviving paths, and one path reaches the target.

4.5.  Topology 4: Dynamic and Emergent

   Child SO instances emerge at runtime based on execution outcomes.
   The topology shape is itself an outcome of execution.

   This topology requires: (a) Dynamic SO creation under
   AGENT_DELEGATED mandates; (b) L1-16 DYNAMIC cluster membership;
   (c) Cedar evaluation at each dynamic creation step.

   Example:  An investigation workflow where an orchestrator SO
   spawns hypothesis SOs dynamically.

4.6.  Topology 5: Cyclic and Re-entrant

   An SO returns to a prior state that it has already occupied.
   Handled by the STATE_REVERSAL TransitionDeclaration mechanism
   defined in draft-sato-soos-sov Section 5.

   This topology does not require the SO Cluster Manager.

4.7.  Kernel Effects by Topology

   INV-1 through INV-16 do not change for any topology.  The kernel
   operates on individual SOs one transition at a time regardless of
   the number of agents or SOs involved in the containing workflow.

   Cross-SO Zone A references are the linking mechanism for all
   topology types.  The SO Cluster Manager (Section 5) provides the
   coordination layer for Topologies 2, 3, and 4.  ProximityEvents
   (Topology 1) and CLUSTER_AGGREGATION_CONDITION_MET (Topologies 2,
   3, 4) are the signals by which completion propagates upward.
   Topology 5 requires no additional kernel mechanism beyond
   STATE_REVERSAL TransitionDeclarations.

5.  SO Cluster Coordination

5.1.  The SO Granularity Rule

   An SO instance is warranted when a thing requires at least one of:
   (1) Governed state; (2) HEM eligibility; (3) Mandate scoping;
   (4) Audit accountability.  Data that does not meet any of these
   criteria SHOULD be modelled as Zone B attachments on an existing
   SO.  This guidance is advisory.

5.2.  Cluster Declaration Protocol

   A cluster is declared after its member SOs are created.  Member
   SOs MUST be created individually before cluster declaration.

5.3.  Cluster Membership Model

   STATIC clusters have a fixed membership declared at creation.
   DYNAMIC clusters allow addClusterMember and removeClusterMember
   operations after declaration.

5.4.  Cluster Registry

   The GEC MUST maintain an in-memory Cluster Registry rebuilt from
   the Event Log on kernel restart (INV-14).

5.5.  Cluster-Enriched Cedar Evaluation

   cluster_context is injected as a Cedar evaluation attribute on
   every transition of a cluster member SO.  Implementations MUST
   ensure cluster_context is populated exclusively from the GEC-
   maintained Cluster Registry and cannot be supplied or manipulated
   by agents.

5.6.  SO Cluster Manager (L1-16)

   The SO Cluster Manager exposes sixteen GEC-level primitives for
   cluster lifecycle management: declareCluster, addClusterMember,
   removeClusterMember, getClusterStatus, mergeCluster, splitCluster,
   dissolveCluster, and related query operations.

5.7.  Aggregation Rules

   Clusters declare one of: ALL_COMPLETE, ANY_COMPLETE, or QUORUM(n).
   CLUSTER_AGGREGATION_CONDITION_MET fires when the condition is
   first satisfied.

5.8.  Visibility Extensions

   HEMContext carries cluster_context for HEM escalation decisions
   involving cluster member sessions.

6.  Orchestrator-Specialist Model

6.1.  GEE Orchestration Mode

   The Goal Execution Engine (GEE) orchestration mode inverts
   control: the GEE calls the orchestrator's reason() function as a
   service within a GEC-driven loop.  The orchestrator MUST NOT call
   gec.transition() or cluster operations directly in GEE mode
   (CONF-GEE-06 of draft-sato-soos-aep).

6.2.  Orchestrator Mandate Scope

   The orchestrator mandate defines the Cedar action set from which
   all sub-agent mandates must be derived (INV-4).  For cluster-
   spanning workflows, the orchestrator mandate MUST include all
   Cedar cluster management actions required for the intended
   topology.

