diff --git a/azalea-brigadier/src/builder/argument_builder.rs b/azalea-brigadier/src/builder/argument_builder.rs
index a1f3d6ae..c6f2146a 100755
--- a/azalea-brigadier/src/builder/argument_builder.rs
+++ b/azalea-brigadier/src/builder/argument_builder.rs
@@ -7,7 +7,7 @@ use crate::{
 };
 
 use super::{literal_argument_builder::Literal, required_argument_builder::Argument};
-use std::{fmt::Debug, rc::Rc, sync::Arc};
+use std::{fmt::Debug, sync::Arc};
 
 #[derive(Debug, Clone)]
 pub enum ArgumentBuilderType {
@@ -20,11 +20,11 @@ pub struct ArgumentBuilder<S> {
     arguments: CommandNode<S>,
 
     command: Command<S>,
-    requirement: Rc<dyn Fn(Rc<S>) -> bool>,
+    requirement: Arc<dyn Fn(Arc<S>) -> bool + Send + Sync>,
     target: Option<Arc<RwLock<CommandNode<S>>>>,
 
     forks: bool,
-    modifier: Option<Rc<RedirectModifier<S>>>,
+    modifier: Option<Arc<RedirectModifier<S>>>,
 }
 
 /// A node that isn't yet built.
@@ -36,7 +36,7 @@ impl<S> ArgumentBuilder<S> {
                 ..Default::default()
             },
             command: None,
-            requirement: Rc::new(|_| true),
+            requirement: Arc::new(|_| true),
             forks: false,
             modifier: None,
             target: None,
@@ -54,17 +54,17 @@ impl<S> ArgumentBuilder<S> {
 
     pub fn executes<F>(mut self, f: F) -> Self
     where
-        F: Fn(&CommandContext<S>) -> i32 + 'static,
+        F: Fn(&CommandContext<S>) -> i32 + Send + Sync + 'static,
     {
-        self.command = Some(Rc::new(f));
+        self.command = Some(Arc::new(f));
         self
     }
 
     pub fn requires<F>(mut self, requirement: F) -> Self
     where
-        F: Fn(Rc<S>) -> bool + 'static,
+        F: Fn(Arc<S>) -> bool + Send + Sync + 'static,
     {
-        self.requirement = Rc::new(requirement);
+        self.requirement = Arc::new(requirement);
         self
     }
 
@@ -75,7 +75,7 @@ impl<S> ArgumentBuilder<S> {
     pub fn fork(
         self,
         target: Arc<RwLock<CommandNode<S>>>,
-        modifier: Rc<RedirectModifier<S>>,
+        modifier: Arc<RedirectModifier<S>>,
     ) -> Self {
         self.forward(target, Some(modifier), true)
     }
@@ -83,7 +83,7 @@ impl<S> ArgumentBuilder<S> {
     pub fn forward(
         mut self,
         target: Arc<RwLock<CommandNode<S>>>,
-        modifier: Option<Rc<RedirectModifier<S>>>,
+        modifier: Option<Arc<RedirectModifier<S>>>,
         fork: bool,
     ) -> Self {
         if !self.arguments.children.is_empty() {
diff --git a/azalea-brigadier/src/builder/required_argument_builder.rs b/azalea-brigadier/src/builder/required_argument_builder.rs
index 9d4d9e0a..0363d204 100755
--- a/azalea-brigadier/src/builder/required_argument_builder.rs
+++ b/azalea-brigadier/src/builder/required_argument_builder.rs
@@ -2,17 +2,17 @@ use super::argument_builder::{ArgumentBuilder, ArgumentBuilderType};
 use crate::{
     arguments::ArgumentType, exceptions::CommandSyntaxException, string_reader::StringReader,
 };
-use std::{any::Any, fmt::Debug, rc::Rc};
+use std::{any::Any, fmt::Debug, rc::Rc, sync::Arc};
 
