diff --git a/Cargo.lock b/Cargo.lock
index 2cfd328a6..b10a0c89f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -263,9 +263,9 @@ dependencies = [
 
 [[package]]
 name = "async-compression"
-version = "0.4.44"
+version = "0.4.46"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "515a1f282e33d55983c499d7e9e87082e81cbc32974825bf9032f928392d5844"
+checksum = "4f10dafd0c8d2e51ae9a748805777613ed0bbe17bf586b76c8311f45c020a32f"
 dependencies = [
  "compression-codecs",
  "compression-core",
@@ -398,9 +398,9 @@ checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 
 [[package]]
 name = "bitflags"
-version = "2.13.1"
+version = "2.13.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b588b76d00fde79687d7646a9b5bdf3cc0f655e0bbd080335a95d7e96f3587da"
+checksum = "3ded4057c258ba199e2d26386d3af3780957ecaee6c4ef4041c6b4b8b97c0b06"
 
 [[package]]
 name = "block-buffer"
@@ -746,9 +746,9 @@ dependencies = [
 
 [[package]]
 name = "compression-codecs"
-version = "0.4.39"
+version = "0.4.41"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2fe67f2944eef52fc7b106b8c9450d243a88701a0c065f7f57235e76abaed7df"
+checksum = "58a6d0db8759036a783bc7c3f7a07f8cef3bf9470eb1db3bc86e8bcd1c5d0fe8"
 dependencies = [
  "compression-core",
  "flate2",
@@ -2242,7 +2242,7 @@ version = "0.11.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4cc00ea907cab49550b7da656f80ebb97be1b997d931fbcd28d39734e17ce592"
 dependencies = [
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
  "inotify-sys",
  "libc",
 ]
@@ -2299,9 +2299,9 @@ checksum = "2f0fb0570afe1fed943c5c3d4102d5358592d8625fda6a0007fdbe65a92fba96"
 
 [[package]]
 name = "ipnet"
-version = "2.12.1"
+version = "2.12.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a756c3fac73139e83f14c2d742155dd2b78d3ee56597b419a0579b7bdd6dd78"
+checksum = "791930b43c0d5973160d90a8f3894509f2b273430f5c5c73b668636d0287c5c0"
 
 [[package]]
 name = "is_terminal_polyfill"
@@ -2403,9 +2403,9 @@ dependencies = [
 
 [[package]]
 name = "js-sys"
-version = "0.3.104"
+version = "0.3.105"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0e0c1080212aad755ea003d18543e8768dd432c48819efd73a7bf1e39b7a5a3a"
+checksum = "ce57d20d1ea864ce2ac172ab472d409214f4fd359f0b2a2775abdf522e2af99e"
 dependencies = [
  "cfg-if",
  "futures-util",
@@ -2428,7 +2428,7 @@ version = "1.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "07293a4e297ac234359b510362495713f75ea345d5307140414f20c69ffeb087"
 dependencies = [
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
  "libc",
 ]
 
@@ -2665,7 +2665,7 @@ version = "0.31.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cf20d2fde8ff38632c426f1165ed7436270b44f199fc55284c38276f9db47c3d"
 dependencies = [
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
  "cfg-if",
  "cfg_aliases",
  "libc",
@@ -2697,7 +2697,7 @@ version = "8.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4d3d07927151ff8575b7087f245456e549fea62edf0ec4e565a5ee50c8402bc3"
 dependencies = [
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
  "fsevent-sys",
  "inotify",
  "kqueue",
@@ -2715,7 +2715,7 @@ version = "2.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "42b8cfee0e339a0337359f3c88165702ac6e600dc01c0cc9579a92d62b08477a"
 dependencies = [
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
 ]
 
 [[package]]
@@ -2806,7 +2806,7 @@ version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2a180dd8642fa45cdb7dd721cd4c11b1cadd4929ce112ebd8b9f5803cc79d536"
 dependencies = [
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
 ]
 
 [[package]]
@@ -3110,7 +3110,7 @@ version = "0.18.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "60769b8b31b2a9f263dae2776c37b1b28ae246943cf719eb6946a1db05128a61"
 dependencies = [
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
  "crc32fast",
  "fdeflate",
  "flate2",
@@ -3335,7 +3335,7 @@ dependencies = [
  "async-trait",
  "axum",
  "base64 0.23.1",
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
  "bytes",
  "colored",
  "console-subscriber",
@@ -3606,7 +3606,7 @@ dependencies = [
  "aes 0.9.3",
  "async-compression",
  "base64 0.23.1",
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
  "bytes",
  "cesu8",
  "cfb8",
@@ -3650,7 +3650,7 @@ name = "pumpkin-world"
 version = "0.1.0+26.2-26.45"
 dependencies = [
  "arc-swap",
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
  "bytes",
  "criterion",
  "crossbeam",
@@ -3789,7 +3789,7 @@ version = "0.5.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ed2bf2547551a7053d6fdfafda3f938979645c44812fbfcda098faae3f1a362d"
 dependencies = [
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
 ]
 
 [[package]]
@@ -3858,11 +3858,11 @@ dependencies = [
 
 [[package]]
 name = "reqwest"
-version = "0.13.4"
+version = "0.13.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "219c5811de6525e5416c7d5d53bb656d3afdbc6c5af816e0802bcfa42dbdc1c3"
+checksum = "16a1cfa75cc186dd73d5818e510e042e40927bccc9c236b061cea97e1eb08029"
 dependencies = [
- "base64 0.22.1",
+ "base64 0.23.1",
  "bytes",
  "futures-channel",
  "futures-core",
@@ -4299,7 +4299,7 @@ version = "1.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b6fe4565b9518b83ef4f91bb47ce29620ca828bd32cb7e408f0062e9930ba190"
 dependencies = [
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
  "errno",
  "libc",
  "linux-raw-sys",
@@ -4318,9 +4318,9 @@ dependencies = [
 
