Proposed specificationSource-located exemplarH1 H3

Publish-subscribe

Decouple producers from consumers.

JOIN POINTtopic_based_event_deliveryRECORD 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.

Pointcut

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

Context: Producers and consumers are decoupled through topics.
Trigger: A message is published to a topic.
Structure: Topic schema, broker or bus, subscribers, and delivery policy.
Effect: Matching subscribers receive the message under declared ordering and durability rules.

Protected contract

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

Requires: Topic identity and event compatibility are defined.
Ensures: Delivery or drop is observable and subscriber selection is attributable.
Invariant: A subscriber cannot read a topic outside its authorization.
Violation: Duplicate, late, or lost delivery follows an explicit semantic contract.

Negative control

Directly invoking known listeners is C02 rather than C03.

Variation & lifecycle

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

Permitted variation

In-process bus, OS socket pubsub, cloud queue, and durable stream.

Test obligation

Test multi-subscriber delivery, no subscriber, disconnect, duplicate, and auth.

Evolution question

Did pubsub gain durability, replay, and authorization?

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

Deliver events by declared topic. Record whether a subscriber received or dropped an event, and make subscriber selection attributable to the topic and compatibility rules.

CODE DESIGN / PYTHON

def publish(event, bus):
    subscribers = bus.subscribers(event.topic)
    delivered = []
    for subscriber in subscribers:
        if not subscriber.accepts(event.schema):
            delivered.append(Dropped(subscriber.id, "schema mismatch"))
            continue
        subscriber.deliver(event)
        delivered.append(Delivered(subscriber.id))
    bus.record(event.id, event.topic, delivered)

Illustrative design sketch. Publish-subscribe needs a delivery record; broadcast is not the same as delivery. 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: topic_based_event_delivery
Source locator: See the source record.
Lexical cue: (?i)\b(?:pub(?:lish)?[_-]?sub(?:scribe)?|topic[_-]?bus|event[_-]?bus|subscriber)\bFrozen expression, v0.1.0. A match is a retrieval cue, not a confirmed implementation.
Aliases: None
Canonical exemplar: mastra-ai/mastrapackages/core/src/events/pubsub.ts:19Support: packages/core/src/events/subscribe-start-position.test.ts:25
Negative control: Directly invoking known listeners is C02 rather than C03.

Scope-anchored review. pohe-agent analyze <repo> --pattern C03 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.

01mastra-ai/mastrapackages/core/src/events/pubsub.ts:19CANONICAL SOURCE 02aaif-goose/goosecrates/goose/src/acp/provider.rs:3687RETRIEVAL CUE 03agno-agi/agnolibs/agno/agno/os/event_streams/in_memory.py:24RETRIEVAL CUE 04anomalyco/opencodepackages/core/src/config/plugin/skill.ts:8RETRIEVAL CUE 05bytedance/deer-flowbackend/packages/harness/deerflow/client.py:969RETRIEVAL 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 COVERAGE24/36

66.7% 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: 25 / 41

Canonical source anchormastra-ai/mastra 899383db98e0packages/core/src/events/pubsub.ts:19

Supporting surfacepackages/core/src/events/subscribe-start-position.test.ts:25

Topic-based publish/subscribe abstraction.

Exploratory retrieval cue Regex / v0.1.0

(?i)\b(?:pub(?:lish)?[_-]?sub(?:scribe)?|topic[_-]?bus|event[_-]?bus|subscriber)\b

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