diff --git a/src/cli.rs b/src/cli.rs
index 5da609a3f..8165c8747 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -181,14 +181,11 @@ pub async fn cli() -> Result<(), Box<dyn Error>> {
             command("to-toml", Box::new(to_toml::to_toml)),
             command("sort-by", Box::new(sort_by::sort_by)),
             command("sort-by", Box::new(sort_by::sort_by)),
-            command("inc", |x| plugin::plugin("inc".into(), x)),
-            command("sum", |x| plugin::plugin("sum".into(), x)),
             Arc::new(Open),
             Arc::new(Where),
             Arc::new(Config),
             Arc::new(SkipWhile),
             Arc::new(Enter),
-            Arc::new(Skip),
         ]);
 
         context.add_sinks(vec![
diff --git a/src/commands.rs b/src/commands.rs
index 20121eb3f..322592348 100644
--- a/src/commands.rs
+++ b/src/commands.rs
@@ -44,6 +44,5 @@ crate use command::command;
 crate use config::Config;
 crate use enter::Enter;
 crate use open::Open;
-crate use skip::Skip;
 crate use skip_while::SkipWhile;
 crate use where_::Where;
diff --git a/src/commands/autoview.rs b/src/commands/autoview.rs
index 55b4b4292..e9f6599f8 100644
--- a/src/commands/autoview.rs
+++ b/src/commands/autoview.rs
@@ -5,7 +5,11 @@ use crate::prelude::*;
 
 pub fn autoview(args: SinkCommandArgs) -> Result<(), ShellError> {
     if args.input.len() > 0 {
-        if let Value::Binary(_) = args.input[0] {
+        if let Spanned {
+            item: Value::Binary(_),
+            ..
+        } = args.input[0]
+        {
             args.ctx.get_sink("binaryview").run(args)?;
         } else if equal_shapes(&args.input) {
             args.ctx.get_sink("table").run(args)?;
diff --git a/src/commands/enter.rs b/src/commands/enter.rs
index 7fd557f6d..9dc105324 100644
--- a/src/commands/enter.rs
+++ b/src/commands/enter.rs
@@ -12,8 +12,12 @@ impl Command for Enter {
     fn config(&self) -> CommandConfig {
         CommandConfig {
             name: self.name().to_string(),
-            positional: vec![PositionalType::mandatory("path", "Block")],
+            positional: vec![PositionalType::mandatory_block("path")],
             rest_positional: false,
+            can_load: vec![],
+            can_save: vec![],
+            is_filter: false,
+            is_sink: false,
             named: indexmap::IndexMap::new(),
         }
     }
@@ -89,9 +93,15 @@ pub fn enter(args: CommandArgs) -> Result<OutputStream, ShellError> {
         }
     };
 
-    stream.push_back(Ok(ReturnSuccess::Action(CommandAction::Enter(
-        parse_as_value(file_extension, contents, contents_span, span)?,
-    ))));
+    match contents {
+        Value::Primitive(Primitive::String(string)) => {
+            stream.push_back(Ok(ReturnSuccess::Action(CommandAction::Enter(
+                parse_as_value(file_extension, string, contents_span, span)?,
+            ))));
+        }
+
+        other => stream.push_back(ReturnSuccess::value(other.spanned(contents_span))),
+    };
 
     Ok(stream.into())
 }
diff --git a/src/commands/from_json.rs b/src/commands/from_json.rs
index f91fa120b..e81d81e28 100644
--- a/src/commands/from_json.rs
+++ b/src/commands/from_json.rs
@@ -27,7 +27,7 @@ fn convert_json_value_to_nu_value(v: &serde_hjson::Value, span: impl Into<Span>)
         serde_hjson::Value::Object(o) => {
             let mut collected = SpannedDictBuilder::new(span);
             for (k, v) in o.iter() {
-                collected.add(k.clone(), convert_json_value_to_nu_value(v, span));
+                collected.insert_spanned(k.clone(), convert_json_value_to_nu_value(v, span));
             }
 
             collected.into_spanned_value()
diff --git a/src/commands/from_toml.rs b/src/commands/from_toml.rs
index a38058f5e..ffea6fd5d 100644
--- a/src/commands/from_toml.rs
+++ b/src/commands/from_toml.rs
@@ -25,7 +25,7 @@ fn convert_toml_value_to_nu_value(v: &toml::Value, span: impl Into<Span>) -> Spa
             let mut collected = SpannedDictBuilder::new(span);
 
