| Internet-Draft | Composite Execution Finality | September 2026 |
| Das | Expires 20 March 2027 | [Page] |
An agent, a payment orchestrator, or a control-plane applicator often intends one Candidate Act that would become real only as several consequences: a settlement post, a ledger write, a tool invoke, a notification, a radio enable. [DAS-HANDLE] specifies verify, consume, and receipt at one Finality Sink. It does not say what "the act was permitted" means when sink S1 has consumed and posted and sink S2 has rejected, timed out, or committed a different digest.¶
Existing distributed-transaction tools already address adjacent problems. Two-phase commit, XA, sagas, TCC, transactional outbox, and workflow engines coordinate steps. OAuth, WIMSE, RATS, and SCITT still name identity, environment, and signed statements. None of them, by themselves, bind N sink-local Execution Handles to one composite Act Digest and require that no child consequence become externally effective unless every required child reaches a defined terminal state.¶
This document specifies Composite Candidate Acts, child handles, a coordinator that may only prepare, a two-phase consume rule, and the distinction between prevention (no child commits unless the composite closes) and mitigation (compensate after a partial post). Compensation is itself a Candidate Act. It is not a silent undo and not a license to skip verify on the original child.¶
This is not a new consensus protocol and not a claim that XA is obsolete. Profiles that cannot obtain prepare-from-every-sink MUST NOT claim all-or-none prevention.¶
Three rejections are expected and are treated as design constraints. "Saga plus handle is enough" is accepted when each saga step already reconstructs the live child, consumes a child handle, and cannot log SUCCESS after a required child rejects; this draft then shrinks to join fields. Prepare across N sinks is a latency tax only if consume-state is global; it is per child handle, and a no_prepare mail or MCP child must use the mitigation profile rather than pretend 2PC. Child sinks reconstruct only their own pending effect, not a mesh-wide CAD. Reviewers who would reject on saga, performance, or reconstruction grounds are asked to read those sections before discarding the document. Criticism, including "this should stay a note in the handle draft," remains invited.¶
This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.¶
Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.¶
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This Internet-Draft will expire on 20 March 2027.¶
Copyright (c) 2026 IETF Trust and the persons identified as the document authors. All rights reserved.¶
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A composite intent C is authorized as a unit: pay vendor X AND write the invoice AND notify finance. If the settlement sink consumes its handle and posts, and the notification sink times out, operators still say "the agent paid." The Candidate Act that was reviewed was not the world that occurred. No child token was forged. The failure is split effectuation of one intended act.¶
Intended C = { pay X, book invoice, notify finance }
+-- S1 SETTLEMENT consume + post EFFECTUATED
C ---+-- S2 CONTROL timeout NON_EFFECTIVE
+-- S3 TOOL never invoked NON_EFFECTIVE
Reviewed act: C
Occurred world: pay X only
Partial commit
!=
composite finality
Two-phase commit and XA serialize prepare/commit across resource managers. Sagas and TCC specify forward actions plus compensations. Outbox and workflow engines order side effects. Those tools should be used. They do not define an Execution Handle per child sink, do not reconstruct each live child act, and do not make "compensation" a second handled Candidate Act.¶
[DAS-HANDLE] closes possession-versus-authority at one
boundary. After that draft, each child can be locally correct and
the composite still wrong. Registries reserve COMPOSITE
as a class and a sink type [DAS-REG]. They do not
specify the protocol.¶
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals.¶
If C is the act that was authorized, and only a proper subset of C's required children have become externally effective, was C effectuated?¶
Prevention profile:
C is EFFECTUATED
iff every required child is EFFECTUATED
under handles bound to C
and no extra child effect is attributed to C.
Otherwise C remains NON_EFFECTIVE
even if some child already moved money or iron.
