more information on packets

packets.md

@@ -87,3 +87,89 @@ This packet seems to provide the client with "trusted hosts". As of writing, thi
 ```
 
 It is unknown what purpose these links serve. It may be a list of links that you are allowed to embed in private messages.
+
+### telemetry.ClientTelemetryPacket
+
+_Client-exclusive_
+
+This packet is used for various purposes. It stores a single `String key` and a `Map<String, Object> metadata`. The `metadata` is optional in the constructor. It's used only three times:
+
+1. Each time a new screen is opened in `GuiUtil` it sends a `ClientTelemetryPacket`:
+
+```java
+Essential.getInstance().getConnectionManager().send(new ClientTelemetryPacket("GUI_OPEN", MapsKt.mapOf(new Pair("name", screen.getClass().getName()))));
+```
+
+Which looks like this:
+
+```json
+{"key": "GUI_OPEN", "metadata": {"name": "[screen.getClass().getName()]"}}
+```
+
+2. Each time you connect, a blank `ClientTelemetryPacket` will be sent:
+
+```java
+this.send(new ClientTelemetryPacket("SESSION_START"));
+```
+
+3. Each time you connect, a `"MINI_STATE"` `ClientTelemetryPacket` will be sent, containing if a specific config setting is on:
+
+```java
+this.send(new ClientTelemetryPacket("MINI_STATE", new HashMap() {
+  {
+    this.put("mini", !EssentialConfig.INSTANCE.getEssentialFull());
+  }
+}));
+```
+
+```java
+public boolean getEssentialFull() {
+  return essentialFull;
+}
+```
+
+```java
+@Property(
+  type = PropertyType.SWITCH,
+  name = "Essential Full",
+  category = "General",
+  subcategory = "Experience",
+  description = "Enables all features available in Essential"
+)
+private static boolean essentialFull = true;
+```
+
+This is not to be confused with the `OnboardingData.hasAcceptedTos()` function. I'm not sure what exactly the Essential Full switch does, but disabling it seems to remove certain networking features.
+
+### mod.ClientModsAnnouncePacket
+
+_Client-exclusive_
+
+_Sent on authentication_
+
+This is a packet that contains:
+
+- The client's Minecraft version
+- The MD5 checksum of every single mod the client has installed
+It's worth noting that the mod with the ID `"feather"` has a fake checksum in both the Fabric and Forge version, regardless of Minecraft version:
+```java
+modId != "feather" ? checksum : "e3d04e686b28b34b5a98ce078e4f9da8"
+```
+Since this is hardcoded, chances are the developers can find out exactly who uses a mod with this ID, where with a normal mod, you're able to spoof the signature by editing the .jar, tampering with the checksum. This is likely the [Feather client](https://feathermc.com/), which Essential devs have [a bit of history](https://twitter.com/Sk1er_/status/1499812679007064066) with.
+
+- The client's mod loader:
+```java
+public static enum Platform {
+  FORGE,
+  FABRIC;
+}
+```
+- The loader's version
+In the Fabric version, it does this by finding the Fabric API, and then condensing its' ID and version to a string:
+```java
+String platformVersion = mod.getId() + ":" + mod.getVersion().getFriendlyString();
+```
+In Forge, it's as simple as:
+```java
+String.valueOf(ForgeVersion.getBuildVersion());
+```