diff --git a/bruno/neon-sprawl-server/inventory/Get inventory.bru b/bruno/neon-sprawl-server/inventory/Get inventory.bru
new file mode 100644
index 0000000..60e701e
--- /dev/null
+++ b/bruno/neon-sprawl-server/inventory/Get inventory.bru
@@ -0,0 +1,41 @@
+meta {
+ name: GET inventory
+ type: http
+ seq: 1
+}
+
+docs {
+ NEO-55: per-player inventory read model; join with GET /game/world/item-definitions for stackMax and slot kinds.
+ Fresh dev server seeds dev-local-1 with empty 24+1 slot grid.
+}
+
+get {
+ url: {{baseUrl}}/game/players/dev-local-1/inventory
+ body: none
+ auth: none
+}
+
+tests {
+ test("returns 200 JSON with schema v1 and fixed slot arrays", function () {
+ expect(res.getStatus()).to.equal(200);
+ expect(res.getHeader("content-type")).to.contain("application/json");
+ const body = res.getBody();
+ expect(body.schemaVersion).to.equal(1);
+ expect(body.playerId).to.equal("dev-local-1");
+ expect(body.bagSlots).to.be.an("array");
+ expect(body.bagSlots.length).to.equal(24);
+ expect(body.equipmentSlots).to.be.an("array");
+ expect(body.equipmentSlots.length).to.equal(1);
+ });
+
+ test("empty slots omit itemId and use quantity 0", function () {
+ const body = res.getBody();
+ for (const slot of body.bagSlots) {
+ expect(slot.slotIndex).to.be.a("number");
+ expect(slot.quantity).to.equal(0);
+ expect(slot.itemId).to.equal(undefined);
+ }
+ expect(body.equipmentSlots[0].quantity).to.equal(0);
+ expect(body.equipmentSlots[0].itemId).to.equal(undefined);
+ });
+}
diff --git a/bruno/neon-sprawl-server/inventory/Post inventory add deny invalid item.bru b/bruno/neon-sprawl-server/inventory/Post inventory add deny invalid item.bru
new file mode 100644
index 0000000..58961dd
--- /dev/null
+++ b/bruno/neon-sprawl-server/inventory/Post inventory add deny invalid item.bru
@@ -0,0 +1,36 @@
+meta {
+ name: POST inventory add deny invalid item
+ type: http
+ seq: 3
+}
+
+docs {
+ NEO-55: unknown itemId denies with invalid_item and echoes unchanged inventory.
+}
+
+post {
+ url: {{baseUrl}}/game/players/dev-local-1/inventory
+ body: json
+ auth: none
+}
+
+body:json {
+ {
+ "schemaVersion": 1,
+ "mutationKind": "add",
+ "itemId": "not-a-prototype-item",
+ "quantity": 1
+ }
+}
+
+tests {
+ test("denies with invalid_item and echoes inventory", function () {
+ expect(res.getStatus()).to.equal(200);
+ const body = res.getBody();
+ expect(body.schemaVersion).to.equal(1);
+ expect(body.applied).to.equal(false);
+ expect(body.reasonCode).to.equal("invalid_item");
+ expect(body.inventory).to.be.an("object");
+ expect(body.inventory.bagSlots.length).to.equal(24);
+ });
+}
diff --git a/bruno/neon-sprawl-server/inventory/Post inventory add.bru b/bruno/neon-sprawl-server/inventory/Post inventory add.bru
new file mode 100644
index 0000000..1be951e
--- /dev/null
+++ b/bruno/neon-sprawl-server/inventory/Post inventory add.bru
@@ -0,0 +1,41 @@
+meta {
+ name: POST inventory add
+ type: http
+ seq: 2
+}
+
+docs {
+ NEO-55: add stack via mutationKind add; see server README inventory HTTP section.
+}
+
+post {
+ url: {{baseUrl}}/game/players/dev-local-1/inventory
+ body: json
+ auth: none
+}
+
+body:json {
+ {
+ "schemaVersion": 1,
+ "mutationKind": "add",
+ "itemId": "scrap_metal_bulk",
+ "quantity": 5
+ }
+}
+
+tests {
+ test("add returns 200 with applied true and updated inventory", function () {
+ expect(res.getStatus()).to.equal(200);
+ const body = res.getBody();
+ expect(body.schemaVersion).to.equal(1);
+ expect(body.applied).to.equal(true);
+ expect(body.reasonCode).to.equal(null);
+ expect(body.inventory).to.be.an("object");
+ expect(body.inventory.playerId).to.equal("dev-local-1");
+ const occupied = body.inventory.bagSlots.filter((s) => s.quantity > 0);
+ expect(occupied.length).to.be.at.least(1);
+ const scrap = occupied.find((s) => s.itemId === "scrap_metal_bulk");
+ expect(scrap).to.be.an("object");
+ expect(scrap.quantity).to.be.at.least(5);
+ });
+}
diff --git a/bruno/neon-sprawl-server/inventory/folder.bru b/bruno/neon-sprawl-server/inventory/folder.bru
new file mode 100644
index 0000000..12b2b71
--- /dev/null
+++ b/bruno/neon-sprawl-server/inventory/folder.bru
@@ -0,0 +1,3 @@
+meta {
+ name: inventory
+}
diff --git a/docs/decomposition/modules/E3_M3_ItemizationAndInventorySchema.md b/docs/decomposition/modules/E3_M3_ItemizationAndInventorySchema.md
index f1bdd31..942bc0e 100644
--- a/docs/decomposition/modules/E3_M3_ItemizationAndInventorySchema.md
+++ b/docs/decomposition/modules/E3_M3_ItemizationAndInventorySchema.md
@@ -68,7 +68,9 @@ Epic 3 **Slice 1** — MVP inventory; `item_created`, transfer failures.
