diff --git a/src/fs/dir.rs b/src/fs/dir.rs
index 9f45ac3..012b2f7 100644
--- a/src/fs/dir.rs
+++ b/src/fs/dir.rs
@@ -2,11 +2,11 @@
 use crate::fs::{DirItem, DirItemIterator, Result};
 
 use super::{
-    path::{DirG, PathReal},
-    FileG, PathG,
+    path::{DirMarker, PathReal},
+    Error, FileMarker, PathMarker,
 };
 
-impl<'base, 'path> PathReal<'base, 'path, DirG> {
+impl<'base, 'path> PathReal<'base, 'path, DirMarker> {
     /// Creates a new, empty directory at the path
     ///
     /// Wrapper for [std::fs::create_dir]
@@ -22,7 +22,7 @@ impl<'base, 'path> PathReal<'base, 'path, DirG> {
     /// ```
     pub fn create(&self) -> Result<()> {
         self.check_error()?;
-        std::fs::create_dir(self.as_pathbuf()).map_err(Into::into)
+        std::fs::create_dir(self.as_pathbuf()).map_err(Error::Io)
     }
 
     /// Recursively create a directory and all of its parent components if they are missing.
@@ -40,7 +40,7 @@ impl<'base, 'path> PathReal<'base, 'path, DirG> {
     /// ```
     pub fn create_all(&self) -> Result<()> {
         self.check_error()?;
-        std::fs::create_dir_all(self.as_pathbuf()).map_err(Into::into)
+        std::fs::create_dir_all(self.as_pathbuf()).map_err(Error::Io)
     }
 
     /// Returns an iterator over the entries within a directory.
@@ -58,14 +58,18 @@ impl<'base, 'path> PathReal<'base, 'path, DirG> {
     /// ```
     pub fn read(&self) -> Result<Box<dyn Iterator<Item = Result<DirItem>>>> {
         self.check_error()?;
-        let read_dir = std::fs::read_dir(self.as_pathbuf())?;
+        let read_dir = std::fs::read_dir(self.as_pathbuf()).map_err(Error::Io)?;
         Ok(Box::new(DirItemIterator::new(read_dir)))
     }
 }
-impl<'base, 'path> TryFrom<PathReal<'base, 'path, PathG>> for PathReal<'base, 'path, FileG> {
+impl<'base, 'path> TryFrom<PathReal<'base, 'path, PathMarker>>
+    for PathReal<'base, 'path, FileMarker>
+{
     type Error = crate::fs::Error;
 
-    fn try_from(path: PathReal<'base, 'path, PathG>) -> std::result::Result<Self, Self::Error> {
+    fn try_from(
+        path: PathReal<'base, 'path, PathMarker>,
+    ) -> std::result::Result<Self, Self::Error> {
         match path.as_file() {
             Ok(Some(dir)) => Ok(dir.clone()),
             Ok(None) => Err(crate::fs::Error::NotADirectory {
@@ -75,10 +79,14 @@ impl<'base, 'path> TryFrom<PathReal<'base, 'path, PathG>> for PathReal<'base, 'p
         }
     }
 }
-impl<'base, 'path> TryFrom<PathReal<'base, 'path, PathG>> for PathReal<'base, 'path, DirG> {
+impl<'base, 'path> TryFrom<PathReal<'base, 'path, PathMarker>>
+    for PathReal<'base, 'path, DirMarker>
+{
     type Error = crate::fs::Error;
 
-    fn try_from(path: PathReal<'base, 'path, PathG>) -> std::result::Result<Self, Self::Error> {
+    fn try_from(
+        path: PathReal<'base, 'path, PathMarker>,
+    ) -> std::result::Result<Self, Self::Error> {
         match path.as_dir() {
             Ok(Some(dir)) => Ok(dir.clone()),
             Ok(None) => Err(crate::fs::Error::NotADirectory {
diff --git a/src/fs/dir_item.rs b/src/fs/dir_item.rs
index 79cb157..c3bad62 100644
--- a/src/fs/dir_item.rs
+++ b/src/fs/dir_item.rs
@@ -4,6 +4,8 @@ use std::{
     path::PathBuf,
 };
 
+use super::Error;
+
 /// Represents an item in a directory
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub enum DirItem {
@@ -26,8 +28,8 @@ impl Iterator for DirItemIterator {
 }
 
 fn map_dir_item(item: std::io::Result<DirEntry>) -> super::Result<DirItem> {
-    let item = item?;
-    let file_type = item.file_type()?;
+    let item = item.map_err(Error::Io)?;
+    let file_type = item.file_type().map_err(Error::Io)?;
     if file_type.is_dir() {
         Ok(DirItem::Dir(item.path()))
     } else if file_type.is_file() {
diff --git a/src/fs/file.rs b/src/fs/file.rs
index 957fe97..5b7c7b4 100644
--- a/src/fs/file.rs
+++ b/src/fs/file.rs
@@ -2,11 +2,12 @@
 use crate::fs::Result;
 
 use super::{
-    path::{FileG, PathReal},
+    path::{FileMarker, PathReal},
     reader::Reader,
+    Error,
 };
 
