reasampler/PLAN.md

PLAN.md — ReaSampler milestone roadmap

Living milestone roadmap for ReaSampler. Derived from CONTEXT.md's 11-step build order; CONTEXT.md remains the authoritative spec — this file is the tickable checklist, not a re-statement of the spec. When a point lands, doc-keeper removes it here and appends it to COMPLETED.md.

Conventions

• One checkbox - [ ] = one discrete, independently-landable point.
• Each milestone opens with a Goal (one line) and a Verify criterion (the acceptance gate; precision invariants pulled in where one applies).
• Verify-in-DAW points require a manual REAPER run; pure points are gated by CTest.
• "See CONTEXT.md §…" points at the authoritative detail — do not duplicate it here.

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Milestone 9 — slots (MPC-style)

Goal: "Capture to slot N" / "insert slot N", MIDI-bindable. CONTEXT.md Build order 9. Verify (in DAW): Slot capture and slot insert fire from MIDI bindings; slot state persists via the index.

• Slot model + slot↔sample assignment.
• "Capture to slot N" / "insert slot N" actions, MIDI-bindable.

Milestone 10 — provenance (re-capture from source)

Goal: Populate Sample.provenance (parent sample id + a capture-recipe fingerprint) on resample-from-sample, and ship a "re-capture from source" action that regenerates a sample from its recorded source. Reconciled with the dual-canvas (Phase D2) model. CONTEXT.md §Data model, §capture; product framing + the settled reconciliation in docs/product/provenance.md. Verify (in DAW): A sample resampled from a bank sample carries its parent id + recipe fingerprint; "re-capture from source" regenerates the file into the bank (never auto-inserting into the timeline — load-bearing principle); re-capture with an unchanged source + request is byte-identical to the original (bit-identical repeats); non-destructive to source items/tracks.

Reshaped from the old "provenance + null-test verify" M10. Cut (fixed by Daniel): the null-test verification action and the true-pre-FX-dry mechanism the old note required — both dropped, see docs/product/provenance.md §What was cut. Kept: provenance + re-capture. The Sample.provenance struct and its JSON round-trip already exist (M1) — M10 populates and consumes the field, it does not add it. Fork picks settled by Daniel (2026-07-23): P1=a thin fingerprint, P2=a bank-only re-capture; P3/P4 moot under P2=a. The points below are locked to that path.

• Populate Sample.provenance on resample-from-sample: parentSampleId (the bank sample the capture derived from) + fxChainSnapshot as a thin capture-recipe fingerprint (scope + source FX-chain identity/hash at capture time — a drift/repro fingerprint, NOT a serialized pre-FX-dry chain to restore; P1=a settled).
• "Re-capture from source" action: regenerate a provenanced sample by re-running its recorded capture request against the source's current state; update the bank file + Sample in place. Bank-only — never inserts/re-places into the timeline (load-bearing principle). Reports if the source drifted since capture.
• Verify: re-capture of an unchanged source is byte-identical to the original capture (bit-identical repeats); non-destructive (FxBypassGuard snapshot/restore as M7); relative-paths-only preserved.

Dual-canvas reconciliation (settled — docs/product/provenance.md): With bank-only re-capture (P2=a), provenance is pure per-sample bank metadata, bank_model and view_mode_model stay decoupled, and M10 touches no canvas code. Dual-canvas compliance is satisfied by staying on the right side of the capture-never-places line — not by any new coupling. Forks P3 (canvas/lane memory in provenance) and P4 (re-capture auto-tag interaction) were only live under re-capture-and-replace (P2=b) and are closed as moot; if the user manually re-places a regenerated sample, the existing D2 mode-aware placement rule governs.

Milestone 11 — polish

Goal: Batch capture (per selected item / per razor area), resample-and-mute-source, conform-on-insert, native OS drag-out. CONTEXT.md Build order 11, §Non-goals (drag-out deferred to last). Verify (in DAW): Each polish action works without regressing the precision invariants; drag-out places a valid file in the OS target.

• Batch capture: per selected item / per razor area.
• Resample-and-mute-source.
• Conform-on-insert (explicit).
• Native OS drag-out (deferred final; InsertMedia path must already work).
• Keybinding help labels: in the docked bank_panel, surface the current key binding for each capture/provenance action (e.g. "Capture Item → ") by querying the SDK for the key bound to the action's command id (kbd_getTextFromCmd(cmd, SectionFromUniqueID(0)) — main section) and formatting a reminder label. Unbound case degrades to the action name with a clear "unbound"/"—" marker (empty/blank return handled explicitly). Split: label-text formatting (binding string + fallback → label) is pure/testable; the SDK binding query + label draw is bank_panel shell.
• Action trigger buttons: clickable bank_panel buttons that fire the capture and provenance actions directly, routing through the existing command-id contract (Main_OnCommand/KBD_OnMainActionEx with the registered command id — the same id minted at registerAction), never re-implementing capture. Split: button hit-testing/layout math is pure/testable (mirror of mode_switch/bank_grid); draw + command dispatch is bank_panel shell.