**Item definitions HTTP (NEO-53):** **`GET /game/world/item-definitions`** — versioned read-only projection (`schemaVersion` **1**, **`items`**) backed by **`IItemDefinitionRegistry`**; Bruno `bruno/neon-sprawl-server/item-definitions/`. Plan: [NEO-53 implementation plan](../../plans/NEO-53-implementation-plan.md).
-**Player inventory store (NEO-54):** **`IPlayerInventoryStore`** + **`PlayerInventoryOperations`** in `server/NeonSprawl.Server/Game/Items/` — fixed **24 bag + 1 equipment** slots, stack limits from catalog, stable deny reason codes; in-memory + Postgres (`V005__player_inventory.sql`). HTTP deferred to NEO-55. Plan: [NEO-54 implementation plan](../../plans/NEO-54-implementation-plan.md).
+**Player inventory store (NEO-54):** **`IPlayerInventoryStore`** + **`PlayerInventoryOperations`** in `server/NeonSprawl.Server/Game/Items/` — fixed **24 bag + 1 equipment** slots, stack limits from catalog, stable deny reason codes; in-memory + Postgres (`V005__player_inventory.sql`). Plan: [NEO-54 implementation plan](../../plans/NEO-54-implementation-plan.md).
+
+**Player inventory HTTP (NEO-55):** **`GET` / `POST /game/players/{id}/inventory`** — versioned snapshot + **`mutationKind`** add/remove backed by **`PlayerInventoryOperations`**; Bruno `bruno/neon-sprawl-server/inventory/`. Plan: [NEO-55 implementation plan](../../plans/NEO-55-implementation-plan.md).
**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).
diff --git a/docs/decomposition/modules/documentation_and_implementation_alignment.md b/docs/decomposition/modules/documentation_and_implementation_alignment.md
index 7fee86f..5d147ec 100644
--- a/docs/decomposition/modules/documentation_and_implementation_alignment.md
+++ b/docs/decomposition/modules/documentation_and_implementation_alignment.md
@@ -54,7 +54,7 @@ Rows appear when work starts; default for unlisted modules is **Planned** / not
| E2.M3 | In Progress | **NEO-45 landed:** prototype **`salvage`** mastery catalog + CI gates (see [NEO-45 plan](../../plans/NEO-45-implementation-plan.md)). **NEO-46 landed:** fail-fast server load under `server/NeonSprawl.Server/Game/Mastery/` — `MasteryCatalogLoader`, `IMasteryCatalogRegistry`, cross-check vs `ISkillDefinitionRegistry`, Slice 4 + **`tierIndex`** 1..N gate; see [NEO-46 plan](../../plans/NEO-46-implementation-plan.md). **NEO-47 landed:** `PerkUnlockEngine`, `IPlayerPerkStateStore` + **`V004`**, level-up hook in skill XP grants; see [NEO-47 plan](../../plans/NEO-47-implementation-plan.md). **NEO-49 landed:** comment-only **`perk_unlock`** telemetry hook site in [`PerkUnlockEngine.TryUnlockPerks`](../../../server/NeonSprawl.Server/Game/Mastery/PerkUnlockEngine.cs) ([NEO-49 plan](../../plans/NEO-49-implementation-plan.md), [`NEO-49` manual QA](../../manual-qa/NEO-49.md)); [server README — Perk unlock telemetry (NEO-49)](../../../server/README.md#perk-unlock-engine-and-telemetry-hooks-neo-47-neo-49). **NEO-48 landed:** **`GET`/`POST /game/players/{id}/perk-state`** — `PerkStateApi` + DTOs in `Game/Mastery/` ([NEO-48](../../plans/NEO-48-implementation-plan.md), [`NEO-48` manual QA](../../manual-qa/NEO-48.md)); [server README — Perk state (NEO-48)](../../../server/README.md#perk-state-neo-48); Bruno `bruno/neon-sprawl-server/perk-state/`. | [NEO-45](../../plans/NEO-45-implementation-plan.md), [NEO-46](../../plans/NEO-46-implementation-plan.md), [NEO-47](../../plans/NEO-47-implementation-plan.md), [NEO-48](../../plans/NEO-48-implementation-plan.md), [NEO-49](../../plans/NEO-49-implementation-plan.md), [E2M3-pre-production-backlog](../../plans/E2M3-pre-production-backlog.md), [E2_M3](E2_M3_MasteryAndPerkUnlocks.md) |