 [[package]]
 name = "rustls"
-version = "0.23.43"
+version = "0.23.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0283386ce02abc0151e1761d08802dfe86c173b0b494af5cbc086574e453da06"
+checksum = "6725596c3f2c3a0aef021139e145d4eafe314a6623e4680ca83852b2c67ab2ba"
 dependencies = [
  "log",
  "once_cell",
@@ -4402,7 +4402,7 @@ version = "18.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "53f6a737db68eb1a8ccff86b584b2fc13eca6a7bb6f78ebc7c529547e3ab9684"
 dependencies = [
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
  "cfg-if",
  "clipboard-win",
  "libc",
@@ -4485,7 +4485,7 @@ version = "3.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b7f4bc775c73d9a02cde8bf7b2ec4c9d12743edf609006c7facc23998404cd1d"
 dependencies = [
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
  "core-foundation",
  "core-foundation-sys",
  "libc",
@@ -5173,7 +5173,7 @@ version = "0.6.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4cfcf7e2740e6fc6d4d688b4ef00650406bb94adf4731e43c096c3a19fe40840"
 dependencies = [
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
  "bytes",
  "futures-util",
  "http",
@@ -5396,9 +5396,9 @@ checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.127"
+version = "0.2.128"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1b70935747edd64d89de3efa29d73789b806c15798f8e7dca4d8ac356b50ce70"
+checksum = "aecb87a33d3b0c5e3b7aa46336eaf486cffafbd281b195e4c8b80d50df2351bf"
 dependencies = [
  "cfg-if",
  "once_cell",
@@ -5409,9 +5409,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-futures"
-version = "0.4.77"
+version = "0.4.78"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6b7777d5cc23d0e91404e53ce2d5e8ec7acae3026b16233dba62cd3246457950"
+checksum = "6ef4c5d3d2cdf5c54f4231181768f5510842e350db025faf1f7163b1030ed928"
 dependencies = [
  "js-sys",
  "wasm-bindgen",
@@ -5419,9 +5419,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.127"
+version = "0.2.128"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "77775f8f3f7217702089053b94958f8f54061a3f663417df76e19cbdcca29bc1"
+checksum = "a690d511e3c1a8b3a55e33511e3c2c00c78415cd23650f32b808627f5696b9ed"
 dependencies = [
  "quote",
  "wasm-bindgen-macro-support",
@@ -5429,22 +5429,22 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.127"
+version = "0.2.128"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e11d33f857dc2fb11b8bc75aee111aa9cbeb12cd9f25efd3d4c2a3dd4e235284"
+checksum = "411e4887f0071ef2d2164a9d5fdf2d20efbef78fccd3a78b0c10a1dc5295e48a"
 dependencies = [
  "bumpalo",
  "proc-macro2",
  "quote",
- "syn 2.0.119",
+ "syn 3.0.5",
  "wasm-bindgen-shared",
 ]
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.127"
+version = "0.2.128"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7ef64dbcc55df09c7e5a46182d181c2cfa3e925f3da937ea764728b4bbb9dcbf"
+checksum = "81941cd78d0c92026c33e5e01312845a4cb1e9af3407f9134b100dd03144103e"
 dependencies = [
  "unicode-ident",
 ]
@@ -5477,7 +5477,7 @@ version = "0.258.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d9a61719f93a87b16d325921e251800c4833f8fab50fa21c7de73aed50086313"
 dependencies = [
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
  "hashbrown 0.17.1",
  "indexmap",
  "semver",
@@ -5502,7 +5502,7 @@ source = "git+https://github.com/bytecodealliance/wasmtime?rev=f6b3140dbb1d9b436
 dependencies = [
  "addr2line",
  "async-trait",
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
  "bumpalo",
  "bytes",
  "cc",
@@ -5699,7 +5699,7 @@ version = "49.0.0-dev"
 source = "git+https://github.com/bytecodealliance/wasmtime?rev=f6b3140dbb1d9b436ef523d14740292c956b0364#f6b3140dbb1d9b436ef523d14740292c956b0364"
 dependencies = [
  "anyhow",
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
  "heck",
  "indexmap",
  "wit-component",
@@ -5712,7 +5712,7 @@ version = "49.0.0-dev"
 source = "git+https://github.com/bytecodealliance/wasmtime?rev=f6b3140dbb1d9b436ef523d14740292c956b0364#f6b3140dbb1d9b436ef523d14740292c956b0364"
 dependencies = [
  "async-trait",
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
  "bytes",
  "cap-primitives",
  "futures",
@@ -5767,9 +5767,9 @@ dependencies = [
 
 [[package]]
 name = "web-sys"
-version = "0.3.104"
+version = "0.3.105"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c435338968042f4f59a557f690a253676d47ce13ceb55d70100e7facf6620a30"
+checksum = "9fbddc4a036f00ec4f18c83445bd3115cb306a91da554919a099d9222fe4a7f8"
 dependencies = [
  "js-sys",
  "wasm-bindgen",
@@ -6129,7 +6129,7 @@ version = "0.36.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3f3fd376f71958b862e7afb20cfe5a22830e1963462f3a17f49d82a6c1d1f42d"
 dependencies = [
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
  "windows-sys 0.59.0",
 ]
 
