> For the complete documentation index, see [llms.txt](https://mirror-networking.gitbook.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mirror-networking.gitbook.io/docs/manual/guides/ids.md).

# IDs

## Asset Id <a href="#asset-id" id="asset-id"></a>

Mirror uses GUID for Asset Ids. Every prefab with a NetworkIdentity component has an Asset Id, which is simply Unity's AssetDatabase.AssetPathToGUID converted to 16 bytes. Mirror needs that to know which prefabs to spawn.

## Scene Id <a href="#scene-id" id="scene-id"></a>

Mirror uses uint for Scene Ids. Every game object with a NetworkIdentity in the scene (hierarchy) is assigned a scene id in OnPostProcessScene. Mirror needs that to distinguish scene objects from each other, because Unity has no unique id for different game objects in the scene.

## Network Instance Id (aka NetId) <a href="#network-instance-id-aka-netid" id="network-instance-id-aka-netid"></a>

Mirror uses uint for NetId. Every NetworkIdentity is assigned a NetId in NetworkIdentity.OnStartServer, or after spawning it. Mirror uses the id when passing messages between client and server to tell which object is the recipient of the message.

## Connection Id <a href="#connection-id" id="connection-id"></a>

Every network connection has a connection id, which is assigned by the low level Transport layer. Connection id 0 is reserved for the local connection when the server is also a client (host)


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://mirror-networking.gitbook.io/docs/manual/guides/ids.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.