             for (k, v) in t.iter() {
-                collected.add(k.clone(), convert_toml_value_to_nu_value(v, span));
+                collected.insert_spanned(k.clone(), convert_toml_value_to_nu_value(v, span));
             }
 
             collected.into_spanned_value()
diff --git a/src/commands/from_xml.rs b/src/commands/from_xml.rs
index 9741592a8..ebfce83e9 100644
--- a/src/commands/from_xml.rs
+++ b/src/commands/from_xml.rs
@@ -32,8 +32,8 @@ fn from_node_to_value<'a, 'd>(
             })
             .collect();
 
-        let mut collected = Dictionary::default();
-        collected.add(name.clone(), Value::List(children_values).spanned(span));
+        let mut collected = SpannedDictBuilder::new(span);
+        collected.insert(name.clone(), Value::List(children_values));
 
         collected.into_spanned_value()
     } else if n.is_comment() {
diff --git a/src/commands/from_yaml.rs b/src/commands/from_yaml.rs
index 0568ddce7..3c9de7302 100644
--- a/src/commands/from_yaml.rs
+++ b/src/commands/from_yaml.rs
@@ -26,7 +26,8 @@ fn convert_yaml_value_to_nu_value(v: &serde_yaml::Value, span: impl Into<Span>)
             for (k, v) in t.iter() {
                 match k {
                     serde_yaml::Value::String(k) => {
-                        collected.add(k.clone(), convert_yaml_value_to_nu_value(v, span));
+                        collected
+                            .insert_spanned(k.clone(), convert_yaml_value_to_nu_value(v, span));
                     }
                     _ => unimplemented!("Unknown key type"),
                 }
diff --git a/src/commands/macros.rs b/src/commands/macros.rs
index 3662378fb..1c5268b67 100644
--- a/src/commands/macros.rs
+++ b/src/commands/macros.rs
@@ -48,6 +48,11 @@ macro_rules! command {
                     name: self.name().to_string(),
                     positional: vec![$($mandatory_positional)*],
                     rest_positional: false,
+                    can_load: vec![],
+                    can_save: vec![],
+                    is_filter: false,
+                    is_sink: false,
+
                     named: {
                         use $crate::parser::registry::NamedType;
 
diff --git a/src/commands/open.rs b/src/commands/open.rs
index 14e253d33..f4a024628 100644
--- a/src/commands/open.rs
+++ b/src/commands/open.rs
@@ -61,12 +61,18 @@ command! {
             }
         };
 
-        stream.push_back(ReturnSuccess::value(parse_as_value(
-            file_extension,
-            contents,
-            contents_span,
-            span,
-        )?));
+        match contents {
+            Value::Primitive(Primitive::String(string)) =>
+                stream.push_back(ReturnSuccess::value(parse_as_value(
+                    file_extension,
+                    string,
+                    contents_span,
+                    span,
+                )?)
+            ),
+
+            other => stream.push_back(ReturnSuccess::value(other.spanned(span))),
+        };
 
         stream
     }
@@ -76,7 +82,7 @@ pub fn fetch(
     cwd: &PathBuf,
     location: &str,
     span: Span,
-) -> Result<(Option<String>, String, Span), ShellError> {
+) -> Result<(Option<String>, Value, Span), ShellError> {
     let mut cwd = cwd.clone();
     if location.starts_with("http:") || location.starts_with("https:") {
         let response = reqwest::get(location);
@@ -107,7 +113,7 @@ pub fn fetch(
                         None => path_extension,
                     };
 
