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Plan — the genesis operation tranche: scope, ladder, and open rulings

Governed by spec/RULING_GENESIS_PERSISTENCE.md (ratified 2026-07-24, 011c68a; identity sub-decision ruled 2026-07-24, ec17d06). That ruling reverses Pass-12 K8 and makes every mutable field of Score operation-authored. This plan is the execution scope: what the tranche touches, in what order, and which questions must be answered before a dispatch contract can be written.

Status: the ladder G1 → G2a → G-minor → G2b is complete; only G3 remains, and it splits into G3a and G3b (ratified 2026-07-29, §4).

G1 landed (3b09595) — CreateInstrument, kind/tag 31.
G2a landed (7df5ca1 + 55eff00) — SetCanvasLayoutDefaults and SetSpellingPrecedence, kinds/tags 32/33, both major 0.
G-minor landed (ff9bd0f) — the chunk schema minor became a derived record; epoch ladder ratified at minors 2–9 (spec/PLAN_GMINOR_SCHEMA_MINOR.md §4), governed by spec/AUDIT_GMINOR_VOCABULARIES.md. Closed P13-S14.
G2b landed — SetTuningContext, kind/tag 34, schema major 3, minor epoch 10. Carried the sole accept-set raise (OperationEnvelopeBlock 2→3) and rewrote the bundle.rs rationale it falsified. Payload is the five-field subset epiphany_core::TuningContextSettings, not the full graph type — §5 trap 7's holdout, resolved in the contract as subset over normalization. Closed P13-S13.
G3a — the four root-level mint families (CreateStaffGroup, CreatePartDefinition, CreateAnalysisLayer, CreateView), kinds/tags 35–38, epoch 11, all schema major 0. Contracted (spec/CONTRACT_GENESIS_G3A_ENTITIES.md), blocked on one unresolved pin: §1.1, the StaffGroup/Staff authorship-authority ruling. With mints only there is no authoring order that yields a bidirectionally consistent staff group, and neither the tree nor the specification says which of Staff.group and StaffGroup.members is authoritative.
G3b — CreateMeasure alone, kind/tag 39, epoch 12, carrying graph invariant 20 and a new PreconditionFailureReason at discriminant 16. Scoped, not contracted.

Deletes are deferred out of G3 entirely (§6.1, ratified 2026-07-29). Both packets are mints only.

§6 lists what still needs ratification. Standing constraint, now with real teeth: pruning MUST NOT be implemented until disposition C lands — after G2b it would discard authored genesis state, not merely re-derivable state.

G1 shipped documentation debt — five normative falsehoods across binary_format.tex, core_spec.tex, and operation_catalog.tex, because its contract declared the normative wire surfaces out of scope. G2a repairs them. The lesson generalises: an operation-vocabulary append is a documented event in four specification documents, and any contract on this track that does not name them all is wrong. See §4's split-cost accounting.

1. The mechanism, and why the tranche is tractable

Every one of the nine surfaces carries a Score field whose type already has a Codec in epiphany-core. Codec is pub(crate), so operations cannot use it — but they do not need to. The established seam is CanonicalValue (codec.rs:3443), and the template is one line:

impl CanonicalEncode for CreateStaffOp {
    fn encode_canonical(&self, out: &mut Vec<u8>) {
        push_lp_bytes(out, &self.staff.canonical_bytes());   // payload.rs:1411
    }
}

canonical_value! (codec.rs:3455) implements the trait by delegating to the existing Codec, introducing no new byte layout, and its generated decode_canonical already does decode → finish() → re-encode → reject on mismatch. So every new operation payload gets strict canonical-form enforcement for free, on the same seam the decode-vector corpus uses.

Concretely: the tranche adds the remaining carried types to canonical_value! and writes one push_lp_bytes line per op. It does not design wire layouts. Every layout it carries is already frozen and already shipping inside Score.

2. Two facts that de-risk this, and one that does not

The tag layer is now safe. operation_kind_tag_vocabulary! (payload.rs:440) is a single source of truth generating the discriminant map, its inverse, and PAYLOAD_FREE — which the decoder, fuzz corpus, conformance vectors, and edit-barrier round-trip all read. A variant added to OperationKindTag without an entry fails to compile. This macro exists because Push 4a added TransposeInterval to a hand-written match and nothing else: the decoder rejected its own encoding, an edit barrier naming it could not be reopened, and four hand-maintained lists — two asserting the tag was unknown — stayed green.