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Open questions to resolve during build

Carried from CONTEXT.md §Open questions — keep visible until each is closed by a landed milestone.

• parseInt narrowing hardening: src/bank_model.cpp parseInt casts int64_t → int via static_cast without a range check; integers that fit in int64 but exceed INT_MAX are implementation-defined. Hardening candidate — add bounds check before the cast when integer-field validation is in scope.
• Capture send/routing isolation (TODO): The FX-scope capture neutralizes out-of-scope FX, gain, and pan — but NOT aux sends. So a downstream coloring send (e.g. a folder → reverb-track send) still routes and blends the reverb into an item/track capture, past the intended isolation point. A true item-level capture should be taken at the isolated graph point — the target scope's output before out-of-scope track FX/gain/pan and before out-of-scope aux/parallel sends. The hard part: distinguish source routing that must be preserved (e.g. a MIDI send T1→T2 where T2's synth is where a MIDI item's audio is actually produced — the "item level" for that MIDI item is T2's synth output) from coloring sends that must be excluded (folder→reverb). Repro: folder F1; T1 (MIDI) sends MIDI to T2 (synth); T1+T2 → F1; F1 sends to reverb T3; capturing the MIDI item on T1 currently includes the reverb, should be isolated to T2's synth output pre-F1 with the MIDI send preserved and the reverb send excluded. Likely approach: snapshot + mute out-of-scope tracks' aux sends during the render while preserving the main/source signal path — needs a rule for which sends are load-bearing.

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Phase D2 — Two-canvas (item-level mode projection; additive to D1)

Design View sub-phase. Extends D1's track-level mode projection to item level via REAPER 7 fixed lanes: on a track present in both stances, each mode owns a fixed lane — the active mode's lane shows and plays, the inactive mode's is hidden and silenced — so a Design take and an Arrange take can share the same track and time position without colliding on the view. Nothing in D1 changes. Runtime floor rises to REAPER 7 for this sub-phase (no version-gate branch; below v7 it is simply unavailable). Authoritative spec: CONTEXT.md §Two-canvas sub-phase (Phase D2 / Phase E) and the surrounding §Design View — additive phase spec. Product framing: docs/product/design-view.md §Two-canvas direction. When a point lands, doc-keeper moves it to COMPLETED.md.

D2-W1 (pure lane extension), D2-W2 (shell: lane application + new-content detection), D2-W3-A (lane minting + item→lane assignment + persist round-trip), and D2-W3-B (item-level mode actions + W3-A polish) have all landed — see COMPLETED.md. Phase D2 is functionally complete.

Deferred: panel UI indicator for per-track lane/mode state (a per-track lane-split marker). The mode switch already shows the active mode; no natural cheap home for a per-track indicator was found in the bank panel. Explicitly deferred — not silently dropped. Can be picked up later if wanted.

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Phase B — Multi-bank (parallel to the M0–M11 capture roadmap and Phase D)

Separate phase namespace. The M-numbers belong to the capture pillar (M0–M11); the D-letters belong to Design View. Multi-bank is a third orthogonal pillar — generalizing the single bank into a pool + named banks — so it takes its own lettered namespace (B1, B2, …). "B" reads for Banks and, like Phase D, keeps the roadmaps from colliding on numbering: Phase B is not "the twelfth capture step," it is a different pillar. Authoritative spec: CONTEXT.md §Multi-bank. Product framing: docs/product/multi-bank.md. When a point lands, doc-keeper moves it to COMPLETED.md.

B1 — bank_book (pure)

Goal: REAPER-free bank registry wrapping N BankIndex instances: pool seeded + privileged, create/rename/reorder/delete named banks, active-bank id, move/copy a sample between banks, JSON round-trip + legacy-migration. The heart of the phase; mirror of bank_model / view_mode_model; BankIndex untouched (additive). CONTEXT.md §Multi-bank (Module architecture — pure). Verify: CTest green. Pool always present, un-deletable, un-renamable, un-evacuable (rules rejected in-model). Active-bank defaults to pool. Move is index-only (source loses entry, destination gains it) and observes destination collapse-by-hash; copy leaves source intact. Delete drops member index entries. Evacuate moves all members to the pool, leaving the bank empty. JSON round-trip lossless across pool-as-bank-zero + named banks + per-bank indices + ordinals + active id. Legacy bank_index JSON parses into { pool } with zero named banks.

• Bank registry: ordered { bank id, display name, ordinal, BankIndex }; pool seeded with fixed id + fixed name; create / rename / reorder / delete named banks (delete drops the bank's member index entries).
• Pool-privilege rules enforced in-model: reject delete-pool, reject rename-pool, reject evacuate-pool, never allow zero banks.
• Active-bank id (get/set; defaults to pool); resolve active bank's BankIndex.
• Move sample between banks (index-only; destination collapse-by-hash observed; source entry removed).
• Copy sample between banks (index-only; source entry retained; destination collapse-by-hash observed).
• Evacuate bank: move every member to the pool (index-only; destination collapse-by-hash observed), leaving the bank empty; pool cannot be evacuated.
• JSON round-trip: pool-as-bank-zero inside the blob + named banks + per-bank indices + ordinals + active id.
• Legacy migration: a bare bank_index JSON promotes to the pool's index with zero named banks (one-way, lossless; blob authoritative thereafter).
• Tests: pool privileges (delete/rename/evacuate rejected); move source-loses/dest-gains; copy source-retained; evacuate empties source into pool with dest collapse; cross-bank same-hash coexistence; dest collapse on move into a bank already holding the hash; JSON lossless; legacy migration.

