EMILIA Protocol, Inc.

US team@emiliaprotocol.ai

sec AI agents authorization evidence effect boundary replay prevention reconciliation Consequential agent actions can cross identity, transport, authorization, policy, and execution systems. Each system can produce a valid artifact while the executor still lacks a safe rule for joining the artifacts to the exact effect, consuming one-time authority, and handling an uncertain outcome. This document defines the Action Evidence Boundary (AEB), an executor-side processing model for that lifecycle. AEB requires native artifact verification, Canonical Action Identifier (CAID) matching, Authorization Evidence Chain (AEC) satisfaction, a separate local authorization decision, durable atomic consumption or reservation, invocation, closed effect outcomes, and authenticated reconciliation. It defines no receipt or token format, no policy language, no universal evidence taxonomy, and no new registry. Native workload credentials, message signatures, attested per-action tokens, permit records, authorization receipts, and status mechanisms retain their own semantics and verifiers.

Introduction A remote executor can receive several independently useful inputs: a workload credential and protected request, a delegation or capability, a pre-execution permit, a human-authorization artifact, and a policy decision. None of those inputs alone answers every question the consequence-owning system has to answer before changing its system of record. The missing contract is at the effect boundary. The executor must determine what exact material action it is about to perform; verify each artifact under its native rules; correlate independently verified representations without guessing; evaluate whether the evidence bundle fills its requirement; make its own authorization decision; consume or reserve any one-time or bounded authority; invoke the effect once; and preserve uncertainty when the effect cannot be observed conclusively. This document defines that contract. Its required order is: EXECUTED +--> FAILED +--> INDETERMINATE --> authenticated reconciliation ]]> Every arrow is conditional. A signature is not authority. Native verification is not action correlation. Action correlation is not evidence satisfaction. Evidence satisfaction is not local authorization. Authorization is not execution. An invocation error is not proof that no effect occurred.

Scope and Non-Goals AEB specifies processing requirements for a boundary that controls a consequential effect. It can be implemented at a protocol gateway, service mesh component, application middleware, execution adapter, or system-of-record write path, provided the deployment states which effect paths the boundary actually mediates. AEB does not define:

• a new authorization receipt, access token, attestation token, permit, credential, or execution-evidence format;
• a native signature, credential, revocation, status, or transparency verification algorithm;
• a policy language, universal authorization decision, or universal human-approval inference;
• general semantic equivalence between actions;
• provider truth, physical truth, legality, safety, wisdom, or complete mediation merely because an AEB implementation is present; or
• a registry for evidence types, states, action mappings, or verifier names.

Conventions and Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 when, and only when, they appear in all capitals, as shown here.

Effect boundary:

The last control point that can withhold the protected mutation before it is submitted to the effecting system.

Relying party:

The party that selects trust inputs, action definitions, mapping profiles, evidence requirements, freshness rules, and local authorization policy, and that relies on the resulting decision.

Native artifact:

An evidence, credential, permit, token, receipt, status, or message-protection object defined outside AEB and verified under its own specification.

Observed action:

The immutable material action constructed by the effect boundary from executor-controlled parsing and system-of-record facts.

Material field:

A field whose change can alter the protected consequence, as declared by the selected CAID action-type definition.

Invocation:

The first dispatch of the frozen authorized action to a component that can cause the protected effect.

Authoritative reconciliation:

An authenticated, audience-bound observation from the effecting provider or system of record that is matched to the original action and operation identifier.

Non-Collapsing Decision and Lifecycle Vocabulary AEB uses the following decisions with the meanings established by the EMILIA architecture and its component drafts:

VERIFIED:

One native artifact passed its native verifier under relying-party-selected trust inputs.

MATCH:

Independently verified artifacts denote the same material action directly or under exact relying-party-pinned CAID mapping profiles.

SATISFIED:

Verified and matched evidence fills every slot in the relying party's AEC requirement.

AUTHORIZED:

The consequence-owning relying party's local policy permits this exact action at this time.

EXECUTED:

The executor records, or an accepted native artifact attests, that the exact effect occurred. This meaning remains bounded by the native source and its trust assumptions.

AEB also names operational lifecycle states:

CONSUMED:

A one-time authorization, challenge, operation key, or equivalent native replay unit has been durably made unavailable for another invocation.

RESERVED:

Bounded state, such as a capability budget, has been durably fenced for the exact operation before invocation.