| E2.M2 | In Progress | **NEO-37 landed:** versioned **`GET /game/players/{id}/skill-progression`** ([NEO-37](../../plans/NEO-37-implementation-plan.md)) — read model for every registered skill; known-player gate via `IPositionStateStore`; [server README — Skill progression snapshot (NEO-37)](../../../server/README.md#skill-progression-snapshot-neo-37); manual QA [`NEO-37`](../../manual-qa/NEO-37.md). **NEO-38 landed:** **`POST`** same path — grant apply, persistence (`IPlayerSkillProgressionStore`, `V003` migration), structured denies + **`levelUps`** ([NEO-38](../../plans/NEO-38-implementation-plan.md)); manual QA [`NEO-38`](../../manual-qa/NEO-38.md); Bruno `bruno/neon-sprawl-server/skill-progression/`; [server README — Skill progression grant (NEO-38)](../../../server/README.md#skill-progression-grant-neo-38). **NEO-39 landed:** data-driven `LevelCurve` content + schema + CI validation (`*_level_curve.json`) with fail-fast startup schema checks; progression GET/POST level resolution now uses `ISkillLevelCurve` content-backed thresholds ([NEO-39](../../plans/NEO-39-implementation-plan.md)); manual QA [`NEO-39`](../../manual-qa/NEO-39.md). **NEO-40 landed:** comment-only telemetry hook sites in [`SkillProgressionSnapshotApi.cs`](../../../server/NeonSprawl.Server/Game/Skills/SkillProgressionSnapshotApi.cs) on **`POST …/skill-progression`** for future **`xp_grant`** / **`level_up`** ([NEO-40](../../plans/NEO-40-implementation-plan.md), [`NEO-40` manual QA](../../manual-qa/NEO-40.md)). **NEO-41 landed:** gather prototype — **`POST …/interact`** with **`kind: resource_node`** grants **`salvage`** + **`activity`** (10 XP) via [`SkillProgressionGrantOperations`](../../../server/NeonSprawl.Server/Game/Skills/SkillProgressionGrantOperations.cs) ([NEO-41](../../plans/NEO-41-implementation-plan.md), [`NEO-41` manual QA](../../manual-qa/NEO-41.md)); [server README — Interaction](../../../server/README.md#interaction-neo-9). **NEO-42 landed (prep):** **`RefineActivitySkillXpGrant`** / **`RefineSkillXpConstants`** + deny-registry factory + tests — same NEO-38 grant stack; **E3.M2** must invoke on craft/refine success ([NEO-42](../../plans/NEO-42-implementation-plan.md), [`NEO-42` manual QA](../../manual-qa/NEO-42.md)); [server README — Craft / refine hook (NEO-42)](../../../server/README.md#craft--refine-hook--skill-xp-neo-42). **NEO-43 landed (prep):** **`MissionRewardSkillXpGrant`** / **`MissionRewardSkillXpConstants`** + deny-registry factory + tests — same NEO-38 grant stack with fixed **`sourceKind: mission_reward`**; **E7.M2** must invoke from quest hand-in ([NEO-43](../../plans/NEO-43-implementation-plan.md), [`NEO-43` manual QA](../../manual-qa/NEO-43.md)); [server README — Mission / quest reward (NEO-43)](../../../server/README.md#mission--quest-reward--skill-xp-neo-43). **Slice 3 still open:** [NEO-44](https://linear.app/neon-sprawl/issue/NEO-44). See [epic_02 — E2.M2 + Slice 3](../epics/epic_02_skills_and_progression.md). | [NEO-37](../../plans/NEO-37-implementation-plan.md), [NEO-38](../../plans/NEO-38-implementation-plan.md), [NEO-39](../../plans/NEO-39-implementation-plan.md), [NEO-40](../../plans/NEO-40-implementation-plan.md), [NEO-41](../../plans/NEO-41-implementation-plan.md), [NEO-42](../../plans/NEO-42-implementation-plan.md), [NEO-43](../../plans/NEO-43-implementation-plan.md), [E2_M2](E2_M2_XpAwardAndLevelEngine.md); label **`E2.M2`** on NEO-37–NEO-41, NEO-42–NEO-44 |
| E3.M1 | In Progress | **NEO-41 landed (prototype):** `POST …/interact` success on **`resource_node`** (`prototype_resource_node_alpha`) applies **`salvage`** skill XP (**`sourceKind: activity`**, 10 XP) via shared NEO-38 grant operations. **Still planned:** `GatherResult`, yields, inventory per [E3_M1](E3_M1_ResourceNodeAndGatherLoop.md). | [NEO-41](../../plans/NEO-41-implementation-plan.md), [E3_M1](E3_M1_ResourceNodeAndGatherLoop.md); `server/NeonSprawl.Server/Game/Interaction/`, `Game/Skills/` |