Phase-B-wide undo (fork R-B, settled 2026-07-24 — batched REAPER undo points). Every index verb across B1–B5 (create/rename/reorder/delete-bank, move, copy, evacuate, remove) wraps its bank/index mutation in a batched REAPER undo point (Undo_BeginBlock / Undo_EndBlock), so one bank operation is one Ctrl-Z. This is a cross-cutting decision that retro-touches B1–B4, not a B5-local one; the per-verb points above inherit it. Must-verify before build: confirm against vendor/reaper-sdk that "reasampler" ext-state mutations participate correctly in Undo_BeginBlock/Undo_EndBlock undo blocks — the whole approach depends on it. See CONTEXT.md §Sample removal (Guardrails) + product notes §Fork R-B.

B-cap — owned-file manifest seam (capture writes; prune consumes in Phase R)

Goal: Capture writes each file it creates into an owned-file manifest persisted in the "reasampler" ext-state, so Phase R prune can later distinguish the bank system's own orphans from hand-dropped files. Consumed only in Phase R (R1/R2) — landed early here because reconstructing the manifest retroactively is a backfill cliff (fork R-D, settled 2026-07-24: defer the feature, design the seam). CONTEXT.md §Prune (Settled decisions — orphan attribution) + product notes §Fork R-D. Verify: every file the capture path creates is recorded in the owned-file manifest; the manifest round-trips through the "reasampler" ext-state (Save / Save As / reopen); relative-paths-only preserved. Prune's consumption of it is Phase R. Depends on: the capture add-path (M7) + persist blob machinery (M4 / B2).

• Capture records each created file into an owned-file manifest (the set of files the book has created), persisted in the "reasampler" ext-state (sibling key or folded into the banks blob — persistence shape is a small build-time residual, not a fork).
• Manifest round-trips: survives Save / Save As / reopen via the M4 blob machinery; relative-paths-only. (Consumed by Phase R R1/R2 — not consumed here.)

B2 — persist slice (banks ↔ project ext state)

Goal: Serialize the book under the banks key in "reasampler" alongside the existing sections, with the pool folded in as bank-zero; migrate a legacy bank_index key into the pool on first load and retire the legacy key; reload-on-open and Save-As survival via the existing M4 machinery. CONTEXT.md §Multi-bank (persist). Verify (in DAW): Banks + named banks + active bank + all per-bank samples survive Save / Save As / close+reopen; relative paths only; bank travels with the .rpp; a project saved before this phase (legacy bank_index only) loads as pool + zero named banks with no sample loss, and after save carries banks with no bank_index written. Depends on: B1. (Persistence-key fork settled — fork 1 (a): pool inside the banks blob, legacy key retired after one-way migration.)

• Serialize/deserialize the book under the banks key (pool-as-bank-zero inside the blob; distinct section from view_state; no bank_index key written going forward).
• Legacy-migration path on load: absent banks + present bank_index → promote into pool, mint the blob, treat blob as authoritative (legacy key retired).
• Session exposes the book; the active bank's BankIndex is the capture add target (route the M7 capture family through it — additive to M7, no M7 rewrite).
• Confirm survival across Save / Save As; confirm legacy-project load path.

B3 — actions

Goal: Bindable action set for the multi-bank workflow. CONTEXT.md §Multi-bank (actions). Verify (in DAW): Each action registered (bindable in Actions list); bank-activate + move/copy + evacuate MIDI-bindable; create/rename/delete/evacuate drive the B1 model via the B2-persisted session. Depends on: B1, B2.

• Create bank / rename bank / delete bank (delete drops member index entries; confirm-on-non-empty offered at the UI layer in B4).
• Evacuate bank → pool (move all members back to the pool; refuses on the pool).
• Activate bank (direct-by-id + cycle).
• Move selected samples → bank / copy selected samples → bank (move is default).
• Pool full-height / banks full-height toggles.
• Register each (command_id/gaccel/hookcommand); bank-activate + move/copy
  • evacuate MIDI-bindable.

B4 — bank_panel vertical split (UI)

Goal: The vertical-split bank window — pool on top, named-banks tab-page region below, full-height toggles — extending the M5 docked grid. CONTEXT.md §Multi-bank (bank_panel). Verify (in DAW): Pool grid renders on top; named-banks tab strip below (empty when no named banks, one tab per named bank); active-bank unmistakably indicated; both full-height toggles collapse the split correctly; sample move/copy affordance works; non-empty delete confirms and offers evacuate; the Design View mode switch in the header is unaffected. Depends on: B1, B2, B3. (Tab rendering + move-affordance mechanics — fork 5 — settled 2026-07-23: LICE-drawn tabs + both move affordances; see Phase B open questions and product notes → Fork 5 — settled.)