-                    Ok((extension, s, span))
+                    Ok((extension, Value::string(s), span))
                 }
                 Err(_) => {
                     return Err(ShellError::labeled_error(
@@ -132,10 +138,10 @@ pub fn fetch(
                 Ok(s) => Ok((
                     cwd.extension()
                         .map(|name| name.to_string_lossy().to_string()),
-                    s,
+                    Value::string(s),
                     span,
                 )),
-                Err(_) => Ok((None, Value::Binary(bytes))),
+                Err(_) => Ok((None, Value::Binary(bytes), span)),
             },
             Err(_) => {
                 return Err(ShellError::labeled_error(
diff --git a/src/commands/plugin.rs b/src/commands/plugin.rs
index 06cd27a45..291e1f051 100644
--- a/src/commands/plugin.rs
+++ b/src/commands/plugin.rs
@@ -55,6 +55,7 @@ pub fn filter_plugin(path: String, args: CommandArgs) -> Result<OutputStream, Sh
 
     let stream = args
         .input
+        .values
         .chain(eos)
         .map(move |v| match v {
             Spanned {
@@ -90,7 +91,7 @@ pub fn filter_plugin(path: String, args: CommandArgs) -> Result<OutputStream, Sh
                                 Ok(params) => params,
                                 Err(e) => {
                                     let mut result = VecDeque::new();
-                                    result.push_back(ReturnValue::Value(Value::Error(Box::new(e))));
+                                    result.push_back(ReturnValue::Err(e));
                                     result
                                 }
                             },
diff --git a/src/commands/skip_while.rs b/src/commands/skip_while.rs
index ce671eb2a..eebaef83f 100644
--- a/src/commands/skip_while.rs
+++ b/src/commands/skip_while.rs
@@ -16,7 +16,7 @@ impl Command for SkipWhile {
     fn config(&self) -> CommandConfig {
         CommandConfig {
             name: self.name().to_string(),
-            positional: vec![PositionalType::mandatory("condition", "Block")],
+            positional: vec![PositionalType::mandatory_block("condition")],
             rest_positional: false,
             named: indexmap::IndexMap::new(),
             is_filter: true,
diff --git a/src/commands/to_json.rs b/src/commands/to_json.rs
index d75586c21..0a79ca48c 100644
--- a/src/commands/to_json.rs
+++ b/src/commands/to_json.rs
@@ -22,7 +22,6 @@ pub fn value_to_json_value(v: &Value) -> serde_json::Value {
         Value::List(l) => {
             serde_json::Value::Array(l.iter().map(|x| value_to_json_value(x)).collect())
         }
-        Value::Error(e) => serde_json::Value::String(e.to_string()),
         Value::Block(_) => serde_json::Value::Null,
         Value::Binary(b) => serde_json::Value::Array(
             b.iter()
diff --git a/src/commands/to_toml.rs b/src/commands/to_toml.rs
index b23ca3519..87cf71ed2 100644
--- a/src/commands/to_toml.rs
+++ b/src/commands/to_toml.rs
@@ -16,7 +16,6 @@ pub fn value_to_toml_value(v: &Value) -> toml::Value {
 
         Value::Filesystem => toml::Value::String("<Filesystem>".to_string()),
         Value::List(l) => toml::Value::Array(l.iter().map(|x| value_to_toml_value(x)).collect()),
-        Value::Error(e) => toml::Value::String(e.to_string()),
         Value::Block(_) => toml::Value::String("<Block>".to_string()),
         Value::Binary(b) => {
             toml::Value::Array(b.iter().map(|x| toml::Value::Integer(*x as i64)).collect())
@@ -38,7 +37,7 @@ pub fn to_toml(args: CommandArgs) -> Result<OutputStream, ShellError> {
     Ok(out
         .values
         .map(move |a| {
-            match toml::to_string(&a) {
+            match toml::to_string(&value_to_toml_value(&a)) {
                 Ok(val) => {
                     return ReturnSuccess::value(
                         Value::Primitive(Primitive::String(val)).spanned(name_span),
@@ -46,7 +45,7 @@ pub fn to_toml(args: CommandArgs) -> Result<OutputStream, ShellError> {
                 }
 
                 Err(err) => Err(ShellError::type_error(
-                    "String",
+                    "serializable to toml",
                     format!("{:?} - {:?}", a.type_name(), err).spanned(name_span),
                 )), // toml::Value::String(String) => {
                     //     return ReturnSuccess::value(
diff --git a/src/format/generic.rs b/src/format/generic.rs
index f5fdf0772..4524911da 100644
--- a/src/format/generic.rs
+++ b/src/format/generic.rs
@@ -36,11 +36,6 @@ impl RenderView for GenericView<'value> {
                 Ok(())
             }
 