-| E3.M3 | In Progress | **NEO-50 landed:** frozen prototype six-item catalog in [`content/items/prototype_items.json`](../../../content/items/prototype_items.json); [`item-def.schema.json`](../../../content/schemas/item-def.schema.json); PR gate + [`validate_content.py`](../../../scripts/validate_content.py). **NEO-51 landed:** fail-fast server load of `content/items/*_items.json` at startup — `server/NeonSprawl.Server/Game/Items/` ([NEO-51](../../plans/NEO-51-implementation-plan.md)); [server README — Item catalog](../../../server/README.md#item-catalog-contentitems-neo-51). **NEO-52 landed:** injectable **`IItemDefinitionRegistry`** + lookup tests ([NEO-52](../../plans/NEO-52-implementation-plan.md)). **NEO-53 landed:** **`GET /game/world/item-definitions`** — `ItemDefinitionsWorldApi` + DTOs in `Game/Items/` ([NEO-53](../../plans/NEO-53-implementation-plan.md), [`NEO-53` manual QA](../../manual-qa/NEO-53.md)); [server README — Item definitions (NEO-53)](../../../server/README.md#item-definitions-neo-53); Bruno `bruno/neon-sprawl-server/item-definitions/`. **NEO-54 landed:** **`IPlayerInventoryStore`** + **`PlayerInventoryOperations`** — 24 bag + 1 equipment slots, stack rules, `V005` migration ([NEO-54](../../plans/NEO-54-implementation-plan.md)); [server README — Player inventory store (NEO-54)](../../../server/README.md#player-inventory-store-neo-54). **Still planned:** per-player inventory HTTP (NEO-55). | [NEO-50](../../plans/NEO-50-implementation-plan.md), [NEO-51](../../plans/NEO-51-implementation-plan.md), [NEO-52](../../plans/NEO-52-implementation-plan.md), [NEO-53](../../plans/NEO-53-implementation-plan.md), [NEO-54](../../plans/NEO-54-implementation-plan.md), [E3M3-prototype-backlog](../../plans/E3M3-prototype-backlog.md), [E3_M3](E3_M3_ItemizationAndInventorySchema.md) |
+| E3.M3 | In Progress | **NEO-50 landed:** frozen prototype six-item catalog in [`content/items/prototype_items.json`](../../../content/items/prototype_items.json); [`item-def.schema.json`](../../../content/schemas/item-def.schema.json); PR gate + [`validate_content.py`](../../../scripts/validate_content.py). **NEO-51 landed:** fail-fast server load of `content/items/*_items.json` at startup — `server/NeonSprawl.Server/Game/Items/` ([NEO-51](../../plans/NEO-51-implementation-plan.md)); [server README — Item catalog](../../../server/README.md#item-catalog-contentitems-neo-51). **NEO-52 landed:** injectable **`IItemDefinitionRegistry`** + lookup tests ([NEO-52](../../plans/NEO-52-implementation-plan.md)). **NEO-53 landed:** **`GET /game/world/item-definitions`** — `ItemDefinitionsWorldApi` + DTOs in `Game/Items/` ([NEO-53](../../plans/NEO-53-implementation-plan.md), [`NEO-53` manual QA](../../manual-qa/NEO-53.md)); [server README — Item definitions (NEO-53)](../../../server/README.md#item-definitions-neo-53); Bruno `bruno/neon-sprawl-server/item-definitions/`. **NEO-54 landed:** **`IPlayerInventoryStore`** + **`PlayerInventoryOperations`** — 24 bag + 1 equipment slots, stack rules, `V005` migration ([NEO-54](../../plans/NEO-54-implementation-plan.md)). **NEO-55 landed:** **`GET`/`POST /game/players/{id}/inventory`** — `PlayerInventoryApi` + DTOs in `Game/Items/` ([NEO-55](../../plans/NEO-55-implementation-plan.md)); [server README — Player inventory (NEO-54 store, NEO-55 HTTP)](../../../server/README.md#player-inventory-neo-54-store-neo-55-http); Bruno `bruno/neon-sprawl-server/inventory/`. **Still planned:** telemetry hook sites (NEO-56). | [NEO-50](../../plans/NEO-50-implementation-plan.md), [NEO-51](../../plans/NEO-51-implementation-plan.md), [NEO-52](../../plans/NEO-52-implementation-plan.md), [NEO-53](../../plans/NEO-53-implementation-plan.md), [NEO-54](../../plans/NEO-54-implementation-plan.md), [NEO-55](../../plans/NEO-55-implementation-plan.md), [E3M3-prototype-backlog](../../plans/E3M3-prototype-backlog.md), [E3_M3](E3_M3_ItemizationAndInventorySchema.md) |
---
diff --git a/docs/plans/NEO-55-implementation-plan.md b/docs/plans/NEO-55-implementation-plan.md
index e355fa9..f356d21 100644
--- a/docs/plans/NEO-55-implementation-plan.md
+++ b/docs/plans/NEO-55-implementation-plan.md
@@ -43,9 +43,9 @@
## Acceptance criteria checklist
-- [ ] GET returns instances + slots for known player (`dev-local-1` seeded empty inventory).
-- [ ] POST add/remove matches E3M3-05 engine rules (`stackMax`, all-or-nothing add, stable **`reasonCode`** denies).
-- [ ] Bruno exercises happy path + at least one deny (`inventory_full` or **`invalid_item`**).
+- [x] GET returns instances + slots for known player (`dev-local-1` seeded empty inventory).
+- [x] POST add/remove matches E3M3-05 engine rules (`stackMax`, all-or-nothing add, stable **`reasonCode`** denies).