@@ -6191,7 +6191,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "481b5c47b2ecce0389b5e08a05557d6a190c9cd761773b8880a8017ee04dc7ef"
 dependencies = [
  "anyhow",
- "bitflags 2.13.1",
+ "bitflags 2.13.2",
  "indexmap",
  "log",
  "serde",
diff --git a/Cargo.toml b/Cargo.toml
index 2db502445..fffda712b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -149,9 +149,9 @@ serde_json = { version = "1.0", default-features = false, features = ["std"] }
 tempfile = { version = "3.27.0", default-features = false }
 proc-macro-error2 = { version = "2", default-features = false }
 aes = { version = "0.9", default-features = false }
-async-compression = { version = "0.4.44", default-features = false }
+async-compression = { version = "0.4.46", default-features = false }
 base64 = { version = "0.23.1", default-features = false, features = ["std"] }
-bitflags = { version = "2.13.1", default-features = false, features = ["std"] }
+bitflags = { version = "2.13.2", default-features = false, features = ["std"] }
 cesu8 = { version = "1.1", default-features = false }
 cfb8 = { version = "0.9", default-features = false }
 colored = { version = "3.1", default-features = false }
@@ -215,7 +215,7 @@ time = { version = "0.3", default-features = false, features = ["std"] }
 arc-swap = { version = "1.9", default-features = false }
 tokio-util = { version = "0.7.19", default-features = false }
 toml = { version = "1.1", default-features = false, features = ["parse", "display", "serde"] }
-reqwest = { version = "0.13.4", default-features = false, features = ["rustls-no-provider", "json", "http2"] }
+reqwest = { version = "0.13.5", default-features = false, features = ["rustls-no-provider", "json", "http2"] }
 notify = { version = "8.2.0", default-features = false, features = ["macos_fsevent"] }
 
 sysinfo = { version = "0.39", default-features = false, features = ["system"] }
diff --git a/crates/pumpkin-gametest/src/model.rs b/crates/pumpkin-gametest/src/model.rs
index 19346d837..df100dee7 100644
--- a/crates/pumpkin-gametest/src/model.rs
+++ b/crates/pumpkin-gametest/src/model.rs
@@ -6,6 +6,18 @@ use serde_json::Value;
 pub enum TestType {
     #[serde(rename = "minecraft:block_based")]
     BlockBased,
+    #[serde(rename = "minecraft:function")]
+    Function,
+}
+
+impl TestType {
+    #[must_use]
+    pub const fn serialized_name(self) -> &'static str {
+        match self {
+            Self::BlockBased => "minecraft:block_based",
+            Self::Function => "minecraft:function",
+        }
+    }
 }
 
 #[derive(Clone, Copy, Debug, Default, Deserialize, Eq, PartialEq)]
@@ -71,6 +83,8 @@ pub struct GameTestDefinition {
     pub instance_type: TestType,
     pub environment: Value,
     pub structure: String,
+    #[serde(default)]
+    pub function: Option<String>,
     pub max_ticks: i32,
     #[serde(default)]
     pub setup_ticks: i32,
@@ -93,7 +107,13 @@ pub struct GameTestDefinition {
 impl GameTestDefinition {
     #[must_use]
     pub fn is_valid(&self) -> bool {
-        self.max_ticks > 0
+        let function_valid = match self.instance_type {
+            TestType::BlockBased => true,
+            TestType::Function => self.function.as_ref().is_some_and(|f| !f.is_empty()),
+        };
+
+        function_valid
+            && self.max_ticks > 0
             && self.setup_ticks >= 0
             && self.max_attempts > 0
             && self.required_successes > 0
diff --git a/crates/pumpkin-protocol/src/java/client/config/feature_flags.rs b/crates/pumpkin-protocol/src/java/client/config/feature_flags.rs
index b2ba8e3fe..e34ed8535 100644
--- a/crates/pumpkin-protocol/src/java/client/config/feature_flags.rs
+++ b/crates/pumpkin-protocol/src/java/client/config/feature_flags.rs
@@ -1,17 +1,20 @@
 use pumpkin_data::packet::clientbound::config::UPDATE_ENABLED_FEATURES;
 use pumpkin_macros::java_packet;
-use pumpkin_util::{resource_location::ResourceLocation, version::JavaMinecraftVersion};
+use pumpkin_util::version::JavaMinecraftVersion;
 
 use crate::{ClientPacket, ser::NetworkWriteExt};
 
 #[java_packet(UPDATE_ENABLED_FEATURES)]
 pub struct CFeatureFlags<'a> {
-    pub features: &'a [ResourceLocation],
+    pub features: &'a [&'a str],
 }
 
+pub type CUpdateEnabledFeatures<'a> = CFeatureFlags<'a>;
+pub type ClientboundUpdateEnabledFeaturesPacket<'a> = CFeatureFlags<'a>;
+
 impl<'a> CFeatureFlags<'a> {
     #[must_use]
-    pub const fn new(features: &'a [ResourceLocation]) -> Self {
+    pub const fn new(features: &'a [&'a str]) -> Self {
         Self { features }
     }
 }
diff --git a/crates/pumpkin/src/data/datapack/mod.rs b/crates/pumpkin/src/data/datapack/mod.rs
index 6b481a50e..68d055a3b 100644
--- a/crates/pumpkin/src/data/datapack/mod.rs
+++ b/crates/pumpkin/src/data/datapack/mod.rs
@@ -20,6 +20,13 @@ use self::test_loader::{
     TestInstance, TestInstanceRegistry, load_test_instances_from_dir, to_registry_entry,
 };
 
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct KnownPackData {
+    pub namespace: String,
+    pub id: String,
+    pub version: String,
+}
+
 #[derive(Clone, Debug)]
 pub struct LoadedDatapack {
     pub id: String,
@@ -29,6 +36,7 @@ pub struct LoadedDatapack {
     pub root_path: PathBuf,
     pub recipe_count: usize,
     pub function_count: usize,
+    pub known_packs: Vec<KnownPackData>,
 }
 