6.3.  Specialist Agent Mandate Issuance

   Each specialist mandate MUST satisfy INV-4 and MUST be
   SO-instance-bound (INV-6) to a specific member SO UUID.  An
   orchestrator MUST NOT issue a mandate granting a specialist
   authority over multiple SO instances in a single mandate.

6.4.  Sub-Agent Failure Recovery

   When a specialist agent fails, expires, or is revoked, the
   primary recovery signal is CLUSTER_MEMBER_REACHED_TERMINAL
   ProximityEvent.  The orchestrator determines whether to continue
   (aggregation rule tolerates the failure), invoke HEM, or
   dissolve.

6.5.  Sub-Agent Session Pooling

   Pooling is opt-in, declared in the cluster MJWT via the
   session_pooling field.  If session_pooling is absent or false,
   sub-agent sessions terminate on task completion (ALE-014
   session_disposition: TERMINATED).  If session_pooling is true,
   completed sessions return to pool (ALE-014 session_disposition:
   RETURNED_TO_POOL) and the following four termination triggers
   apply.

   A pooled sub-agent session MUST terminate on the first of:

   T-A  Orchestrator session terminates (cascade termination).
   T-B  pool_idle_timeout expires without a new task mandate
        being issued.
   T-C  Orchestrator emits Action::"ReleasePooledSession" --
        Cedar PERMIT required.
   T-D  Cumulative resource consumption reaches
        session_resource_ceiling.

   Mandate lifecycle under pooling: session (KIA handshake, PT
   scoring history, resource consumption) MAY persist across tasks.
   Mandate (MJWT, Cedar scope, specific delegated goal) MUST be
   reissued per task.  Each task mandate carries predecessor_
   mandate_id referencing the prior task mandate for audit chain
   continuity.

   New cluster MJWT fields:

      session_pooling           Boolean.  Optional.  Default: false.
      pool_idle_timeout         Integer (seconds).  REQUIRED if
                                session_pooling is true.
      session_resource_ceiling  Integer.  Optional.  Cumulative
                                resource limit across all task
                                mandates for a pooled session.

7.  Kernel Events

   This section specifies the GEC events introduced by this
   document.  All GEC events MUST be signed by the KIA keypair
   (INV-9 of draft-sato-soos-kia).

   Events defined in MAD-01 (Sections 7.1 through 7.9) are
   unchanged.  The following events are added in MAD-02.

7.1.  CREATE_SOVEREIGN_OBJECT  [unchanged from MAD-01]

7.2.  CLUSTER_DECLARED  [unchanged from MAD-01]

7.3.  CLUSTER_MEMBER_ADDED  [unchanged from MAD-01]

7.4.  CLUSTER_MEMBER_REMOVED  [unchanged from MAD-01]

7.5.  CLUSTER_MERGED  [unchanged from MAD-01]

7.6.  CLUSTER_SPLIT  [unchanged from MAD-01]

7.7.  CLUSTER_DISSOLVED  [unchanged from MAD-01]

7.8.  ProximityEvent: CLUSTER_MEMBER_REACHED_TERMINAL
      [unchanged from MAD-01]

7.9.  ProximityEvent: CLUSTER_AGGREGATION_CONDITION_MET
      [unchanged from MAD-01]

7.10.  MANDATE_REVOCATION_ISSUED (updated)

   Unchanged from MAD-01 except: the revoked_jtis array MUST also
   include the predecessor_mandate_id chain for any reissued mandates
   in the delegation tree at the time of revocation.

7.11.  New MAD-02 Events

   DEADLOCK_DETECTED
      Emitted by cluster coordinator on R-7 trigger.
      Fields: event_type, event_id, timestamp, cluster_id,
      participating_session_ids (array), contested_so_ids (array),
      mandate_ids (array), deadlock_timeout, gec_signature.