Canonical-form enforcement is inherited, not written. Per §1.

But OperationKind::discriminant() is still a hand-written match (payload.rs:253), and it is a different space from the tag space. They are not aligned and must not be assumed so — RespellPitch is kind 2 and tag 3; InsertEvent is 0 in both. The tag space reserves 16 for Registered; the kind space does not. Both are append-only under req:binfmt:kind-discriminants. Next free: kind 35, tag 35 (re-verified 2026-07-29 against payload.rs:390, :714; this line read "kind 31, tag 31" before G1 landed).

3. The nine surfaces, and what each costs

Only one of the nine forces the accept-set raise. Verified by reading each carried type's fields for mandatory (non-Option) appends above major 0:

Surface	Op	Carried type	`schema_major()`	Raise?
`instruments`	`CreateInstrument`	`Instrument`	2 (mandatory `sound_config`, `default_clef`)	no
`canvas.layout_defaults`	`SetCanvasLayoutDefaults`	`CanvasLayoutDefaults`	0	no
`spelling_precedence`	`SetSpellingPrecedence`	`SpellingPrecedence`	0	no
`staff_groups`	`CreateStaffGroup`	`StaffGroup`	0	no
`parts`	`CreatePartDefinition`	`PartDefinition`	0	no
`analysis_layers`	`CreateAnalysisLayer`	`AnalysisLayer`	0	no
`views`	`CreateView`	`ViewDefinition`	0	no
`StaffInstance.measures`	`CreateMeasure`	`Measure`	0	no
`tuning_context`	`SetTuningContext`	`ScoreTuningContext`	3	YES

The op-block accept-set is already 2 (bundle.rs:69), so CreateInstrument at major 2 costs nothing — it sits exactly where CreateStaff already sits. SetTuningContext is the sole surface that drags OperationEnvelopeBlock to 3.

Each op touches roughly thirteen places: the op struct, the OperationKind variant, discriminant(), tag(), schema_major(), CanonicalEncode, the tag vocabulary entry, the envdecode.rs decode arm and its validation, the reduce.rs arm, both textproj_kind.rs arms (production :217, parse :523), validate.rs, vectors.rs, the fuzz/valuegen.rs generators, plus operation_catalog.tex. Nine surfaces at thirteen touch points is not one dispatch.

4. The ladder

G1 — the spine (`CreateInstrument` only)

CreateInstrument is the single missing link between an empty score and a note. Score::empty (graph.rs:1747) gives Canvas::default() and empty vectors; from there the chain is

Score::empty → CreateInstrument (MISSING) → CreateStaff ✓ → CreateRegion ✓
             → CreateStaffInstance ✓ → CreateVoice ✓ → InsertEvent ✓

Every arrow but the first already exists and already has graph-aware preconditions. So one operation satisfies the ruling's acceptance criteria 1 and 3 — a document created empty and given only operations materializes a note-bearing Score, and opening it from a bundle reaches a note, which is what unblocks T1b.

G1 also carries the two constraints that are not per-surface:

The identity cursor. From-empty reduction sets next_counter to 1 + max(counter) over ids authored by the reducing replica in the log, leaving the seed untouched when that replica authored none (ruling §3). This is the first time reduction writes identity at all — epiphany-ops has no .identity reference today. Wants a test that mints from a reduced score and asserts no collision with the log.
From-empty must reduce with a graph. new_onto with an empty score enforces preconditions from the first operation; the base-free mode skips them by design, because it has no universe to check against (reduce.rs:3721, :3824). A from-empty document through the wrong entry point silently loses referential enforcement. Name it and test it.

No accept-set raise. No wire change. Highest value per unit of risk in the whole tranche.