 #[derive(Clone, Debug, PartialEq, Eq)]
@@ -121,7 +129,7 @@ impl DatapackManager {
                             continue;
                         }
 
-                        let (description, pack_format) = read_pack_mcmeta(&pack_path);
+                        let (description, pack_format, known_packs) = read_pack_mcmeta(&pack_path);
 
                         let (pack_recipe_count, pack_function_count, pack_test_instance_count) =
                             load_pack_contents(
@@ -144,6 +152,7 @@ impl DatapackManager {
                             root_path: pack_path,
                             recipe_count: pack_recipe_count,
                             function_count: pack_function_count,
+                            known_packs,
                         });
                     }
                 }
@@ -226,6 +235,119 @@ impl DatapackManager {
         entries
     }
 
+    /// Returns the list of known packs for client configuration / pack synchronization,
+    /// matching vanilla's `server.getResourceManager().listPacks().flatMap(p -> p.location().knownPackInfo().stream())`.
+    pub fn get_known_packs<'a>(
+        &self,
+        server: &Server,
+        server_version: &'a str,
+        loaded_packs: &'a [LoadedDatapack],
+    ) -> Vec<pumpkin_protocol::KnownPack<'a>> {
+        use pumpkin_protocol::KnownPack;
+
+        let mut known_packs = Vec::new();
+
+        // 1. Primary vanilla core pack
+        known_packs.push(KnownPack {
+            namespace: "minecraft",
+            id: "core",
+            version: server_version,
+        });
+
+        // 2. Built-in feature packs that are enabled
+        let enabled_packs = Self::get_enabled_packs(server);
+        for pack_name in &enabled_packs {
+            let id: &'static str = match pack_name.as_str() {
+                "trade_rebalance" => "trade_rebalance",
+                "minecart_improvements" => "minecart_improvements",
+                "redstone_experiments" => "redstone_experiments",
+                "bundle" => "bundle",
+                _ => continue,
+            };
+            let pack = KnownPack {
+                namespace: "minecraft",
+                id,
+                version: server_version,
+            };
+            if !known_packs
+                .iter()
+                .any(|p| p.namespace == pack.namespace && p.id == pack.id)
+            {
+                known_packs.push(pack);
+            }
+        }
+
+        // 3. Loaded packs with known_pack info from pack.mcmeta
+        for pack in loaded_packs {
+            for kp in &pack.known_packs {
+                let p = KnownPack {
+                    namespace: &kp.namespace,
+                    id: &kp.id,
+                    version: &kp.version,
+                };
+                if !known_packs.iter().any(|existing| {
+                    existing.namespace == p.namespace
+                        && existing.id == p.id
+                        && existing.version == p.version
+                }) {
+                    known_packs.push(p);
+                }
+            }
+        }
+
+        known_packs
+    }
+
+    /// Returns the enabled world feature flags (e.g. `minecraft:vanilla`, `minecraft:trade_rebalance`,
+    /// `minecraft:minecart_improvements`, `minecraft:redstone_experiments`, `minecraft:bundle`).
+    #[must_use]
+    pub fn get_enabled_features(&self, server: &Server) -> Vec<&'static str> {
+        let enabled_packs = Self::get_enabled_packs(server);
+        Self::resolve_enabled_features(&enabled_packs)
+    }
+
+    /// Resolves enabled feature flag names given a list of enabled pack names.
+    #[must_use]
+    pub fn resolve_enabled_features(enabled_packs: &[String]) -> Vec<&'static str> {
+        let mut features = vec!["minecraft:vanilla"];
+
+        for pack_name in enabled_packs {
+            let feature: &'static str = match pack_name.as_str() {
+                "trade_rebalance" | "file/trade_rebalance" => "minecraft:trade_rebalance",
+                "minecart_improvements" | "file/minecart_improvements" => {
+                    "minecraft:minecart_improvements"
+                }
+                "redstone_experiments" | "file/redstone_experiments" => {
+                    "minecraft:redstone_experiments"
+                }
+                "bundle" | "file/bundle" => "minecraft:bundle",
+                _ => {
+                    if let Some(stripped) = pack_name.strip_prefix("file/") {
+                        match stripped {
+                            "trade_rebalance" => "minecraft:trade_rebalance",
+                            "minecart_improvements" => "minecraft:minecart_improvements",
+                            "redstone_experiments" => "minecraft:redstone_experiments",
+                            "bundle" => "minecraft:bundle",
+                            _ => continue,
+                        }
+                    } else {
+                        continue;
+                    }
+                }
+            };
+            if !features.contains(&feature) {
+                features.push(feature);
+            }
+        }
+
+        features
+    }
+
+    #[must_use]
+    pub fn is_feature_enabled(&self, server: &Server, feature: &str) -> bool {
+        self.get_enabled_features(server).contains(&feature)
+    }
+
     /// Loads a Java Edition structure NBT from the currently enabled datapacks.
     ///
     /// Structure identifiers are resource locations such as
@@ -520,7 +642,7 @@ impl DatapackManager {
                 .get_world_path()
                 .join("datapacks")
                 .join(stripped);
-            let (desc, format) = read_pack_mcmeta(&pack_path);
+            let (desc, format, _) = read_pack_mcmeta(&pack_path);
             (resolved_name.clone(), stripped.to_string(), desc, format)
         } else {
             (
@@ -821,7 +943,7 @@ fn load_pack_contents(
     )
 }
 