+- [x] Bruno exercises happy path + at least one deny (`inventory_full` or **`invalid_item`**).
## Technical approach
diff --git a/server/NeonSprawl.Server.Tests/Game/Items/PlayerInventoryApiTests.cs b/server/NeonSprawl.Server.Tests/Game/Items/PlayerInventoryApiTests.cs
new file mode 100644
index 0000000..218d1ea
--- /dev/null
+++ b/server/NeonSprawl.Server.Tests/Game/Items/PlayerInventoryApiTests.cs
@@ -0,0 +1,182 @@
+using System.Linq;
+using System.Net;
+using System.Net.Http.Json;
+using NeonSprawl.Server.Game.Items;
+using Xunit;
+
+namespace NeonSprawl.Server.Tests.Game.Items;
+
+/// Regression tests for GET/POST …/inventory (NEO-55).
+public sealed class PlayerInventoryApiTests
+{
+ private static PlayerInventoryMutationRequest Mutation(
+ string mutationKind,
+ string itemId,
+ int quantity,
+ int schemaVersion = PlayerInventoryMutationRequest.CurrentSchemaVersion) =>
+ new()
+ {
+ SchemaVersion = schemaVersion,
+ MutationKind = mutationKind,
+ ItemId = itemId,
+ Quantity = quantity,
+ };
+
+ [Fact]
+ public async Task GetInventory_ShouldReturnNotFound_WhenPlayerUnknown()
+ {
+ // Arrange
+ await using var factory = new InMemoryWebApplicationFactory();
+ var client = factory.CreateClient();
+
+ // Act
+ var response = await client.GetAsync("/game/players/missing-player/inventory");
+
+ // Assert
+ Assert.Equal(HttpStatusCode.NotFound, response.StatusCode);
+ }
+
+ [Fact]
+ public async Task GetInventory_ShouldReturnSchemaV1_WithEmptyFixedSlotArrays()
+ {
+ // Arrange
+ await using var factory = new InMemoryWebApplicationFactory();
+ var client = factory.CreateClient();
+
+ // Act
+ var response = await client.GetAsync("/game/players/dev-local-1/inventory");
+
+ // Assert
+ Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+ var body = await response.Content.ReadFromJsonAsync();
+ Assert.NotNull(body);
+ Assert.Equal(PlayerInventorySnapshotResponse.CurrentSchemaVersion, body!.SchemaVersion);
+ Assert.Equal("dev-local-1", body.PlayerId);
+ Assert.Equal(PlayerInventorySnapshot.BagSlotCount, body.BagSlots.Count);
+ Assert.Single(body.EquipmentSlots);
+ Assert.All(body.BagSlots, static slot =>
+ {
+ Assert.Null(slot.ItemId);
+ Assert.Equal(0, slot.Quantity);
+ });
+ Assert.All(body.EquipmentSlots, static slot =>
+ {
+ Assert.Null(slot.ItemId);
+ Assert.Equal(0, slot.Quantity);
+ });
+ Assert.Equal(Enumerable.Range(0, PlayerInventorySnapshot.BagSlotCount), body.BagSlots.Select(static s => s.SlotIndex));
+ Assert.Equal(0, body.EquipmentSlots[0].SlotIndex);
+ }
+
+ [Fact]
+ public async Task PostInventory_ShouldReturnBadRequest_WhenSchemaVersionMismatch()
+ {
+ // Arrange
+ await using var factory = new InMemoryWebApplicationFactory();
+ var client = factory.CreateClient();
+ var request = Mutation("add", "scrap_metal_bulk", quantity: 1, schemaVersion: 99);
+
+ // Act
+ var response = await client.PostAsJsonAsync("/game/players/dev-local-1/inventory", request);
+
+ // Assert
+ Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
+ }
+
+ [Fact]
+ public async Task PostInventory_ShouldReturnBadRequest_WhenMutationKindUnknown()
+ {
+ // Arrange
+ await using var factory = new InMemoryWebApplicationFactory();
+ var client = factory.CreateClient();
+ var request = Mutation("consume", "scrap_metal_bulk", quantity: 1);
+
+ // Act
+ var response = await client.PostAsJsonAsync("/game/players/dev-local-1/inventory", request);
+
+ // Assert
+ Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
+ }
+
+ [Fact]
+ public async Task PostInventory_ShouldReturnNotFound_WhenPlayerUnknown()
+ {
+ // Arrange
+ await using var factory = new InMemoryWebApplicationFactory();
+ var client = factory.CreateClient();
+
+ // Act
+ var response = await client.PostAsJsonAsync(
+ "/game/players/missing-player/inventory",
+ Mutation("add", "scrap_metal_bulk", quantity: 1));
+
+ // Assert
+ Assert.Equal(HttpStatusCode.NotFound, response.StatusCode);
+ }
+
+ [Fact]
+ public async Task PostInventory_ShouldApplyAdd_WithUpdatedSnapshot()
+ {
+ // Arrange
+ await using var factory = new InMemoryWebApplicationFactory();
+ var client = factory.CreateClient();
+
+ // Act
+ var response = await client.PostAsJsonAsync(