DISPATCH_PENDING:

A durable intent record binds the frozen action, operation identifier, provider environment, and reservation before any effecting dispatch can occur. Recovery treats a stranded intent as uncertain, not as unused authority.

INVOKED:

The protected effect was dispatched using the frozen authorized action and operation identifier.

FAILED:

Authoritative executor or reconciliation evidence establishes that the invoked operation did not cause the protected effect. A local exception or timeout alone is not sufficient.

INDETERMINATE:

Invocation began, but available authoritative evidence does not establish whether the protected effect occurred.

CONSUMED, RESERVED, DISPATCH_PENDING, INVOKED, FAILED, and INDETERMINATE are lifecycle terms, not new evidence types or IANA registry values. A deployment MAY use different local labels if their semantics are at least as strict.

Relying-Party Inputs and Pins The requester, presenter, agent, and mutable intermediary context are untrusted inputs. They MAY propose an action and present native artifacts. They MUST NOT select or weaken the controls used to accept that request. Before evaluating an action, the relying party MUST configure or pin, as applicable:

• the supported native artifact revisions, verifier adapters, algorithms, trust anchors, issuers, audiences, and status sources;
• the CAID suite, action-type definition source, exact source descriptors, and mapping-profile digests;
• the AEC requirement and the admissible native evidence roles for each slot;
• local policy identifiers, policy epochs, tenant and organization boundaries, and any separation-of-duty rule;
• the trusted clock, maximum ages, validity windows, allowed skew, and revocation or status freshness requirements;
• the durable replay, consumption, reservation, and operation-key namespaces; and
• the protected executor, provider environment, reconciliation endpoint, and authenticated provider or system-of-record identities.

A label, key, profile identifier, requirement, status assertion, or policy identifier carried only in presenter-controlled data MUST NOT become its own trust anchor. Missing, conflicting, unsupported, or ambiguous required configuration MUST fail closed.

Required Processing Model

Construct the Observed Material Action The effect boundary MUST construct an immutable observed action from effect-relevant facts it controls. Depending on the application, those facts can include the protocol operation, tool or method, target resource, tenant, account, amount, currency, destination, environment, input digest, and unique operation identifier. The boundary MUST resolve a relying-party-pinned CAID action-type definition and include every field that definition declares material. It MUST NOT copy a requester-supplied action digest, CAID, amount, destination, or resource reference without deriving or checking the corresponding fact at the protected boundary. If the boundary cannot determine all material fields, it MUST refuse before invocation. The observed action MUST be frozen for the remainder of the lifecycle. A later adapter MUST NOT reconstruct a different action from mutable request state after authorization.

Verify Each Native Artifact Each required native artifact MUST be verified independently under its own specification and relying-party-selected trust inputs before CAID mapping or AEC evaluation. The AEB implementation MUST use the integrity-protected payload returned by the native verifier, or a projection for which the adapter establishes integrity coverage of every projected field. A successful signature check is only one possible step of native verification. Schema, algorithm, issuer, audience, key status, validity, proof-of-possession, freshness, replay, and native policy checks remain those of the selected native profile. A verifier exception, unavailable required status source, unsupported critical field, or ambiguous result MUST become a bounded refusal, never an allow path. The output of this stage is VERIFIED for each accepted artifact. An artifact that has not reached VERIFIED MUST NOT participate in action mapping or fill an AEC requirement slot.

Establish CAID Material-Action MATCH The boundary MUST recompute the CAID of the observed action under the selected suite and definition source. It MUST compare every action-bound required artifact to that observed action using direct CAID equality or the Action-Mapping Profile defined by . Cross-format mapping MUST occur only after native verification and MUST use the exact source media type, schema version, target action type, definition source, and mapping-profile digest pinned by the relying party. Every target material field MUST be covered. Missing, lossy, unknown, unpinned, conflicting, or ambiguous mappings yield INDETERMINATE under CAID and MUST fail a required MATCH. AEB MUST NOT guess equivalence from names, natural-language descriptions, trace identifiers, or presenter assertions. MATCH is content correlation only. It does not validate a native artifact and does not authorize execution.

