# E3.M3 — ItemizationAndInventorySchema

## Summary

| Field | Value |
|--------|--------|
| **Module ID** | E3.M3 |
| **Epic** | [Epic 3 — Crafting Economy](../epics/epic_03_crafting_economy.md) |
| **Stage target** | Prototype |
| **Status** | Planned — Slice 1 backlog [NEO-50](https://linear.app/neon-sprawl/issue/NEO-50)–[NEO-56](https://linear.app/neon-sprawl/issue/NEO-56) ([E3M3-prototype-backlog](../../plans/E3M3-prototype-backlog.md); see [dependency register](module_dependency_register.md)) |

## Purpose

Item definitions, rarity/quality, stackability, and equipment metadata plus `InventorySlot` representation. Foundation for craft outputs, quest rewards, combat loot, and trade.

## Responsibilities

- Version `ItemDef` / `ItemInstance` schema; enforce stack and slot rules server-side.

## Key contracts

| Contract | Role |
|----------|------|
| `ItemDef` | Static template data. |
| `ItemInstance` | Per-item state (stack, durability hook, binds). |
| `InventorySlot` | Container model for players and exchanges. |

## Module dependencies

- **None**

## Dependents (by design)

- **E3.M2**, **E3.M4**, **E5.M3**, **E7.M2**, **E8.M3**, and any system moving items.

## Related implementation slices

Epic 3 **Slice 1** — MVP inventory; `item_created`, transfer failures.

**Linear backlog (decomposed):** [E3M3-prototype-backlog.md](../../plans/E3M3-prototype-backlog.md) — **E3M3-01** [NEO-50](https://linear.app/neon-sprawl/issue/NEO-50) (content + CI) through **E3M3-07** [NEO-56](https://linear.app/neon-sprawl/issue/NEO-56) (telemetry hooks). Prototype **frozen item ids:** `scrap_metal_bulk`, `refined_plate_stock`, `field_stim_mk0`, `survey_drone_kit`, `contract_handoff_token`, `prototype_armor_shell`.

## Source anchors

- Master plan: [`neon_sprawl_vision.plan.md`](../../../neon_sprawl_vision.plan.md) — Epic 3.
- [Module dependency register](module_dependency_register.md)