diff --git a/src/bundle/mod.rs b/src/bundle/mod.rs
new file mode 100644
index 0000000000..dabef9770f
--- /dev/null
+++ b/src/bundle/mod.rs
@@ -0,0 +1,54 @@
+// Copyright 2023 The Sigstore Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Useful types for Sigstore bundles.
+
+use std::fmt::Display;
+
+pub use sigstore_protobuf_specs::Bundle;
+
+// Known Sigstore bundle media types.
+#[derive(Clone, Copy, Debug)]
+pub enum Version {
+    Bundle0_1,
+    Bundle0_2,
+}
+
+impl TryFrom<&str> for Version {
+    type Error = ();
+
+    fn try_from(value: &str) -> Result<Self, Self::Error> {
+        match value {
+            "application/vnd.dev.sigstore.bundle+json;version=0.1" => Ok(Version::Bundle0_1),
+            "application/vnd.dev.sigstore.bundle+json;version=0.2" => Ok(Version::Bundle0_2),
+            _ => Err(()),
+        }
+    }
+}
+
+impl From<Version> for &str {
+    fn from(value: Version) -> Self {
+        match value {
+            Version::Bundle0_1 => "application/vnd.dev.sigstore.bundle+json;version=0.1",
+            Version::Bundle0_2 => "application/vnd.dev.sigstore.bundle+json;version=0.2",
+        }
+    }
+}
+
+impl Display for Version {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str((*self).into())?;
+        Ok(())
+    }
+}