# context7 — DOTS library IDs & query playbook

**context7 is the primary source of truth for every DOTS API, signature, and "current best practice."** Unity's Entities/Netcode packages change between minor versions; training-data recall is stale. Resolve → query before writing DOTS code.

## Flow

1. `resolve-library-id(libraryName, query)` → pick the Context7 ID (prefer High reputation + high snippet count + version matching the **installed** package).
2. `query-docs(libraryId, query)` with a *specific* question ("How do I declare an IInputComponentData and read it in a predicted system in Netcode 1.x?"), not a bare keyword.
3. Cross-check working patterns against the official **ECS Samples** repo ID below.
4. Limit: ≤3 `resolve` calls and ≤3 `query` calls per question (the tool enforces this). Reuse IDs across a session.

## Pin to the installed version

Before querying, read the installed version from `Packages/packages-lock.json` (or `manage_packages action=list`). If it differs from a seed ID's version, **re-resolve** and prefer the doc set matching what's installed. The seeds below were captured during skill authoring and may lag the project.

## Seed library IDs (re-resolve if installed version differs)

| Package | Primary Context7 ID | Alt | Notes |
|---|---|---|---|
| **Entities (DOTS)** | `/websites/unity3d_packages_com_unity_entities_1_4` | `/needle-mirror/com.unity.entities` | ~7,099 snippets, High. Core ECS. |
| **Netcode for Entities** | `/websites/unity3d_packages_com_unity_netcode_1_10_api` | `/websites/unity3d_packages_com_unity_netcode_1_9` | ~2,512 snippets, High. Ghosts/prediction/RPC/input. |
| **Entities Graphics** | `/websites/unity3d_packages_com_unity_entities_graphics_1_4` | — | Rendering entities under URP/HDRP. |
| **Official ECS Samples** | `/unity-technologies/entitycomponentsystemsamples` | — | Working sample patterns; Entities, Netcode, Physics, Graphics. |
| **Unity Physics** | resolve at runtime | — | `resolve-library-id(libraryName="Unity Physics", query="DOTS collision/triggers")`. |
| **Burst** | resolve at runtime | — | `libraryName="Unity Burst"`. |
| **Collections** | resolve at runtime | — | `libraryName="Unity Collections"` (Native/Unsafe containers, allocators). |
| **Mathematics** | resolve at runtime | — | `libraryName="Unity Mathematics"` (float3/quaternion/math). |

> Confirm Netcode for Entities is `com.unity.netcode` (the ECS netcode), **not** `com.unity.netcode.gameobjects` (Netcode for GameObjects). They are different products.

## Query patterns that work (examples)

- "Entities 1.x: declare an `IJobEntity` that writes through an `EntityCommandBuffer.ParallelWriter` and schedule it with the right dependency."
- "Netcode for Entities: minimal `GhostAuthoringComponent` + `[GhostField]` setup for a predicted player-controlled ghost."
- "Netcode for Entities: read `IInputComponentData` inside a system in `PredictedSimulationSystemGroup`, filtered by `Simulate`."
- "Entities: correct `Baker<T>` use of `GetEntity` with `TransformUsageFlags` and `DependsOn`."
- "Netcode for Entities: subclass `ClientServerBootstrap` to create client/server worlds and target systems with `WorldSystemFilter`."
- "Entities: `IEnableableComponent` vs add/remove tag — API and when each is cheaper."

## When NOT to use context7

- Genre/design precedent ("how do other games pace waves") → `WebSearch`/`WebFetch`.
- Pure C#/algorithm questions unrelated to a library → reason directly.
- The project's own conventions/design → `CLAUDE.md` + the vault.