G2 — the settings setters, split in two

All three ride the SetMetadata LWW pattern (reduce.rs:2814), seeded for value-restoring undo (:1385). But they do not sit at the same major, and only one of them is a compatibility event. Verified 2026-07-28 against the working tree:

SetSpellingPrecedence → SpellingPrecedence. Major 0: the frozen decode_v0_score/decode_v1_score/decode_v2_score walks and the live Codec all read this field through plain Codec::dec (codec.rs:2673, :3249, :3372) — it has never been versioned.
SetCanvasLayoutDefaults → CanvasLayoutDefaults. Major 0. The type is labelled "schema major 1" (graph.rs:836), but the versioning lives in the containing Canvas walk, not the leaf: dec_canvas_v0 (codec.rs:2775) default-fills the whole field while enc_canvas_v1 (:3158) writes it through the live Codec. As a standalone payload it has exactly one layout.
SetTuningContext → ScoreTuningContext. Major 3, and unconditionally so. enc_tuning_context_v2 (codec.rs:3293) writes three fields; the live Codec writes five. A default smufl and an empty overrides still append bytes, so there is no value for which a lower-major layout exists — this is a CreateInstrument-shaped arm, not a CreateRegion-shaped one.

So the split is not tidiness. Two of the three move no wire bound at all, and the accept-set raise is a one-way door: once a block can be born at v3, an older reader meeting one preserves the bundle read-only (bundle/src/error.rs:257). Spending that in the same packet as two major-0 leaf setters buries it.

G2a — SetCanvasLayoutDefaults + SetSpellingPrecedence. Both land in schema_major()'s catch-all _ => 0 arm (payload.rs:262) with no arm added; adding them to the => 2 arm would be the bug. No epiphany-bundle change of any kind.

G2b — SetTuningContext alone, carrying the raise, the bundle.rs prose, and the S13 close. Sequenced after G-minor, not immediately after G2a — see that section: G2b appends kind 34, and the sweep is scoped to 24–33. bundle.rs:58 documents the current cap with the tuning-context rationale in prose — "no operation payload embeds the tuning context, so no op block is ever born at v3". G2b is precisely what falsifies that sentence, so the comment must move with the number. Same for DECISIONS.md's superseded prohibition, which is already marked.

The cost of splitting, stated honestly — and it is larger than first written. Each packet appends to the operation vocabulary, and that is a documented event in three companions, not one:

text_projection.tex — a new kind production is a document-surface change (the G1 precedent), so COMPANION_VERSION bumps per packet: 0.8.0 → 0.9.0 → 0.10.0, each re-sweeping five live version sites plus a changelog row and re-flipping the negative superseded_companion_version vector.
binary_format.tex — payload-layout and tag rows per kind, plus a version bump and a Revision History row (the 0.2.0 entry is the precedent).
operation_catalog.tex — a \section per kind, plus a version bump and a changelog paragraph.

Plus core_spec.tex's normative OperationKind/OperationKindTag listings and its spelled-out payload counts, and a regenerated vector corpus, per packet. So the split roughly doubles the documentation work, and G2b pays it again in full. Still the cheaper of the two risks — burying a one-way accept-set door in a packet of routine work is worse than repeating a mechanical sweep — but it is not the small tax the first draft implied.

P13-S13 closes at G2b — and on the metadata precedent, not on the canonical base. The base cannot carry a v3 tuning context: it is role-bound to major 0 (mis_stamped_canonical_base, bundle.rs:866). It does not need to. The canonical base is a MaterializedState (reduce.rs:504) — effects, conflicts, anomalies, objects, spellings, breaks, page-breaks, pending — which embeds no graph values for any field, including metadata, op-authored since M2d and durable purely through its operations. S13's claim was "no canonical carrier embeds it at all: no operation authors it". G2b makes an operation author it, and the op log is canonical.

What that sharpens. The standing prohibition on pruning (blocked on disposition C) stops being a performance concern the moment G2b lands: pruning would then discard authored genesis state, not merely re-derivable state. G2b's contract must state this as an explicit non-goal.