-impl<'base, 'path> PathReal<'base, 'path, FileG> {
+impl<'base, 'path> PathReal<'base, 'path, FileMarker> {
     /// Returns a [Reader] for the file.
     ///
     /// ```
@@ -38,6 +39,6 @@ impl<'base, 'path> PathReal<'base, 'path, FileG> {
     /// ```
     pub fn write<C: AsRef<[u8]>>(&self, contents: C) -> Result<()> {
         self.check_error()?;
-        std::fs::write(self.as_pathbuf(), contents).map_err(Into::into)
+        std::fs::write(self.as_pathbuf(), contents).map_err(Error::Io)
     }
 }
diff --git a/src/fs/mod.rs b/src/fs/mod.rs
index fc187c6..4c27148 100644
--- a/src/fs/mod.rs
+++ b/src/fs/mod.rs
@@ -1,10 +1,31 @@
-/// Provides an injectable reference to part of the filesystem.
-///
-/// Create a new `FileSystem` to access a directory using `kxio::fs::new(path)`.
-/// Create a new `TempFileSystem` to access a temporary directory using `kxio::fs::temp()?`;
-///
-/// `TempFileSystem` derefs automaticalyl to `FileSystem` so can be used anywhere
-/// you would use `FileSystem`.
+//! Provides an injectable reference to part of the filesystem.
+//!
+//! Create a new `FileSystem` to access a directory using `kxio::fs::new(path)`.
+//! Create a new `TempFileSystem` to access a temporary directory using `kxio::fs::temp()?`;
+//!
+//! `TempFileSystem` derefs automaticalyl to `FileSystem` so can be used anywhere
+//! you would use `FileSystem`.
+//!
+//! ```
+//! # use std::path::PathBuf;
+//! # use kxio::fs::FileSystem;
+//! # use kxio::fs::PathReal;
+//! # use kxio::fs::DirHandle;
+//! # use kxio::fs::FileHandle;
+//! # fn try_main() -> kxio::fs::Result<()> {
+//! let fs = kxio::fs::temp()?;
+//! let fs: FileSystem = kxio::fs::new(fs.base().to_path_buf());
+//! let dir_path: PathBuf = fs.base().join("foo");
+//! let dir: DirHandle = fs.dir(&dir_path);
+//! dir.create()?;
+//! let file_path = dir_path.join("bar.txt");
+//! let file: FileHandle = fs.file(&file_path);
+//! file.write("new file contents")?;
+//! let reader = file.reader()?;
+//! assert_eq!(reader.to_string(), "new file contents");
+//! # Ok(())
+//! # }
+//! ```
 use std::path::PathBuf;
 
 mod dir;
@@ -20,7 +41,7 @@ pub use dir_item::{DirItem, DirItemIterator};
 pub use path::*;
 pub use reader::Reader;
 pub use result::{Error, Result};
-pub use system::FileSystem;
+pub use system::{DirHandle, FileHandle, FileSystem, PathHandle};
 
 /// Creates a new `FileSystem` for the path.
 ///
diff --git a/src/fs/path.rs b/src/fs/path.rs
index dc3459c..50169d5 100644
--- a/src/fs/path.rs
+++ b/src/fs/path.rs
@@ -6,19 +6,23 @@ use std::{
 
 use crate::fs::{Error, Result};
 
+/// Marker trait for the type of [PathReal].
 pub trait PathType {}
 
+/// Path marker for the type of [PathReal].
 #[derive(Clone, Debug)]
-pub struct PathG;
-impl PathType for PathG {}
+pub struct PathMarker;
+impl PathType for PathMarker {}
 
+/// File marker for the type of [PathReal].
 #[derive(Clone, Debug)]
-pub struct FileG;
-impl PathType for FileG {}
+pub struct FileMarker;
+impl PathType for FileMarker {}
 
+/// Dir marker for the type of [PathReal].
 #[derive(Clone, Debug)]
-pub struct DirG;
-impl PathType for DirG {}
+pub struct DirMarker;
+impl PathType for DirMarker {}
 
