diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0abdf27..88cad5c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,8 +1,6 @@
 name: CI
 
 on:
-  push:
-    branches: ["**"]
   pull_request:
   workflow_dispatch:
 
@@ -69,14 +67,6 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-cargo-
 
-      - name: Validate required submodules exist
-        shell: bash
-        run: |
-          set -euo pipefail
-          test -f siderust-ffi/Cargo.toml
-          test -f siderust-ffi/siderust/dev-deps/tempoch/tempoch-ffi/Cargo.toml
-          test -f qtty-cpp/CMakeLists.txt
-
       - name: Configure (CMake)
         shell: bash
         run: |
@@ -93,7 +83,7 @@ jobs:
         shell: bash
         run: |
           set -euo pipefail
-          ctest --test-dir build --output-on-failure
+          ctest --test-dir build --output-on-failure -L siderust_cpp
 
       - name: Build docs (Doxygen)
         shell: bash
diff --git a/.gitignore b/.gitignore
index fe8e720..5ade5e6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,7 @@ cmake-build-*/
 out/
 build-make/
 build-verify/
+build-ci-config-check/
 
 # IDE files
 .vscode/
diff --git a/.gitmodules b/.gitmodules
index cc58636..b0aa42e 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,9 +1,9 @@
-[submodule "siderust-ffi"]
-	path = siderust-ffi
-	url = git@github.com:Siderust/siderust-ffi.git
 [submodule "qtty-cpp"]
 	path = qtty-cpp
 	url = git@github.com:VPRamon/qtty-cpp.git
 [submodule "tempoch-cpp"]
 	path = tempoch-cpp
 	url = git@github.com:Siderust/tempoch-cpp.git
+[submodule "siderust"]
+	path = siderust
+	url = git@github.com:Siderust/siderust.git
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6b1d2ef..751413a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -10,9 +10,9 @@ option(SIDERUST_BUILD_DOCS "Enable Doxygen documentation target." ON)
 find_program(CARGO_BIN cargo REQUIRED)
 
 # ---------------------------------------------------------------------------
-# Paths to siderust-ffi
+# Paths to siderust-ffi (inside the siderust submodule)
 # ---------------------------------------------------------------------------
-set(SIDERUST_FFI_DIR       ${CMAKE_CURRENT_SOURCE_DIR}/siderust-ffi)
+set(SIDERUST_FFI_DIR       ${CMAKE_CURRENT_SOURCE_DIR}/siderust/siderust-ffi)
 
 set(SIDERUST_FFI_INCLUDE_DIR ${SIDERUST_FFI_DIR}/include)
 
@@ -29,7 +29,7 @@ endif()
 # ---------------------------------------------------------------------------
 # Platform-specific library paths
 # ---------------------------------------------------------------------------
-set(SIDERUST_ARTIFACT_DIR ${SIDERUST_FFI_DIR}/target/release)
+set(SIDERUST_ARTIFACT_DIR ${CMAKE_CURRENT_SOURCE_DIR}/siderust/target/release)
 
 if(APPLE)
     set(SIDERUST_LIBRARY_PATH ${SIDERUST_ARTIFACT_DIR}/libsiderust_ffi.dylib)
@@ -115,9 +115,9 @@ endif()
 
 # RPATH for shared library lookup at runtime
 if(APPLE)
-    set(_siderust_rpath "@loader_path/../siderust-ffi/target/release;@loader_path/../tempoch-cpp/tempoch/tempoch-ffi/target/release;@loader_path/../qtty-cpp/qtty/target/release")
+    set(_siderust_rpath "@loader_path/../siderust/target/release;@loader_path/../tempoch-cpp/tempoch/tempoch-ffi/target/release;@loader_path/../qtty-cpp/qtty/target/release")
 elseif(UNIX)
-    set(_siderust_rpath "$ORIGIN/../siderust-ffi/target/release:$ORIGIN/../tempoch-cpp/tempoch/tempoch-ffi/target/release:$ORIGIN/../qtty-cpp/qtty/target/release")
+    set(_siderust_rpath "$ORIGIN/../siderust/target/release:$ORIGIN/../tempoch-cpp/tempoch/tempoch-ffi/target/release:$ORIGIN/../qtty-cpp/qtty/target/release")
 endif()
 
