diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..1d953f4
--- /dev/null
+++ b/.envrc
@@ -0,0 +1 @@
+use nix
diff --git a/.gitignore b/.gitignore
index 4b9ab5a..fbdc12d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 /target
 .fuf
+/testing
diff --git a/shell.nix b/shell.nix
new file mode 100644
index 0000000..856f661
--- /dev/null
+++ b/shell.nix
@@ -0,0 +1,3 @@
+{ pkgs ? import <nixpkgs> { } }: pkgs.mkShell {
+  packages = with pkgs; [ rustup tree ];
+}
diff --git a/src/cli/commands/db.rs b/src/cli/commands/db.rs
index 1daefa8..5bd1521 100644
--- a/src/cli/commands/db.rs
+++ b/src/cli/commands/db.rs
@@ -3,7 +3,7 @@
 use color_eyre::{eyre::Context, Result};
 use std::path::PathBuf;
 
-use crate::{cli::utils, workspace::Workspace};
+use crate::{cli::utils, db::Address, workspace::Workspace};
 
 pub fn save_file(workspace: &Workspace, paths: &[PathBuf]) -> Result<()> {
     for path in paths {
@@ -11,7 +11,7 @@ pub fn save_file(workspace: &Workspace, paths: &[PathBuf]) -> Result<()> {
 
         let address = workspace
             .db
-            .save_file(&file)
+            .save_blob(&file)
             .wrap_err("saving file to database")?;
 
         utils::print(format_args!("{address}\n")).wrap_err("printing output")?;
@@ -19,3 +19,23 @@ pub fn save_file(workspace: &Workspace, paths: &[PathBuf]) -> Result<()> {
 
     Ok(())
 }
+
+pub fn save_tree(workspace: &Workspace, paths: &[PathBuf]) -> Result<()> {
+    for path in paths {
+        let dir = utils::dir_from_path(path)?;
+        let address = crate::tree::save_tree(workspace, &dir)?;
+        utils::print(format_args!("{address}\n")).wrap_err("printing output")?;
+    }
+
+    Ok(())
+}
+
+pub fn read_blob(workspace: &Workspace, address: Address) -> Result<()> {
+    let content = workspace
+        .db
+        .read_blob(address)
+        .wrap_err_with(|| format!("reading blog {address}"))?;
+
+    utils::print_bytes(&content).wrap_err("printing bytes")?;
+    Ok(())
+}
diff --git a/src/cli/mod.rs b/src/cli/mod.rs
index 7e16c72..b8cae54 100644
--- a/src/cli/mod.rs
+++ b/src/cli/mod.rs
@@ -13,7 +13,7 @@ use cap_std::fs::Dir;
 use clap::{Parser, Subcommand};
 use color_eyre::{eyre::Context, Result};
 
-use crate::workspace;
+use crate::{db::Address, workspace};
 
 #[derive(Debug, Parser)]
 #[command(name = "fuf")]
@@ -41,6 +41,15 @@ pub enum DbCommand {
         #[arg(required = true)]
         paths: Vec<PathBuf>,
     },
+    /// Save a tree (directory) into the database and get the hash.
+    SaveTree {
+        #[arg(required = true)]
+        paths: Vec<PathBuf>,
+    },
+    /// Reads the blob behind an address.
+    ReadBlob {
+        hash: Address,
+    }
 }
 
 pub fn main() -> Result<()> {
@@ -69,6 +78,8 @@ pub fn run_command(cwd: &Path, cli: Cli) -> Result<()> {
 
             match command {
                 DbCommand::SaveFile { paths } => commands::db::save_file(&workspace, &paths),
+                DbCommand::SaveTree { paths } => commands::db::save_tree(&workspace, &paths),
+                DbCommand::ReadBlob { hash: address } => commands::db::read_blob(&workspace, address),
             }
         }
     }
diff --git a/src/cli/utils.rs b/src/cli/utils.rs
index 2b6b551..35838f9 100644
--- a/src/cli/utils.rs
+++ b/src/cli/utils.rs
@@ -1,7 +1,12 @@
+use cap_std::fs::Dir;
 ///! Utilities for the CLI functions. These should *not* be used outside of the CLI-specific code!
-use color_eyre::{eyre::Context, Result};
+use color_eyre::{
+    eyre::{bail, Context},
+    Result,
+};
 use std::{
     fmt::Display,
+    fs::File,
     io::{self, Write},
     path::Path,
 };
@@ -11,6 +16,14 @@ pub(super) fn read_file(path: &Path) -> Result<Vec<u8>> {
     std::fs::read(path).wrap_err_with(|| format!("trying to open {}", path.display()))
 }
 
+pub fn dir_from_path(path: &Path) -> Result<Dir> {
+    let dir = File::open(path).wrap_err_with(|| format!("opening directory {}", path.display()))?;
+    if !dir.metadata()?.is_dir() {
+        bail!("{} is not a directory", path.display());
+    }
+    Ok(Dir::from_std_file(dir))
+}
+
 /// Prints the content to stdout. Handles `BrokenPipe` by ignoring the rror.
 /// Does *not* exit for `BrokenPipe`
 pub(super) fn print(content: impl Display) -> io::Result<()> {
@@ -21,3 +34,14 @@ pub(super) fn print(content: impl Display) -> io::Result<()> {
         Err(e) => Err(e),
     }
 }
+
+/// Prints the bytes to stdout. Handles `BrokenPipe` by ignoring the rror.
+/// Does *not* exit for `BrokenPipe`
+pub(super) fn print_bytes(content: &[u8]) -> io::Result<()> {
+    let result = std::io::stdout().lock().write_all(content);
+    match result {
+        Ok(()) => Ok(()),
+        Err(e) if e.kind() == io::ErrorKind::BrokenPipe => Ok(()),
+        Err(e) => Err(e),
+    }
+}
diff --git a/src/db.rs b/src/db.rs
index 467c7bd..9109be1 100644
--- a/src/db.rs
+++ b/src/db.rs
@@ -14,6 +14,7 @@
 //! ```
 
 use std::io::{self, Read};
+use std::str::FromStr;
 use std::{fmt::Display, io::Write};
 
 use cap_std::fs::Dir;
@@ -51,15 +52,16 @@ impl Db {
         Ok(Self { objects })
     }
 