-fn read_pack_mcmeta(pack_path: &Path) -> (String, u32) {
+fn read_pack_mcmeta(pack_path: &Path) -> (String, u32, Vec<KnownPackData>) {
     let mcmeta_path = pack_path.join("pack.mcmeta");
     if let Ok(content) = fs::read_to_string(mcmeta_path)
         && let Ok(val) = serde_json::from_str::<serde_json::Value>(&content)
@@ -838,9 +960,49 @@ fn read_pack_mcmeta(pack_path: &Path) -> (String, u32) {
             .and_then(|p| p.get("pack_format"))
             .and_then(serde_json::Value::as_u64)
             .unwrap_or(61) as u32;
-        return (description, pack_format);
+
+        let mut known_packs = Vec::new();
+        let parse_item = |item: &serde_json::Value| -> Option<KnownPackData> {
+            let ns = item.get("namespace").and_then(serde_json::Value::as_str)?;
+            let id = item.get("id").and_then(serde_json::Value::as_str)?;
+            let ver = item.get("version").and_then(serde_json::Value::as_str)?;
+            Some(KnownPackData {
+                namespace: ns.to_string(),
+                id: id.to_string(),
+                version: ver.to_string(),
+            })
+        };
+
+        if let Some(packs_array) = val.get("known_packs").and_then(serde_json::Value::as_array) {
+            for item in packs_array {
+                if let Some(kp) = parse_item(item) {
+                    known_packs.push(kp);
+                }
+            }
+        } else if let Some(item) = val.get("known_pack") {
+            if let Some(kp) = parse_item(item) {
+                known_packs.push(kp);
+            }
+        } else if let Some(pack_obj) = pack {
+            if let Some(packs_array) = pack_obj
+                .get("known_packs")
+                .and_then(serde_json::Value::as_array)
+            {
+                for item in packs_array {
+                    if let Some(kp) = parse_item(item) {
+                        known_packs.push(kp);
+                    }
+                }
+            } else if let Some(item) = pack_obj.get("known_pack")
+                && let Some(kp) = parse_item(item)
+            {
+                known_packs.push(kp);
+            }
+        }
+
+        return (description, pack_format, known_packs);
     }
-    (String::new(), 61)
+    (String::new(), 61, Vec::new())
 }
 