+ "/game/players/dev-local-1/inventory",
+ Mutation("add", "scrap_metal_bulk", quantity: 10));
+
+ // Assert
+ Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+ var body = await response.Content.ReadFromJsonAsync();
+ Assert.NotNull(body);
+ Assert.True(body!.Applied);
+ Assert.Null(body.ReasonCode);
+ Assert.Equal("dev-local-1", body.Inventory.PlayerId);
+ var occupied = body.Inventory.BagSlots.Where(static s => s.Quantity > 0).ToList();
+ Assert.Single(occupied);
+ Assert.Equal("scrap_metal_bulk", occupied[0].ItemId);
+ Assert.Equal(10, occupied[0].Quantity);
+ }
+
+ [Fact]
+ public async Task PostInventory_ShouldDenyUnknownItem_WithInvalidItem_AndLeaveInventoryEmpty()
+ {
+ // Arrange
+ await using var factory = new InMemoryWebApplicationFactory();
+ var client = factory.CreateClient();
+
+ // Act
+ var response = await client.PostAsJsonAsync(
+ "/game/players/dev-local-1/inventory",
+ Mutation("add", "not-a-prototype-item", quantity: 1));
+
+ // Assert
+ Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+ var body = await response.Content.ReadFromJsonAsync();
+ Assert.NotNull(body);
+ Assert.False(body!.Applied);
+ Assert.Equal(PlayerInventoryReasonCodes.InvalidItem, body.ReasonCode);
+ Assert.All(body.Inventory.BagSlots, static slot => Assert.Equal(0, slot.Quantity));
+ }
+
+ [Fact]
+ public async Task PostInventory_ShouldDenyRemove_WithInsufficientQuantity()
+ {
+ // Arrange
+ await using var factory = new InMemoryWebApplicationFactory();
+ var client = factory.CreateClient();
+
+ // Act
+ var response = await client.PostAsJsonAsync(
+ "/game/players/dev-local-1/inventory",
+ Mutation("remove", "scrap_metal_bulk", quantity: 1));
+
+ // Assert
+ Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+ var body = await response.Content.ReadFromJsonAsync();
+ Assert.NotNull(body);
+ Assert.False(body!.Applied);
+ Assert.Equal(PlayerInventoryReasonCodes.InsufficientQuantity, body.ReasonCode);
+ }
+}
diff --git a/server/NeonSprawl.Server/Game/Items/PlayerInventoryApi.cs b/server/NeonSprawl.Server/Game/Items/PlayerInventoryApi.cs
new file mode 100644
index 0000000..a8135a7
--- /dev/null
+++ b/server/NeonSprawl.Server/Game/Items/PlayerInventoryApi.cs
@@ -0,0 +1,134 @@
+using NeonSprawl.Server.Game.PositionState;
+
+namespace NeonSprawl.Server.Game.Items;
+
+///
+/// Maps GET/POST /game/players/{{id}}/inventory — read snapshot and add/remove mutations (NEO-55).
+///
+public static class PlayerInventoryApi
+{
+ public static WebApplication MapPlayerInventoryApi(this WebApplication app)
+ {
+ app.MapGet(
+ "/game/players/{id}/inventory",
+ (string id, IPositionStateStore positions, IPlayerInventoryStore store) =>
+ {
+ var trimmedId = id.Trim();
+ if (trimmedId.Length == 0 || !positions.TryGetPosition(trimmedId, out _))
+ {
+ return Results.NotFound();
+ }
+
+ if (!store.TryGetSnapshot(trimmedId, out var snapshot))
+ {
+ return Results.NotFound();
+ }
+
+ return Results.Json(MapSnapshot(trimmedId, snapshot));
+ });
+
+ app.MapPost(
+ "/game/players/{id}/inventory",
+ (string id, PlayerInventoryMutationRequest? body, IPositionStateStore positions,
+ IItemDefinitionRegistry registry, IPlayerInventoryStore store) =>
+ {
+ if (body is null || body.SchemaVersion != PlayerInventoryMutationRequest.CurrentSchemaVersion)
+ {
+ return Results.BadRequest();
+ }
+
+ if (!TryParseMutationKind(body.MutationKind, out var isAdd))
+ {
+ return Results.BadRequest();
+ }
+
+ var trimmedId = id.Trim();
+ if (trimmedId.Length == 0 || !positions.TryGetPosition(trimmedId, out _))
+ {
+ return Results.NotFound();
+ }
+
+ var outcome = isAdd
+ ? PlayerInventoryOperations.TryAddStack(trimmedId, body.ItemId, body.Quantity, registry, store)
+ : PlayerInventoryOperations.TryRemoveStack(trimmedId, body.ItemId, body.Quantity, registry, store);
+
+ return outcome.Kind switch
+ {
+ PlayerInventoryMutationKind.StoreMissing => Results.NotFound(),
+ PlayerInventoryMutationKind.Denied => Results.Json(
+ BuildMutationResponse(trimmedId, applied: false, outcome.ReasonCode, outcome.Snapshot, store)),
+ PlayerInventoryMutationKind.Applied => Results.Json(