   DEADLOCK_RESOLVED
      Emitted on successful human arbitration.
      Fields: event_type, event_id, timestamp, cluster_id,
      resolution_mandate_id, arbitrator_principal_id,
      resumed_session_ids (array), gec_signature.

   DEADLOCK_TIMEOUT_REVOCATION
      Emitted for each session auto-revoked after deadlock_timeout.
      Fields: event_type, event_id, timestamp, session_id,
      mandate_id, cluster_id, gec_signature.

   INV4_VIOLATION
      Emitted on horizontal non-contamination violation attempt.
      Fields: event_type, event_id, timestamp, attempting_session_id,
      target_so_id, zone_authority_mandate_id, cedar_deny_result,
      gec_signature.

   CASCADE_TIMEOUT_EXTENDED
      Flag on cascade revocation records where completion exceeded
      30 seconds.
      Fields: event_type, event_id, timestamp, cascade_duration_seconds,
      declared_timeout, gec_signature.

   CASCADE_TIMEOUT_REVOCATION
      Emitted for each session revoked due to non-response during
      cascade.
      Fields: event_type, event_id, timestamp, session_id, mandate_id,
      gec_signature.

   CONTINUATION_AWAITING_PRINCIPAL
      Emitted after R-1, R-2, R-4, or R-7 revocation pending
      principal reauthorisation.
      Fields: event_type, event_id, timestamp, revoked_mandate_id,
      revocation_trigger, gec_signature.

   CONTINUATION_ISSUED_BY_OPERATOR
      Emitted when operator issues continuation mandate for R-3,
      R-5, or R-6.
      Fields: event_type, event_id, timestamp, revoked_mandate_id,
      continuation_mandate_id, operator_principal_id,
      principal_notification_deadline, gec_signature.

   PRINCIPAL_NOTIFIED
      Emitted when operator notification is delivered to human
      principal.
      Fields: event_type, event_id, timestamp,
      continuation_mandate_id, notification_channel,
      gec_signature.

8.  Cedar Actions

   The following Cedar actions are introduced by this document.  All
   actions MUST be registered in the SOOS Cedar namespace.

   Actions from MAD-01 are unchanged:
   SOOS::Action::CreateSovereignObject
   SOOS::Action::DeclareCluster
   SOOS::Action::AddClusterMember
   SOOS::Action::RemoveClusterMember
   SOOS::Action::MergeCluster
   SOOS::Action::SplitCluster
   SOOS::Action::DissolveCluster

   New in MAD-02:

   SOOS::Action::ResolveDeadlock
      Required on resolution mandate before any DEADLOCK-suspended
      session is resumed.  Evaluated by cluster coordinator.

   SOOS::Action::ApproveBudgetTransfer
      Required before any cluster resource budget transfer is
      activated.  Evaluated by cluster coordinator.

   SOOS::Action::ApproveDelegation
      Required for Class 3-4 BLOCKING delegation where HEM
      escalation is not triggered.

   SOOS::Action::RetryDelegation
      Required before a TIMEOUT-failed delegation is retried under
      a new mandate.

   SOOS::Action::ReleasePooledSession
      Required for orchestrator to release a pooled sub-agent
      session (T-C termination trigger).

9.  Conformance

   Conformance requirements from MAD-01 (CONF-MAD-01 through
   CONF-MAD-14, CONF-MAD-GEC-01, CONF-MAD-GEC-02) are unchanged.

   New in MAD-02:

   CONF-MAD-INV4-01  Implementations MUST include the INV-17
                     horizontal non-contamination Tier 0-B Cedar
                     policy in the baseline policy set.  Absence
                     is detectable via KIA cedar_policy_hash.

   CONF-MAD-BT-01    Cluster coordinators MUST evaluate
                     Action::"ApproveBudgetTransfer" via Cedar
                     before activating any resource transfer.
                     Direct mandate mutation is non-conforming.