 /// Represents a path in the filesystem.
 ///
@@ -63,7 +67,7 @@ impl<'base, 'path, T: PathType> PathReal<'base, 'path, T> {
     }
 
     fn validate(base: &Path, path: &Path) -> Option<Error> {
-        match PathReal::<PathG>::clean_path(path) {
+        match PathReal::<PathMarker>::clean_path(path) {
             Err(error) => Some(error),
             Ok(path) => {
                 if !path.starts_with(base) {
@@ -166,7 +170,7 @@ impl<'base, 'path, T: PathType> PathReal<'base, 'path, T> {
     /// #    Ok(())
     /// # }
     /// ```
-    pub fn as_dir(&self) -> Result<Option<PathReal<'base, 'path, DirG>>> {
+    pub fn as_dir(&self) -> Result<Option<PathReal<'base, 'path, DirMarker>>> {
         self.check_error()?;
         if self.as_pathbuf().is_dir() {
             Ok(Some(PathReal::new(self.base, self.path)))
@@ -189,7 +193,7 @@ impl<'base, 'path, T: PathType> PathReal<'base, 'path, T> {
     /// #    Ok(())
     /// # }
     /// ```
-    pub fn as_file(&self) -> Result<Option<PathReal<'base, 'path, FileG>>> {
+    pub fn as_file(&self) -> Result<Option<PathReal<'base, 'path, FileMarker>>> {
         self.check_error()?;
         if self.as_pathbuf().is_file() {
             Ok(Some(PathReal::new(self.base, self.path)))
@@ -198,8 +202,8 @@ impl<'base, 'path, T: PathType> PathReal<'base, 'path, T> {
         }
     }
 }
-impl From<PathReal<'_, '_, PathG>> for PathBuf {
-    fn from(path: PathReal<PathG>) -> Self {
+impl From<PathReal<'_, '_, PathMarker>> for PathBuf {
+    fn from(path: PathReal<PathMarker>) -> Self {
         path.base.join(path.path)
     }
 }
diff --git a/src/fs/reader.rs b/src/fs/reader.rs
index a9b4d46..1b64784 100644
--- a/src/fs/reader.rs
+++ b/src/fs/reader.rs
@@ -3,13 +3,15 @@ use std::{fmt::Display, path::Path, str::Lines};
 
 use crate::fs::Result;
 
+use super::Error;
+
 /// A reader for a file.
 pub struct Reader {
     contents: String,
 }
 impl Reader {
     pub(super) fn new(path: &Path) -> Result<Self> {
-        let contents = std::fs::read_to_string(path)?;
+        let contents = std::fs::read_to_string(path).map_err(Error::Io)?;
         Ok(Self { contents })
     }
 
diff --git a/src/fs/result.rs b/src/fs/result.rs
index bd38f1d..9e924b5 100644
--- a/src/fs/result.rs
+++ b/src/fs/result.rs
@@ -1,14 +1,12 @@
 //
 use std::path::PathBuf;
 
-use derive_more::From;
-
 /// Represents a error accessing the file system.
 ///
 /// Any failure is related to `std::io`, a Path Traversal
 /// (i.e. trying to escape the base of the `FileSystem`),
 /// or attempting to use a file as a directory or /vise versa/.
-#[derive(Debug, From, derive_more::Display)]
+#[derive(Debug, derive_more::Display)]
 pub enum Error {
     Io(std::io::Error),
 
@@ -24,6 +22,11 @@ pub enum Error {
     NotADirectory {
         path: PathBuf,
     },
+
+    #[display("Path must be a file: {path:?}")]
+    NotAFile {
+        path: PathBuf,
+    },
 }
 impl std::error::Error for Error {}
 impl Clone for Error {
@@ -36,6 +39,7 @@ impl Clone for Error {
                 path: path.clone(),
             },
             Error::NotADirectory { path } => Error::NotADirectory { path: path.clone() },
+            Error::NotAFile { path } => Error::NotAFile { path: path.clone() },
         }
     }
 }
diff --git a/src/fs/system.rs b/src/fs/system.rs
index 1fbe9c8..7398d63 100644
--- a/src/fs/system.rs
+++ b/src/fs/system.rs
@@ -3,22 +3,34 @@ use std::path::{Path, PathBuf};
 
 use crate::fs::{Error, Result};
 
-use super::path::{DirG, FileG, PathG, PathReal};
+use super::path::{DirMarker, FileMarker, PathMarker, PathReal};
 
 /// Represents to base of a section of a file system.
 #[derive(Clone, Debug)]
 pub struct FileSystem {
     base: PathBuf,
 }
+
+/// Represents a directory path in the filesystem.
+pub type DirHandle<'base, 'path> = PathReal<'base, 'path, DirMarker>;
+
+/// Represents a file path in the filesystem.
+pub type FileHandle<'base, 'path> = PathReal<'base, 'path, FileMarker>;
+
+/// Represents a path in the filesystem.
+pub type PathHandle<'base, 'path> = PathReal<'base, 'path, PathMarker>;
+
 impl FileSystem {
     pub const fn new(base: PathBuf) -> Self {
         Self { base }
     }
 
