diff --git a/rust/Cargo.lock b/rust/Cargo.lock
--- a/rust/Cargo.lock
+++ b/rust/Cargo.lock
@@ -487,6 +487,10 @@
 ]
 
 [[package]]
+name = "rhg"
+version = "0.1.0"
+
+[[package]]
 name = "rustc_version"
 version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/rust/Cargo.toml b/rust/Cargo.toml
--- a/rust/Cargo.toml
+++ b/rust/Cargo.toml
@@ -1,3 +1,3 @@
 [workspace]
-members = ["hg-core", "hg-cpython"]
+members = ["hg-core", "hg-cpython", "rhg"]
 exclude = ["chg", "hgcli"]
diff --git a/rust/rhg/Cargo.toml b/rust/rhg/Cargo.toml
new file mode 100644
--- /dev/null
+++ b/rust/rhg/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "rhg"
+version = "0.1.0"
+authors = ["Antoine Cezar <antoine.cezar@octobus.net>"]
+edition = "2018"
+
+[dependencies]
+
diff --git a/rust/rhg/README.md b/rust/rhg/README.md
new file mode 100644
--- /dev/null
+++ b/rust/rhg/README.md
@@ -0,0 +1,4 @@
+# rhg
+
+This project provides a fastpath Rust implementation of the Mercurial (`hg`)
+version control tool.
diff --git a/rust/rhg/rustfmt.toml b/rust/rhg/rustfmt.toml
new file mode 100644
--- /dev/null
+++ b/rust/rhg/rustfmt.toml
@@ -0,0 +1,3 @@
+max_width = 79
+wrap_comments = true
+error_on_line_overflow = true
diff --git a/rust/rhg/src/exitcode.rs b/rust/rhg/src/exitcode.rs
new file mode 100644
--- /dev/null
+++ b/rust/rhg/src/exitcode.rs
@@ -0,0 +1,4 @@
+pub type ExitCode = i32;
+
+/// Command not implemented by rhg
+pub const UNIMPLEMENTED_COMMAND: ExitCode = 252;
diff --git a/rust/rhg/src/main.rs b/rust/rhg/src/main.rs
new file mode 100644
--- /dev/null
+++ b/rust/rhg/src/main.rs
@@ -0,0 +1,5 @@
+mod exitcode;
+
+fn main() {
+    std::process::exit(exitcode::UNIMPLEMENTED_COMMAND)
+}