+ BuildMutationResponse(trimmedId, applied: true, reasonCode: null, outcome.Snapshot, store)),
+ _ => throw new InvalidOperationException($"Unexpected inventory mutation outcome: {outcome.Kind}"),
+ };
+ });
+
+ return app;
+ }
+
+ internal static PlayerInventorySnapshotResponse MapSnapshot(string playerId, PlayerInventorySnapshot snapshot) =>
+ new()
+ {
+ PlayerId = playerId,
+ SchemaVersion = PlayerInventorySnapshotResponse.CurrentSchemaVersion,
+ BagSlots = MapSlots(snapshot.BagSlots),
+ EquipmentSlots = MapSlots(snapshot.EquipmentSlots),
+ };
+
+ private static IReadOnlyList MapSlots(InventorySlotState[] slots)
+ {
+ var rows = new InventorySlotStateJson[slots.Length];
+ for (var i = 0; i < slots.Length; i++)
+ {
+ var slot = slots[i];
+ rows[i] = slot.IsEmpty
+ ? new InventorySlotStateJson { SlotIndex = slot.SlotIndex, Quantity = 0 }
+ : new InventorySlotStateJson
+ {
+ SlotIndex = slot.SlotIndex,
+ ItemId = slot.ItemId,
+ Quantity = slot.Quantity,
+ };
+ }
+
+ return rows;
+ }
+
+ private static PlayerInventoryMutationResponse BuildMutationResponse(
+ string playerId,
+ bool applied,
+ string? reasonCode,
+ PlayerInventorySnapshot? snapshot,
+ IPlayerInventoryStore store)
+ {
+ if (snapshot is null && !store.TryGetSnapshot(playerId, out snapshot))
+ {
+ snapshot = PlayerInventorySnapshot.Empty();
+ }
+
+ return new PlayerInventoryMutationResponse
+ {
+ Applied = applied,
+ ReasonCode = reasonCode,
+ Inventory = MapSnapshot(playerId, snapshot!),
+ };
+ }
+
+ private static bool TryParseMutationKind(string? raw, out bool isAdd)
+ {
+ if (string.Equals(raw, "add", StringComparison.OrdinalIgnoreCase))
+ {
+ isAdd = true;
+ return true;
+ }
+
+ if (string.Equals(raw, "remove", StringComparison.OrdinalIgnoreCase))
+ {
+ isAdd = false;
+ return true;
+ }
+
+ isAdd = false;
+ return false;
+ }
+}
diff --git a/server/NeonSprawl.Server/Game/Items/PlayerInventoryDtos.cs b/server/NeonSprawl.Server/Game/Items/PlayerInventoryDtos.cs
new file mode 100644
index 0000000..ddd75db
--- /dev/null
+++ b/server/NeonSprawl.Server/Game/Items/PlayerInventoryDtos.cs
@@ -0,0 +1,76 @@
+using System.Text.Json.Serialization;
+
+namespace NeonSprawl.Server.Game.Items;
+
+/// JSON body for GET /game/players/{{id}}/inventory (NEO-55).
+public sealed class PlayerInventorySnapshotResponse
+{
+ public const int CurrentSchemaVersion = 1;
+
+ [JsonPropertyName("schemaVersion")]
+ public int SchemaVersion { get; init; } = CurrentSchemaVersion;
+
+ [JsonPropertyName("playerId")]
+ public required string PlayerId { get; init; }
+
+ /// Fixed bag slots 0..23 in ascending order.
+ [JsonPropertyName("bagSlots")]
+ public required IReadOnlyList BagSlots { get; init; }
+
+ /// Fixed equipment slot index 0.
+ [JsonPropertyName("equipmentSlots")]
+ public required IReadOnlyList EquipmentSlots { get; init; }
+}
+
+/// POST body for inventory add/remove (NEO-55).
+public sealed class PlayerInventoryMutationRequest
+{
+ public const int CurrentSchemaVersion = 1;
+
+ [JsonPropertyName("schemaVersion")]
+ public int SchemaVersion { get; init; }
+
+ /// add or remove (ordinal ignore-case).
+ [JsonPropertyName("mutationKind")]
+ public required string MutationKind { get; init; }
+
+ [JsonPropertyName("itemId")]
+ public required string ItemId { get; init; }
+
+ [JsonPropertyName("quantity")]
+ public int Quantity { get; init; }
+}
+
+/// POST response for inventory mutations — applied or structured deny (NEO-55).
+public sealed class PlayerInventoryMutationResponse
+{
+ public const int CurrentSchemaVersion = 1;
+
+ [JsonPropertyName("schemaVersion")]
+ public int SchemaVersion { get; init; } = CurrentSchemaVersion;
+
+ [JsonPropertyName("applied")]
+ public bool Applied { get; init; }
+
+ /// null on success; stable snake_case deny codes from on deny.
+ [JsonPropertyName("reasonCode")]
+ public string? ReasonCode { get; init; }
+
+ [JsonPropertyName("inventory")]
+ public required PlayerInventorySnapshotResponse Inventory { get; init; }
+}
+
+/// Wire shape for one inventory slot in GET/POST responses.
+public sealed class InventorySlotStateJson
+{
+ [JsonPropertyName("slotIndex")]
+ public int SlotIndex { get; init; }
+
+ /// Omitted when the slot is empty.