-    pub fn save_file(&self, content: &[u8]) -> Result<Address> {
+    pub fn save_blob(&self, content: &[u8]) -> Result<Address> {
         let hash = Address(blake3::hash(content));
 
         let prefix_dir = self
             .open_prefix_dir(hash)
             .wrap_err("opening prefix dir for saving file")?;
 
-        let suffix = &hash.0.to_hex()[2..];
-        match prefix_dir.create(suffix) {
+        let full_name = hash.0.to_hex();
+        let full_name = full_name.as_str();
+        match prefix_dir.create(full_name) {
             Ok(mut file) => {
                 file.write_all(content)
                     .wrap_err("writing contents of file")?;
@@ -70,7 +72,7 @@ impl Db {
                 if cfg!(debug_assertions) {
                     let mut existing_content = Vec::new();
                     let _: usize = prefix_dir
-                        .open(suffix)
+                        .open(full_name)
                         .wrap_err("opening file")?
                         .read_to_end(&mut existing_content)
                         .wrap_err("reading existing content")?;
@@ -86,6 +88,11 @@ impl Db {
         Ok(hash)
     }
 
+    pub fn read_blob(&self, address: Address) -> Result<Vec<u8>> {
+        let prefix_dir = self.open_prefix_dir(address).wrap_err("opening prefix dir for reading file")?;
+        prefix_dir.read(address.0.to_hex().as_str()).wrap_err("reading file")
+    }
+
     fn open_prefix_dir(&self, hash: Address) -> Result<Dir> {
         let hash_string = hash.0.to_hex();
         let prefix = &hash_string[..2];
@@ -129,3 +136,11 @@ impl Display for Address {
         f.write_str(&self.0.to_hex())
     }
 }
+
+impl FromStr for Address {
+    type Err = blake3::HexError;
+
+    fn from_str(s: &str) -> std::prelude::v1::Result<Self, Self::Err> {
+        blake3::Hash::from_str(s).map(Self)
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index fc245b6..78e36de 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,4 @@
 pub mod cli;
 mod db;
+mod tree;
 mod workspace;
diff --git a/src/tree.rs b/src/tree.rs
new file mode 100644
index 0000000..8af32e0
--- /dev/null
+++ b/src/tree.rs
@@ -0,0 +1,98 @@
+use std::io::Read;
+
+use cap_std::fs::Dir;
+use color_eyre::{
+    eyre::{bail, Context, ContextCompat},
+    Result,
+};
+
+use crate::{db::Address, workspace::Workspace};
+
+pub(crate) struct Tree {
+    pub(crate) children: Vec<TreeChild>,
+}
+
+pub(crate) struct TreeChild {
+    address: Address,
+    name: String,
+    kind: TreeChildType,
+}
+
+pub(crate) enum TreeChildType {
+    Dir,
+    File,
+}
+
+pub(crate) fn save_tree(workspace: &Workspace, directory: &Dir) -> Result<Address> {
+    let mut tree = vec![];
+
+    for entry in directory.entries().wrap_err("reading directory")? {
+        let entry = entry.wrap_err("reading directory")?;
+
+        let filetype = entry.file_type().wrap_err("getting entry file type")?;
+        let file_name = entry.file_name();
+        let file_name = file_name.to_str().wrap_err("non-UTF-8 file name")?;
+        if file_name.contains(['\n', '\r']) {
+            bail!("file name {file_name} contains a newline, which is not supported");
+        }
+
+        match () {
+            () if filetype.is_dir() => {
+                let inner_dir = entry.open_dir().wrap_err("opening directory")?;
+                let inner_address = save_tree(workspace, &inner_dir)
+                    .wrap_err_with(|| format!("saving directory {file_name}"))?;
+                tree.push(TreeChild {
+                    address: inner_address,
+                    name: file_name.to_owned(),
+                    kind: TreeChildType::Dir,
+                });
+            }
+            () if filetype.is_file() => {
+                let wrap_err = || format!("reading {file_name}");
+                let mut file = entry.open().wrap_err_with(wrap_err)?;
+                let mut content = vec![];
+                file.read_to_end(&mut content).wrap_err_with(wrap_err)?;
+                let address = workspace
+                    .db
+                    .save_blob(&content)
+                    .wrap_err("saving file to database")?;
+                tree.push(TreeChild {
+                    address,
+                    name: file_name.to_owned(),
+                    kind: TreeChildType::File,
+                });
+            }
+            _ => {
+                bail!("file {file_name} with type {filetype:?} is not supported")
+            }
+        }
+    }
+
+    let mut content = vec![];
+    Tree { children: tree }.serialize(&mut content);
+
+    workspace
+        .db
+        .save_blob(&content)
+        .wrap_err("saving tree blob")
+}
+
+impl Tree {
+    pub(crate) fn serialize(&self, out: &mut Vec<u8>) {
+        use std::io::Write;
+        for child in &self.children {
+            write!(
+                out,
+                "{}",
+                match child.kind {
+                    TreeChildType::Dir => "D",
+                    TreeChildType::File => "F",
+                }
+            )
+            .unwrap();
+            write!(out, " {}", child.address).unwrap();
+            write!(out, " {}", child.name).unwrap();
+            write!(out, "\n").unwrap();
+        }
+    }
+}