-            Value::Error(e) => {
-                host.stdout(&format!("{:?}", e));
-                Ok(())
-            }
-
             Value::Binary(_) => {
                 host.stdout("<Binary>");
                 Ok(())
diff --git a/src/object/base.rs b/src/object/base.rs
index 04662972a..8b8a5a24d 100644
--- a/src/object/base.rs
+++ b/src/object/base.rs
@@ -299,10 +299,6 @@ impl Value {
         }
     }
 
-    crate fn debug(&'a self) -> ValueDebug<'a> {
-        ValueDebug { value: self }
-    }
-
     pub fn data_descriptors(&self) -> Vec<String> {
         match self {
             Value::Primitive(_) => vec![],
@@ -314,7 +310,6 @@ impl Value {
                 .collect(),
             Value::Block(_) => vec![],
             Value::List(_) => vec![],
-            Value::Error(_) => vec![],
             Value::Filesystem => vec![],
             Value::Binary(_) => vec![],
         }
@@ -356,7 +351,6 @@ impl Value {
             Value::Object(o) => o.get_data(desc),
             Value::Block(_) => MaybeOwned::Owned(Value::nothing()),
             Value::List(_) => MaybeOwned::Owned(Value::nothing()),
-            Value::Error(e) => MaybeOwned::Owned(Value::string(&format!("{:#?}", e))),
             Value::Binary(_) => MaybeOwned::Owned(Value::nothing()),
         }
     }
@@ -512,7 +506,7 @@ crate fn select_fields(obj: &Value, fields: &[String], span: impl Into<Span>) ->
     let descs = obj.data_descriptors();
 
     for field in fields {
-        match descs.iter().find(|d| d.name.is_string(field)) {
+        match descs.iter().find(|d| *d == field) {
             None => out.insert(field, Value::nothing()),
             Some(desc) => out.insert(desc.clone(), obj.get_data(desc).borrow().clone()),
         }
diff --git a/src/object/dict.rs b/src/object/dict.rs
index ecad28507..e0844dda5 100644
--- a/src/object/dict.rs
+++ b/src/object/dict.rs
@@ -80,7 +80,7 @@ impl Dictionary {
         let mut out = Dictionary::default();
 
         for (key, value) in self.entries.iter() {
-            out.add(key.clone(), value.copy());
+            out.add(key.clone(), value.clone());
         }
 
         out
@@ -150,7 +150,7 @@ impl From<SpannedListBuilder> for Spanned<Value> {
 #[derive(Debug)]
 pub struct SpannedDictBuilder {
     span: Span,
-    dict: IndexMap<DataDescriptor, Spanned<Value>>,
+    dict: IndexMap<String, Spanned<Value>>,
 }
 
 impl SpannedDictBuilder {
@@ -161,16 +161,12 @@ impl SpannedDictBuilder {
         }
     }
 
-    pub fn insert(&mut self, key: impl Into<DataDescriptor>, value: impl Into<Value>) {
+    pub fn insert(&mut self, key: impl Into<String>, value: impl Into<Value>) {
         self.dict
             .insert(key.into(), value.into().spanned(self.span));
     }
 
-    pub fn insert_spanned(
-        &mut self,
-        key: impl Into<DataDescriptor>,
-        value: impl Into<Spanned<Value>>,
-    ) {
+    pub fn insert_spanned(&mut self, key: impl Into<String>, value: impl Into<Spanned<Value>>) {
         self.dict.insert(key.into(), value.into());
     }
 
diff --git a/src/parser/parse/span.rs b/src/parser/parse/span.rs
index fb885e0c6..3886f40e1 100644
--- a/src/parser/parse/span.rs
+++ b/src/parser/parse/span.rs
@@ -4,22 +4,15 @@ use getset::Getters;
 use serde::{Serialize, Serializer};
 use serde_derive::Deserialize;
 
-#[derive(new, Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Deserialize, Hash, Getters)]
+#[derive(
+    new, Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Serialize, Deserialize, Hash, Getters,
+)]
 #[get = "crate"]
 pub struct Spanned<T> {
     pub span: Span,
     pub item: T,
 }
 