• Vertical split: pool grid region (top) + named-banks tab-page region (bottom).
• Named-banks tab strip: LICE-drawn (matching the M5 grid + Design View segmented switch, not SWELL-native — fork 5a); one tab per named bank; empty state when none. Verify LICE tab draw against the M5 reference before use.
• Tab-strip overflow/scroll affordance — in scope from the start (fork 5a): a naive fixed-width LICE strip breaks down at ~8–12 tabs, so ship scroll/chevron overflow with the strip, do not defer it.
• Pool full-height / banks full-height toggle affordances wired to B3.
• Active-bank indicator — visually unmistakable (settled constraint); placement (per-region header / single readout / lit-tab) is the residual polish detail.
• Create / rename / delete / activate / evacuate affordances driving B3 actions.
• Delete confirms on a non-empty bank, naming the evacuate alternative.
• Sample move affordance — both (fork 5b): a "move to bank" menu on the current selection (bindable front-end for the B3 move action) and drag-between-regions. Copy is the deliberate secondary act, offered on the menu.
• Drag mis-drop mitigation (fork 5b): clear drop-target highlighting on the destination region/tab during a drag; a mis-drop is recoverable by design (move is index-only and reversible). Verify the drag hit-test doesn't collide with the M5 grid's multi-select drag.

B5 — sample-remove (the missing sample-level verb)

Goal: Drop an individual Sample's index entry from a bank or the pool — the sample-level companion to move/copy/evacuate/delete-bank. Index-only, non-destructive to the file; exposes the BankIndex::remove primitive that bank_model already has (wires it, does not add it). CONTEXT.md §Sample removal. Product framing + open forks: docs/product/removal-and-prune.md §Sample-remove. Verify (in DAW): Remove drops the selected sample's entry from the target bank; a same-hash entry in another bank is untouched (no cross-bank dedup); pool contents are removable while pool-container privileges hold; removing the last index reference to a file leaves that file on disk (orphaned until prune — never deleted by remove); non-destructive (index + ext-state only, no file, no timeline item). Depends on: B1, B2, B3 (action set), B4 (panel affordance).

• Surface BankIndex::remove through bank_book: remove a Sample from a bank's index; pool contents removable, pool-container privileges unchanged.
• "Remove selected sample(s)" action (command_id/gaccel/hookcommand), MIDI-bindable; carries a scope: this-bank | all-banks seam (fork R-A, settled 2026-07-24: this-bank is the default and only surfaced affordance; all-banks stays a latent seam-only parameter, not shipped).
• bank_panel remove affordance on the current selection (reuse M5 selection model, as move/copy do).
• Confirm-on-last-reference guardrail: remove that orphans a file (no other bank references it) confirms, naming the orphaned-until-prune consequence; remove of a still-referenced sample does not confirm.
• Tests: remove drops the target entry; same-hash entry in another bank survives; remove-from-pool allowed; last-reference remove leaves an orphan (file untouched); non-destructive (no file/timeline mutation).

Phase B open questions

All five forks settled by Daniel (2026-07-23): persistence key = fold pool into banks, retire legacy key (1a); delete drops members + add evacuate verb (2); move is the default gesture (3); active-bank/shown-tab distinct with an unmistakable indicator (4); LICE-drawn tabs + overflow, and both move affordances with drop-highlighting (5). Folded into CONTEXT.md §Multi-bank + the B1–B4 points above. Phase B is fully settled and ready to scope into implementation waves. One polish detail remains:

• Active-bank indicator placement — per-region headers vs. single header readout vs. lit-tab. "Unmistakable" is settled; only placement is open. Polish detail. (touches B4)

B5 sample-remove forks — settled 2026-07-24:

• R-A — remove scope. Settled: this-bank. Removes the entry from the bank in view only; the scope: this-bank | all-banks seam stays in the action signature but all-banks is a latent parameter, not a surfaced verb. Folded into the B5 action point above.
• R-B — undo model (Phase-B-wide). Settled: batched REAPER undo points (Undo_BeginBlock/Undo_EndBlock), one bank op = one Ctrl-Z. Applies across B1–B5 (retro-touches B1–B4) — captured as the cross-cutting note under B1 above, with the ext-state-participation SDK check as a must-verify-before-build. Both in docs/product/removal-and-prune.md §Fork R-A / §Fork R-B.

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Phase R — Reclaim (file lifecycle: the prune path)

New pillar, own lettered namespace. Prune is the file-lifecycle path the capture and multi-bank specs forward-reference throughout ("files persist on disk until prune") but that had no phase, module, or point. It is the only operation in ReaSampler that deletes bytes off disk. Namespaced R (Reclaim) alongside M/D/B because it is a distinct pillar — it serves every orphan-producing path (delete-bank, sample-remove B5, potentially M10 re-capture), not just Multi-bank, and it carries a new risk class (file deletion) with its own invariants. Authoritative spec: CONTEXT.md §Prune — file-lifecycle spec. Product framing + phase-placement justification + forks: docs/product/removal-and-prune.md §Prune. When a point lands, doc-keeper moves it to COMPLETED.md.

