diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1c0addc..c8b93a1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -38,7 +38,12 @@ jobs:
 
       - name: Install system dependencies
         run: sudo apt-get install -y libopenblas-dev
-        
+
+      - name: Install R
+        uses: r-lib/actions/setup-r@v2
+        with:
+          r-version: release
+
       - name: Install Rust
         uses: dtolnay/rust-toolchain@stable
         with:
@@ -47,10 +52,10 @@ jobs:
       - uses: Swatinem/rust-cache@v2
 
       - name: Run Clippy
-        run: cargo clippy --workspace --exclude ci_python --exclude ci_r --exclude ci_js --all-targets -- -D warnings
+        run: cargo clippy --workspace --exclude ci_python --exclude ci_js --all-targets -- -D warnings
 
   test:
-    name: Test Suite
+    name: Rust Tests
     needs: [fmt, clippy]
     runs-on: ${{ matrix.os }}
     strategy:
@@ -76,7 +81,43 @@ jobs:
       - uses: Swatinem/rust-cache@v2
 
       - name: Build
-        run: cargo build --workspace --exclude ci_python --exclude ci_r --exclude ci_js --verbose
+        run: cargo build --workspace --exclude ci_python --exclude cir --exclude ci_js --verbose
 
       - name: Run tests
-        run: cargo test --workspace --exclude ci_python --exclude ci_r --exclude ci_js --verbose
+        run: cargo test --workspace --exclude ci_python --exclude cir --exclude ci_js --verbose
+
+  r-test:
+    name: R Package Tests
+    needs: [fmt, clippy]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+
+      - name: Install system dependencies
+        run: sudo apt-get install -y libopenblas-dev
+
+      - name: Install R
+        uses: r-lib/actions/setup-r@v2
+        with:
+          r-version: release
+
+      - name: Install Rust
+        uses: dtolnay/rust-toolchain@stable
+
+      - uses: Swatinem/rust-cache@v2
+
+      - name: Install R package dependencies
+        uses: r-lib/actions/setup-r-dependencies@v2
+        with:
+          working-directory: crates/cir
+          extra-packages: any::devtools, any::rextendr
+
+      - name: Generate Makevars and R wrappers
+        working-directory: crates/cir
+        run: rextendr::document()
+        shell: Rscript {0}
+
+      - name: Run R tests
+        working-directory: crates/cir
+        run: devtools::test(reporter = "summary")
+        shell: Rscript {0}
diff --git a/Cargo.lock b/Cargo.lock
index be46ed0..93463ca 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -94,9 +94,9 @@ checksum = "5e764a1d40d510daf35e07be9eb06e75770908c27d411ee6c92109c9840eaaf7"
 
 [[package]]
 name = "bitflags"
-version = "2.11.0"
+version = "2.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "843867be96c8daad0d758b57df9392b6d8d271134fce549de6ce169ff98a92af"
+checksum = "c4512299f36f043ab09a583e57bceb5a5aab7a73db1805848e8fef3c9e8c78b3"
 
 [[package]]
 name = "block-buffer"
@@ -139,7 +139,7 @@ checksum = "9ff11ddd2af3b5e80dd0297fee6e56ac038d9bdc549573cdb51bd6d2efe7f05e"
 dependencies = [
  "num-complex",
  "num-traits",
- "rand 0.8.5",
+ "rand 0.8.6",
  "serde",
 ]
 
@@ -154,9 +154,9 @@ dependencies = [
 
 [[package]]
 name = "cc"
-version = "1.2.59"
+version = "1.2.60"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b7a4d3ec6524d28a329fc53654bbadc9bdd7b0431f5d65f1a56ffb28a1ee5283"
+checksum = "43c5703da9466b66a946814e1adf53ea2c90f10063b86290cc9eb67ce3478a20"
 dependencies = [
  "find-msvc-tools",
  "shlex",
@@ -192,7 +192,7 @@ dependencies = [
  "ndarray-linalg",
  "ordered-float",
  "proptest",
- "rand 0.9.2",
+ "rand 0.9.4",
  "rand_distr 0.5.1",
  "statrs",
 ]
@@ -214,13 +214,6 @@ dependencies = [
  "pyo3",
 ]
 
