diff --git a/src/commands.rs b/src/commands.rs
index 9d3f4165f2..c22d85ac10 100644
--- a/src/commands.rs
+++ b/src/commands.rs
@@ -1,3 +1,4 @@
+crate mod args;
 crate mod cd;
 crate mod command;
 crate mod ls;
diff --git a/src/commands/args.rs b/src/commands/args.rs
index 51bf37e7e8..183876b584 100644
--- a/src/commands/args.rs
+++ b/src/commands/args.rs
@@ -1,6 +1,31 @@
-use crate::Value;
+use crate::object::Value;
+use derive_new::new;
+use std::collections::VecDeque;
 
-#[derive(Debug, Clone)]
-pub struct Args {
-    args: Vec<Value>,
+#[derive(Debug, Default)]
+pub struct ObjectStream {
+    queue: VecDeque<Value>,
+}
+
+#[derive(Debug, Default)]
+pub struct Streams {
+    success: ObjectStream,
+    error: ObjectStream,
+    warning: ObjectStream,
+    debug: ObjectStream,
+    trace: ObjectStream,
+    verbose: ObjectStream,
+}
+
+#[derive(Debug, new)]
+pub struct Args {
+    argv: Vec<Value>,
+    #[new(default)]
+    streams: Streams,
+}
+
+impl Args {
+    crate fn first(&self) -> Option<&Value> {
+        self.argv.first()
+    }
 }
diff --git a/src/commands/cd.rs b/src/commands/cd.rs
index be05608aa2..3a9cfc1521 100644
--- a/src/commands/cd.rs
+++ b/src/commands/cd.rs
@@ -1,6 +1,7 @@
 use crate::errors::ShellError;
 use crate::object::process::Process;
 use crate::object::{DirEntry, ShellObject, Value};
+use crate::Args;
 use derive_new::new;
 use std::path::{Path, PathBuf};
 use sysinfo::SystemExt;
@@ -11,14 +12,20 @@ pub struct CdBlueprint;
 impl crate::CommandBlueprint for CdBlueprint {
     fn create(
         &self,
-        args: Vec<String>,
+        args: Args,
         host: &dyn crate::Host,
         env: &mut crate::Environment,
-    ) -> Box<dyn crate::Command> {
-        Box::new(Cd {
+    ) -> Result<Box<dyn crate::Command>, ShellError> {
+        let target = match args.first() {
+            // TODO: This needs better infra
+            None => return Err(ShellError::new(format!("cd must take one arg"))),
+            Some(v) => v.as_string()?.clone(),
+        };
+
+        Ok(Box::new(Cd {
             cwd: env.cwd().to_path_buf(),
-            target: args[0].clone(),
-        })
+            target,
+        }))
     }
 }
 
diff --git a/src/commands/command.rs b/src/commands/command.rs
index ebbddc4fa6..a62a593eed 100644
--- a/src/commands/command.rs
+++ b/src/commands/command.rs
@@ -5,10 +5,10 @@ use std::path::PathBuf;
 pub trait CommandBlueprint {
     fn create(
         &self,
-        args: Vec<String>,
+        args: crate::Args,
         host: &dyn crate::Host,
         env: &mut crate::Environment,
-    ) -> Box<dyn Command>;
+    ) -> Result<Box<dyn Command>, ShellError>;
 }
 
 crate enum CommandAction {
diff --git a/src/commands/ls.rs b/src/commands/ls.rs
index 5a6461f1c7..4c34874c1b 100644
--- a/src/commands/ls.rs
+++ b/src/commands/ls.rs
@@ -1,6 +1,7 @@
 use crate::errors::ShellError;
 use crate::object::process::Process;
 use crate::object::{DirEntry, ShellObject, Value};
+use crate::Args;
 use crate::{Command, CommandSuccess};
 use derive_new::new;
 use std::path::PathBuf;
@@ -12,13 +13,13 @@ pub struct LsBlueprint;
 impl crate::CommandBlueprint for LsBlueprint {
     fn create(
         &self,
-        args: Vec<String>,
+        args: Args,
         host: &dyn crate::Host,
         env: &mut crate::Environment,
-    ) -> Box<dyn Command> {
-        Box::new(Ls {
+    ) -> Result<Box<dyn Command>, ShellError> {
+        Ok(Box::new(Ls {
             cwd: env.cwd().to_path_buf(),
-        })
+        }))
     }
 }
 
diff --git a/src/commands/ps.rs b/src/commands/ps.rs
index 2d8dfc9195..faf2687bbb 100644
--- a/src/commands/ps.rs
+++ b/src/commands/ps.rs
@@ -15,11 +15,11 @@ pub struct PsBlueprint {
 impl crate::CommandBlueprint for PsBlueprint {
     fn create(
         &self,
-        args: Vec<String>,
+        args: crate::Args,
         host: &dyn crate::Host,
         env: &mut crate::Environment,
-    ) -> Box<dyn Command> {
-        Box::new(Ps::new(self.system.clone()))
+    ) -> Result<Box<dyn Command>, ShellError> {
+        Ok(Box::new(Ps::new(self.system.clone())))
     }
 }
 
diff --git a/src/main.rs b/src/main.rs
index 6e76bef240..83d892c2ae 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -9,11 +9,14 @@ mod format;
 mod object;
 mod parser;
 
+crate use crate::commands::args::{Args, Streams};
 crate use crate::commands::command::{Command, CommandAction, CommandBlueprint, CommandSuccess};
 crate use crate::env::{Environment, Host};
 crate use crate::errors::ShellError;
 crate use crate::format::RenderView;
 use crate::object::base::{ToEntriesView, ToGenericView};
+use crate::object::Value;
+
 use ansi_term::Color;
 use conch_parser::lexer::Lexer;
 use conch_parser::parse::DefaultParser;
@@ -81,14 +84,16 @@ fn main() -> Result<(), Box<Error>> {
                 }
 
                 let command = &parsed[0][0].name();
-                let args = parsed[0][1..]
+                let arg_list = parsed[0][1..]
                     .iter()
-                    .map(|i| i.name().to_string())
+                    .map(|i| Value::string(i.name().to_string()))
                     .collect();
 
+                let args = Args::new(arg_list);
+
                 match commands.get_mut(*command) {
                     Some(command) => {
-                        let mut instance = command.create(args, &mut host, &mut env);
+                        let mut instance = command.create(args, &mut host, &mut env)?;
                         let result = instance.run()?;
 
                         for action in result.action {
diff --git a/src/object/base.rs b/src/object/base.rs
index b2d75c234a..4946d89bf5 100644
--- a/src/object/base.rs
+++ b/src/object/base.rs
@@ -1,3 +1,4 @@
+use crate::errors::ShellError;
 use crate::format::{EntriesView, GenericView};
 use crate::object::desc::DataDescriptor;
 use chrono::NaiveDateTime;
@@ -67,6 +68,15 @@ impl Value {
         }
     }
 
+    crate fn as_string(&self) -> Result<String, ShellError> {
+        match self {
+            Value::Primitive(Primitive::String(s)) => Ok(s.to_string()),
+
+            // TODO: this should definitely be more general with better errors
+            other => Err(ShellError::new(format!("Expected string, got {:?}", other))),
+        }
+    }
+
     crate fn string(s: impl Into<String>) -> Value {
         Value::Primitive(Primitive::String(s.into()))
     }