 /// An argument node type. The `T` type parameter is the type of the argument,
 /// which can be anything.
 #[derive(Clone)]
 pub struct Argument {
     pub name: String,
-    parser: Rc<dyn ArgumentType>,
+    parser: Arc<dyn ArgumentType + Send + Sync>,
 }
 impl Argument {
-    pub fn new(name: &str, parser: Rc<dyn ArgumentType>) -> Self {
+    pub fn new(name: &str, parser: Arc<dyn ArgumentType + Send + Sync>) -> Self {
         Self {
             name: name.to_string(),
             parser,
@@ -40,6 +40,9 @@ impl Debug for Argument {
 }
 
 /// Shortcut for creating a new argument builder node.
-pub fn argument<S>(name: &str, parser: impl ArgumentType + 'static) -> ArgumentBuilder<S> {
-    ArgumentBuilder::new(Argument::new(name, Rc::new(parser)).into())
+pub fn argument<S>(
+    name: &str,
+    parser: impl ArgumentType + Send + Sync + 'static,
+) -> ArgumentBuilder<S> {
+    ArgumentBuilder::new(Argument::new(name, Arc::new(parser)).into())
 }
diff --git a/azalea-brigadier/src/command_dispatcher.rs b/azalea-brigadier/src/command_dispatcher.rs
index 0d84171e..384a28dd 100755
--- a/azalea-brigadier/src/command_dispatcher.rs
+++ b/azalea-brigadier/src/command_dispatcher.rs
@@ -13,8 +13,8 @@ use std::{cmp::Ordering, collections::HashMap, mem, rc::Rc, sync::Arc};
 /// The root of the command tree. You need to make this to register commands.
 #[derive(Default)]
 pub struct CommandDispatcher<S>
-// where
-//     Self: Sync + Send,
+where
+    Self: Sync + Send,
 {
     pub root: Arc<RwLock<CommandNode<S>>>,
 }
@@ -32,7 +32,7 @@ impl<S> CommandDispatcher<S> {
         build
     }
 
-    pub fn parse(&self, command: StringReader, source: Rc<S>) -> ParseResults<S> {
+    pub fn parse(&self, command: StringReader, source: Arc<S>) -> ParseResults<S> {
         let context = CommandContextBuilder::new(self, source, self.root.clone(), command.cursor());
         self.parse_nodes(&self.root, &command, context).unwrap()
     }
@@ -91,7 +91,7 @@ impl<S> CommandDispatcher<S> {
                     let parse = self
                         .parse_nodes(redirect, &reader, child_context)
                         .expect("Parsing nodes failed");
-                    context.with_child(Rc::new(parse.context));
+                    context.with_child(Arc::new(parse.context));
                     return Ok(ParseResults {
                         context,
                         reader: parse.reader,
@@ -144,7 +144,7 @@ impl<S> CommandDispatcher<S> {
     pub fn execute(
         &self,
         input: StringReader,
-        source: Rc<S>,
+        source: Arc<S>,
     ) -> Result<i32, CommandSyntaxException> {
         let parse = self.parse(input, source);
         Self::execute_parsed(parse)
diff --git a/azalea-brigadier/src/context/command_context.rs b/azalea-brigadier/src/context/command_context.rs
index 88af2002..1734bb05 100755
--- a/azalea-brigadier/src/context/command_context.rs
+++ b/azalea-brigadier/src/context/command_context.rs
@@ -9,15 +9,15 @@ use std::{any::Any, collections::HashMap, fmt::Debug, rc::Rc, sync::Arc};
 
 /// A built `CommandContextBuilder`.
 pub struct CommandContext<S> {
-    pub source: Rc<S>,
+    pub source: Arc<S>,
     pub input: String,
     pub arguments: HashMap<String, ParsedArgument>,
     pub command: Command<S>,
     pub root_node: Arc<RwLock<CommandNode<S>>>,
     pub nodes: Vec<ParsedCommandNode<S>>,
     pub range: StringRange,
-    pub child: Option<Rc<CommandContext<S>>>,
-    pub modifier: Option<Rc<RedirectModifier<S>>>,
+    pub child: Option<Arc<CommandContext<S>>>,
+    pub modifier: Option<Arc<RedirectModifier<S>>>,
     pub forks: bool,
 }
 