   CONF-MAD-15       deadlock_timeout MUST be present in all
                     cluster MJWTs.  Absence is a conformance
                     violation.  (REJECT cluster MJWT without
                     this field)

   CONF-MAD-16       continuation_reason MUST be present on all
                     continuation mandates.  (REJECT)

   CONF-MAD-17       predecessor_mandate_id MUST be present on all
                     reissued mandates (BUDGET_TRANSFER and other
                     reissuance triggers).  (REJECT)

   CONF-MAD-18       Cluster mode activation steps (Section 3.9.4)
                     MUST complete atomically before the joining
                     session begins execution.  (REJECT session
                     start if activation incomplete)

   CONF-MAD-GEC-03   When a monitoring agent session fires
                     HEM_TIER1_OBSERVED with confidence PROBABLE or
                     EVIDENT, the GEC MUST surface the escalation to
                     any execution agent sessions operating on
                     related Sovereign Objects within the same GEC
                     trust domain.  Cross-session propagation MUST
                     occur via the Cluster Registry notification
                     path; agents MUST NOT communicate directly.
                     (REJECT cluster configurations that lack a
                     registered notification path)

10.  Open Issues

10.1.  OQ-S-41: Cross-Principal SO Coordination  [unchanged]

10.2.  OQ-S-43: Nested Clusters  [unchanged]

10.3.  OQ-S-44: Cluster-Scope Cedar Evaluation  [unchanged]

10.4.  OQ-S-45: Propagation Timeout Normalization

   Section 3.6.2 recommends a 30-second threshold for the
   CASCADE_TIMEOUT_EXTENDED flag.  Whether this threshold value
   should be normative (MUST), operator-configurable with a minimum
   floor, or an implementation-specific recommendation is unresolved.

   In latency-sensitive network management deployments (the ICON
   use case), 30 seconds may be unacceptably long.  In regulated
   enterprise deployments, 30 seconds may be too short to complete
   mandatory GAR recording.  A successor document SHOULD define a
   timeout negotiation mechanism at cluster declaration time.

   OQ-S-45 is tracked as LOW priority and does not block v1.

11.  Security Considerations

11.1.  Confused Deputy Attack at Delegation Hops  [unchanged]

11.2.  Cluster Scope as an Attack Surface  [unchanged]

11.3.  Ghost Execution on Cluster Dissolution  [unchanged]

11.4.  Cascade Revocation in Large Delegation Trees

   In workflows with deep delegation trees, a CASCADE_TO_DESCENDANTS
   revocation may affect a large number of active sessions
   simultaneously.  Implementations MUST handle the atomic revocation
   of large descendant sets without partial failure.  The
   MANDATE_REVOCATION_ISSUED event records the complete set of revoked
   jtis; the GEC MUST add all listed jtis to the Revocation Registry
   atomically.

   In fan-out topologies where specialist agents are distributed
   across network segments, atomic revocation of descendant mandates
   in the Party Registry does not guarantee that active specialist
   sessions have received the revocation signal.  An agent that is
   unreachable at the time of cascade revocation cannot be terminated
   at the authority layer.  Implementations MUST define a propagation
   timeout (SHOULD NOT exceed 30 seconds for single-region clusters)
   after which any specialist session that has not confirmed
   revocation receipt is reclassified as UNKNOWN completion state
   and treated as PARTIAL per Section 3.6.3.  Operator notification
   via the HEM escalation chain is REQUIRED for all UNKNOWN-
   reclassified sessions.  (See OQ-S-45, Section 10.4.)

11.5.  Propagation Completeness in Fan-Out Topologies

   The Narrowing Property (INV-4) and CASCADE_TO_DESCENDANTS
   (Section 3.5) guarantee that the authority decision (mandate
   revocation) is atomic at the Party Registry layer.  They do not
   guarantee that active agent sessions holding the revoked mandate
   have received the termination signal, particularly in fan-out
   topologies where specialist agents may be behind network
   partitions or operating in offline-attenuated mode.