Evaluate AEC Evidence Satisfaction The boundary MUST submit only natively verified, action-matched evidence to an AEC verifier configured with the relying party's requirement. The requirement used for the decision MUST come from relying-party configuration, not from a presenter-controlled AEC member. Every required evidence role MUST be filled by an artifact whose native verifier and adapter are accepted for that role. A workload identity MUST NOT silently fill a policy-permit or human-authorization slot. A machine-policy decision MUST NOT silently fill a named-human slot. A generic operator signature MUST NOT be interpreted as evidence that a human operated a system or performed a named approval ceremony. Only a successful AEC evaluation under these inputs reaches SATISFIED. UNSATISFIED, malformed, unsupported, or ambiguous results MUST withhold invocation.

Make the Local Authorization Decision The consequence-owning executor MUST make a separate local authorization decision after SATISFIED. It MUST evaluate the exact observed action, audience, tenant, organization, policy epoch, freshness, current credential and authority status, separation of duties, local risk controls, and any bounded capability state. Credential revocation and per-action authorization evidence answer different questions. A current non-revocation or status result can establish that a credential remains acceptable under local policy; it does not prove that the credential holder authorized this action. A per-action authorization artifact does not prove that every credential in its trust path remains current. When policy requires both, the boundary MUST verify both without substituting one for the other. The boundary reaches AUTHORIZED only if local policy permits the exact action at the decision time. SATISFIED alone MUST NOT trigger reservation or invocation.

Atomically Consume or Reserve Before Invocation After AUTHORIZED and before invocation, the boundary MUST perform the durable state transition required by the native evidence and local policy. This can include consuming a one-time authorization, challenge nonce, or operation key; reserving a bounded capability or budget; and fencing the operation to one owner across replicas. The transition MUST be atomic within the relying party's durable state domain. Its key MUST be derived from verified evidence or the executor-owned observed action and operation identifier, never from a presenter-selected decoy. If the store is unavailable, non-atomic, stale, or reports an ambiguous result, the boundary MUST refuse before invocation. AEB does not claim atomicity between a local store and an unrelated remote provider. It requires the local consume or reserve transition to occur first so that any uncertainty after dispatch cannot make the same authority available for an uncontrolled second effect.

Invoke the Frozen Action Before any call, message, or byte can reach an effecting component, the boundary MUST durably enter DISPATCH_PENDING for the frozen observed action that reached AUTHORIZED and CONSUMED or RESERVED. The record MUST bind the action digest, operation identifier, provider environment, audience, reservation or consumption record, and adapter. Failure or ambiguity while writing this record MUST withhold dispatch. The boundary MUST invoke only from that durable state. It MUST use a stable, action-bound, unique operation identifier or idempotency key where the provider supports one. After dispatch begins, it MUST durably record INVOKED or a terminal outcome before reporting success to the requester. The adapter MUST receive only the authority and evidence necessary for the downstream interface. It MUST NOT accept mutable intermediary or caller context that changes a material field after the boundary's authorization decision.

Classify the Effect Outcome After invocation begins, the boundary MUST classify the result as EXECUTED, FAILED, or INDETERMINATE. On restart, a DISPATCH_PENDING operation without an authoritative terminal record MUST be promoted to INDETERMINATE before any retry or release, because the process cannot establish that dispatch did not begin.

• EXECUTED requires an authoritative response or accepted native execution evidence matched to the exact action, operation identifier, provider environment, and audience.
• FAILED requires authoritative evidence that the invoked operation did not cause the protected effect. A local parse error, exception, timeout, connection loss, process crash, or missing response is not by itself such evidence.
• INDETERMINATE is REQUIRED whenever invocation may have reached the effecting system but the available authoritative evidence does not establish EXECUTED or FAILED.

For EXECUTED, the boundary MUST commit any reserved spend and preserve the terminal evidence. For FAILED, it MUST preserve the failure evidence and follow the native reservation policy. For INDETERMINATE, it MUST preserve or consume the reservation, refuse reuse of the authorization and operation identifier, and prohibit a blind replay.

Perform Authenticated Reconciliation An INDETERMINATE operation, including one recovered from a stranded DISPATCH_PENDING record, MUST remain closed until reconciliation authenticates the provider or system of record and matches the result to the original action, operation identifier, provider environment, audience, target resource, and every application-specific material field. Reconciliation MAY move INDETERMINATE to EXECUTED when authoritative evidence establishes that the exact effect occurred. It MAY move INDETERMINATE to FAILED when authoritative evidence establishes that it did not occur. Missing, stale, conflicting, unauthenticated, or action-mismatched observations MUST leave the operation INDETERMINATE. Reconciliation MUST NOT resurrect the original authorization or silently release its one-time replay unit. If policy permits a later attempt after an authoritative FAILED result, that attempt MUST use a new action instance and complete the lifecycle required by local policy. An implementation MUST NOT invoke again merely because a timeout elapsed or because the caller retried.