G2b holdout — accidental_extensions, and why a naïve full-value SetTuningContext would be wrong. ScoreTuningContext's Codec deliberately drops accidental_extensions on encode and default-fills it to Vec::new() on decode (core/src/codec.rs:1939) — the field is staged out of schema major 3 and lands at a later one. Meanwhile OperationSet::accept stores the authored envelope as an object, not as bytes (ops/src/opset.rs:70). So a SetTuningContext carrying a non-empty accidental_extensions would reduce with those extensions present on the authoring replica, and reduce without them on any replica that received the document through serialization — a silent divergence between a live session and the same document reloaded.

canonical_value! does not catch this. Its generated decode_canonical compares bytes (decode → finish() → re-encode → reject on mismatch); it never compares against the originating value, so a field that never reached the bytes is invisible to it. G2b needs a normalization-or-subset pin before dispatch — either the payload carries a wire-complete subset type, or the operation normalizes the field away at construction and refuses a non-empty one. Decide that in the G2b contract, not in its implementation. Does not block G2a.

G-minor — the schema-minor sweep (ruled 2026-07-28)

Ladder order is G2a → G-minor → G2b, and the order is load-bearing. The sweep is scoped to kinds 24–33, which is exactly what exists once G2a lands. Run G2b first and it appends kind 34 into a vocabulary the sweep has already been scoped against, so either the sweep grows mid-flight or 34 ships with the same defect the rung exists to retire. G2b therefore sequences after G-minor and inherits working machinery — the same reasoning that put the accept-set raise in its own packet.

binary_format.tex:2330 requires a writer to raise the chunk schema minor when it emits a discriminant appended after the minor it declares — a MUST with a stated rationale, so that an unknown-discriminant decode failure is attributable to version skew rather than corruption. No writer has ever done it: SchemaVersion::for_major (bundle/src/ids.rs:204) maps a major to a fixed constant — V0 is {0, 1}, not {0, 0} (ids.rs:173); V1/V2/V3 carry minor 0 — and, decisively, accepts only a major, so no per-kind additive minor can reach it. Both staging paths likewise derive only the major (testkit/src/bundle_harness.rs:25, textproj/src/serialize.rs:183).

So kinds 24–27, 28–29, 30, and 31 already carry no additive record, and G2a takes that to 32–33 knowingly. Filed as P13-S14. Ruled: one retroactive sweep over 24–33 after G2a, rather than blocking G2a on a debt already eight kinds deep or paying for two partial sweeps.

What the rung owes — policy and epoch ladder both ratified 2026-07-28; see spec/PLAN_GMINOR_SCHEMA_MINOR.md §4 and the governing inventory spec/AUDIT_GMINOR_VOCABULARIES.md:

a global additive epoch (minors 2–9, one per additive event), not the per-kind minor this paragraph originally proposed — that was rejected, because it cannot represent multiple independent vocabularies inside one block, and its obvious generalisation is worse: an old OperationKind 23 would numerically mask a newly appended OperationPayload 3;
introduced_minor assigned per variant, per vocabulary, co-located with the discriminant in an exhaustive macro/match with no wildcard arm, so a new variant cannot compile without an epoch;
an envelope's required minor = the max over every discriminant it actually emits (outer payload variant, primitive kind, every nested additive variant), and a block's = the max over its envelopes;
content-minimal derivation for the other payload roles — including the manifest, which takes a barrier tag's epoch when it names one;
a for_major replacement that accepts a minor, and both staging paths.

The scope is not "kinds 24–33." The audit found appends in three further vocabularies (OperationPayload 3, ReanchorReason 6, PreconditionFailureReason 10–15) and a reachability path to OperationKindTag through the manifest with no operation envelope involved. Orthogonal to the major accept-set, which stays 2 through G2a and rises to 3 only at G2b.

G3 — the remaining entity families, split in two (ratified 2026-07-29)

All five ride the CreateStaff set-union mint pattern (reduce.rs:4075) with byte-identical re-carry idempotence. Graph-aware referential preconditions per the ruling §2:

CreateStaffGroup.members, CreatePartDefinition.staves → live Staffs
CreateView.active_layers → live AnalysisLayers
CreateMeasure → a live StaffInstance

Mints only. Deletes are deferred out of G3 — see §6.1, which also supersedes this section's former "deleting an entity with live dependents → refuse (container-not-empty)" line.