   Implementations MUST track confirmation receipts for revocation
   signals delivered to active specialist sessions.  An active
   session that has not confirmed receipt within the propagation
   timeout (Section 11.4, cascade_timeout SHOULD NOT exceed 30
   seconds) MUST be reclassified as UNKNOWN completion state.  The
   GEC MUST generate a SESSION_REVOCATION_UNCONFIRMED event for each
   such session and route it to the HEM escalation chain.

   This requirement closes the gap identified in [OIF-REVOC]:
   offline-attenuated agents that cannot receive revocation signals
   are surfaced to human operators rather than left in an unmonitored
   state.

   Formal analysis of propagation completeness properties in large
   delegation trees is identified as future work.

11.6.  DEADLOCK as a Denial-of-Service Vector

   A malicious agent that deliberately holds resource locks to induce
   DEADLOCK conditions could use R-7 as a denial-of-service attack
   against a cluster.  The deadlock_timeout auto-revocation
   mechanism (Section 3.6.5) limits the blast radius: all
   participating sessions are revoked after deadlock_timeout, and
   the cluster returns to a recoverable state.

   Operators SHOULD set deadlock_timeout conservatively for high-
   value clusters.  Cedar policy governing Action::"ApproveDelegation"
   and cluster membership SHOULD be reviewed for conditions that
   could enable induced deadlock by a compromised session.

11.7.  Horizontal Non-Contamination Enforcement Completeness

   INV-17 horizontal non-contamination (Section 3.7.1) is enforced
   as a Tier 0-B Cedar policy.  The security guarantee depends on
   the completeness of the Zone A designation for sensitive
   Sovereign Objects.  An operator that designates a resource as
   Zone B when Zone A is warranted removes horizontal non-
   contamination protection for that resource.  Operators MUST
   apply Zone A designation to all resources where cross-session
   contamination would constitute a governance failure.

12.  IANA Considerations

   This document has no IANA actions at this time.  A successor
   document will define the SOOS Cedar action namespace registry.

13.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997,
              <https://www.rfc-editor.org/rfc/rfc2119>.

   [RFC7519]  Jones, M., Bradley, J., and N. Sakimura, "JSON Web
              Token (JWT)", RFC 7519, May 2015,
              <https://www.rfc-editor.org/rfc/rfc7519>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in
              RFC 2119 Key Words", BCP 14, RFC 8174, May 2017,
              <https://www.rfc-editor.org/rfc/rfc8174>.

   [CAEP]     Tulshibagwale, A. et al., "Continuous Access Evaluation
              Protocol (CAEP)", OpenID Foundation, 2024,
              <https://openid.net/specs/openid-caep-1_0.html>.

   [SSF]      Tulshibagwale, A. et al., "OpenID Shared Signals
              Framework", OpenID Foundation, 2024,
              <https://openid.net/specs/openid-sharedsignals-
              framework-1_0.html>.

   [SOOS-AEP]  Sato, T., "Agent Execution Protocol",
               draft-sato-soos-aep-01, Work in Progress, June 2026.

   [SOOS-HEM]  Sato, T., "Human Escalation Mechanism",
               draft-sato-soos-hem-04, Work in Progress, June 2026.

   [SOOS-KIA]  Sato, T., "Kernel Identity and Attestation",
               draft-sato-soos-kia-02, Work in Progress, June 2026.

   [SOOS-MJWT] Sato, T., "Mandate JWT",
               draft-sato-soos-mjwt-01, June 2026.

   [SOOS-SOV]  Sato, T., "Sovereign Object",
               draft-sato-soos-sov-01, June 2026.

   [SOOS-GAR]  Sato, T., "Governance Audit Record",
               draft-sato-soos-gar-02, Work in Progress, June 2026.