 fn load_recipes_from_dir(
@@ -946,4 +1108,87 @@ mod tests {
             "Unknown function tag: #test:missing"
         );
     }
+
+    #[test]
+    fn read_pack_mcmeta_parses_known_packs() {
+        let temp_dir = tempfile::tempdir().expect("tempdir");
+        let pack_path = temp_dir.path();
+
+        // 1. Test root known_packs array
+        let mcmeta_content = r#"{
+            "pack": {
+                "description": "Test Pack",
+                "pack_format": 61
+            },
+            "known_packs": [
+                {
+                    "namespace": "example",
+                    "id": "content",
+                    "version": "1.0.0"
+                }
+            ]
+        }"#;
+        std::fs::write(pack_path.join("pack.mcmeta"), mcmeta_content).unwrap();
+
+        let (desc, format, known_packs) = super::read_pack_mcmeta(pack_path);
+        assert_eq!(desc, "Test Pack");
+        assert_eq!(format, 61);
+        assert_eq!(known_packs.len(), 1);
+        assert_eq!(known_packs[0].namespace, "example");
+        assert_eq!(known_packs[0].id, "content");
+        assert_eq!(known_packs[0].version, "1.0.0");
+
+        // 2. Test nested pack.known_packs
+        let mcmeta_content_nested = r#"{
+            "pack": {
+                "description": "Nested Pack",
+                "pack_format": 61,
+                "known_packs": [
+                    {
+                        "namespace": "nested",
+                        "id": "pack",
+                        "version": "2.0.0"
+                    }
+                ]
+            }
+        }"#;
+        std::fs::write(pack_path.join("pack.mcmeta"), mcmeta_content_nested).unwrap();
+
+        let (_, _, known_packs) = super::read_pack_mcmeta(pack_path);
+        assert_eq!(known_packs.len(), 1);
+        assert_eq!(known_packs[0].namespace, "nested");
+        assert_eq!(known_packs[0].id, "pack");
+        assert_eq!(known_packs[0].version, "2.0.0");
+    }
+
+    #[test]
+    fn resolve_enabled_features_works() {
+        // Default only vanilla
+        let default_features = DatapackManager::resolve_enabled_features(&[]);
+        assert_eq!(default_features, ["minecraft:vanilla"]);
+
+        // With minecart improvements
+        let minecart_features =
+            DatapackManager::resolve_enabled_features(&["file/minecart_improvements".to_string()]);
+        assert_eq!(
+            minecart_features,
+            ["minecraft:vanilla", "minecraft:minecart_improvements"]
+        );
+
+        // Multiple experimental features
+        let multi_features = DatapackManager::resolve_enabled_features(&[
+            "trade_rebalance".to_string(),
+            "redstone_experiments".to_string(),
+            "file/bundle".to_string(),
+        ]);
+        assert_eq!(
+            multi_features,
+            [
+                "minecraft:vanilla",
+                "minecraft:trade_rebalance",
+                "minecraft:redstone_experiments",
+                "minecraft:bundle"
+            ]
+        );
+    }
 }
diff --git a/crates/pumpkin/src/data/datapack/test_loader.rs b/crates/pumpkin/src/data/datapack/test_loader.rs
index 6bf6930ec..444c5f0bb 100644
--- a/crates/pumpkin/src/data/datapack/test_loader.rs
+++ b/crates/pumpkin/src/data/datapack/test_loader.rs
@@ -96,14 +96,11 @@ fn load_test_instances_recursive(
 #[must_use]
 pub fn to_registry_entry(entry_id: String, instance: &TestInstance) -> RegistryEntryData {
     let mut nbt = NbtCompound::new();
-    nbt.put_string(
-        "type",
-        match instance.instance_type {
-            TestType::BlockBased => "minecraft:block_based",
-        }
-        .to_string(),
-    );
+    nbt.put_string("type", instance.instance_type.serialized_name().to_string());
     nbt.put("environment", json_value_to_nbt(&instance.environment));
+    if let Some(function) = &instance.function {
+        nbt.put_string("function", function.clone());
+    }
     nbt.put_string("structure", instance.structure.clone());
     nbt.put_int("max_ticks", instance.max_ticks);
     nbt.put_int("setup_ticks", instance.setup_ticks);
@@ -203,4 +200,66 @@ mod tests {
         assert!(!instance.sky_access);
         assert_eq!(instance.padding, 0);
     }
+
+    #[test]
+    fn loads_function_test_instance_with_vanilla_defaults() {
+        let dir = tempfile::tempdir().expect("temp dir");
+
+        fs::write(
+            dir.path().join("always_pass.json"),
+            r#"{
+                "type": "minecraft:function",
+                "environment": "minecraft:default",
+                "function": "minecraft:always_pass",
+                "max_ticks": 1,
+                "required": false,
+                "setup_ticks": 1,
+                "structure": "minecraft:empty"
+            }"#,
+        )
+        .expect("write test instance");
+
+        let mut registry = TestInstanceRegistry::new();
+        let loaded = load_test_instances_from_dir("minecraft", dir.path(), &mut registry);
+
+        assert_eq!(loaded, 1);
+
+        let instance = registry
+            .get("minecraft:always_pass")
+            .expect("test instance should be registered");
+
+        assert_eq!(instance.instance_type, TestType::Function);
+        assert_eq!(
+            instance.environment,
+            Value::String("minecraft:default".into())
+        );
+        assert_eq!(instance.function.as_deref(), Some("minecraft:always_pass"));
+        assert_eq!(instance.structure, "minecraft:empty");
+        assert_eq!(instance.max_ticks, 1);
+        assert_eq!(instance.setup_ticks, 1);
+        assert!(!instance.required);
+        assert_eq!(instance.rotation, GameTestRotation::None);
+        assert!(!instance.manual_only);
+        assert_eq!(instance.max_attempts, 1);
+        assert_eq!(instance.required_successes, 1);
+        assert!(!instance.sky_access);
+        assert_eq!(instance.padding, 0);
+    }
+
+    #[test]
+    fn loads_embedded_test_instances_including_always_pass() {
+        let mut registry = TestInstanceRegistry::new();
+        let count = load_embedded_test_instances(&mut registry);
+        assert!(count > 0);
+
+        let always_pass = registry
+            .get("minecraft:always_pass")
+            .expect("minecraft:always_pass should be successfully parsed and registered");
+        assert_eq!(always_pass.instance_type, TestType::Function);
+        assert_eq!(
+            always_pass.function.as_deref(),
+            Some("minecraft:always_pass")
+        );
+        assert_eq!(always_pass.structure, "minecraft:empty");
+    }
 }
diff --git a/crates/pumpkin/src/net/java/config/known_packs.rs b/crates/pumpkin/src/net/java/config/known_packs.rs
index 7e45c3db9..06ca6f636 100644
--- a/crates/pumpkin/src/net/java/config/known_packs.rs
+++ b/crates/pumpkin/src/net/java/config/known_packs.rs
@@ -8,8 +8,10 @@ impl JavaClient {
         let version = self.version.load();
 
         if version.supports_configuration_state() {
-            self.send_packet(&CFeatureFlags::new(&["minecraft:vanilla".to_string()]))
-                .await;
+            if version < JavaMinecraftVersion::V_1_20_5 {
+                let features = server.get_enabled_features();
+                self.send_packet(&CFeatureFlags::new(&features)).await;
+            }
 
             let test_instance_entries =
                 server.datapack_manager.get_test_instance_registry_entries();
diff --git a/crates/pumpkin/src/net/java/config/mod.rs b/crates/pumpkin/src/net/java/config/mod.rs
index 6167e3ab5..0b2a386ab 100644
--- a/crates/pumpkin/src/net/java/config/mod.rs
+++ b/crates/pumpkin/src/net/java/config/mod.rs
@@ -11,7 +11,7 @@ use crate::{
 use core::str;
 use pumpkin_data::registry::Registry;
 use pumpkin_protocol::{
-    ConnectionState, KnownPack,
+    ConnectionState,
     java::{
         client::config::{CFeatureFlags, CFinishConfig, CKnownPacks, CRegistryData, CUpdateTags},
         server::config::{
@@ -20,7 +20,7 @@ use pumpkin_protocol::{
         },
     },
 };
-use pumpkin_util::{Hand, text::TextComponent};
+use pumpkin_util::{Hand, text::TextComponent, version::JavaMinecraftVersion};
 use tracing::{debug, trace, warn};
 
 const BRAND_CHANNEL_PREFIX: &str = "minecraft:brand";
diff --git a/crates/pumpkin/src/net/java/config/resource_pack.rs b/crates/pumpkin/src/net/java/config/resource_pack.rs
index da174d573..1f008506e 100644
--- a/crates/pumpkin/src/net/java/config/resource_pack.rs
+++ b/crates/pumpkin/src/net/java/config/resource_pack.rs
@@ -69,16 +69,15 @@ impl JavaClient {
                 self.id
             );
         }
-        self.send_known_packs().await;
+        self.send_known_packs(server).await;
     }
 
