Proposed specificationSource-located exemplarH3

Session-tree version control

Branch or revisit execution history.

JOIN POINTconversation_history_branchRECORD 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 Session-tree version control, showing role collaboration and a numbered message sequence — FIG. P26 / OBJECT INTERACTIONS
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Pointcut

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

Context: Execution history can be checkpointed and branched.
Trigger: A fork, checkout, rewind, or restore is requested at an event boundary.
Structure: Node identity, ancestry, checkpoint payload, and branch creation operation.
Effect: The new branch starts from the requested stable history without mutating its ancestors.

Protected contract

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

Requires: Event boundary is stable and enough state exists to resume.
Ensures: New branch records parent, boundary, and provenance; invalid boundaries are rejected.
Invariant: Branch operations never rewrite unrelated history.
Violation: External side effects are not rolled back and must be reported as irreversible.

Negative control

Workspace checkpoint without conversation branching is only partial.

Variation & lifecycle

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

Permitted variation

Transcript fork, session copy, Git-style checkpoint, event UUID branch, and rewind.

Test obligation

Test valid fork, invalid boundary, branch isolation, restore, and side-effect caveat.

Evolution question

Did workspace checkpointing converge with conversation trees?

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

Branch a conversation only at a stable event boundary. The new branch must record its parent, boundary, and provenance, and invalid or missing boundaries must be rejected.

CODE DESIGN / PYTHON

def branch(session, boundary_event_id):
    parent = session.events.by_id(boundary_event_id)
    if parent is None or not parent.is_boundary:
        raise InvalidBranch(boundary_event_id)
    child = session.fork(
        parent_id=session.id,
        boundary=parent.id,
        state=parent.snapshot(),
        provenance=session.provenance(),
    )
    return child

Illustrative design sketch. A rewind without provenance destroys the audit trail that made it useful. 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_history_branch
Source locator: Barbaste et al., Table 12, p. 53 (Pi; OpenHands conversation tree, “Session-Tree Version Control”); source label
Lexical cue: (?i)\b(?:checkpoint|session[_-]?tree|fork[_-]?(?:session|conversation|thread)|branch[_-]?(?:session|conversation))\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/impl/local_conversation.py:861Support: tests/sdk/conversation/local/test_conversation_tree.py:1
Negative control: Workspace checkpoint without conversation branching is only partial.

Scope-anchored review. pohe-agent analyze <repo> --pattern P26 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/impl/local_conversation.py:861CANONICAL SOURCE 02aaif-goose/goosecrates/goose-cli/src/session/streaming_buffer.rs:227RETRIEVAL CUE 03agno-agi/agnolibs/agno/agno/sandbox/base.py:11RETRIEVAL CUE 04anomalyco/opencodepackages/ai/src/index.ts:227RETRIEVAL CUE 05bytedance/deer-flowbackend/packages/extension-api/deerflow_extension_api/agent_runs.py:116RETRIEVAL 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 COVERAGE30/36

83.3% 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: 32 / 41

Canonical source anchorOpenHands/software-agent-sdk 5c524ad65d81openhands-sdk/openhands/sdk/conversation/impl/local_conversation.py:861

Supporting surfacetests/sdk/conversation/local/test_conversation_tree.py:1

Fork conversation at a stable event boundary.

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.