   [SOOS-CAP]  Sato, T., "The Constitutional AI Protocol (CAP) for
               Agentic AI Systems",
               draft-sato-soos-cap-03, Work in Progress, June 2026.

   [SOOS-IDP]  Sato, T., "Intent Declaration Primitive",
               draft-sato-soos-idp-04, Work in Progress, June 2026.

14.  Informative References

   [OIF-REVOC] OpenID Foundation, "Agentic AI Authorization
               Challenges: Revocation Across Attenuated Delegation
               Chains", arXiv:2604.23280, April 2026.
               Note: cited as an explicit acknowledgment of the gap
               that Section 3.6 closes.

   [SPICE-ACTOR-CHAIN]
               Looker, T. et al., "SPICE Actor Chain",
               draft-mw-spice-actor-chain-05, Work in Progress, 2026.

   [OAUTH-ATTENUATING]
               Niyikiza, J. et al., "Attenuating Agent Tokens",
               draft-niyikiza-oauth-attenuating-agent-tokens-00,
               Work in Progress, 2026.

   [ICON-PS]   Nair, et al., "Observability, Intervention and Control
               of Network Management Agents -- Problem Statement",
               draft-nair-icon-problem-statement, 2026.

   [AUDIT-BOF] Kuehlewind, M. and Birkholz, H., "Agent Use of
               Delegation and Interaction Traceability (AUDIT)",
               draft-kuehlewind-audit-architecture-00, May 2026.

   [AUTHZEN]   McGuinness, K. et al., "AuthZEN 1.0",
               OpenID Foundation, January 2026.

   [OAUTH-TXN-TOKENS]
               Tulshibagwale, A., Fletcher, G., and P. Kasselman,
               "Transaction Tokens",
               draft-ietf-oauth-transaction-tokens-08, 2026.

Acknowledgements

   The SO Instance Topology Types defined in Section 4 were developed
   through structured architectural review of the SOOS Cluster 1
   Examination (Session 8).  The SO Cluster coordination primitives
   in Section 5 were developed in dedicated OQ-S-28 resolution work
   (Session 10).  The Narrowing Property builds on the delegation
   model work in draft-mw-spice-actor-chain and the AuthZEN 1.0
   PEP/PDP separation model.  The session revocation model (Section
   3.6) was developed through structured architectural review of the
   DR-MAD-REC-01 Discussion Record (June 2026).  The authors thank
   George Fletcher, Karl McGuinness, and the OAuth Working Group for
   Transaction Tokens and attenuating token work that informed the
   credential-layer analysis in Appendix B.

Appendix B.  Related Work

   This appendix situates MAD within the IETF multi-agent landscape.
   The central observation is that the agentic AI standards stack
   operates across three distinct layers: the credential/token layer
   (SPICE, OAuth, WIMSE); the communication/session layer (ACP, A2A);
   and the governance-state layer.  MAD operates exclusively at the
   governance-state layer.

B.1.  SPICE Actor Chain  [unchanged from MAD-01]

B.2.  OAuth Attenuating Agent Tokens  [unchanged from MAD-01]

B.3.  OAuth Transaction Tokens  [unchanged from MAD-01]

B.4.  Agent Communication Protocol (ACP)  [unchanged from MAD-01]

B.5.  A2A Protocol  [unchanged from MAD-01]

B.6.  AuthZEN 1.0  [unchanged from MAD-01]

B.7.  SOOS Companion Drafts

   This document is one of twelve SOOS IETF individual submissions.
   References updated to current versions:

   draft-sato-soos-idp-04   Intent Declaration Primitive.
   draft-sato-soos-hem-04   Human Escalation Mechanism.
   draft-sato-soos-gar-02   Governance Audit Record.
   draft-sato-soos-cap-03   The Constitutional AI Protocol (CAP).
   draft-sato-soos-sov-01   Sovereign Object.
   draft-sato-soos-mjwt-01  Mandate JWT.
   draft-sato-soos-aep-01   Agent Execution Protocol.
   draft-sato-soos-kia-02   Kernel Identity and Attestation.
   draft-sato-soos-pt-02    Progressive Trust.
   draft-sato-soos-faip-01  Federated Agent Intelligence Protocol.
   draft-sato-soos-cap-rrs-01  CAP Regulation Record Schema.