Declaration and Challenge Semantics A deployment MAY publish a static declaration describing protected actions, material fields, evidence requirements, challenge methods, and effect-boundary placement. Such a declaration is discovery metadata. It MUST NOT override the relying party's live, local enforcement configuration. An unsupported declaration version MUST be ignored as discovery input; it cannot weaken or replace live enforcement. An action that the live boundary configuration cannot classify or process under a supported version MUST fail closed. When required evidence is absent or unacceptable, a boundary MAY use its application protocol to return a dynamic challenge. A challenge MUST identify the boundary-computed action, the missing evidence roles, the policy context, an intended audience, a short expiry, and a single-use unpredictable nonce or equivalent replay unit. The nonce MUST NOT be consumed merely because untrusted bytes parse. It MUST be consumed atomically only after the selected native verifier establishes the integrity and challenge binding of an in-window presentation, and before that presentation can reach SATISFIED or authorize an effect. A presentation that is malformed, unauthenticated, expired, or not bound to the challenge MUST be refused without burning the nonce. A natively verified, challenge-bound presentation consumes the nonce whether or not the remaining evidence satisfies the requirement. Follow-up challenges MUST remain bound to the original boundary-computed action and MUST NOT derive that action from presenter input. A declaration or challenge authorizes nothing, reserves nothing, and promises no execution. A satisfied challenge still proceeds through native verification, MATCH, SATISFIED, local AUTHORIZED, and atomic consumption or reservation. This document intentionally defines no new manifest object, challenge object, well-known URI, HTTP status code, or media type.

Native Evidence and Transport Boundaries

WIMSE and HTTP Message Signatures WIMSE workload credentials and the WIMSE HTTP Message Signatures profile can provide end-to-end workload authentication and message integrity for the request components covered by the validated signature, including a body protected by a validated content digest. HTTP Message Signatures provide the underlying component-signing mechanism. AEB consumes those results; it does not redefine them. A validated WIMSE request can establish which workload possessed the protected key and that covered message components were not modified undetectably. It does not by itself establish CAID MATCH, AEC SATISFIED, named-human authorization, local AUTHORIZED, one-time consumption, or execution. The AI Agent Authentication and Authorization framework and the WIMSE authorization-evidence profile describe adjacent runtime authorization and signed-evidence compositions. AEB treats their selected credentials, tokens, and evidence records as native inputs. It does not replace their issuance, verification, or authorization semantics. Headers, routing metadata, forwarded identity, trace context, or other values that an intermediary can add, remove, or mutate outside the validated end-to-end integrity coverage MUST NOT be load-bearing authorization evidence. They MAY be used for routing or diagnostics. If such a value affects the protected consequence, the boundary MUST derive it independently or require it to be covered by accepted native integrity and the observed action's material binding.

Attested Per-Action Tokens and Permit Records Attested per-action tokens, including artifacts described by a deployment as OASNT-like, remain native evidence formats. AEB does not assign that descriptive label a token type, claim set, registry entry, or trust meaning. The selected native verifier determines what the token proves and exposes its integrity-protected action commitment, issuer, audience, validity, freshness, status, and bounded result to the AEB adapter. SCITT Permit records defined by likewise remain native pre-execution decision evidence. AEB does not reserialize a Permit or convert it into an AEB receipt. It verifies the selected Permit revision through its native adapter, maps its protected material action only through a pinned CAID profile, and assigns it only to evidence roles permitted by the relying party's AEC requirement. A native format's valid signature proves only the statement and signer semantics that format defines. It does not, without an additional accepted profile and evidence, prove that a natural person operated the workload, understood the action, held authority, or performed a particular approval ceremony.

Conformance and Deployment Claims An implementation conforms to AEB only if every protected invocation follows the ordered processing model in and fails closed on every missing or ambiguous required transition. A deployment MUST document:

• the protected action types and the effect paths actually mediated;
• the trusted configuration and durable-state boundaries;
• the native verifier revisions and relying-party pins;
• the method used to derive material action fields at the boundary;
• the consumption, reservation, and cross-replica fencing mechanism;
• the authoritative sources and matching rules used for reconciliation; and
• all direct, break-glass, administrator, alternate-protocol, and system-of-record paths that bypass the AEB implementation.

