Proposed specificationSource-located exemplarH1

Asynchronous state machine

Make waiting and resumption explicit.

JOIN POINTasynchronous_wait_and_resumeRECORD STATUSCandidate · v0.1.0

UML class view

The proposed contract drawn as participant roles, received calls, and numbered dependencies.

Object interactions

The same roles and calls as a class collaboration and a numbered message sequence.

Object interaction diagram for Asynchronous state machine, showing role collaboration and a numbered message sequence — FIG. P03 / OBJECT INTERACTIONS
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Pointcut

Where the mechanism applies. All four dimensions belong to the proposed match, not just its vocabulary.

Context: A harness run may pause for external work or user input.
Trigger: An event requests suspension or arrives to resume a paused run.
Structure: Enumerated states, legal transitions, event identity, and resumption state.
Effect: A resumed run follows only the legal transition and preserves durable state.

Protected contract

The obligation that clients, operators, and auditors should be able to rely on.

Requires: State can be serialized or retained and incoming events can be identified.
Ensures: Accepted events move the machine to a defined state and duplicate events are handled.
Invariant: No transition crosses from a disallowed state or executes twice after replay.
Violation: Invalid, duplicate, or interrupted events leave a recoverable state or raise explicitly.

Negative control

An enum without transition enforcement is not sufficient.

Variation & lifecycle

The hot spot is admitted only where the protected semantics survive.

Permitted variation

Transition dispatch, persistence backend, and recovery policy.

Test obligation

Test illegal transitions, duplicate events, interruption, and resume.

Evolution question

Did implicit control flow become an observable durable state machine?

Prompt + code design

An illustrative prompt and a small design sketch for the proposed contract. Names and APIs are invented; this is not a repository excerpt.

PROMPT SKETCH

Treat a paused run as an explicit state, not a sleeping function. Persist the state token before waiting, accept only known events, and reject duplicate or illegal transitions with a typed error.

CODE DESIGN / PYTHON

TRANSITIONS = {
    "ready": {"start": "running"},
    "running": {"wait": "waiting", "finish": "done"},
    "waiting": {"resume": "running", "cancel": "cancelled"},
}

def apply(state, event, store):
    target = TRANSITIONS.get(state.status, {}).get(event.kind)
    if target is None:
        raise IllegalTransition(state.status, event.kind)
    next_state = state.with_status(target, event_id=event.id)
    store.save(next_state)
    return next_state

Illustrative design sketch. The durable record, not an in-memory coroutine, is the resumable unit. This example is a teaching aid, not implementation evidence or a conformance claim.

Detection & matching

The frozen rule that retrieves this record, the canonical source exemplar, and the control that should stay unmatched.

Join point: asynchronous_wait_and_resume
Source locator: Barbaste et al., §6.2, p. 14 (Codex, “Tokio Async State Machine”); generalized label
Lexical cue: (?i)\bstate[_-]?machine\b|\b(?:transition|transitions|legal_states)\bFrozen expression, v0.1.0. A match is a retrieval cue, not a confirmed implementation.
Aliases: None
Canonical exemplar: langchain-ai/langgraphlibs/langgraph/langgraph/graph/state.py:131Support: libs/langgraph/tests/test_subgraph_persistence_async.py:63
Negative control: An enum without transition enforcement is not sufficient.

Scope-anchored review. pohe-agent analyze <repo> --pattern P03 anchors the cue to its enclosing declaration and checks a separate operational signature for all four pointcut dimensions. Missing roles and negative-control risks remain visible; a structural match is not E2/E3. Calibration report ↗

Repository files

Up to five public files retrieved by the frozen cue and pinned to the audited commit. A match is a place to inspect, not a confirmed implementation.

01langchain-ai/langgraphlibs/langgraph/langgraph/graph/state.py:131CANONICAL SOURCE 02aaif-goose/goosecrates/goose/src/acp/server.rs:14RETRIEVAL CUE 03affaan-m/ECCskills/operator-approval-loop/references/approval_claims.py:17RETRIEVAL CUE 04agno-agi/agnolibs/agno/agno/company/manager.py:238RETRIEVAL CUE 05Aider-AI/aideraider/website/_includes/leaderboard_table.js:286RETRIEVAL CUE

Evidence & provenance

Each layer answers a different question. Do not substitute retrieval for review.

Source-located exemplar

A concrete source anchor is available for this proposed record. It is one exemplar, not evidence that all repositories—or every contract field—conform.

Review boundary: this candidate and its specification come from an AI-assisted study. Independent human validation remains open.

ANY-EVIDENCE FAMILY COVERAGE34/36

94.4% of repository families in the frozen panel have at least one current cue, historical cue, or canonical source layer. This is not confirmed prevalence.

Current lexical-cue repositories: 37 / 41

Canonical source anchorlangchain-ai/langgraph 5847733bcb18libs/langgraph/langgraph/graph/state.py:131

Supporting surfacelibs/langgraph/tests/test_subgraph_persistence_async.py:63

State graph with typed transitions and async execution.

Exploratory retrieval cue Regex / v0.1.0

(?i)\bstate[_-]?machine\b|\b(?:transition|transitions|legal_states)\b

This expression is a discovery instrument only. A match is a retrieval cue—not a confirmed implementation, pointcut match, or contract proof.