+ [JsonPropertyName("itemId")]
+ [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+ public string? ItemId { get; init; }
+
+ [JsonPropertyName("quantity")]
+ public int Quantity { get; init; }
+}
diff --git a/server/NeonSprawl.Server/Program.cs b/server/NeonSprawl.Server/Program.cs
index 55c9d79..77cda31 100644
--- a/server/NeonSprawl.Server/Program.cs
+++ b/server/NeonSprawl.Server/Program.cs
@@ -38,6 +38,7 @@ app.MapInteractionApi();
app.MapInteractablesWorldApi();
app.MapSkillDefinitionsWorldApi();
app.MapItemDefinitionsWorldApi();
+app.MapPlayerInventoryApi();
app.MapSkillProgressionSnapshotApi();
app.MapPerkStateApi();
if (app.Environment.IsDevelopment() ||
diff --git a/server/README.md b/server/README.md
index 12944f2..d4cf729 100644
--- a/server/README.md
+++ b/server/README.md
@@ -58,16 +58,27 @@ On success, **Information** logs include the resolved items directory path, dist
curl -sS -i "http://localhost:5253/game/world/item-definitions"
```
-## Player inventory store (NEO-54)
+## Player inventory (NEO-54 store, NEO-55 HTTP)
-Server-authoritative per-player inventory lives in **`Game/Items/`** as **`IPlayerInventoryStore`** + **`PlayerInventoryOperations`**. There is **no HTTP surface in NEO-54** — **`GET` / `POST` inventory** lands in [NEO-55](../../docs/plans/NEO-55-implementation-plan.md).
+Server-authoritative per-player inventory lives in **`Game/Items/`** as **`IPlayerInventoryStore`** + **`PlayerInventoryOperations`**. **NEO-55** exposes versioned **`GET` / `POST /game/players/{id}/inventory`** for manual QA and future client. Plan: [NEO-55 implementation plan](../../docs/plans/NEO-55-implementation-plan.md); Bruno: `bruno/neon-sprawl-server/inventory/`.
| Container | Fixed slots | Accepts `inventorySlotKind` |
|-----------|-------------|-------------------------------|
| **Bag** | **24** (indices 0–23) | `bag` |
| **Equipment** | **1** (index 0) | `equipment` |
-**Mutations:** **`TryAddStack`** and **`TryRemoveStack`** route items by catalog metadata, merge stacks up to **`ItemDef.stackMax`**, and use **all-or-nothing** adds (no partial silent loss). Stable deny **`reasonCode`** values:
+**GET** returns **`schemaVersion` 1**, **`playerId`**, **`bagSlots`** (length 24), **`equipmentSlots`** (length 1). Empty slots use **`quantity: 0`** with **`itemId`** omitted. **404** when the player is unknown (position gate) or missing from the inventory store.
+
+**POST** body (**`schemaVersion` 1**): **`mutationKind`** **`add`** or **`remove`**, **`itemId`**, **`quantity`**. Response: **`applied`**, **`reasonCode`** (`null` on success), **`inventory`** snapshot echo. **400** on schema mismatch or unknown **`mutationKind`**; **404** on unknown player; **200** with **`applied: false`** + stable deny codes on rule failure.
+
+```bash
+curl -sS "http://localhost:5253/game/players/dev-local-1/inventory"
+curl -sS -X POST "http://localhost:5253/game/players/dev-local-1/inventory" \
+ -H "Content-Type: application/json" \
+ -d '{"schemaVersion":1,"mutationKind":"add","itemId":"scrap_metal_bulk","quantity":5}'
+```
+
+**Engine rules (NEO-54):** **`TryAddStack`** and **`TryRemoveStack`** route items by catalog metadata, merge stacks up to **`ItemDef.stackMax`**, and use **all-or-nothing** adds (no partial silent loss). Stable deny **`reasonCode`** values:
| Code | Meaning |
|------|---------|
@@ -76,7 +87,7 @@ Server-authoritative per-player inventory lives in **`Game/Items/`** as **`IPlay
| **`insufficient_quantity`** | Remove requested more than held |
| **`invalid_quantity`** | Non-positive quantity |
-**Persistence:** same **[NEO-29-style](#position-persistence-neo-8) split** as skill progression — **`player_inventory`** in PostgreSQL when **`ConnectionStrings:NeonSprawl`** is set (DDL [`V005__player_inventory.sql`](../db/migrations/V005__player_inventory.sql), sparse occupied-slot rows), otherwise in-memory fallback seeding the configured dev player. Plan: [NEO-54 implementation plan](../../docs/plans/NEO-54-implementation-plan.md).
+**Persistence:** same **[NEO-29-style](#position-persistence-neo-8) split** as skill progression — **`player_inventory`** in PostgreSQL when **`ConnectionStrings:NeonSprawl`** is set (DDL [`V005__player_inventory.sql`](../db/migrations/V005__player_inventory.sql), sparse occupied-slot rows), otherwise in-memory fallback seeding the configured dev player. Store/engine plan: [NEO-54 implementation plan](../../docs/plans/NEO-54-implementation-plan.md).
## Mastery catalog (`content/mastery`, NEO-46)