@@ -56,8 +56,8 @@ impl<S> Debug for CommandContext<S> {
 }
 
 impl<S> CommandContext<S> {
-    pub fn copy_for(&self, source: Rc<S>) -> Self {
-        if Rc::ptr_eq(&source, &self.source) {
+    pub fn copy_for(&self, source: Arc<S>) -> Self {
+        if Arc::ptr_eq(&source, &self.source) {
             return self.clone();
         }
         CommandContext {
diff --git a/azalea-brigadier/src/context/command_context_builder.rs b/azalea-brigadier/src/context/command_context_builder.rs
index 54063879..78088941 100755
--- a/azalea-brigadier/src/context/command_context_builder.rs
+++ b/azalea-brigadier/src/context/command_context_builder.rs
@@ -9,18 +9,18 @@ use crate::{
     modifier::RedirectModifier,
     tree::{Command, CommandNode},
 };
-use std::{collections::HashMap, fmt::Debug, rc::Rc, sync::Arc};
+use std::{collections::HashMap, fmt::Debug, sync::Arc};
 
 pub struct CommandContextBuilder<'a, S> {
     pub arguments: HashMap<String, ParsedArgument>,
     pub root: Arc<RwLock<CommandNode<S>>>,
     pub nodes: Vec<ParsedCommandNode<S>>,
     pub dispatcher: &'a CommandDispatcher<S>,
-    pub source: Rc<S>,
+    pub source: Arc<S>,
     pub command: Command<S>,
-    pub child: Option<Rc<CommandContextBuilder<'a, S>>>,
+    pub child: Option<Arc<CommandContextBuilder<'a, S>>>,
     pub range: StringRange,
-    pub modifier: Option<Rc<RedirectModifier<S>>>,
+    pub modifier: Option<Arc<RedirectModifier<S>>>,
     pub forks: bool,
 }
 
@@ -44,7 +44,7 @@ impl<S> Clone for CommandContextBuilder<'_, S> {
 impl<'a, S> CommandContextBuilder<'a, S> {
     pub fn new(
         dispatcher: &'a CommandDispatcher<S>,
-        source: Rc<S>,
+        source: Arc<S>,
         root_node: Arc<RwLock<CommandNode<S>>>,
         start: usize,
     ) -> Self {
@@ -66,7 +66,7 @@ impl<'a, S> CommandContextBuilder<'a, S> {
         self.command = command.clone();
         self
     }
-    pub fn with_child(&mut self, child: Rc<CommandContextBuilder<'a, S>>) -> &Self {
+    pub fn with_child(&mut self, child: Arc<CommandContextBuilder<'a, S>>) -> &Self {
         self.child = Some(child);
         self
     }
@@ -92,7 +92,7 @@ impl<'a, S> CommandContextBuilder<'a, S> {
             nodes: self.nodes.clone(),
             source: self.source.clone(),
             command: self.command.clone(),
-            child: self.child.clone().map(|c| Rc::new(c.build(input))),
+            child: self.child.clone().map(|c| Arc::new(c.build(input))),
             range: self.range.clone(),
             forks: self.forks,
             modifier: self.modifier.clone(),
diff --git a/azalea-brigadier/src/modifier.rs b/azalea-brigadier/src/modifier.rs
index d40d59f9..bebdd0cb 100755
--- a/azalea-brigadier/src/modifier.rs
+++ b/azalea-brigadier/src/modifier.rs
@@ -1,6 +1,6 @@
-use std::rc::Rc;
+use std::sync::Arc;
 
 use crate::{context::CommandContext, exceptions::CommandSyntaxException};
 
 pub type RedirectModifier<S> =
-    dyn Fn(&CommandContext<S>) -> Result<Vec<Rc<S>>, CommandSyntaxException>;
+    dyn Fn(&CommandContext<S>) -> Result<Vec<Arc<S>>, CommandSyntaxException> + Send + Sync;
diff --git a/azalea-brigadier/src/tree/mod.rs b/azalea-brigadier/src/tree/mod.rs
index 902e288b..cec972dc 100755
--- a/azalea-brigadier/src/tree/mod.rs
+++ b/azalea-brigadier/src/tree/mod.rs
@@ -10,9 +10,9 @@ use crate::{
     modifier::RedirectModifier,
     string_reader::StringReader,
 };
-use std::{collections::HashMap, fmt::Debug, hash::Hash, ptr, rc::Rc, sync::Arc};
+use std::{collections::HashMap, fmt::Debug, hash::Hash, ptr, sync::Arc};
 