 # ---------------------------------------------------------------------------
@@ -137,10 +137,10 @@ enable_testing()
 # ---------------------------------------------------------------------------
 # Example
 # ---------------------------------------------------------------------------
-add_executable(demo examples/demo.cpp)
-target_link_libraries(demo PRIVATE siderust_cpp)
+add_executable(siderust_demo examples/demo.cpp)
+target_link_libraries(siderust_demo PRIVATE siderust_cpp)
 if(DEFINED _siderust_rpath)
-    set_target_properties(demo PROPERTIES
+    set_target_properties(siderust_demo PROPERTIES
         BUILD_RPATH ${_siderust_rpath}
         INSTALL_RPATH ${_siderust_rpath}
     )
@@ -205,7 +205,9 @@ if(DEFINED _siderust_rpath)
 endif()
 
 include(GoogleTest)
-gtest_discover_tests(test_siderust)
+gtest_discover_tests(test_siderust
+    PROPERTIES LABELS "siderust_cpp"
+)
 
 # ---------------------------------------------------------------------------
 # Installation
diff --git a/Dockerfile b/Dockerfile
index eda0374..195f524 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -25,8 +25,8 @@ WORKDIR /workspace
 COPY . /workspace
 
 # Fail early if required submodules are missing from the build context.
-RUN test -f siderust-ffi/Cargo.toml && \
-    test -f siderust/tempoch/tempoch-ffi/Cargo.toml && \
+RUN test -f siderust/siderust-ffi/Cargo.toml && \
+    test -f tempoch-cpp/tempoch/tempoch-ffi/Cargo.toml && \
     test -f qtty-cpp/CMakeLists.txt
 
 # Validate the container toolchain by configuring, building, testing, and generating docs.
diff --git a/README.md b/README.md
index 3ceb21c..d4609f6 100644
--- a/README.md
+++ b/README.md
@@ -59,7 +59,7 @@ cmake ..
 cmake --build .
 
 # Run example
-./demo
+./siderust_demo
 ./coordinates_examples
 ./coordinate_systems_example
 ./solar_system_bodies_example
diff --git a/include/siderust/altitude.hpp b/include/siderust/altitude.hpp
index 2d17767..58c63ca 100644
--- a/include/siderust/altitude.hpp
+++ b/include/siderust/altitude.hpp
@@ -88,7 +88,7 @@ inline std::vector<Period> periods_from_c(tempoch_period_mjd_t* ptr, uintptr_t c
     for (uintptr_t i = 0; i < count; ++i) {
         result.push_back(Period::from_c(ptr[i]));
     }
-    tempoch_periods_free(ptr, count);
+    siderust_periods_free(ptr, count);
     return result;
 }
 
diff --git a/qtty-cpp b/qtty-cpp
index f7a7ba6..953ebe1 160000
--- a/qtty-cpp
+++ b/qtty-cpp
@@ -1 +1 @@
-Subproject commit f7a7ba6e720f7d8c005ae5c0950aaf73771ce1cb
+Subproject commit 953ebe15bcd6f1b929d4516970e5127e2e1ad953
diff --git a/siderust b/siderust
new file mode 160000
index 0000000..74c9456
--- /dev/null
+++ b/siderust
@@ -0,0 +1 @@
+Subproject commit 74c9456db9279b13d2c88516a47a5aefcbbe6130
diff --git a/siderust-ffi b/siderust-ffi
deleted file mode 160000
index f587e3f..0000000
--- a/siderust-ffi
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit f587e3fcd52bdaf71e6462bc4b30b56a93aa3fa5