Boundary (load-bearing): remove creates orphans; prune reclaims them. No operation other than prune deletes a file; prune deletes only files no index references. A bank op that deletes a file is still a bug.

Depends on: B1, B2 (needs the multi-bank book to union the referenced-set across all banks) and B5 conceptually (sample-remove is a primary orphan-producer, so remove-then-prune is the coherent pair — mirror of evacuate-then-delete). Does not depend on the B3/B4 UI.

R1 — prune-reconcile core (pure)

Goal: REAPER-free, filesystem-free reconciler — given the files present in the bank folder, the files referenced by the book (unioned across all banks, pool included), and the owned-file manifest (fork R-D, written from capture onward by B-cap), compute the orphan set (owned ∩ present) − referenced. The mirror of ViewModeModel::reconcile(liveGuids), one level down (files instead of GUIDs). CONTEXT.md §Prune (Module architecture — pure). Verify: CTest green. Prune null test: a folder whose every file is referenced deletes nothing; prune returns exactly (owned ∩ present) − referenced and nothing else. Referenced-set unioned across every bank (a file referenced by any bank — including via a copy — is never an orphan); a present-but-not-owned file (a hand-dropped file) is never an orphan.

• Prune-reconcile pure function: (present, referenced, owned) → orphans, computing (owned ∩ present) − referenced; referenced unioned across the whole book (copies keep a file alive).
• Tests: prune null test (all-referenced → empty); orphan = (owned∩present)− referenced; a copied file referenced by a second bank survives; a present-but- unowned (hand-dropped) file is never reclaimed; empty folder / empty book / empty manifest edge cases.

R2 — prune shell + persist wiring (filesystem I/O, thin)

Goal: Enumerate the current project bank folder (M4 project-relative resolution), supply the referenced-set and the owned-file manifest (from B-cap) from the session, feed the pure core, and produce a dry-run manifest. No deletion in this wave — the report path only. CONTEXT.md §Prune (persist / prune shell). Verify (in DAW): Dry-run reports the orphan count + reclaimed size (+ file list for a small set) against the resolved current bank folder; resolves paths the same way the index does (survives a Save-As relocation); deletes nothing. Depends on: R1, B1, B2.

• Prune shell: enumerate the resolved current bank folder; feed the pure core.
• Session supplies the referenced-set (union across the book) and the owned-file manifest (written by B-cap); resolve the bank folder via the M4 project-relative machinery.
• Dry-run manifest: orphan count + reclaimed size (+ files for a small set); no deletion in this wave.

R3 — deletion + action (the destructive step, guarded)

Goal: The confirmed deletion step, the bindable "Prune bank folder" action, and a bank_panel prune button: dry-run-first, confirm-with-manifest, then reclaim the orphan set — via OS trash where portably available (fork R-C), else unlink. CONTEXT.md §Prune (guardrails, API). Verify (in DAW): "Prune bank folder" (action or panel button) reports first, deletes only on explicit confirm, and reclaims exactly the orphan set — never a referenced file, never a hand-dropped non-bank file; the referenced/owned-set safety holds; deletions route to OS trash where available; non-bank and capture invariants untouched. Depends on: R2 (and B-cap's owned-file manifest). All forks settled 2026-07-24.

• "Prune bank folder" action (command_id/gaccel/hookcommand), dry-run-first, confirm-to-delete.
• bank_panel prune button (fork R-E) that fires the "Prune bank folder" action through the existing command-id contract — the panel affordance alongside the bindable action; split: button hit-test/layout is pure (mirror of mode_switch/bank_grid), draw + dispatch is bank_panel shell.
• Deletion mechanism (fork R-C, settled trash-preferred): route to OS trash where a portable move-to-trash is verified available, else unlink behind the dry-run/confirm guardrail. Verify the platform move-to-trash surface before use (per platform).
• Orphan attribution (fork R-D, settled owned-file manifest): reclaim only (owned ∩ present) − referenced — the bank system's own leavings, never a hand-dropped folder file. (Manifest written by B-cap; consumed via R1/R2.)

Phase R forks — settled 2026-07-24

• Fork R-C — deletion mechanism. Settled: trash-preferred, unlink fallback. Route to OS trash where a portable move-to-trash is available (recoverable), else unlink behind strong dry-run/confirm. Per-platform trash surface (SWELL / Win SHFileOperation·IFileOperation / macOS trashItemAtURL: / Linux XDG) is a must-verify before use. Folded into R3.
• Fork R-D — orphan attribution. Settled: owned-file manifest, (owned ∩ present) − referenced; folder-sweep rejected as unsafe. Seam lands early — the manifest is written from capture onward (new B-cap point in Phase B), not reconstructed at prune time; R1/R2 consume it. Persistence shape (sibling "reasampler" key vs. banks blob) is a small build-time residual.
• Fork R-E — trigger. Settled: manual action + bank_panel button, dry-run-first, confirm-to-delete. No background sweep. The earlier optional delete-time "…and prune now" convenience was not selected — out of scope. Folded into R3.

