diff --git a/tools/src/bin/parser/main.rs b/tools/src/bin/parser/main.rs
index 3b29a83..dda1452 100644
--- a/tools/src/bin/parser/main.rs
+++ b/tools/src/bin/parser/main.rs
@@ -1,79 +1,28 @@
 use clap::Parser;
 
+use tools::Recipe;
+use tools::Repo;
+
 #[derive(Debug, clap::Parser)]
 #[command(version, about, long_about = None)]
 struct Args {
+    // The name of the recipe to build.
     target: String,
-}
 
-// #[derive(Debug, serde::Deserialize)]
-// enum Quantity {
-//     Count(usize),
-//     Amount(String),
-// }
-
-#[derive(Debug, serde::Deserialize)]
-struct Input {
-    /// Each input has either a `quantity` (for discrete things, like
-    /// apples or bearings) or an `amount` (for continuous things,
-    /// like rope or flour).
-    ///
-    /// FIXME: Is there a good way to handle the "units" of the
-    /// quantity/amount? Maybe the units could default to "count", but
-    /// be optionally overridden by the recipe to things like "meters"
-    /// (of tubing) or "grams" (of chromic acid).  Then this struct
-    /// would be `quantity: usize, units: Option<Unit>`.
-    quantity: Option<usize>,
-    amount: Option<String>,
-}
-
-#[derive(Debug, serde::Deserialize)]
-struct Operator {
-    skills: Vec<String>,
-}
-
-#[derive(Debug, serde::Deserialize)]
-struct Dependencies {
-    tools: Vec<String>,
-    operator: Operator,
-}
-
-#[derive(Debug, serde::Deserialize)]
-struct Action {
-    process: String,
-}
-
-#[derive(Debug, serde::Deserialize)]
-struct Recipe {
-    /// `[inputs]` is a Table where each key the the name (unique id)
-    /// of a recipe in the repo, and the value is an Input object.
-    inputs: std::collections::HashMap<String, Input>,
-
-    dependencies: Dependencies,
-    action: Action,
-
-    /// If a recipe has no `[outputs]`, we assume it produces 1x of the
-    /// thing identified by the name of the recipe.
-    ///
-    /// FIXME: Or is that always the case, and we should have no outputs
-    /// section?  None of the recipes we've been doodling around with
-    /// have anything like byproducts or waste streams...
-    outputs: Option<Vec<String>>,
-}
-
-fn validate_recipe(recipe: &Recipe) -> anyhow::Result<()> {
-    // if recipe.inputs.len() == 0 {
-    //     Err("recipe has no inputs!");
-    // }
-    Ok(())
+    /// Directory containing the repo of all repositories.
+    #[arg(short, long)]
+    repo: String,
 }
 
 fn main() -> anyhow::Result<()> {
     let args = Args::parse();
+
+    let repo_contents = std::fs::read_dir(args.repo).unwrap();
+
     let target_str = std::fs::read_to_string(args.target)?;
     let recipe: Recipe = toml::from_str(&target_str)?;
     println!("{recipe:#?}");
-    let r = validate_recipe(&recipe);
+    let r = tools::recipe::validate_recipe(&recipe);
     println!("valid?  {r:#?}");
     Ok(())
 }
diff --git a/tools/src/lib.rs b/tools/src/lib.rs
new file mode 100644
index 0000000..fbe3eac
--- /dev/null
+++ b/tools/src/lib.rs
@@ -0,0 +1,5 @@
+pub mod recipe;
+pub use recipe::Recipe;
+
+pub mod repo;
+pub use repo::Repo;
diff --git a/tools/src/recipe.rs b/tools/src/recipe.rs
new file mode 100644
index 0000000..480615a
--- /dev/null
+++ b/tools/src/recipe.rs
@@ -0,0 +1,62 @@
+// #[derive(Debug, serde::Deserialize)]
+// enum Quantity {
+//     Count(usize),
+//     Amount(String),
+// }
+
+#[derive(Debug, serde::Deserialize)]
+pub struct Input {
+    /// Each input has either a `quantity` (for discrete things, like
+    /// apples or bearings) or an `amount` (for continuous things,
+    /// like rope or flour).
+    ///
+    /// FIXME: Is there a good way to handle the "units" of the
+    /// quantity/amount? Maybe the units could default to "count", but
+    /// be optionally overridden by the recipe to things like "meters"
+    /// (of tubing) or "grams" (of chromic acid).  Then this struct
+    /// would be `quantity: usize, units: Option<Unit>`.
+    quantity: Option<usize>,
+    amount: Option<String>,
+}
+
+#[derive(Debug, serde::Deserialize)]
+pub struct Operator {
+    skills: Vec<String>,
+}
+
+#[derive(Debug, serde::Deserialize)]
+pub struct Dependencies {
+    tools: Vec<String>,
+    operator: Operator,
+}
+
+#[derive(Debug, serde::Deserialize)]
+pub struct Action {
+    process: String,
+}
+
+#[derive(Debug, serde::Deserialize)]
+pub struct Recipe {
+    /// `[inputs]` is a Table where each key the the name (unique id)
+    /// of a recipe in the repo, and the value is an Input object.
+    inputs: std::collections::HashMap<String, Input>,
+
+    dependencies: Dependencies,
+
+    action: Action,
+
+    /// If a recipe has no `[outputs]`, we assume it produces 1x of the
+    /// thing identified by the name of the recipe.
+    ///
+    /// FIXME: Or is that always the case, and we should have no outputs
+    /// section?  None of the recipes we've been doodling around with
+    /// have anything like byproducts or waste streams...
+    outputs: Option<Vec<String>>,
+}
+
+pub fn validate_recipe(recipe: &Recipe) -> anyhow::Result<()> {
+    // if recipe.inputs.len() == 0 {
+    //     Err("recipe has no inputs!");
+    // }
+    Ok(())
+}
diff --git a/tools/src/repo.rs b/tools/src/repo.rs
new file mode 100644
index 0000000..3e966a8
--- /dev/null
+++ b/tools/src/repo.rs
@@ -0,0 +1,6 @@
+use crate::recipe::Recipe;
+
+pub struct Repo {
+    path: String,
+    recipes: std::collections::HashMap<String, Recipe>,
+}