Neither packet moves a wire bound, and neither touches a typed-id vocabulary. Verified 2026-07-29 against the working tree:

All five carried types are schema major 0. No versioned walk exists for StaffGroup, PartDefinition, AnalysisLayer, or ViewDefinition — both decode_v0_score (codec.rs:2698) and the live walk (:3274) read them through plain Codec::dec. Measure is the CanvasLayoutDefaults shape: the versioning lives in the containing enc_staff_instance_v1 (codec.rs:3070), not the leaf, and every walk carries measures.
TypedObjectId already carries all five variants (ids.rs:496, :499, :500, :512, :517). No append, no discriminant event.
All four G3a types already have a Codec and a TextValue — both are generated by the one struct_codec! macro (codec.rs:510, :522), so no textvalue_graph.rs work. What they lack is a canonical_value! entry.

G3a closes a live defect, not merely a completeness gap. All five object kinds become Live only through base ingest (reduce.rs:1449–:1563); no operation mints any of them. So CreateStaff's group precondition (reduce.rs:4119) is currently unsatisfiable under from-empty reduction — a document built only from operations can never author a grouped staff — and TimeAnchor::Measure (reduce.rs:1280) can never resolve. G1 opened this by making from-empty reachable; G3a closes the staff-group half of it.

G3a — the four root-level mints. Kinds/tags 35–38, epoch 11. Self-contained: CreateView's precondition target is minted by CreateAnalysisLayer in the same packet. No new graph invariant; it owes only the invariant-10 prose reconciliation (§6.3).

G3b — CreateMeasure alone. Kind/tag 39, epoch 12. CreateMeasure is shaped differently from its four siblings: measures is nested on StaffInstance (graph.rs:611), not a Score-level vector, so its precondition reaches three levels down through canvas.regions[].staff_instances(). It additionally carries graph invariant 20 and a new PreconditionFailureReason at discriminant 16 — a second wire vocabulary append at the same epoch. The split exists so that a normative Chapter 5 listing append is not buried inside a packet of routine mints — the same reasoning that kept the accept-set raise out of G2a.

5. Traps

Two unaligned discriminant spaces, one macro-guarded and one not (§2).
bundle.rs's cap comment is prose that encodes a rationale, not just a number. Moving the number without the prose leaves a confident falsehood in the file that most directly governs accept-sets.
Minimal stamping is a pure function of the value. CreateInstrument is unconditionally 2 (its major-2 appends are not Options), unlike CreateRegion/SetStaffLayout, which are value-dependent. Do not copy the value-dependent arm shape.
Round-trip locking cannot see a self-consistent reorder. The lesson of 3b-i: a swap applied to both codec halves passed 1283 tests and 8/8 conformance. New payloads want decode-vector entries pinned to literal bytes, not just round-trip tests.
Score::empty seeds tuning_context with a default, so SetTuningContext's reduction must distinguish "never authored" from "authored to the default value" if undo is to restore correctly. Withdrawn 2026-07-28 — this is not a trap, and SetMetadata already proves it. Score::empty seeds metadata with a default exactly as it seeds tuning_context (graph.rs:1749, :1757), and the base ingest then runs metadata_chain.seed(score.metadata.clone()) (reduce.rs:1385) under a comment stating the purpose outright: the score-level LWW chains seed with the base values so a value-restoring undo of the first operational write restores the pre-operational state. Since from-empty reduces onto Score::empty (trap-free only through reduce_operation_set_onto — G1 pin 10), the seed runs, and undoing the first write yields Restore(Some(Predecessor::Base(default))). Restoring the default is correct in both the never-authored and the authored-to-default case, so the distinction is unobservable and must stay so. The Predecessor::Base vs ::Write distinction earns its keep only for the canonical bookkeeping families (spellings, breaks, page_breaks, reduce.rs:707), where a base predecessor returns a map key to absence. ScoreTuningContext is an always-valued Score field, like metadata: there is no absent state to return to. All three G2 setters copy set_metadata structurally.
Adding an OperationKind variant is NOT containable to core + ops — the G1 lesson, and the one claim this plan previously got wrong. Rust exhaustiveness forces an arm in epiphany-editor-core's subjects_of (barriers.rs:313), and because epiphany-testkit depends on editor-core, a missing arm blocks conformance and requirement_labels — the gate cannot run at all. Five further sites bake in a literal that only surfaces once the workspace compiles: layout-ir/src/barrier.rs:1156 (a tag "one past the vocabulary"), testkit/tests/text_projection_grammar.rs:315 (a hardcoded kind count, with its message string at the same site), testkit/src/generators.rs:1908 (a drawn-discriminant range plus a never-drawn guard at :1947), testkit/src/layout_stub.rs:1373 (the same range restated in prose that carries the coverage claim), and textproj/src/vectors.rs (a negative vector whose "wrong version" is the one each bump moves to). Every G2/G3 contract MUST enumerate these and budget the boundary crossing up front. (All four citations re-verified 2026-07-29; the three carried in earlier revisions had drifted — barriers.rs:437, barrier.rs:1105, text_projection_grammar.rs:307 — which is exactly the failure mode a contract's touch table exists to prevent.)