Both docs of record: docs/product/removal-and-prune.md §Fork R-C/R-D/R-E and CONTEXT.md §Prune (Settled forks).

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Phase V — Versioning & release (release-milestone pillar, own lettered namespace)

New pillar, own lettered namespace. Version scheme + beta side-channel — the release-deployment path M11 forward-implies but that had no phase or points. Namespaced V (Versioning) alongside M/D/B/R because it is a distinct concern (build identity + channel isolation) that touches CMake, main.cpp's forever-stable command-id contract, and the "reasampler" ext-state — not a capture step. Product framing + the full option analysis: docs/product/versioning- and-release.md. Forks V1–V4 SETTLED (Daniel, 2026-07-26) — semver via project(VERSION) + ext-state version stamp prioritized first-wave; plain -beta suffix; console line + panel readout (about-box deferred); and beta ships as a separate, fully isolated coexisting binary (beta-in-isolation) — a reversal of the note's original one-at-a-time recommendation. Deploy/CD wiring (now two named artifacts per platform) hands off to dev-ops. Build-scoped points to be drawn up.

Settled decisions (Daniel, 2026-07-26 — see docs/product/versioning-and-release.md)

• V1 — version scheme: APPROVED as recommended. Semver, single source of truth in CMake project(reaper_reasampler VERSION x.y.z), threaded into the binary. The "reasampler" ext-state writing-version stamp is prioritized to the first wave, not deferred — every project saved without the stamp is harder to migrate later, so the migration seam lands early.
• V2 — beta suffix: plain -beta. project(VERSION) owns the release triple; beta carries a -beta suffix. git describe decoration considered and rejected for legibility.
• V3 — user-visible home: recommendation accepted. Startup console line ("ReaSampler x.y.z loaded") + a bank-panel version/channel readout; about-box deferred. Panel placement is the residual polish call.
• V4 — beta channel shape: BETA-IN-ISOLATION (full coexistence). Reverses the original recommendation. Beta ships as a separate binary (reaper_reasampler_ beta) with an isolated ext-state namespace (distinct from stable's "reasampler" — a beta cannot corrupt a stable project's saved state) and an isolated forever-stable command-id prefix (beta/stable keybindings don't collide), so both install and run side-by-side. Built through a compile-time channel flag (-DREASAMPLER_CHANNEL=beta) as the mechanism. Two permanent commitments locked in: a second forever-stable command-id prefix and a second ext-state namespace. Dev-ops: the build now produces two named artifacts (stable + beta) per platform.

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Phase S — MIDI-playback instrument (native VST3 sampler; a second build artifact)

New pillar, own lettered namespace, and — uniquely — a second build artifact. Every prior phase ships inside the one reaper_reasampler extension binary; Phase S does not. A REAPER extension cannot be a MIDI-triggered instrument (it is not a node in any track's signal chain), so the instrument is a separate native VST3 plugin the user instantiates on an instrument track, reading ReaSampler's banks and playing them MIDI-triggered. Namespaced S (Sampler) rather than "D" (Daniel's call — "D" collides with Design View). Authoritative spec: CONTEXT.md §MIDI-playback instrument — additive phase spec (Phase S). Product framing + the settled decision record (D1/D5/D6 locked, D-A..D-D settled 2026-07-26): docs/product/midi-playback.md. When a point lands, doc-keeper moves it to COMPLETED.md.

Locked (see docs/product/midi-playback.md §4): D1 native VST3 (not JSFX); D5 Windows-only / VST3-only / REAPER-only; D6 two products, tightly integrated via the VST-host bridge (live "reasampler" ext-state, project-aware). Settled forks (2026-07-26): D-A bare Steinberg VST3 SDK + LICE editor (no JUCE); D-B split seam with root-note + loop-points added to Sample now; D-C Tier 0–1 committed (Tier 2 held, Tier 3 optional-forever); D-D embedded TCP/MCP UI scheduled as a later in-phase point (after the main editor exists).

Second build artifact (load-bearing, flagged up front): Phase S produces a separate VST3 binary alongside reaper_reasampler. The Steinberg VST3 SDK is a new vendored dependency (vendor at the spike — an implementation-time prerequisite, not done here), and CMake grows a second target with Windows VST3 module-export/bundle wiring. Both are established by S1 so nothing downstream leans on an unbuilt target.

