# E3.M3 — Prototype story backlog (ItemizationAndInventorySchema)

Working backlog for **Epic 3 — Slice 1** ([items and inventory MVP](../decomposition/epics/epic_03_crafting_economy.md#slice-1---items-and-inventory-mvp)). Decomposition and contracts: [E3.M3 — ItemizationAndInventorySchema](../decomposition/modules/E3_M3_ItemizationAndInventorySchema.md).

**Labels (Linear):** every issue **`E3.M3`**; add **`server`** / **`Feature`** or **`Story`** as listed per issue.

**Precursor (do not re-scope):** gather **skill XP** on `resource_node` interact is **E3.M1** anchor only ([NEO-41](https://linear.app/neon-sprawl/issue/NEO-41)) — no `GatherResult` / inventory yet. This module owns **`ItemDef`**, **`ItemInstance`**, **`InventorySlot`**, and server-authoritative player inventory.

**Prototype item spine (frozen in E3M3-01):** six rows covering **material → intermediate → consumable → utility → quest token → equip stub** for the gather→refine→craft loop ([items.md](../game-design/items.md), [gathering.md](../game-design/gathering.md), [crafting.md](../game-design/crafting.md)).

**Linear issues (created):** attach `docs/plans/NEO-*-implementation-plan.md` on the same branch as implementation work.

| Slug | Linear |
|------|--------|
| E3M3-01 | [NEO-50](https://linear.app/neon-sprawl/issue/NEO-50) |
| E3M3-02 | [NEO-51](https://linear.app/neon-sprawl/issue/NEO-51) |
| E3M3-03 | [NEO-52](https://linear.app/neon-sprawl/issue/NEO-52) |
| E3M3-04 | [NEO-53](https://linear.app/neon-sprawl/issue/NEO-53) |
| E3M3-05 | [NEO-54](https://linear.app/neon-sprawl/issue/NEO-54) |
| E3M3-06 | [NEO-55](https://linear.app/neon-sprawl/issue/NEO-55) |
| E3M3-07 | [NEO-56](https://linear.app/neon-sprawl/issue/NEO-56) |

**Dependency graph in Linear:** E3M3-02 blocked by E3M3-01. E3M3-03 blocked by E3M3-02. E3M3-04 and E3M3-05 blocked by E3M3-03. E3M3-06 blocked by E3M3-05. E3M3-07 blocked by E3M3-05 (may parallel E3M3-06).

---

## Story order (recommended)

| Order | Slug | Depends on |
|-------|------|------------|
| 1 | **E3M3-01** | None (content spine) |
| 2 | **E3M3-02** | E3M3-01 |
| 3 | **E3M3-03** | E3M3-02 |
| 4 | **E3M3-04** | E3M3-03 |
| 5 | **E3M3-05** | E3M3-03 |
| 6 | **E3M3-06** | E3M3-05 |
| 7 | **E3M3-07** | E3M3-05 |

**Downstream (separate modules):** [E3.M1](../decomposition/modules/E3_M1_ResourceNodeAndGatherLoop.md) Slice 2 gather yields → inventory grants; [E3.M2](../decomposition/modules/E3_M2_RefinementAndRecipeExecution.md) craft I/O; [NEO-42](https://linear.app/neon-sprawl/issue/NEO-42) refine XP hook invokes after craft success.

---

### E3M3-01 — Prototype ItemDef starter set + schemas + CI

**Goal:** Lock content shape and CI validation for a **frozen six-item** prototype catalog before any server load.

**In scope**

- `content/schemas/item-def.schema.json` (or equivalent single-catalog schema).
- `content/items/prototype_items.json` with stable ids: `scrap_metal_bulk`, `refined_plate_stock`, `field_stim_mk0`, `survey_drone_kit`, `contract_handoff_token`, `prototype_armor_shell` (names/display may change; **ids frozen**).
- `scripts/validate_content.py`: schema validation, duplicate `id`, required `prototypeRole` coverage (one row per archetype), exact six-id allowlist for prototype.
- Designer note in [E3_M3](../decomposition/modules/E3_M3_ItemizationAndInventorySchema.md) + `content/README.md`: stack rules, slot kinds (bag vs equip stub), v1 scope (no durability mutation).

**Out of scope**

- Server loader, inventory store, HTTP, client HUD.

**Acceptance criteria**

- [x] PR gate validates item JSON against schema.
- [x] Exactly six prototype item ids; duplicate `id` fails CI.
- [x] Stable id list documented in module doc freeze box.

**Landed ([NEO-50](https://linear.app/neon-sprawl/issue/NEO-50)):** [`content/items/prototype_items.json`](../../content/items/prototype_items.json), [`item-def.schema.json`](../../content/schemas/item-def.schema.json), CI gates in [`validate_content.py`](../../scripts/validate_content.py); plan [NEO-50-implementation-plan.md](NEO-50-implementation-plan.md).

---

### E3M3-02 — Server item catalog load (fail-fast)

**Goal:** Disk → host: startup load of `content/items/*.json` with CI-parity validation.

**In scope**

- Loader + registry interface under `server/NeonSprawl.Server/Game/Items/` (path TBD in plan).
- Fail-fast on malformed files, duplicate ids, unknown enum values.
- Unit tests (AAA) for loader happy path and failure modes.

**Out of scope**

- Per-player inventory, HTTP.

**Acceptance criteria**

- [ ] Server refuses boot when item catalog invalid (mirror E2.M1 catalog behavior).
- [ ] Registry resolves `ItemDef` by `id`.

