Proposed specificationSource-located exemplarH1 H3

Event-sourced conversation engine

Reconstruct state from recorded events.

JOIN POINTconversation_state_projectionRECORD 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 Event-sourced conversation engine, showing role collaboration and a numbered message sequence — FIG. P14 / OBJECT INTERACTIONS
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Pointcut

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

Context: Conversation state is derived from recorded events.
Trigger: A new event is appended or history is loaded.
Structure: Event schema, sequence or identity rules, and a projector.
Effect: The current view is reproducible from the event history.

Protected contract

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

Requires: Events are immutable enough to replay and schema versions are identifiable.
Ensures: Applying the same ordered events yields the same semantic state.
Invariant: Projection never mutates historical event identity.
Violation: Missing, incompatible, or corrupt events produce recoverable migration or rejection.

Negative control

A mutable message array without projection semantics is insufficient.

Variation & lifecycle

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

Permitted variation

Event type unions, snapshots, migrations, local or remote persistence.

Test obligation

Test full replay, snapshot-plus-tail replay, schema evolution, and partial history.

Evolution question

Did conversation state move behind an append-and-project boundary?

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

Project conversation state from immutable events. Replaying the same ordered events must produce the same semantic state, even when snapshots or schema migrations are used.

CODE DESIGN / PYTHON

def project(events, initial_state):
    state = initial_state
    for event in sorted(events, key=lambda item: item.seq):
        handler = HANDLERS.get(event.kind)
        if handler is None:
            raise UnknownEvent(event.kind)
        state = handler(state, event)
    return state

Illustrative design sketch. State is a projection; an event with no handler is a contract violation, not a no-op. 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: conversation_state_projection
Source locator: See the source record.
Lexical cue: (?i)\b(?:event[_-]?sourc(?:e|ed|ing)|conversation[_-]?events|append[_-]?event|projection)\bFrozen expression, v0.1.0. A match is a retrieval cue, not a confirmed implementation.
Aliases: None
Canonical exemplar: OpenHands/software-agent-sdkopenhands-sdk/openhands/sdk/conversation/state.py:342Support: tests/sdk/conversation/local/test_state_serialization.py:234
Negative control: A mutable message array without projection semantics is insufficient.

Scope-anchored review. pohe-agent analyze <repo> --pattern P14 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.

01OpenHands/software-agent-sdkopenhands-sdk/openhands/sdk/conversation/state.py:342CANONICAL SOURCE 02aaif-goose/goosecrates/goose-mcp/src/autovisualiser/templates/assets/d3.min.js:2RETRIEVAL CUE 03agno-agi/agnolibs/agno/agno/db/base.py:56RETRIEVAL CUE 04Aider-AI/aideraider/website/assets/asciinema/asciinema-player.min.js:1RETRIEVAL CUE 05anomalyco/opencodepackages/ai/src/route/client.ts:594RETRIEVAL 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 COVERAGE31/36

86.1% 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: 34 / 41

Canonical source anchorOpenHands/software-agent-sdk 5c524ad65d81openhands-sdk/openhands/sdk/conversation/state.py:342

Supporting surfacetests/sdk/conversation/local/test_state_serialization.py:234

State updated by appending events and rebuilding a view.

Exploratory retrieval cue Regex / v0.1.0

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