-pub type Command<S> = Option<Rc<dyn Fn(&CommandContext<S>) -> i32>>;
+pub type Command<S> = Option<Arc<dyn Fn(&CommandContext<S>) -> i32 + Send + Sync>>;
 
 /// An ArgumentBuilder that has been built.
 #[non_exhaustive]
@@ -24,10 +24,10 @@ pub struct CommandNode<S> {
     pub arguments: HashMap<String, Arc<RwLock<CommandNode<S>>>>,
 
     pub command: Command<S>,
-    pub requirement: Rc<dyn Fn(Rc<S>) -> bool>,
+    pub requirement: Arc<dyn Fn(Arc<S>) -> bool + Send + Sync>,
     pub redirect: Option<Arc<RwLock<CommandNode<S>>>>,
     pub forks: bool,
-    pub modifier: Option<Rc<RedirectModifier<S>>>,
+    pub modifier: Option<Arc<RedirectModifier<S>>>,
 }
 
 impl<S> Clone for CommandNode<S> {
@@ -90,7 +90,7 @@ impl<S> CommandNode<S> {
         }
     }
 
-    pub fn can_use(&self, source: Rc<S>) -> bool {
+    pub fn can_use(&self, source: Arc<S>) -> bool {
         (self.requirement)(source)
     }
 
@@ -221,7 +221,7 @@ impl<S> Default for CommandNode<S> {
             arguments: HashMap::new(),
 
             command: None,
-            requirement: Rc::new(|_| true),
+            requirement: Arc::new(|_| true),
             redirect: None,
             forks: false,
             modifier: None,
@@ -257,7 +257,7 @@ impl<S> PartialEq for CommandNode<S> {
             // idk how to do this better since we can't compare `dyn Fn`s
             if let Some(otherexecutes) = &other.command {
                 #[allow(clippy::vtable_address_comparisons)]
-                if !Rc::ptr_eq(selfexecutes, otherexecutes) {
+                if !Arc::ptr_eq(selfexecutes, otherexecutes) {
                     return false;
                 }
             } else {
diff --git a/azalea-brigadier/tests/command_dispatcher_test.rs b/azalea-brigadier/tests/command_dispatcher_test.rs
index fb0085ba..4479cfa2 100755
--- a/azalea-brigadier/tests/command_dispatcher_test.rs
+++ b/azalea-brigadier/tests/command_dispatcher_test.rs
@@ -1,4 +1,4 @@
-use std::rc::Rc;
+use std::sync::Arc;
 
 use azalea_brigadier::{
     arguments::integer_argument_type::integer,
@@ -25,7 +25,7 @@ fn create_and_execute_command() {
 
     assert_eq!(
         subject
-            .execute("foo".into(), Rc::new(CommandSource {}))
+            .execute("foo".into(), Arc::new(CommandSource {}))
             .unwrap(),
         42
     );
@@ -38,7 +38,7 @@ fn create_and_execute_offset_command() {
 
     assert_eq!(
         subject
-            .execute(input_with_offset("/foo", 1), Rc::new(CommandSource {}))
+            .execute(input_with_offset("/foo", 1), Arc::new(CommandSource {}))
             .unwrap(),
         42
     );
@@ -52,13 +52,13 @@ fn create_and_merge_commands() {
 
     assert_eq!(
         subject
-            .execute("base foo".into(), Rc::new(CommandSource {}))
+            .execute("base foo".into(), Arc::new(CommandSource {}))
             .unwrap(),
         42
     );
     assert_eq!(
         subject
-            .execute("base bar".into(), Rc::new(CommandSource {}))
+            .execute("base bar".into(), Arc::new(CommandSource {}))
             .unwrap(),
         42
     );
@@ -70,7 +70,7 @@ fn execute_unknown_command() {
     subject.register(literal("bar"));
     subject.register(literal("baz"));
 