-[[package]]
-name = "ci_r"
-version = "0.1.0"
-dependencies = [
- "ci_core",
-]
-
 [[package]]
 name = "ciborium"
 version = "0.2.2"
@@ -248,11 +241,20 @@ dependencies = [
  "half",
 ]
 
+[[package]]
+name = "cir"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "ci_core",
+ "extendr-api",
+]
+
 [[package]]
 name = "clap"
-version = "4.6.0"
+version = "4.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b193af5b67834b676abd72466a96c1024e6a6ad978a1f484bd90b85c94041351"
+checksum = "1ddb117e43bbf7dacf0a4190fef4d345b9bad68dfc649cb349e7d17d28428e51"
 dependencies = [
  "clap_builder",
 ]
@@ -545,6 +547,38 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "extendr-api"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "803569de0d273b4bf281871046a7d63a23cc12776bdb5b63de5c1e81aae30728"
+dependencies = [
+ "extendr-ffi",
+ "extendr-macros",
+ "ndarray",
+ "once_cell",
+ "paste",
+ "readonly",
+]
+
+[[package]]
+name = "extendr-ffi"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ba82ddd48e85202654997b81e4b1d39c0c54b5dcd7cae92705f807bf528efcf"
+
+[[package]]
+name = "extendr-macros"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ba8fad8d2a0d0651b1947042cf3a8beddc73d39cec3485b200fdfd24cb3bb6aa"
+dependencies = [
+ "lazy_static",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "fastrand"
 version = "2.4.1"
@@ -694,9 +728,9 @@ dependencies = [
 
 [[package]]
 name = "hashbrown"
-version = "0.16.1"
+version = "0.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "841d1cc9bed7f9236f321df977030373f4a4163ae1a7dbfe1a51a2c1a51d9100"
+checksum = "4f467dd6dccf739c208452f8014c75c18bb8301b050ad1cfb27153803edb0f51"
 
 [[package]]
 name = "heck"
@@ -867,12 +901,12 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "2.13.1"
+version = "2.14.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "45a8a2b9cb3e0b0c1803dbb0758ffac5de2f425b23c28f518faabd9d805342ff"
+checksum = "d466e9454f08e4a911e14806c24e16fba1b4c121d1ea474396f396069cf949d9"
 dependencies = [
  "equivalent",
- "hashbrown 0.16.1",
+ "hashbrown 0.17.0",
  "serde",
  "serde_core",
 ]
@@ -927,9 +961,9 @@ checksum = "8f42a60cbdf9a97f5d2305f08a87dc4e09308d1276d28c869c684d7777685682"
 
 [[package]]
 name = "js-sys"
-version = "0.3.94"
+version = "0.3.95"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2e04e2ef80ce82e13552136fabeef8a5ed1f985a96805761cbb9a2c34e7664d9"
+checksum = "2964e92d1d9dc3364cae4d718d93f227e3abb088e747d92e0395bfdedf1c12ca"
 dependencies = [
  "once_cell",
  "wasm-bindgen",
@@ -948,18 +982,18 @@ dependencies = [
 
 [[package]]
 name = "lapack-sys"
-version = "0.15.0"
+version = "0.14.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "314b879030845b68571809a6978e52d3b67ac5fba07e77b1b317b484092e2fb5"
+checksum = "447f56c85fb410a7a3d36701b2153c1018b1d2b908c5fbaf01c1b04fac33bcbe"
 dependencies = [
  "libc",
 ]
 
 [[package]]
 name = "lax"
-version = "0.18.0"
+version = "0.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bda593cb87a3b1c06625e73710812005caf1523e45b0b898adcd7716602f8ba2"
+checksum = "1048f58cdc36e726e1c5ef81ec7ac9b1be2fce6b705786514b5a4f8c63487867"
 dependencies = [
  "cauchy",
  "intel-mkl-src",
@@ -984,9 +1018,9 @@ checksum = "09edd9e8b54e49e587e4f6295a7d29c3ea94d469cb40ab8ca70b288248a81db2"
 
