Tianyi Cui
b88afa8a72
The producer-source refactor introduced the unreleased V4 discriminator code-mode even though this source identifies images deferred from successful PTC subcalls. Name it ptc-mode before V4 ships so persisted attribution matches the producer and does not freeze obsolete terminology into new logs. Keep the live writer, V3-to-V4 migration output, collision guard, and reserved producer policy aligned. Both released tools-code-mode and tools-ptc plugin lookup keys map to ptc-mode. Preserve those historical keys, opaque message text and IDs, all frozen V0-to-V3 generations, and recorded Session inputs. Update the owning tests, producer documentation, current catalog, and V4 acknowledgement. The canonical schema audit identifies exactly three changed roots; reversing only the source literal restores each prior digest. The large generated JSON diff comes from graph ordering, with 61 roots and 572 types retained. Validation: the seven-file focused run passed 298 tests and exposed four stale current-output expectations in two migration files. After correcting those expectations, both files passed all 23 tests. All 41 documentation gates and full lint passed; frozen generations and recorded inputs are unchanged.
description
| description |
|---|
| Review and maintain recorded Session persistence-type changes, their schema snapshots, and compatibility decisions. |
Persistence-type change records
English | 中文
Summary
Use this reference to inspect an acknowledged Session persistence-type change and its predecessor. Each record binds a compatibility decision to exact generated schemas. Local checks compare the current source with the recorded history using only files in the checkout. Start with the review cookbook when changing a persisted type.
For older tagged versions, use the prerelease archive. It reconstructs alpha/RC type differences for historical reading and format validation; its observations do not serve as current compatibility acknowledgements.
For complete schemas grouped by Session format, use the format references. Their coverage follows the writer constant, including intermediate formats without a release tag.
Table of Contents
Files and ownership
The generated catalog provides readable declarations and digests; the schema inventory contains the normalized types. Roots cover the logical Session header, the physical JSONL header line, the event envelope, and every repository-declared event. Referenced types contribute transitively to each affected root's digest.
Each dated record has four sibling files:
| File | Owner |
|---|---|
YYYY-MM-DD-slug.md |
English acknowledgement with kind: persistence-change, one machine declaration, compatibility reasoning, and verification evidence |
YYYY-MM-DD-slug.zh.md |
Chinese counterpart with the identical machine declaration |
YYYY-MM-DD-slug.i18n.yaml |
Generated bilingual consistency record |
YYYY-MM-DD-slug.schema.json |
Generated complete after schemas for the affected roots that remain present |
The record template defines the authored format. Record creation accepts a bilingual prose input and generates the machine declaration, snapshots, catalog pair, and consistency records. The verifier reads the machine declaration once from the English file and checks the Chinese declaration for equality. A declaration names each affected root, its predecessor record, its after digest, and its compatibility decision. A new root has no predecessor; a deletion has no after schema and retains an explicit tombstone.
Compatibility rules
Every detected structural change requires an acknowledgement. Record creation and update infer the minimum decision from these fixed rules; an explicit --decision is a checked assertion. The rules apply to the complete change, so an allowed change cannot hide a simultaneous breaking change.
| Detected change | Minimum decision |
|---|---|
| Add an optional event-body property, including its complete subtree | same-version |
| Make a required event-body property optional | same-version |
| Add an ordinary event type | same-version |
| Add an explicitly qualified attribution kind to a user/developer source slot whose before and after schemas carry the same supported policy | same-version |
| Make an optional property required, add a required property, change an existing type, or remove/rename a property or event | version-bump |
| Change the Session header or event envelope | version-bump |
The extractor accepts an explicit @persistenceSource binding for a core-owned source property on a literal user or developer role; it does not infer a binding from an unannotated type. A producer qualifies its MessageSourceMap entry with @persistenceAttribution. Qualification promises that an unknown kind and its JSON metadata survive reading without the producer, and that the kind imposes no validation, replay, or authority requirement. A producer may inspect its own kind to resume duplicate suppression; other readers must preserve and derive the recorded messages without that projection. The recorded schema retains the binding, policy version, literal kind discriminator, preservation promise, and qualified kind set. Inventory format 2 stores those promises; extraction without a bound policy retains format 1. Session format versions are independent. Both compared snapshots must carry compatible policy state. Existing kind groups still receive ordinary structural comparison; removals, unmarked additions, policy changes, and unrelated breaking changes remain strict. Multiple context-form alternatives with the same wire kind form one group.
A same-version explanation states why old records can omit the addition and why older readers can ignore it without changing replay. For required-to-optional changes, it explains how readers handle an absent value. The checker validates the type classification; reviewers assess the explanation. A version-bump record includes the increasing header version in the same transition and follows the Session-format procedure.
When a reader rejects a JSON property by name, declare the property as optional never and mark it with argument-free @persistenceReserved. The extractor retains the forbidden field, so allowing a JSON value later requires an existing-field type change. Required or JSON-valued properties cannot carry this marker. Unmarked optional never and undefined properties retain their existing omission behavior.
History and limitations
One baseline records the complete initial inventory. Later records use their predecessor's after schema as the before schema. The verifier rejects missing predecessors, cycles, duplicate successors for one root, digest mismatches, and current roots that disagree with their latest records. Independent roots can advance independently. Two changes to the same predecessor require a single ordered history after integration.
Accepted records describe historical transitions; preserve their machine declarations and schema snapshots when adding a successor. An unaccepted terminal record can be refreshed explicitly; the command rejects baselines and records with dependants. The tree cannot establish review acceptance. Verification proves consistency within the tree, not that history was never rewritten. No Git ref, remote service, or released checkout supplies the baseline.
Digests describe declared persistence types, not runtime validation or behavior. Ordinary comments, source locations, alias names, and harmless declaration reordering do not affect them. Compatibility annotations are recorded policy data and do affect digests. Unannotated version-1 snapshots retain their original normalization, fingerprints, and strict classification; policy-bearing graphs use a separate fingerprint domain. Object fields, union alternatives, intersection operands, and index signatures can be reordered when their resolved types stay the same; tuple positions and numeric enum values remain significant. Catalog text and source locations may still change, so regenerate stale artifacts without adding an acknowledgement for an unchanged digest. Opaque types such as unknown expose no hidden structure to compare. Behavior-only changes and structures hidden inside opaque values are outside this mechanism's scope. The decision records these trade-offs.
Dev Note
Working context for maintainers — click to expand
None.