-impl<T: Serialize> Serialize for Spanned<T> {
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-    where
-        S: Serializer,
-    {
-        self.item.serialize(serializer)
-    }
-}
-
 impl<T> Spanned<T> {
     pub fn spanned(self, span: impl Into<Span>) -> Spanned<T> {
         Spanned::from_item(self.item, span.into())
diff --git a/src/parser/registry.rs b/src/parser/registry.rs
index d168d9dbb..4447b496c 100644
--- a/src/parser/registry.rs
+++ b/src/parser/registry.rs
@@ -40,18 +40,19 @@ pub enum PositionalType {
     Optional(String, PositionalValue),
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 pub enum PositionalValue {
     Value,
     Block,
 }
 
 impl PositionalType {
-    crate fn mandatory(name: &str, kind: &str) -> PositionalType {
-        match kind {
-            "Block" => PositionalType::Mandatory(name.to_string(), PositionalValue::Block),
-            _ => PositionalType::Mandatory(name.to_string(), PositionalValue::Value),
-        }
+    pub fn mandatory(name: &str) -> PositionalType {
+        PositionalType::Mandatory(name.to_string(), PositionalValue::Value)
+    }
+
+    pub fn mandatory_block(name: &str) -> PositionalType {
+        PositionalType::Mandatory(name.to_string(), PositionalValue::Block)
     }
 
     crate fn to_coerce_hint(&self) -> Option<ExpressionKindHint> {
@@ -76,7 +77,7 @@ impl PositionalType {
 #[get = "crate"]
 pub struct CommandConfig {
     pub name: String,
-    crate positional: Vec<PositionalType>,
+    pub positional: Vec<PositionalType>,
     pub rest_positional: bool,
     pub named: IndexMap<String, NamedType>,
     pub is_filter: bool,
diff --git a/src/plugin.rs b/src/plugin.rs
index fcf0addde..448912278 100644
--- a/src/plugin.rs
+++ b/src/plugin.rs
@@ -1,4 +1,4 @@
-use crate::{Args, CommandConfig, ReturnValue, ShellError, Value};
+use crate::{Args, CommandConfig, ReturnValue, ShellError, Spanned, Value};
 use serde::{Deserialize, Serialize};
 use std::io;
 
@@ -11,11 +11,11 @@ pub trait Plugin {
         ))
     }
     #[allow(unused)]
-    fn filter(&mut self, input: Value) -> Result<Vec<ReturnValue>, ShellError> {
+    fn filter(&mut self, input: Spanned<Value>) -> Result<Vec<ReturnValue>, ShellError> {
         Err(ShellError::string("`filter` not implemented in plugin"))
     }
     #[allow(unused)]
-    fn sink(&mut self, args: Args, input: Vec<Value>) {}
+    fn sink(&mut self, args: Args, input: Vec<Spanned<Value>>) {}
 
     fn quit(&mut self) {
         return;
@@ -127,7 +127,7 @@ fn send_response<T: Serialize>(result: T) {
 pub enum NuCommand {
     config,
     begin_filter { params: Args },
-    filter { params: Value },
-    sink { params: (Args, Vec<Value>) },
+    filter { params: Spanned<Value> },
+    sink { params: (Args, Vec<Spanned<Value>>) },
     quit,
 }
diff --git a/src/plugins/binaryview.rs b/src/plugins/binaryview.rs
index f839d12bc..b96e0e160 100644
--- a/src/plugins/binaryview.rs
+++ b/src/plugins/binaryview.rs
@@ -1,6 +1,6 @@
 use crossterm::{cursor, terminal, Attribute, RawScreen};
 use indexmap::IndexMap;
-use nu::{serve_plugin, Args, CommandConfig, Plugin, ShellError, Value};
+use nu::{serve_plugin, Args, CommandConfig, Plugin, ShellError, Spanned, Value};
 use pretty_hex::*;
 
 struct BinaryView;
@@ -15,8 +15,7 @@ impl Plugin for BinaryView {
     fn config(&mut self) -> Result<CommandConfig, ShellError> {
         Ok(CommandConfig {
             name: "binaryview".to_string(),
-            mandatory_positional: vec![],
-            optional_positional: vec![],
+            positional: vec![],
             can_load: vec![],
             can_save: vec![],
             is_filter: false,
@@ -26,10 +25,13 @@ impl Plugin for BinaryView {
         })
     }
 
