diff --git a/rust/indexes/Cargo.toml b/rust/indexes/Cargo.toml
--- a/rust/indexes/Cargo.toml
+++ b/rust/indexes/Cargo.toml
@@ -12,3 +12,8 @@
 [dependencies]
 radixbuf = { path = "../radixbuf" }
 error-chain = "0.11"
+
+[dependencies.cpython]
+git = "https://github.com/dgrunwald/rust-cpython"
+default-features = false
+features = ["extension-module-2-7"]
diff --git a/rust/indexes/src/lib.rs b/rust/indexes/src/lib.rs
--- a/rust/indexes/src/lib.rs
+++ b/rust/indexes/src/lib.rs
@@ -11,3 +11,7 @@
 
 pub mod errors;
 pub mod nodemap;
+
+#[allow(non_camel_case_types)]
+#[allow(dead_code)]
+pub mod pyext;
diff --git a/rust/indexes/src/pyext.rs b/rust/indexes/src/pyext.rs
new file mode 100644
--- /dev/null
+++ b/rust/indexes/src/pyext.rs
@@ -0,0 +1,59 @@
+// Copyright 2017 Facebook, Inc.
+//
+// This software may be used and distributed according to the terms of the
+// GNU General Public License version 2 or any later version.
+
+use cpython::{PyResult, PyBytes, PyObject};
+use cpython::buffer::PyBuffer;
+use nodemap::NodeRevMap;
+use std::mem::size_of;
+use std::slice;
+
+py_module_initializer!(indexes, initindexes, PyInit_indexes, |py, m| {
+    try!(m.add_class::<nodemap>(py));
+    Ok(())
+});
+
+py_class!(class nodemap |py| {
+    data nodemap: NodeRevMap<'static>;
+
+    // Keep their references so Python won't free them.
+    // This will cause dead code warning.
+    data changelog_slice: PyBuffer;
+    data index_slice: PyBuffer;
+
+    def __new__(_cls, changelog: &PyObject, index: &PyObject) -> PyResult<nodemap> {
+        let changelog_buf = PyBuffer::get(py, changelog)?;
+        let index_buf = PyBuffer::get(py, index)?;
+        let nm = NodeRevMap::new(pybuf_to_slice(&changelog_buf), pybuf_to_slice(&index_buf))?;
+        nodemap::create_instance(py, nm, changelog_buf, index_buf)
+    }
+
+    def __getitem__(&self, key: PyBytes) -> PyResult<Option<u32>> {
+        Ok(self.nodemap(py).node_to_rev(key.data(py))?)
+    }
+
+    def __contains__(&self, key: PyBytes) -> PyResult<bool> {
+        Ok(self.nodemap(py).node_to_rev(key.data(py))?.is_some())
+    }
+
+    def partialmatch(&self, hex: PyBytes) -> PyResult<Option<PyBytes>> {
+        Ok(self.nodemap(py).hex_prefix_to_node(hex.data(py))?.map(|b| PyBytes::new(py, b)))
+    }
+
+    def build(&self) -> PyResult<PyBytes> {
+        let buf = self.nodemap(py).build_incrementally()?;
+        let slice = unsafe { slice::from_raw_parts(buf.as_ptr() as *const u8, buf.len() * 4) };
+        Ok(PyBytes::new(py, slice))
+    }
+
+    def lag(&self) -> PyResult<u32> {
+        Ok(self.nodemap(py).lag())
+    }
+});
+
+#[inline]
+fn pybuf_to_slice<T>(buf: &PyBuffer) -> &'static [T] {
+    let len = buf.len_bytes() / size_of::<T>();
+    unsafe { slice::from_raw_parts(buf.buf_ptr() as *const T, len) }
+}