diff --git a/.cargo/config.toml b/.cargo/config.toml
new file mode 100644
index 0000000..0eb087e
--- /dev/null
+++ b/.cargo/config.toml
@@ -0,0 +1,2 @@
+[build]
+rustflags = ["-D", "warnings"]
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..f6f7b40
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,28 @@
+[workspace]
+resolver = "2"
+members = ["common", "daemon", "cli", "gui"]
+# GUI excluded from default builds because it requires libgtk-4-dev + libadwaita-1-dev
+# at link time. Build it explicitly with `cargo build -p ubuntu-fido-gui`.
+default-members = ["common", "daemon", "cli"]
+
+[workspace.package]
+version = "0.1.0"
+edition = "2021"
+license = "Apache-2.0"
+authors = ["Dangerous Things <ops@dangerousthings.com>"]
+repository = "https://github.com/dangerousthings/ubuntu-fido"
+rust-version = "1.78"
+
+[workspace.dependencies]
+zbus = "4"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+toml = "0.8"
+anyhow = "1"
+thiserror = "1"
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }
+tokio = { version = "1", features = ["full"] }
+clap = { version = "4", features = ["derive"] }
+ctap-hid-fido2 = "3"
+nix = { version = "0.28", features = ["user", "process", "fs"] }
diff --git a/common/Cargo.toml b/common/Cargo.toml
new file mode 100644
index 0000000..9b448a6
--- /dev/null
+++ b/common/Cargo.toml
@@ -0,0 +1,13 @@
+[package]
+name = "ubuntu-fido-common"
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+
+[dependencies]
+serde = { workspace = true }
+toml = { workspace = true }
+thiserror = { workspace = true }
+
+[dev-dependencies]
+serde_json = { workspace = true }
diff --git a/common/src/lib.rs b/common/src/lib.rs
new file mode 100644
index 0000000..505cbef
--- /dev/null
+++ b/common/src/lib.rs
@@ -0,0 +1,2 @@
+pub mod policy;
+pub mod types;
diff --git a/common/src/policy.rs b/common/src/policy.rs
new file mode 100644
index 0000000..8768f20
--- /dev/null
+++ b/common/src/policy.rs
@@ -0,0 +1 @@
+// Policy parsing implemented in Phase 2.
diff --git a/common/src/types.rs b/common/src/types.rs
new file mode 100644
index 0000000..ad091d2
--- /dev/null
+++ b/common/src/types.rs
@@ -0,0 +1,35 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "lowercase")]
+pub enum Mode {
+    Disabled,
+    Optional,
+    Required,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
+#[serde(rename_all = "lowercase")]
+pub enum Method {
+    Fido2,
+    Totp,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn mode_serializes_to_lowercase() {
+        let m = Mode::Required;
+        let s = serde_json::to_string(&m).unwrap();
+        assert_eq!(s, "\"required\"");
+    }
+
+    #[test]
+    fn method_serializes_to_lowercase() {
+        let m = Method::Fido2;
+        let s = serde_json::to_string(&m).unwrap();
+        assert_eq!(s, "\"fido2\"");
+    }
+}
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
new file mode 100644
index 0000000..85f3606
--- /dev/null
+++ b/rust-toolchain.toml
@@ -0,0 +1,4 @@
+[toolchain]
+channel = "stable"
+components = ["rustfmt", "clippy"]
+profile = "minimal"