¶
That last sentence is the operational cost. If a profile cannot prevent the child post, it must not advertise all-or-none prevention.¶
An enterprise agent is allowed to settle a vendor invoice only as a unit with the ERP booking and an audit mail. Settlement posts in 80 ms. ERP is in a change window. Mail is a third-party API with no prepare. A coordinator that "retries notify later" has not effectuated C. It has effectuated a different act: pay-without-book.¶
Authorized C17 = pay + book + notify [all required]
After S1 post, S2 reject:
world = paid, not booked
C17 = still NON_EFFECTIVE
C18 = "notify later about a payment already posted"
is a new CAD
and needs its own handle
The attacker need not forge handles. Relevant failures:¶
Goal: define when a multi-sink Candidate Act may be called EFFECTUATED, PREPARED, ABORTED, or COMPENSATING, using the objects in [DAS-HANDLE].¶
Non-goals: a new Paxos/Raft; replacing XA or workflow engines; requiring every SaaS to implement prepare; claiming exactly-once delivery across the open Internet; automatic legal netting of a posted payment.¶
Composite Candidate Act (C): A Candidate Act whose intended consequence is the conjunction of two or more child consequences.¶
Child Act C_i: The component that one sink would effectuate.¶
Required child: A child that MUST reach EFFECTUATED for C to reach EFFECTUATED.¶
Optional child: A child that MUST NOT block C if it fails, and MUST NOT be advertised as part of C's authorized unit if it is skipped. Optional children SHOULD be separate acts.¶
Coordinator: The component that records composite state. It is not a Finality Sink for a child effect unless it is also that child's sink.¶
Prepare: Child sink has verified the live child act, reserved consume-state, and promises not to post until commit or abort.¶
Compensation act: A new Candidate Act that would reverse or contain a child effect that already escaped. It uses a new handle.¶
A composite CAD is a CAD whose consequence_class and
coordinator sink_type are COMPOSITE
[DAS-REG]. It MUST list children explicitly.¶
composite_cad = {
candidate_act_id,
composite_act_digest, // over canonical child list
consequence_class: "COMPOSITE",
children: [
{ child_id, cad_i, sink_i, required: true|false },
...
],
join_rule: "ALL_REQUIRED",
expires_at,
generations
}
ALL_REQUIRED:
every child with required=true must EFFECTUATE
for C to EFFECTUATE.
QUORUM / BEST_EFFORT:
MUST NOT be used in a prevention profile
for FINANCIAL, PHYSICAL, RF, CLINICAL, MODEL_RELEASE.
¶
Each required child has its own Execution Handle EH_i issued by the PED. EH_i MUST bind:¶
act_digest of child CAD_i¶
sink_id of S_i¶
composite_id = C.candidate_act_id¶
reuse_policy compatible with the child class¶
A child handle MUST NOT be accepted at a sink whose consume would not serve that composite_id. Presenting EH_i for a standalone payment that is not C is EF-023 or EF-040 [DAS-REG].¶
The coordinator MAY hold a composite handle EH_C whose digest is the composite Act Digest. EH_C authorizes the coordinator to drive prepare/commit/abort. It does not authorize S_i to post.¶
issue
|
v
NON_EFFECTIVE
|
children verify
v
PREPARED -------- abort / timeout ------> ABORTED
|
all required commit
v
EFFECTUATED
If any required child already posted
and others cannot:
EFFECTUATED is forbidden
|
v
COMPENSATING -- compensation C' --> CONTAINED
|
+--> UNKNOWN (compensation also split)
Prevention profile forbids entering COMPENSATING
because a required child posted before join.
Child sinks use the handle draft states locally: verify, consume (here: reserve / commit / abort), receipt. C's state is a join of those receipts, not a vote by the model that proposed C.¶
Each S_i MUST reconstruct live child CAD_i from the pending local effect, not from a coordinator-supplied blob alone [DAS-HANDLE]. Coordinator-supplied CAD_i is a hint. Digest mismatch is EF-023.¶
Prepare is consume-state reservation without external effect.¶
S_i.prepare(EH_i, live_cad_i):
verify handle and reconstruct digest
if fail: receipt REJECTED, do not reserve
if consume-store down: EF-081, fail closed
reserve EH_i (not yet posted)
return PREPARED
Coordinator:
if any required child not PREPARED
before deadline:
abort all prepared children
C = ABORTED
¶
A sink that cannot reserve without posting (typical third-party
mail or card API) MUST be declared no_prepare=true. A
composite that includes a required no_prepare sink MUST NOT use
the prevention profile. It MAY use mitigation: post last, or
accept COMPENSATING.¶
Coordinator.commit(C):
require all required children PREPARED
require EH_C still current
for each S_i:
S_i.commit(EH_i) // post + CONSUMED
if all required EFFECTUATED:
C = EFFECTUATED
emit composite receipt
else:
// prevention profile: this branch
// should be unreachable if prepare held
C = COMPENSATING
Coordinator.abort(C):
for each PREPARED S_i:
S_i.abort(EH_i) // release reserve, no post
C = ABORTED
¶
| Rule | C EFFECTUATED when | Prevention claim |
|---|---|---|
| ALL_REQUIRED | every required child EFFECTUATED | Yes, if every required sink supports prepare |
| ALL_THEN_OPTIONAL | required set EFFECTUATED; optional attempted | Only over the required set |
| QUORUM(k) | any k children | No for high-consequence classes |
| BEST_EFFORT | coordinator tried | Never |
If a required child has already posted, C cannot become EFFECTUATED and cannot become cleanly ABORTED. A compensation Candidate Act C' MAY be issued: reverse the post, hold the funds, disable the radio, retract the tool side effect.¶
EH_pay CONSUMED + posted
EH_book REJECTED
Forbidden:
S_pay.undo(EH_pay) // handle already consumed
Required:
C' = "return funds for composite C17"
new CAD', new EH'
S_pay.verify/consume(EH')
C = COMPENSATING then CONTAINED
only if C' EFFECTUATED
Success of C' is not success of C. Receipts MUST keep the two identifiers distinct. Failure of C' leaves C in UNKNOWN containment and MUST be visible.¶
prepare_deadline exceeded
-> abort all PREPARED children
-> C = ABORTED
commit sent, coordinator dies
-> children stay PREPARED until
commit, abort, or child-local reserve TTL
-> reserve TTL MUST fail closed
(no automatic post)
child PREPARED, never hears commit/abort
-> on TTL: abort locally
-> report EF-080 / EF-081 if store cannot decide
¶
Automatic commit on coordinator silence is forbidden in the prevention profile. That pattern is how partial posts happen.¶
Required(C) = { i | child_i.required }
Prepared(C) = { i in Required(C) | S_i.state == PREPARED }
Posted(C) = { i in Required(C) | S_i.state == EFFECTUATED }
Rejected(C) = { i in Required(C) | S_i.state == REJECTED }
C.EFFECTUATED iff Posted(C) == Required(C)
AND no child digest diverged
AND join_rule == ALL_REQUIRED
or ALL_THEN_OPTIONAL
C.ABORTED iff Posted(C) empty
AND (Rejected(C) nonempty
OR prepare_deadline missed)
C.COMPENSATING iff Posted(C) nonempty
AND Posted(C) != Required(C)
PreventionWellFormed(C) iff
join_rule == ALL_REQUIRED
AND every required S_i supports prepare
AND no required S_i has no_prepare
AND reserve TTL fail-closed
PreventionWellFormed(C) == false
==> MUST NOT claim all-or-none prevention
¶
function effectuate_composite(C, handles):
if not PreventionWellFormed(C):
return mitigation_mode(C, handles) # different claim
prepared = []
for child in required(C):
live = child.sink.reconstruct()
r = child.sink.prepare(handles[child], live)
if r.decision != "PREPARED":
abort_all(prepared)
return receipt(C, "ABORTED", r.reason_code)
prepared.append(child)
for child in prepared:
r = child.sink.commit(handles[child])
if r.decision != "EFFECTUATED":
return receipt(C, "COMPENSATING", "EF-044")
return receipt(C, "EFFECTUATED", consume_outcome="CONSUMED")
function compensate(C, child_posted):
C2 = new_cad(reverse_of(child_posted), parent=C.id)
eh2 = PED.issue(C2)
return child_posted.sink.verify_consume(eh2)
¶
| Existing tool | Supplies | Still required |
|---|---|---|
| XA / 2PC | Prepare/commit wire to RMs | Child Act Digest + handle bind |
| Saga / TCC | Forward + compensate graph | Compensation as new handle; no silent undo |
| Outbox / workflow | Ordered jobs, retries | Retries are new attempts, not C success |
| SCITT | Logged composite receipt | Log is not child commit |
| Single-sink handle | Local authority | This join |
ef-composite-strict: ALL_REQUIRED, every required sink supports prepare, reserve TTL fail-closed, compensation is a new act, coordinator receipt insufficient.¶
ef-composite-mitigation: at least one required sink is no_prepare; document the escaped-effect window; MUST NOT claim prevention.¶
The invitation in the abstract to treat "saga plus handle is enough" as a successful review outcome is deliberate. The same is true of the performance and reconstruction objections. This section states where those objections are accepted.¶
If each saga step is already a handle-using sink — reconstruct live child, prepare or consume, fail closed — then this draft is a join profile on top of that saga, not a replacement for it. XA resource managers that expose prepare, and PSP authorize/capture pairs, are the same pattern under other names.¶
The residual cases this draft still names:¶
Accepted:
saga / XA / workflow
AS coordinator
child Execution Handle
AS per-sink authority
Not accepted as prevention:
saga success
without child PREPARED/EFFECTUATED receipts
compensate(original_token)
after the original handle is CONSUMED
BEST_EFFORT notify
advertised as C EFFECTUATED
¶