B.8.  ICON Initiative: Control Pillar  [unchanged from MAD-01]

B.9.  AUDIT Working Group  [unchanged from MAD-01]

B.10. DAWN Working Group  [unchanged from MAD-01]

B.11. OpenID Foundation: Revocation Across Attenuated Delegation
      Chains

   A survey of agentic AI authorization challenges published through
   the OpenID Foundation (arXiv:2604.23280, April 2026) explicitly
   identifies revocation across offline-attenuated delegation chains
   as "largely unsolved."  The paper identifies three open problems:
   (a) cascading revocation signals to agents that issued further
   sub-agent credentials offline; (b) determining completion state
   of in-flight operations at the moment of revocation; and (c) the
   absence of a standard event type for the agentic revocation case.

   This document directly addresses all three.  INV-4 and the mandate
   issuance tree (Section 3.2) make delegation chains online-
   verifiable.  The CAEP profile (Section 3.6.2) defines the
   standard event type.  Partial-completion handling (Section 3.6.3)
   specifies the governance response to (b).

   The OpenID Foundation observation is cited as the gap statement
   that motivates Section 3.6 of this document.

Appendix C.  Vibe Coding Assets

   This appendix provides structured machine-readable references to
   support AI-assisted implementation of MAD.  Informative.

C.1.  Protocol Summary

   Protocol: Multi-Agent Delegation (MAD)
   Version:  draft-sato-soos-mad-02
   Family:   SOOS protocol suite
   Role:     Coordination governance layer for multi-agent workflows --
             authority narrowing (INV-4), cascade revocation, partial-
             completion classification, cluster coordination
   Stack position: Coordinates across AEP (per-agent execution),
                   SOV (governed object lifecycle), MJWT (delegation
                   credentials), HEM (human oversight at delegation
                   hops), GAR (full workflow audit record), and CAP
                   (prohibition floor at every delegation level).

C.2.  Key Identifiers

   Core invariants: INV-4 (Narrowing Property), INV-15 (UNKNOWN ≠
     CLEAN), INV-16 (completion_state REQUIRED in GAR on revocation)

   Revocation triggers: R-1 (CAP Tier 0-A), R-2 (Scope Boundary),
     R-3 (Non-Response), R-4 (Irreversible Threshold), R-5 (Rotation),
     R-6 (Operator Override), R-7 (DEADLOCK)

   Completion states: CLEAN, PARTIAL, UNKNOWN

   Topology ALE events: ALE-013 (DELEGATION_INITIATED),
     ALE-014 (DELEGATION_COMPLETED), ALE-015 (DELEGATION_FAILED),
     ALE-016 (CLUSTER_TOPOLOGY_CHANGE)

   Cluster Cedar actions: ResolveDeadlock, ApproveBudgetTransfer,
     ApproveDelegation, RetryDelegation, ReleasePooledSession

   Conformance (new in MAD-02): CONF-MAD-GEC-03, CONF-MAD-INV4-01,
     CONF-MAD-BT-01, CONF-MAD-15 through CONF-MAD-18

C.3.  Canonical Reference

   Specification:  https://soosproject.ai/drafts/mad
   Datatracker:    https://datatracker.ietf.org/doc/draft-sato-soos-mad/
   Stack overview: https://soosproject.ai/stack

Author's Address

   Tom Sato
   MyAuberge K.K.
   Chino, Nagano, Japan
   Email: tomsato@myauberge.jp
   URI:   https://soosproject.ai/drafts/mad