-    fn sink(&mut self, _args: Args, input: Vec<Value>) {
+    fn sink(&mut self, _args: Args, input: Vec<Spanned<Value>>) {
         for v in input {
             match v {
-                Value::Binary(b) => {
+                Spanned {
+                    item: Value::Binary(b),
+                    ..
+                } => {
                     let _ = view_binary(&b);
                 }
                 _ => {}
diff --git a/src/plugins/inc.rs b/src/plugins/inc.rs
index d301ab07e..c9257da13 100644
--- a/src/plugins/inc.rs
+++ b/src/plugins/inc.rs
@@ -1,11 +1,8 @@
 use indexmap::IndexMap;
 use nu::{
-    serve_plugin, Args, CommandConfig, Plugin, PositionalType, Primitive, ReturnValue, ShellError,
-    Spanned, Value,
+    serve_plugin, Args, CommandConfig, Plugin, PositionalType, Primitive, ReturnSuccess,
+    ReturnValue, ShellError, Spanned, SpannedItem, Value,
 };
-use nu::{Primitive, ReturnSuccess, ReturnValue, ShellError, Spanned, SpannedItem, Value};
-use serde::{Deserialize, Serialize};
-use std::io;
 
 struct Inc {
     inc_by: i64,
@@ -16,87 +13,47 @@ impl Inc {
     }
 }
 
-fn send_response<T: Serialize>(result: Vec<T>) {
-    let response = JsonRpc::new("response", result);
-    let response_raw = serde_json::to_string(&response).unwrap();
-    println!("{}", response_raw);
-}
-
-fn send_error(error: ShellError) {
-    let message: ReturnValue = Err(error);
-    send_response(vec![message])
-}
-
-#[derive(Debug, Serialize, Deserialize)]
-#[serde(tag = "method")]
-#[allow(non_camel_case_types)]
-pub enum NuCommand {
-    init { params: Vec<Spanned<Value>> },
-    filter { params: Spanned<Value> },
-    quit,
-}
-
-fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let mut inc_by = 1;
-
-    loop {
-        let mut input = String::new();
-        match io::stdin().read_line(&mut input) {
-            Ok(_) => {
-                let command = serde_json::from_str::<NuCommand>(&input);
-
-                match command {
-                    Ok(NuCommand::init { params }) => {
-                        for param in params {
-                            match param {
-                                Spanned {
-                                    item: Value::Primitive(Primitive::Int(i)),
-                                    ..
-                                } => {
-                                    inc_by = i;
-                                }
-                                _ => {
-                                    send_error(ShellError::string("Unrecognized type in params"));
-                                }
-                            }
-                        }
-                    }
-                    Ok(NuCommand::filter { params }) => match params {
-                        Spanned {
-                            item: Value::Primitive(Primitive::Int(i)),
-                            span,
-                        } => {
-                            send_response(vec![ReturnSuccess::value(
-                                Value::int(i + inc_by).spanned(span),
-                            )]);
-                        }
-                        Spanned {
-                            item: Value::Primitive(Primitive::Bytes(b)),
-                            span,
-                        } => {
-                            send_response(vec![ReturnSuccess::value(
-                                Value::bytes(b + inc_by as u128).spanned(span),
-                            )]);
-                        }
-                        _ => {
-                            send_error(ShellError::string("Unrecognized type in stream"));
-                        }
-                    },
-                    Ok(NuCommand::quit) => {
-                        break;
-                    }
-                    Err(_) => {
-                        send_error(ShellError::string("Unrecognized type in stream"));
+impl Plugin for Inc {
+    fn config(&mut self) -> Result<CommandConfig, ShellError> {
+        Ok(CommandConfig {
+            name: "inc".to_string(),
+            positional: vec![PositionalType::mandatory("Increment")],
+            can_load: vec![],
+            can_save: vec![],
+            is_filter: true,
+            is_sink: false,
+            named: IndexMap::new(),
+            rest_positional: true,
+        })
+    }
+    fn begin_filter(&mut self, args: Args) -> Result<(), ShellError> {
+        if let Some(args) = args.positional {
+            for arg in args {
+                match arg {
+                    Spanned {
+                        item: Value::Primitive(Primitive::Int(i)),
+                        ..
+                    } => {
+                        self.inc_by = i;
                     }
                     _ => return Err(ShellError::string("Unrecognized type in params")),
                 }
             }
-            Err(_) => {
-                send_error(ShellError::string("Unrecognized type in stream"));
-            }
-            Value::Primitive(Primitive::Bytes(b)) => Ok(vec![ReturnValue::Value(Value::bytes(
-                b + self.inc_by as u64,
-            ))]),
+        }
+
+        Ok(())
+    }
+
+    fn filter(&mut self, input: Spanned<Value>) -> Result<Vec<ReturnValue>, ShellError> {
+        let span = input.span;
+
+        match input.item {
+            Value::Primitive(Primitive::Int(i)) => Ok(vec![ReturnSuccess::value(
+                Value::int(i + self.inc_by).spanned(span),
+            )]),
+            Value::Primitive(Primitive::Bytes(b)) => Ok(vec![ReturnSuccess::value(
+                Value::bytes(b + self.inc_by as u64).spanned(span),
+            )]),
             x => Err(ShellError::string(format!(
                 "Unrecognized type in stream: {:?}",
                 x
diff --git a/src/plugins/skip.rs b/src/plugins/skip.rs
index 14e3a5dee..8fc852a6b 100644
--- a/src/plugins/skip.rs
+++ b/src/plugins/skip.rs
@@ -1,6 +1,7 @@
 use indexmap::IndexMap;
 use nu::{
-    serve_plugin, Args, CommandConfig, Plugin, Primitive, ReturnValue, ShellError, Spanned, Value,
+    serve_plugin, Args, CommandConfig, Plugin, Primitive, ReturnSuccess, ReturnValue, ShellError,
+    Spanned, Value,
 };
 