 [[package]]
 name = "libc"
-version = "0.2.184"
+version = "0.2.185"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "48f5d2a454e16a5ea0f4ced81bd44e4cfc7bd3a507b61887c99fd3538b28e4af"
+checksum = "52ff2c0fe9bc6cb6b14a0592c2ff4fa9ceb83eea9db979b0487cd054946a2b8f"
 
 [[package]]
 name = "libm"
@@ -996,9 +1030,9 @@ checksum = "b6d2cec3eae94f9f509c767b45932f1ada8350c4bdb85af2fcab4a3c14807981"
 
 [[package]]
 name = "libredox"
-version = "0.1.15"
+version = "0.1.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7ddbf48fd451246b1f8c2610bd3b4ac0cc6e149d89832867093ab69a17194f08"
+checksum = "e02f3bb43d335493c96bf3fd3a321600bf6bd07ed34bc64118e9293bdffea46c"
 dependencies = [
  "bitflags",
  "libc",
@@ -1061,7 +1095,7 @@ dependencies = [
  "num-complex",
  "num-rational",
  "num-traits",
- "rand 0.8.5",
+ "rand 0.8.6",
  "rand_distr 0.4.3",
  "simba",
  "typenum",
@@ -1086,9 +1120,9 @@ dependencies = [
 
 [[package]]
 name = "ndarray"
-version = "0.17.2"
+version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "520080814a7a6b4a6e9070823bb24b4531daac8c4627e08ba5de8c5ef2f2752d"
+checksum = "882ed72dce9365842bf196bdeedf5055305f11fc8c03dee7bb0194a6cad34841"
 dependencies = [
  "approx",
  "cblas-sys",
@@ -1104,9 +1138,9 @@ dependencies = [
 
 [[package]]
 name = "ndarray-linalg"
-version = "0.18.1"
+version = "0.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eb0783188ff249ab498417e0477f7fade3b312d1d287314ca76de570d9a83ee0"
+checksum = "820b7fdcc3f1fd48c31f4c85bdefe93ef2d0e8b69ff955c4d499ea6db2f19d44"
 dependencies = [
  "cauchy",
  "katexit",
@@ -1114,7 +1148,7 @@ dependencies = [
  "ndarray",
  "num-complex",
  "num-traits",
- "rand 0.8.5",
+ "rand 0.8.6",
  "thiserror 2.0.18",
 ]
 
@@ -1135,7 +1169,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "73f88a1307638156682bada9d7604135552957b7818057dcef22705b4d509495"
 dependencies = [
  "num-traits",
- "rand 0.8.5",
+ "rand 0.8.6",
  "serde",
 ]
 
@@ -1267,9 +1301,9 @@ dependencies = [
 
 [[package]]
 name = "openssl"
-version = "0.10.76"
+version = "0.10.78"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "951c002c75e16ea2c65b8c7e4d3d51d5530d8dfa7d060b4776828c88cfb18ecf"
+checksum = "f38c4372413cdaaf3cc79dd92d29d7d9f5ab09b51b10dded508fb90bb70b9222"
 dependencies = [
  "bitflags",
  "cfg-if",
@@ -1299,9 +1333,9 @@ checksum = "7c87def4c32ab89d880effc9e097653c8da5d6ef28e6b539d313baaacfbafcbe"
 
 [[package]]
 name = "openssl-sys"
-version = "0.9.112"
+version = "0.9.114"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "57d55af3b3e226502be1526dfdba67ab0e9c96fc293004e79576b2b9edb0dbdb"
+checksum = "13ce1245cd07fcc4cfdb438f7507b0c7e4f3849a69fd84d52374c66d83741bb6"
 dependencies = [
  "cc",
  "libc",
@@ -1347,9 +1381,9 @@ checksum = "9b4f627cb1b25917193a259e49bdad08f671f8d9708acfd5fe0a8c1455d87220"
 