+    /// Returns the base of the [FileSystem].
     pub fn base(&self) -> &Path {
         &self.base
     }
 
+    /// Returns a [PathBuf] for the path.
     pub fn path_of(&self, path: PathBuf) -> Result<PathBuf> {
         let path_of = self.base.as_path().join(path);
         self.validate(&path_of)?;
@@ -26,7 +38,21 @@ impl FileSystem {
     }
 
     /// Access the path as a directory.
-    pub fn dir<'base, 'path>(&'base self, path: &'path Path) -> PathReal<'base, 'path, DirG> {
+    ///
+    /// The path must exist and be a directory.
+    ///
+    /// If the path does not exist, or is not a directory, an error is returned.
+    ///
+    /// ```
+    /// # fn try_main() -> kxio::fs::Result<()> {
+    /// let fs = kxio::fs::temp()?;
+    /// let path = fs.base().join("foo");
+    /// let dir = fs.dir(&path);
+    /// dir.create()?;
+    /// # Ok(())
+    /// # }
+    /// ```
+    pub fn dir<'base, 'path>(&'base self, path: &'path Path) -> DirHandle<'base, 'path> {
         let mut dir = PathReal::new(self.base(), path);
 
         if dir.error.is_none() {
@@ -46,11 +72,56 @@ impl FileSystem {
         dir
     }
 
-    pub fn file<'base, 'path>(&'base self, path: &'path Path) -> PathReal<'base, 'path, FileG> {
-        PathReal::new(self.base(), path)
+    /// Access the path as a file.
+    ///
+    /// The path must exist and be a file.
+    ///
+    /// If the path does not exist, or is not a file, an error is returned.
+    ///
+    /// ```
+    /// # fn try_main() -> kxio::fs::Result<()> {
+    /// let fs = kxio::fs::temp()?;
+    /// let path = fs.base().join("foo");
+    /// let file = fs.file(&path);
+    /// file.write("new file contents")?;
+    /// # Ok(())
+    /// # }
+    /// ```
+    pub fn file<'base, 'path>(&'base self, path: &'path Path) -> FileHandle<'base, 'path> {
+        let mut file = PathReal::new(self.base(), path);
+
+        if file.error.is_none() {
+            if let Ok(exists) = file.exists() {
+                if exists {
+                    if let Ok(is_file) = file.is_file() {
+                        if !is_file {
+                            file.put(Error::NotAFile {
+                                path: file.as_pathbuf(),
+                            })
+                        }
+                    }
+                }
+            }
+        }
+
+        file
     }
 
-    pub fn path<'base, 'path>(&'base self, path: &'path Path) -> PathReal<'base, 'path, PathG> {
+    /// Access the path as a path.
+    ///
+    /// The path must exist.
+    ///
+    /// If the path does not exist, an error is returned.
+    ///
+    /// ```
+    /// # fn try_main() -> kxio::fs::Result<()> {
+    /// let fs = kxio::fs::temp()?;
+    /// let path = fs.base().join("foo");
+    /// let path_handle = fs.path(&path);
+    /// # Ok(())
+    /// # }
+    /// ```
+    pub fn path<'base, 'path>(&'base self, path: &'path Path) -> PathHandle<'base, 'path> {
         PathReal::new(self.base(), path)
     }
 
@@ -71,7 +142,7 @@ impl FileSystem {
         let abs_path = if path.is_absolute() {
             path.to_path_buf()
         } else {
-            std::env::current_dir()?.join(path)
+            std::env::current_dir().map_err(Error::Io)?.join(path)
         }
         .clean();
         Ok(abs_path)
diff --git a/src/fs/temp.rs b/src/fs/temp.rs
index a93e024..3d550f4 100644
--- a/src/fs/temp.rs
+++ b/src/fs/temp.rs
@@ -2,7 +2,7 @@ use std::sync::{Arc, Mutex};
 
 use tempfile::TempDir;
 
-use super::FileSystem;
+use super::{Error, FileSystem};
 
 #[derive(Clone, Debug)]
 pub struct TempFileSystem {
@@ -11,7 +11,7 @@ pub struct TempFileSystem {
 }
 impl TempFileSystem {
     pub fn new() -> super::Result<Self> {
-        let temp_dir = tempfile::tempdir()?;
+        let temp_dir = tempfile::tempdir().map_err(Error::Io)?;
         let base = temp_dir.path().to_path_buf();
         let temp_dir = Arc::new(Mutex::new(temp_dir));
         let real = super::new(base);