-    pub async fn send_known_packs(&self) {
+    pub async fn send_known_packs(&self, server: &Server) {
+        let features = server.get_enabled_features();
+        self.send_packet(&CFeatureFlags::new(&features)).await;
         let version_str = self.version.load().to_string();
-        self.send_packet(&CKnownPacks::new(&[KnownPack {
-            namespace: "minecraft",
-            id: "core",
-            version: &version_str,
-        }]))
-        .await;
+        let loaded_packs = server.datapack_manager.get_loaded_packs();
+        let known_packs = server.get_known_packs(&version_str, &loaded_packs);
+        self.send_packet(&CKnownPacks::new(&known_packs)).await;
     }
 }
diff --git a/crates/pumpkin/src/net/java/login/known_packs.rs b/crates/pumpkin/src/net/java/login/known_packs.rs
index 09c57893a..2102fe4d9 100644
--- a/crates/pumpkin/src/net/java/login/known_packs.rs
+++ b/crates/pumpkin/src/net/java/login/known_packs.rs
@@ -2,11 +2,13 @@
 use super::*;
 
 impl PendingConnection {
-    pub async fn handle_known_packs(&mut self) {
+    pub async fn handle_known_packs(&mut self, server: &Server) {
         let version = self.version.load();
         if version.supports_configuration_state() {
-            self.send_packet_now(&CFeatureFlags::new(&["minecraft:vanilla".to_string()]))
-                .await;
+            if version < JavaMinecraftVersion::V_1_20_5 {
+                let features = server.get_enabled_features();
+                self.send_packet_now(&CFeatureFlags::new(&features)).await;
+            }
             let registry = pumpkin_data::registry::Registry::get_synced(version);
             for reg in &registry {
                 self.send_packet_now(&CRegistryData::new(&reg.registry_id, &reg.registry_entries))
diff --git a/crates/pumpkin/src/net/java/login/login_acknowledged.rs b/crates/pumpkin/src/net/java/login/login_acknowledged.rs
index 725d42c47..a0712267c 100644
--- a/crates/pumpkin/src/net/java/login/login_acknowledged.rs
+++ b/crates/pumpkin/src/net/java/login/login_acknowledged.rs
@@ -97,21 +97,20 @@ impl PendingConnection {
 
             self.send_packet_now(&resource_pack).await;
         } else if self.version.load() >= JavaMinecraftVersion::V_1_20_5 {
-            self.send_known_packs().await;
+            self.send_known_packs(server).await;
         } else {
-            self.handle_known_packs().await;
+            self.handle_known_packs(server).await;
         }
         debug!("login acknowledged");
         None
     }
 
-    pub async fn send_known_packs(&mut self) {
+    pub async fn send_known_packs(&mut self, server: &Server) {
+        let features = server.get_enabled_features();
+        self.send_packet_now(&CFeatureFlags::new(&features)).await;
         let version_str = self.version.load().to_string();
-        self.send_packet_now(&CKnownPacks::new(&[KnownPack {
-            namespace: "minecraft",
-            id: "core",
-            version: &version_str,
-        }]))
-        .await;
+        let loaded_packs = server.datapack_manager.get_loaded_packs();
+        let known_packs = server.get_known_packs(&version_str, &loaded_packs);
+        self.send_packet_now(&CKnownPacks::new(&known_packs)).await;
     }
 }
diff --git a/crates/pumpkin/src/net/java/login/mod.rs b/crates/pumpkin/src/net/java/login/mod.rs
index 150c76c3c..1f7e70658 100644
--- a/crates/pumpkin/src/net/java/login/mod.rs
+++ b/crates/pumpkin/src/net/java/login/mod.rs
@@ -1,7 +1,7 @@
 use arc_swap::ArcSwap;
 use pumpkin_data::translation;
 use pumpkin_protocol::{
-    ConnectionState, KnownPack, Label, Link, LinkType,
+    ConnectionState, Label, Link, LinkType,
     java::client::{
         config::{
             CConfigAddResourcePack, CConfigServerLinks, CFeatureFlags, CFinishConfig, CKnownPacks,
diff --git a/crates/pumpkin/src/net/java/pending.rs b/crates/pumpkin/src/net/java/pending.rs
index b00d291cb..abf2eb94b 100644
--- a/crates/pumpkin/src/net/java/pending.rs
+++ b/crates/pumpkin/src/net/java/pending.rs
@@ -420,7 +420,7 @@ impl PendingConnection {
                 }
             }
             id if id == SKnownPacks::to_id(version) => {
-                self.handle_known_packs().await;
+                self.handle_known_packs(server).await;
                 Ok(None)
             }
             id if id == SConfigResourcePack::to_id(version) => {
@@ -509,19 +509,33 @@ impl PendingConnection {
             match packet.response_result() {
                 ResourcePackResponseResult::Downloaded
                 | ResourcePackResponseResult::DownloadSuccess
-                | ResourcePackResponseResult::Accepted
                 | ResourcePackResponseResult::Discarded
-                | ResourcePackResponseResult::Unknown(_) => {}
+                | ResourcePackResponseResult::Unknown(_) => {
+                    if self.version.load() >= JavaMinecraftVersion::V_1_20_5 {
+                        self.send_known_packs(server).await;
+                    } else {
+                        self.handle_known_packs(server).await;
+                    }
+                }
+                ResourcePackResponseResult::Accepted => {}
                 ResourcePackResponseResult::Declined => {
                     if resource_config.force {
                         self.kick(TextComponent::text("Required resource pack was declined"))
                             .await;
+                    } else if self.version.load() >= JavaMinecraftVersion::V_1_20_5 {
+                        self.send_known_packs(server).await;
+                    } else {
+                        self.handle_known_packs(server).await;
                     }
                 }
                 ResourcePackResponseResult::DownloadFail => {
                     if resource_config.force {
                         self.kick(TextComponent::text("Failed to download resource pack"))
                             .await;
+                    } else if self.version.load() >= JavaMinecraftVersion::V_1_20_5 {
+                        self.send_known_packs(server).await;
+                    } else {
+                        self.handle_known_packs(server).await;
                     }
                 }
                 ResourcePackResponseResult::InvalidUrl => {
diff --git a/crates/pumpkin/src/net/java/play/client_command.rs b/crates/pumpkin/src/net/java/play/client_command.rs
index 6c323785d..afdb65c15 100644
--- a/crates/pumpkin/src/net/java/play/client_command.rs
+++ b/crates/pumpkin/src/net/java/play/client_command.rs
@@ -67,9 +67,25 @@ impl JavaClient {
             return;
         }
 