-    let execute_result = subject.execute("foo".into(), Rc::new(CommandSource {}));
+    let execute_result = subject.execute("foo".into(), Arc::new(CommandSource {}));
 
     let err = execute_result.err().unwrap();
     match err.type_ {
@@ -85,7 +85,7 @@ fn execute_impermissible_command() {
     let mut subject = CommandDispatcher::new();
     subject.register(literal("foo").requires(|_| false));
 
-    let execute_result = subject.execute("foo".into(), Rc::new(CommandSource {}));
+    let execute_result = subject.execute("foo".into(), Arc::new(CommandSource {}));
 
     let err = execute_result.err().unwrap();
     match err.type_ {
@@ -100,7 +100,7 @@ fn execute_empty_command() {
     let mut subject = CommandDispatcher::new();
     subject.register(literal(""));
 
-    let execute_result = subject.execute("".into(), Rc::new(CommandSource {}));
+    let execute_result = subject.execute("".into(), Arc::new(CommandSource {}));
 
     let err = execute_result.err().unwrap();
     match err.type_ {
@@ -115,7 +115,7 @@ fn execute_unknown_subcommand() {
     let mut subject = CommandDispatcher::new();
     subject.register(literal("foo").executes(|_| 42));
 
-    let execute_result = subject.execute("foo bar".into(), Rc::new(CommandSource {}));
+    let execute_result = subject.execute("foo bar".into(), Arc::new(CommandSource {}));
 
     let err = execute_result.err().unwrap();
     match err.type_ {
@@ -130,7 +130,7 @@ fn execute_incorrect_literal() {
     let mut subject = CommandDispatcher::new();
     subject.register(literal("foo").executes(|_| 42).then(literal("bar")));
 
-    let execute_result = subject.execute("foo baz".into(), Rc::new(CommandSource {}));
+    let execute_result = subject.execute("foo baz".into(), Arc::new(CommandSource {}));
 
     let err = execute_result.err().unwrap();
     match err.type_ {
@@ -150,7 +150,7 @@ fn execute_ambiguous_incorrect_argument() {
             .then(literal("baz")),
     );
 
-    let execute_result = subject.execute("foo unknown".into(), Rc::new(CommandSource {}));
+    let execute_result = subject.execute("foo unknown".into(), Arc::new(CommandSource {}));
 
     let err = execute_result.err().unwrap();
     match err.type_ {
@@ -174,7 +174,7 @@ fn execute_subcommand() {
 
     assert_eq!(
         subject
-            .execute("foo =".into(), Rc::new(CommandSource {}))
+            .execute("foo =".into(), Arc::new(CommandSource {}))
             .unwrap(),
         100
     );
@@ -185,7 +185,7 @@ fn parse_incomplete_literal() {
     let mut subject = CommandDispatcher::new();
     subject.register(literal("foo").then(literal("bar").executes(|_| 42)));
 
-    let parse = subject.parse("foo ".into(), Rc::new(CommandSource {}));
+    let parse = subject.parse("foo ".into(), Arc::new(CommandSource {}));
     assert_eq!(parse.reader.remaining(), " ");
     assert_eq!(parse.context.nodes.len(), 1);
 }
@@ -195,7 +195,7 @@ fn parse_incomplete_argument() {
     let mut subject = CommandDispatcher::new();
     subject.register(literal("foo").then(argument("bar", integer()).executes(|_| 42)));
 
-    let parse = subject.parse("foo ".into(), Rc::new(CommandSource {}));
+    let parse = subject.parse("foo ".into(), Arc::new(CommandSource {}));
     assert_eq!(parse.reader.remaining(), " ");
     assert_eq!(parse.context.nodes.len(), 1);
 }
@@ -212,7 +212,7 @@ fn execute_ambiguious_parent_subcommand() {
 
     assert_eq!(
         subject
-            .execute("test 1 2".into(), Rc::new(CommandSource {}))
+            .execute("test 1 2".into(), Arc::new(CommandSource {}))
             .unwrap(),
         100
     );
@@ -232,7 +232,7 @@ fn execute_ambiguious_parent_subcommand_via_redirect() {
 
     assert_eq!(
         subject
-            .execute("redirect 1 2".into(), Rc::new(CommandSource {}))
+            .execute("redirect 1 2".into(), Arc::new(CommandSource {}))
             .unwrap(),
         100
     );
@@ -248,7 +248,7 @@ fn execute_redirected_multiple_times() {
 
     let input = "redirected redirected actual";
 