S1 — opening spike: VST3 skeleton + IPlugView↔LICE bridge (proof + second target)

Goal: Stand up the second build artifact and prove the two least-trodden unknowns before the engine build leans on them: (1) a silent-but-loading VST3 SingleComponentEffect skeleton that REAPER hosts, and (2) an IPlugView that hosts a LICE-drawn surface. Converts §1a's experienced-estimates (Windows module-export names, factory-macro spellings, exact bridge marshalling) into verified fact. CONTEXT.md §Phase S (build shape, module architecture, API surface). Prerequisite (implementation-time): vendor the Steinberg VST3 SDK (a new submodule/dependency alongside reaper-sdk / WDL); confirm whether VSTGUI is bundled (moot for D-A but resolves the noted fallback rung). Verify (in DAW): the VST3 skeleton loads in REAPER on an instrument track, enumerates via GetPluginFactory, sets up an event-in + audio-out bus, and runs an empty process without error; an IPlugView opens and draws a LICE surface with a working hit-test; the VST-host bridge resolves GetProjExtState by name and reads a known "reasampler" value. Nothing plays yet — this is the loading/drawing/bridge proof.

• CMake second target: a separate VST3 module artifact built alongside reaper_reasampler (Windows VST3 export/bundle wiring; GetPluginFactory + InitDll/ExitDll — verify exact export names against the vendored SDK).
• SingleComponentEffect skeleton: factory + class registration, initialize declaring an event-input bus + an audio-output bus (no audio input), setupProcessing, setActive, empty process. Loads silently in REAPER.
• IPlugView↔LICE bridge spike: open a plugin editor window hosting a LICE-drawn surface (window creation/sizing, host→draw/hit-test event routing), reusing the bank_panel LICE/SWELL competence. The decision's one real unknown — prove it here. (VSTGUI is the noted fallback only if this proves gnarlier than the panel work suggests.)
• Bridge read spike: resolve GetProjExtState/EnumProjExtState by name over the host callback (hostcb opcode 0xdeadf00d), fetch host project context (0xdeadf00e), and read a known "reasampler" ext-state value. Verify opcodes + marshalling against reaper_plugin.h / video_processor.h / reaper_plugin_functions.h.

S2 — Sample intrinsic fields (root note + loop points; in the extension)

Goal: Add the two bank-intrinsic seam fields to Sample — root note (MIDI note the sample was recorded at; distinct from the existing optional musical key) and loop points (sustain-loop start/end, sample-accurate, zero-crossing-aware) — as an additive field extension with JSON round-trip, populated at/after capture. This touches the extension codebase, is independently shippable, and lands early to close the backfill cliff before the instrument consumes the fields. CONTEXT.md §Phase S (seam fields, D-B). Same additive shape as provenance (M1). Verify: CTest green. Round-trip lossless across the new fields; pre-existing samples (no root note / loop points) deserialize with clean defaults (no loss, no migration break); capture populates root note where derivable and loop points where set; relative-paths-only unaffected; BankIndex behavior unchanged (purely additive). Depends on: nothing in Phase S (extension-only; can land before or in parallel with S1).

• Add rootNote (optional MIDI note) + loopStart/loopEnd (optional sample-accurate loop points) to Sample; JSON serialize/deserialize with clean defaults for samples lacking them (additive, backward-compatible — mirror of how provenance was added).
• Populate the fields on capture where derivable (root note) / settable (loop points); leave them cleanly empty otherwise. No existing Sample field changes.
• Tests: full round-trip lossless including the new fields; a legacy Sample JSON (no new fields) parses with defaults and re-serializes without loss; additive invariant (no change to existing fields, dedup, tier, or BankIndex behavior).

S3 — pure sampler core (voice engine / envelope / keymap / repitch)

Goal: The REAPER-free and VST3-free sampler core — voice allocation/polyphony, amplitude envelope (ADSR), key→sample and velocity→sample mapping (the keymap), repitch/interpolation from root note, keymap resolution — unit-tested in CTest against known signals. The heart of the phase (D3); the mirror of bank_model/peaks/view_mode_model/bank_book; test it hard. The core is invariant under the build-shape choice — no VST3 or REAPER type at its boundary. CONTEXT.md §Phase S (pure core, module architecture). Verify: CTest green. Voice allocation is correct under polyphony (note-on/off, voice stealing where bounded); ADSR shape asserted against a known signal (mirror of peaks); repitch from root note produces the expected pitch ratio; keymap resolution maps a (note, velocity) to the correct sample/zone; the core takes and returns only plain data (no VST3/REAPER types) — enforced by the test target linking neither SDK. Depends on: S2 (consumes rootNote / loop points as core inputs).

• Voice engine: polyphonic voice allocation (note-on/off, bounded voice stealing), per-voice state, mono-and-basic-polyphony sufficient for Tier 0.
• Amplitude envelope (ADSR) math — asserted against a known signal.
• Repitch/interpolation from root note (chromatic pitch ratio across the keyboard); loop-point-aware sustain for held notes.
• Keymap model + resolution: key ranges/zones (Tier-1 shape) and the (note, velocity) → sample/zone query; Tier-0 chromatic-from-single-root as the degenerate case.
• Tests: voice allocation under polyphony + stealing; ADSR envelope shape; repitch pitch-ratio correctness; keymap resolution (single-root chromatic + zoned); core boundary is plain-data-only (no VST3/REAPER types).