An implementation placed beside a write path is not complete mediation. A deployment MUST NOT claim complete mediation unless the protected system rejects all material alternate paths or subjects them to an equivalent boundary. Observe-only operation MAY be useful during deployment, but it MUST NOT be described as enforcement.

Security Considerations Cross-binding. An attacker can splice a valid permit, approval, credential, or receipt for action A into a request for action B. Native verification before mapping, executor-owned action construction, exact CAID matching, and a relying-party-pinned AEC requirement are all required defenses. Omitting any one of them reopens the attack. Mutable context. Intermediary-added headers and agent annotations are convenient but are not trustworthy merely because they arrived on an authenticated hop. Every load-bearing field needs accepted end-to-end integrity coverage or independent derivation at the effect boundary. Time of check and time of use. The action passed to the executor must be the frozen action that was verified, matched, satisfied, authorized, and consumed or reserved. Mutable aliases, provider defaults, exchange rates, destinations, branch heads, and policy epochs can change a consequence after approval; profiles must bind or revalidate them as material fields. Replay and distributed state. Process-local caches are insufficient where replicas can invoke the same effect. Replay, consumption, reservation, and operation ownership state must be durable, atomic, and shared across every boundary instance that can reach the protected executor. Freshness and revocation. Expiration, nonce checks, credential status, authority status, and policy epoch are separate checks. A fresh message does not make a revoked credential valid, and a current credential does not make old per-action evidence fresh. Indeterminate effects. Retrying after a timeout can duplicate a payment, mutation, disclosure, or physical action. An invocation that might have reached the provider consumes the operation's retry right until authenticated reconciliation resolves the exact outcome. Caller assurances and unauthenticated webhooks do not resolve it. Signature overclaiming. A cryptographic signature can establish control of a key and integrity of covered content under a selected verification profile. It does not inherently identify a human, prove human operation, prove comprehension, establish legal authority, or prove execution. Boundary bypass. A correct AEB implementation does not protect direct database credentials, alternate APIs, shell access, administrator consoles, side channels, or actuator paths that bypass it. Deployment topology and credential placement are security properties, not implementation details.

Privacy Considerations Action objects and evidence can expose identities, destinations, resources, policy choices, commercial relationships, and sensitive operational timing. Deployments SHOULD minimize the evidence passed to the executor and retained in portable records, use opaque high-entropy references where appropriate, and avoid treating a plain digest of low-entropy personal data as anonymization. Reconciliation queries can disclose that an operation is disputed or uncertain. They SHOULD be authenticated, authorized, rate-limited, and limited to the exact operation. AEB does not require public disclosure of native evidence or local policy.

Relationship to EMILIA and Adjacent Work CAID owns typed material-action identity and exact, relying-party-pinned cross-format mapping. AEB invokes CAID after native verification and does not extend CAID with trust semantics. AEC owns heterogeneous evidence composition and the SATISFIED or UNSATISFIED result under a relying-party requirement. AEB invokes AEC and then makes the separate local authorization and effect-lifecycle decisions. Authorization Receipts define one native action-bound organizational approval artifact and its receipt-specific consumption semantics. AEB does not make that format mandatory and does not generalize every native artifact into an EMILIA receipt. This document is intended to absorb the lifecycle responsibilities of draft-schrock-agent-action-manifest-00, draft-schrock-authorization-evidence-challenge-00, and draft-schrock-ep-enforcement-point-00. Static declaration, dynamic challenge, fail-closed enforcement, one-time consumption, invocation, and outcome handling are specified here as one boundary lifecycle. Their earlier wire shapes remain historical inputs; AEB conformance does not require a new common envelope for them.

IANA Considerations This document has no IANA actions. In particular, it creates no registry for native evidence types, lifecycle labels, verifier adapters, action mappings, or policy identifiers.

References Normative References EMILIA Protocol, Inc. EMILIA Protocol, Inc. Informative References EMILIA Protocol, Inc.

Acknowledgments External review sharpened the boundaries between workload and message integrity, per-action authorization evidence, credential status, human operation, and executor-owned effect control. Those distinctions are load-bearing in this document. Acknowledgment does not imply endorsement.