-        let level_info = player.world().level_info.load();
+        let world = player.world();
+        let level_info = world.level_info.load();
+        let minecart_improvements_enabled = world.server.upgrade().map_or_else(
+            || {
+                level_info
+                    .data_packs
+                    .enabled
+                    .iter()
+                    .any(|p| p == "minecart_improvements" || p == "file/minecart_improvements")
+            },
+            |s| s.is_feature_enabled("minecraft:minecart_improvements"),
+        );
+
         let rules: Vec<(String, String)> = GameRule::all()
             .iter()
+            .filter(|rule| match rule {
+                GameRule::MaxMinecartSpeed => minecart_improvements_enabled,
+                _ => true,
+            })
             .map(|rule| {
                 (
                     rule.to_string(),
diff --git a/crates/pumpkin/src/net/java/play/set_game_rule.rs b/crates/pumpkin/src/net/java/play/set_game_rule.rs
index cde6304d5..41d37e5f5 100644
--- a/crates/pumpkin/src/net/java/play/set_game_rule.rs
+++ b/crates/pumpkin/src/net/java/play/set_game_rule.rs
@@ -13,6 +13,20 @@ impl JavaClient {
             return;
         }
 
+        let world = player.world();
+        let minecart_improvements_enabled = world.server.upgrade().map_or_else(
+            || {
+                world
+                    .level_info
+                    .load()
+                    .data_packs
+                    .enabled
+                    .iter()
+                    .any(|p| p == "minecart_improvements" || p == "file/minecart_improvements")
+            },
+            |s| s.is_feature_enabled("minecraft:minecart_improvements"),
+        );
+
         for entry in &packet.entries {
             let key = entry
                 .game_rule_key
@@ -23,6 +37,14 @@ impl JavaClient {
                 continue;
             };
 
+            if *rule == GameRule::MaxMinecartSpeed && !minecart_improvements_enabled {
+                warn!(
+                    "Player {} tried to set game rule {} which is not enabled by feature flags",
+                    player.gameprofile.name, entry.game_rule_key
+                );
+                continue;
+            }
+
             let level_info = player.world().level_info.load();
             let current_val = level_info.game_rules.get(rule);
             match current_val {
diff --git a/crates/pumpkin/src/server/mod.rs b/crates/pumpkin/src/server/mod.rs
index 66532fdb0..bd2daf9fd 100644
--- a/crates/pumpkin/src/server/mod.rs
+++ b/crates/pumpkin/src/server/mod.rs
@@ -564,6 +564,26 @@ impl Server {
         }
     }
 
+    #[must_use]
+    pub fn get_known_packs<'a>(
+        &self,
+        server_version: &'a str,
+        loaded_packs: &'a [crate::data::datapack::LoadedDatapack],
+    ) -> Vec<pumpkin_protocol::KnownPack<'a>> {
+        self.datapack_manager
+            .get_known_packs(self, server_version, loaded_packs)
+    }
+
+    #[must_use]
+    pub fn get_enabled_features(&self) -> Vec<&'static str> {
+        self.datapack_manager.get_enabled_features(self)
+    }
+
+    #[must_use]
+    pub fn is_feature_enabled(&self, feature: &str) -> bool {
+        self.datapack_manager.is_feature_enabled(self, feature)
+    }
+
     pub async fn save_all(&self) -> Result<(), String> {
         if let Err(err) = self.save_world_info() {
             error!("Failed to save world info: {err}");
diff --git a/crates/pumpkin/src/server/server_test_manager.rs b/crates/pumpkin/src/server/server_test_manager.rs
index 36646e59a..315419ea4 100644
--- a/crates/pumpkin/src/server/server_test_manager.rs
+++ b/crates/pumpkin/src/server/server_test_manager.rs
@@ -7,6 +7,7 @@ use pumpkin_data::{BlockState, BlockStateId};
 use pumpkin_gametest::{
     BlockBasedTest, GameTestError, GameTestManager, GameTestReporter, GameTestResult,
     GameTestRotation, GameTestRunner, GameTestSession, GameTestStructureTemplate, GameTestWorld,
+    TestType,
 };
 pub use pumpkin_gametest::{GameTestBatchReport, GameTestRetryOptions};
 use pumpkin_nbt::NbtCompound;
@@ -149,6 +150,13 @@ async fn prepare_test_run(
             GameTestError::World(format!("Unknown test instance '{}'", request.test_id))
         })?;
 
+    if test_instance.instance_type != TestType::BlockBased {
+        return Err(GameTestError::World(format!(
+            "Test instance '{}' has unsupported type '{:?}' (only block-based tests can be executed currently)",
+            request.test_id, test_instance.instance_type
+        )));
+    }
+
     let structure = server
         .datapack_manager
         .load_structure(&test_instance.structure)