diff --git a/rust/hg-core/src/lib.rs b/rust/hg-core/src/lib.rs
--- a/rust/hg-core/src/lib.rs
+++ b/rust/hg-core/src/lib.rs
@@ -23,6 +23,7 @@
 pub mod matchers;
 pub mod revlog;
 pub use revlog::*;
+pub mod operations;
 pub mod utils;
 
 // Remove this to see (potential) non-artificial compile failures. MacOS
diff --git a/rust/hg-core/src/operations/mod.rs b/rust/hg-core/src/operations/mod.rs
new file mode 100644
--- /dev/null
+++ b/rust/hg-core/src/operations/mod.rs
@@ -0,0 +1,9 @@
+/// An interface for high-level hg operations.
+///
+/// A distinction is made between operation and commands.
+/// An operation is what can be done whereas a command is what is exposed by
+/// the cli. A single command can use several operations to achieve its goal.
+pub trait Operation<T> {
+    type Error;
+    fn run(&self) -> Result<T, Self::Error>;
+}