If reviewers produce a saga profile that already forbids those four cases, this document should shrink to that profile plus the composite CAD fields. That outcome is welcome.¶
ALL_REQUIRED prepare adds one reservation round to every required child before any child posts. On a payment rail that is already authorize-then-capture, that round already exists. On a three-sink agent path where mail cannot prepare, the honest profile is mitigation: do not claim all-or-none, or split notify into a later act.¶
Consume-state remains per child handle, not one lock for the whole composite. The coordinator persists join state; it does not serialize unrelated composites. Automatic commit on coordinator silence is still forbidden in the strict profile, because that is how partial posts happen.¶
Children do not reconstruct the composite CAD. Each sink reconstructs only its child: the payment it would post, the tool it would invoke, the row it would write. The coordinator compares child receipts and the composite digest over the declared child list. A mesh hop that is not a child sink does not reconstruct anything.¶
If a child sink cannot observe the fields that change its own effect, that child cannot be in a prevention-profile composite. It can be an optional later act. Hiding that limitation inside a caller-supplied composite blob is how split reality occurs.¶
A minimal demonstration is more useful than another join diagram: one MCP (or payment) middleware that consumes a child handle, one second sink that can prepare, and a coordinator that aborts when the second child rejects — including the case where a prompt-injected destination changes only one child's digest. This document does not ship that code. An implementation that does is invited.¶
Agent products already chain tools: pay, ticket, mail, CRM write. Cloud workflow services already run sagas. PSPs already split authorize and capture. Those roadmaps are complementary. This document does not assert that any named orchestrator is unsafe, incomplete, or required to implement prepare.¶
PSP authorize/capture ~ prepare/commit at SETTLEMENT Cloud workflow / saga ~ coordinator + compensation graph MCP tool chain ~ children; often no_prepare Agent runtime ~ proposer of C, not the join¶
A PSP capture API that already holds an authorization and voids it on timeout is already a prepare-capable SETTLEMENT sink under another name. An MCP server that cannot reserve a Gmail send is a no_prepare TOOL_DISPATCH sink. Putting both in one "strict" composite would be a mis-profile, not a vendor defect.¶
Named companies are not claimed as reviewers, implementers, or endorsers. Corrections and requests to remove a framing are invited. Silence is not agreement.¶
This document does not claim that any named group should adopt the work.¶
Relevant only if child handles are token profiles. OAuth should not own actuation join.¶
Relevant if child actors are workloads on different hops. Workload identity is not composite join.¶
Relevant to coordinator HTTP resources and problem+json mapping of EF-044 / COMPENSATING.¶
Useful for whether all-or-none across administrative domains is in scope for the IETF at all.¶
Individual -00. No IANA request in this revision beyond codes already reserved in [DAS-REG].¶
Coordinator compromise is not child-sink compromise, but a malicious coordinator can withhold abort and leave reserves hanging. Child sinks MUST expire reserves fail-closed. Treating a coordinator signature as a settlement receipt recreates bearer authority at the wrong layer. Quorum join on financial or physical children is a safety bug, not an availability feature.¶
A composite CAD lists every child destination. That list can reveal a payment, a patient-adjacent system, and a mail target together. Coordinators SHOULD store child digests and sink ids, and SHOULD omit raw arguments from composite receipts sent off-path.¶
This version does not request IANA action. It uses
COMPOSITE, EF-044, and profile names already
proposed in [DAS-REG]. A later revision MAY add
ef-composite-strict and ef-composite-mitigation
to the profile registry.¶
The most useful criticism is that XA plus per-resource handles already yields this join, or that mitigation sagas are the only honest Internet profile. Either result should shrink the draft. Named-product corrections are welcome. Silence is not endorsement.¶
Local handle correctness at each sink does not make a multi-sink intent final. C is effectuated only when every required child is effectuated under handles bound to C. If a required child cannot prepare, the honest claim is mitigation plus a later compensation act — not all-or-none prevention.¶
CHILD POST
!=
COMPOSITE FINALITY
SAGA COMPENSATION
!=
THE ORIGINAL ACT SUCCEEDED
PREPARE ALL REQUIRED
or
DO NOT CLAIM PREVENTION
¶