-    let parse = subject.parse(input.into(), Rc::new(CommandSource {}));
+    let parse = subject.parse(input.into(), Arc::new(CommandSource {}));
     assert_eq!(parse.context.range.get(input), "redirected");
     assert_eq!(parse.context.nodes.len(), 1);
     assert_eq!(*parse.context.root.read(), *root.read());
@@ -287,19 +287,19 @@ fn execute_redirected_multiple_times() {
 fn execute_redirected() {
     let mut subject = CommandDispatcher::new();
 
-    let source1 = Rc::new(CommandSource {});
-    let source2 = Rc::new(CommandSource {});
+    let source1 = Arc::new(CommandSource {});
+    let source2 = Arc::new(CommandSource {});
 
-    let modifier = move |_: &CommandContext<CommandSource>| -> Result<Vec<Rc<CommandSource>>, CommandSyntaxException> {
+    let modifier = move |_: &CommandContext<CommandSource>| -> Result<Vec<Arc<CommandSource>>, CommandSyntaxException> {
             Ok(vec![source1.clone(), source2.clone()])
         };
 
     let concrete_node = subject.register(literal("actual").executes(|_| 42));
     let redirect_node =
-        subject.register(literal("redirected").fork(subject.root.clone(), Rc::new(modifier)));
+        subject.register(literal("redirected").fork(subject.root.clone(), Arc::new(modifier)));
 
     let input = "redirected actual";
-    let parse = subject.parse(input.into(), Rc::new(CommandSource {}));
+    let parse = subject.parse(input.into(), Arc::new(CommandSource {}));
     assert_eq!(parse.context.range.get(input), "redirected");
     assert_eq!(parse.context.nodes.len(), 1);
     assert_eq!(*parse.context.root.read(), *subject.root.read());
@@ -314,7 +314,7 @@ fn execute_redirected() {
     assert_eq!(*parse.context.root.read(), *subject.root.read());
     assert_eq!(parent.nodes[0].range, parent.range);
     assert_eq!(*parent.nodes[0].node.read(), *concrete_node.read());
-    assert_eq!(parent.source, Rc::new(CommandSource {}));
+    assert_eq!(parent.source, Arc::new(CommandSource {}));
 
     assert_eq!(CommandDispatcher::execute_parsed(parse).unwrap(), 2);
 }
@@ -329,7 +329,7 @@ fn execute_orphaned_subcommand() {
             .executes(|_| 42),
     );
 
-    let result = subject.execute("foo 5".into(), Rc::new(CommandSource {}));
+    let result = subject.execute("foo 5".into(), Arc::new(CommandSource {}));
     assert!(result.is_err());
     let result = result.unwrap_err();
     assert_eq!(
@@ -348,7 +348,7 @@ fn execute_invalid_other() {
 
     assert_eq!(
         subject
-            .execute("world".into(), Rc::new(CommandSource {}))
+            .execute("world".into(), Arc::new(CommandSource {}))
             .unwrap(),
         42
     );
@@ -364,7 +364,7 @@ fn parse_no_space_separator() {
             .executes(|_| 42),
     );
 
-    let result = subject.execute("foo$".into(), Rc::new(CommandSource {}));
+    let result = subject.execute("foo$".into(), Arc::new(CommandSource {}));
     assert!(result.is_err());
     let result = result.unwrap_err();
     assert_eq!(
@@ -384,7 +384,7 @@ fn execute_invalid_subcommand() {
             .executes(|_| 42),
     );
 
-    let result = subject.execute("foo bar".into(), Rc::new(CommandSource {}));
+    let result = subject.execute("foo bar".into(), Arc::new(CommandSource {}));
     assert!(result.is_err());
     let result = result.unwrap_err();
     // this fails for some reason, i blame mojang