 struct NewSkip {
@@ -16,8 +17,7 @@ impl Plugin for NewSkip {
     fn config(&mut self) -> Result<CommandConfig, ShellError> {
         Ok(CommandConfig {
             name: "skip".to_string(),
-            mandatory_positional: vec![],
-            optional_positional: vec![],
+            positional: vec![],
             can_load: vec![],
             can_save: vec![],
             is_filter: true,
@@ -44,9 +44,9 @@ impl Plugin for NewSkip {
         Ok(())
     }
 
-    fn filter(&mut self, input: Value) -> Result<Vec<ReturnValue>, ShellError> {
+    fn filter(&mut self, input: Spanned<Value>) -> Result<Vec<ReturnValue>, ShellError> {
         if self.skip_amount == 0 {
-            Ok(vec![ReturnValue::Value(input)])
+            Ok(vec![ReturnSuccess::value(input)])
         } else {
             self.skip_amount -= 1;
             Ok(vec![])
diff --git a/src/plugins/tree.rs b/src/plugins/tree.rs
index a7a2da86a..9c3f40b8f 100644
--- a/src/plugins/tree.rs
+++ b/src/plugins/tree.rs
@@ -1,6 +1,6 @@
 use derive_new::new;
 use indexmap::IndexMap;
-use nu::{serve_plugin, Args, CommandConfig, Plugin, ShellError, Value};
+use nu::{serve_plugin, Args, CommandConfig, Plugin, ShellError, Spanned, Value};
 use ptree::item::StringItem;
 use ptree::output::print_tree_with;
 use ptree::print_config::PrintConfig;
@@ -31,7 +31,6 @@ impl TreeView {
                 }
             }
             Value::Block(_) => {}
-            Value::Error(_) => {}
             Value::Filesystem => {}
             Value::Binary(_) => {}
         }
@@ -85,8 +84,7 @@ impl Plugin for TreeViewer {
     fn config(&mut self) -> Result<CommandConfig, ShellError> {
         Ok(CommandConfig {
             name: "tree".to_string(),
-            mandatory_positional: vec![],
-            optional_positional: vec![],
+            positional: vec![],
             can_load: vec![],
             can_save: vec![],
             is_filter: false,
@@ -96,12 +94,11 @@ impl Plugin for TreeViewer {
         })
     }
 
-    fn sink(&mut self, _args: Args, input: Vec<Value>) {
+    fn sink(&mut self, _args: Args, input: Vec<Spanned<Value>>) {
         if input.len() > 0 {
             for i in input.iter() {
                 let view = TreeView::from_value(&i);
                 let _ = view.render_view();
-                //handle_unexpected(&mut *host, |host| crate::format::print_view(&view, host));
             }
         }