S4 — Tier 0: "the bank plays" (single sample, chromatic)

Goal: The honest MVP — one bank sample mapped chromatically across the keyboard from its root note, basic polyphony, a simple amp envelope, velocity→volume. Wire the S3 core into the S1 VST3 shell over the live-state seam (bridge-read bank + audio via the M4 project-relative path machinery). Editor deferrable behind a parameters-only default view. CONTEXT.md §Phase S (Tier 0, seams). Delivers the core promise. Verify (in DAW): on an instrument track, the VST3 plays a chosen bank sample MIDI-triggered, repitched chromatically from its root note, with basic polyphony, an amp envelope, and velocity→volume; it reads the live "reasampler" bank via the bridge and resolves the WAV audio the same project-relative way persist does; following the active project works; it never captures and never inserts into the arrange (read-only over the bank). Depends on: S1, S2, S3.

• VST3 process marshalling: read MIDI note-on/off/velocity off the event bus, drive the S3 core, write per-voice audio to the output bus.
• Live-state seam: read the bank index + selected sample's root note from "reasampler" ext-state via the bridge; resolve the WAV audio path the M4 project-relative way (shared convention with persist, not re-implemented).
• Sample selection UI (minimal, in the IPlugView LICE editor or a parameters-only default view): choose which bank sample this instance plays.
• Tier-0 playback: chromatic-from-root, basic polyphony, amp envelope, velocity→volume — plays in REAPER's routing/record/render path like any VSTi.

S5 — Tier 1: "a keymap" (zoned multisamples, per-sample root notes)

Goal: Multiple bank samples zoned across the keyboard (key ranges), each with its own root note — a captured kit (one-shots) or a multisampled instrument (same instrument sampled at several pitches) plays correctly. One sample per key-region. CONTEXT.md §Phase S (Tier 1). Where the root-note + key-range seam fields earn their place. Verify (in DAW): a keymap of several bank samples plays correctly zoned across the keyboard, each repitched from its own root note within its range; a captured kit and a multisampled instrument both play as expected; the keymap is authored in the instrument (performance map) while root notes come from the bank intrinsics (S2); editing the keymap does not touch the bank. Depends on: S4.

• Keymap editor in the IPlugView LICE editor: assign bank samples to key ranges (low/high note per sample), each with its own root note (from S2 intrinsics, overridable in the performance map).
• Tier-1 playback: zoned resolution — a note picks its zone's sample and repitches from that sample's root note; one sample per key-region.
• Performance-map persistence: the keymap (zones, per-sample assignment) is the instrument's own state — held in the instrument (read/written over the live "reasampler" seam per D-B's data-ownership split), never written back as a bank intrinsic.

S6 — embedded TCP/MCP UI (D-D — scheduled in-phase, after the editor)

Goal: Render a compact keymap/level strip inline in the track/mixer control panel via reaper_plugin_fx_embed.h (IReaperUIEmbedInterface) — the same Cockos surface REAPER's own embedded FX use — so the instrument draws inline, not only in its own window. Composes with the S1/S5 LICE editor path (same LICE-class drawing). Scheduled, not deferred (D-D settled 2026-07-26): a real later point, sequenced last because it is polish over a Tier-0 need — but on the roadmap. CONTEXT.md §Phase S (embedded UI, D-D). Verify (in DAW): the instrument draws a compact inline strip in the TCP/MCP (not only its own editor window); the inline surface reflects and (where offered) edits the keymap/levels; the embed lifecycle is clean (open/close/resize); the same LICE drawing as the main editor is reused. Depends on: S5 (composes over the existing LICE editor). Must-verify before build: the IReaperUIEmbedInterface contract + embed message/lifecycle against vendor/reaper-sdk/sdk/reaper_plugin_fx_embed.h.

• Implement IReaperUIEmbedInterface on the VST3; draw a compact keymap/level strip inline in the TCP/MCP using the same LICE surface as the editor.
• Embed lifecycle (open/close/resize/hit-test inline) handled cleanly; reflects the live keymap/levels.

Phase S — held and optional-forever (noted, not specified)

• Tier 2 — "expressive" (HELD). Velocity layers, round-robin (anti-machine-gun), full ADSR, per-sample tuning/gain trim, sustain loops. The next depth increment once Tier 0–1 proves the instrument belongs — its points are not drawn up here.
• Tier 3 — "instrument polish" (optional-forever). Filters, filter/pitch envelopes, LFOs, per-voice pan, choke groups, a modest FX slot. A direction to leave room for, never a commitment.

Phase S — must-verify-before-build (carried from CONTEXT.md §Phase S)

• Steinberg VST3 SDK surface — interface members, base-class overrides, factory-macro spellings, Windows module-export symbol names (InitDll/ExitDll/GetPluginFactory), and whether VSTGUI is bundled. Several are §1a experienced-estimates until S1 confirms them against the vendored SDK.
• VST-host bridge — opcodes 0xdeadf00d (resolve-by-name) / 0xdeadf00e (host context) and the exact call marshalling, against reaper_plugin.h / video_processor.h / reaper_plugin_functions.h.
• IReaperUIEmbedInterface — embed contract + message/lifecycle, against reaper_plugin_fx_embed.h (needed only at S6).