---

### E3M3-03 — Item definition registry + DI

**Goal:** Injectable `IItemDefinitionRegistry` consumed by inventory and future craft/gather paths.

**In scope**

- `ItemDefinitionRegistry` implementation + DI registration.
- Unit tests (AAA): lookup, unknown id, prototype row metadata.

**Out of scope**

- HTTP, persistence, stack mutation.

**Acceptance criteria**

- [ ] Host resolves registry from DI; unknown `itemId` distinguishable from valid ids in tests.

---

### E3M3-04 — GET world item-definitions

**Goal:** Versioned read-only catalog for client preview, Bruno, and future codegen — mirror [NEO-36](https://linear.app/neon-sprawl/issue/NEO-36) skill-definitions pattern.

**In scope**

- `GET /game/world/item-definitions` + DTOs + API tests (AAA).
- Bruno folder `bruno/neon-sprawl-server/item-definitions/`.
- `server/README.md` section.

**Out of scope**

- Per-player inventory mutation.

**Acceptance criteria**

- [ ] GET returns all six prototype defs with schema version field.
- [ ] Bruno happy path documented.

---

### E3M3-05 — Player inventory store + stack/slot rules engine

**Goal:** Server-authoritative `ItemInstance` bags with stack limits and structured deny reasons; persistence (in-memory + Postgres + migration).

**In scope**

- `IPlayerInventoryStore`, migration `V00X__player_inventory` (number in plan).
- Inventory operations: add stack, remove stack, slot capacity, `inventory_full` / `invalid_item` / `insufficient_quantity` reason codes.
- Unit + integration tests (AAA); mirror NEO-8/NEO-38 persistence policy.

**Out of scope**

- HTTP, Bruno, client HUD.
- Craft/gather automatic grants (callers in E3.M1 / E3.M2).

**Acceptance criteria**

- [ ] Add/remove respects `ItemDef` stack max from catalog.
- [ ] Full bag returns stable `reasonCode` without partial silent loss.
- [ ] Postgres + in-memory parity tests.

---

### E3M3-06 — Player inventory HTTP + Bruno

**Goal:** Versioned **GET** snapshot and **POST** grant/consume (or add/remove) for manual QA and future client.

**In scope**

- `GET /game/players/{id}/inventory` and mutating POST (exact path/shape in implementation plan).
- Known-player gate via `IPositionStateStore` (NEO-37 pattern).
- Bruno `bruno/neon-sprawl-server/inventory/`.
- `server/README.md`; API tests (AAA).

**Out of scope**

- Godot HUD — **[Epic 3 Slice 5](E3S5-client-prototype-backlog.md#e3s5-01--client-inventory-snapshot-hud-e3m3)** ([NEO-72](https://linear.app/neon-sprawl/issue/NEO-72)).
- Gather node depletion ([E3.M1](../decomposition/modules/E3_M1_ResourceNodeAndGatherLoop.md)).

**Acceptance criteria**

- [ ] GET returns instances + slots for seeded player.
- [ ] POST add/remove matches engine rules from E3M3-05.
- [ ] Bruno exercises happy path + at least one deny (`inventory_full` or unknown item).

---

### E3M3-07 — `item_created` / transfer-failure telemetry hook sites

**Goal:** Comment-only hooks on inventory mutation success/deny for future E9.M1 catalog events **`item_created`** and transfer failures.

**In scope**

- Hook placement in inventory engine (and POST path if applicable).
- `TODO(E9.M1)` comments; no production logging.
- README + module doc pointer.

**Out of scope**

- Telemetry ingest, dashboards.

**Acceptance criteria**

- [ ] Hook sites documented in code and `server/README.md`.
- [ ] Matches Epic 3 Slice 1 telemetry vocabulary in [epic_03](../decomposition/epics/epic_03_crafting_economy.md).

---

## After this backlog

- **[E3.M1](../decomposition/modules/E3_M1_ResourceNodeAndGatherLoop.md)** Slice 2 decomposed — [E3M1-prototype-backlog.md](E3M1-prototype-backlog.md) ([NEO-57](https://linear.app/neon-sprawl/issue/NEO-57)–[NEO-64](https://linear.app/neon-sprawl/issue/NEO-64)).
- **[E3.M2](../decomposition/modules/E3_M2_RefinementAndRecipeExecution.md)** Slice 3 decomposed — [E3M2-prototype-backlog.md](E3M2-prototype-backlog.md) ([NEO-65](https://linear.app/neon-sprawl/issue/NEO-65)–[NEO-71](https://linear.app/neon-sprawl/issue/NEO-71)).
- **Epic 3 Slice 5 (client)** — [E3S5-client-prototype-backlog.md](E3S5-client-prototype-backlog.md) ([NEO-72](https://linear.app/neon-sprawl/issue/NEO-72)–[NEO-75](https://linear.app/neon-sprawl/issue/NEO-75)); inventory HUD is **E3S5-01** [NEO-72](https://linear.app/neon-sprawl/issue/NEO-72).
- Track delivery in Linear; keep `blockedBy` links synchronized if scope changes.
- For each issue kickoff, add `docs/plans/{NEO-XX}-implementation-plan.md` per [story-kickoff](../../.cursor/rules/story-kickoff.md).
- Add `docs/manual-qa/{NEO-XX}.md` when HTTP surfaces land (E3M3-06+).

## Related docs

- [E3_M3_ItemizationAndInventorySchema.md](../decomposition/modules/E3_M3_ItemizationAndInventorySchema.md)
- [epic_03_crafting_economy.md](../decomposition/epics/epic_03_crafting_economy.md)
- [items.md](../game-design/items.md)
- [E2_M1_SkillDefinitionRegistry.md](../decomposition/modules/E2_M1_SkillDefinitionRegistry.md) (catalog pattern precedent)