6. Open rulings — needed before a dispatch contract

~~Delete/modify coverage per family.~~ Ratified 2026-07-29: mints only. All five deletes are deferred out of G3.

The precedent is not one precedent but a clean split, verified against the vocabulary: every paired create+delete family — CrossCutting, Region, StaffInstance, Voice, RepeatStructure — is a nested container with owned children, while both unpaired mints, CreateStaff (23) and CreateInstrument (31), are root-level Score vectors. G3's families land on both sides of that line.

This section's former sentence "deleting an entity with live dependents → refuse (container-not-empty)" is superseded and MUST NOT be treated as a contract. It conflates two different semantics. ContainerNotEmpty is explicitly about owned children — "a container that still has live children" (ops/src/effect.rs:156). The G3 hazard is the opposite shape: deleting a StaffGroup orphans no children, it dangles inbound references from independently-live objects (Staff.group; likewise AnalysisLayer ← View.active_layers). A correct refusal needs a new typed PreconditionFailureReason — the space currently runs 0–15 — which is a further wire vocabulary append with its own epoch. Each delete is also a full kind+tag append carrying its own four-document sweep. Deferred as its own rung if wanted; nothing in G3 depends on it.
~~decomposition_attachments.~~ Ratified 2026-07-29: derived, not authored. It stays out of the operation vocabulary and keeps its place in the eight-field table. The creation path is the prepass (core/src/prepass.rs:382); reduction only ever removes invalidated attachments (ops/src/reduce.rs:2559, its sole mention, a retain). (Citation re-verified 2026-07-29; the earlier reduce.rs:2342 had drifted.)
The measure/meter invariant. Semantics ruled 2026-07-29; the invariant itself lands in G3b. Measure.time_signature is an optional explicit display/declaration at the measure start — neither an override of the metric grid nor a cache of it:
- the effective grid is StaffInstance.local_metric_grid, falling back to the region's default_metric_grid;
- Some(id) MUST resolve and equal the grid signature active at that measure's start;
- None means inherit the active signature and display no new signature;
- where positions are determinable, authored measure boundaries MUST stay consistent with the active signature's measure_duration. Pickup handling remains deferred.
Invariant 20 covers agreement and boundary consistency only — it MUST NOT duplicate reference resolution, which invariant 10 already performs. G3b additionally adds a typed failure reason (e.g. MeasureMeterMismatch) at discriminant 16, epoch 12.

Correction of record. An earlier scoping claimed invariant 10 "covers cross-cutting refs, not this". That was false, and it was read off the variant's doc comment rather than the check body. Invariant 10's body already resolves a staff's group, a group's members, a part's staves, a view's active layers (core/src/invariants.rs:1122–:1156) and measure and grid time-signature references (:1180–:1212), with a direct test at :3596. Its doc comment (invariants.rs:59–:62) names only cross-cutting structures and event-internal references, so the prose materially understates the check across exactly the five reference classes G3 authors. G3a owes that prose reconciliation; it adds no invariant enum entry.
Ladder shape. G1/G2/G3 as above, or a different cut. Ratified 2026-07-24, and amended 2026-07-28: G2 splits into G2a (the two major-0 setters) and G2b (SetTuningContext alone, carrying the accept-set raise and the S13 close). See §4.

Related: spec/RULING_GENESIS_PERSISTENCE.md, spec/ANALYSIS_GENESIS_PERSISTENCE.md, spec/PLAN_EDITOR_APP.md §Ruling B / §3.7, spec/PLAN_PUSH4B_TUNING.md (the tranche mold), spec/PASS13_CANDIDATES.md (S13).

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