 [[package]]
 name = "pkg-config"
-version = "0.3.32"
+version = "0.3.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7edddbd0b52d732b21ad9a5fab5c704c14cd949e5e9a1ec5929a24fded1b904c"
+checksum = "19f132c84eca552bf34cab8ec81f1c1dcc229b811638f9d283dceabe58c5569e"
 
 [[package]]
 name = "plain"
@@ -1393,9 +1427,9 @@ checksum = "c33a9471896f1c69cecef8d20cbe2f7accd12527ce60845ff44c153bb2a21b49"
 
 [[package]]
 name = "portable-atomic-util"
-version = "0.2.6"
+version = "0.2.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "091397be61a01d4be58e7841595bd4bfedb15f1cd54977d79b8271e94ed799a3"
+checksum = "c2a106d1259c23fac8e543272398ae0e3c0b8d33c88ed73d0cc71b0f1d902618"
 dependencies = [
  "portable-atomic",
 ]
@@ -1469,7 +1503,7 @@ dependencies = [
  "bit-vec",
  "bitflags",
  "num-traits",
- "rand 0.9.2",
+ "rand 0.9.4",
  "rand_chacha 0.9.0",
  "rand_xorshift",
  "regex-syntax",
@@ -1565,9 +1599,9 @@ checksum = "f8dcc9c7d52a811697d2151c701e0d08956f92b0e24136cf4cf27b57a6a0d9bf"
 
 [[package]]
 name = "rand"
-version = "0.8.5"
+version = "0.8.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
+checksum = "5ca0ecfa931c29007047d1bc58e623ab12e5590e8c7cc53200d5202b69266d8a"
 dependencies = [
  "libc",
  "rand_chacha 0.3.1",
@@ -1576,9 +1610,9 @@ dependencies = [
 
 [[package]]
 name = "rand"
-version = "0.9.2"
+version = "0.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6db2770f06117d490610c7488547d543617b21bfa07796d7a12f6f1bd53850d1"
+checksum = "44c5af06bb1b7d3216d91932aed5265164bf384dc89cd6ba05cf59a35f5f76ea"
 dependencies = [
  "rand_chacha 0.9.0",
  "rand_core 0.9.5",
@@ -1629,7 +1663,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "32cb0b9bc82b0a0876c2dd994a7e7a2683d3e7390ca40e6886785ef0c7e3ee31"
 dependencies = [
  "num-traits",
- "rand 0.8.5",
+ "rand 0.8.6",
 ]
 
 [[package]]
@@ -1639,7 +1673,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6a8615d50dcf34fa31f7ab52692afec947c4dd0ab803cc87cb3b0b4570ff7463"
 dependencies = [
  "num-traits",
- "rand 0.9.2",
+ "rand 0.9.4",
 ]
 
 [[package]]
@@ -1659,9 +1693,9 @@ checksum = "60a357793950651c4ed0f3f52338f53b2f809f32d83a07f72909fa13e4c6c1e3"
 
 [[package]]
 name = "rayon"
-version = "1.11.0"
+version = "1.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "368f01d005bf8fd9b1206fb6fa653e6c4a81ceb1466406b81792d87c5677a58f"
+checksum = "fb39b166781f92d482534ef4b4b1b2568f42613b53e5b6c160e24cfbfa30926d"
 dependencies = [
  "either",
  "rayon-core",
@@ -1677,11 +1711,22 @@ dependencies = [
  "crossbeam-utils",
 ]
 
+[[package]]
+name = "readonly"
+version = "0.2.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2a62d85ed81ca5305dc544bd42c8804c5060b78ffa5ad3c64b0fb6a8c13d062"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "redox_syscall"
-version = "0.7.3"
+version = "0.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6ce70a74e890531977d37e532c34d45e9055d2409ed08ddba14529471ed0be16"
+checksum = "f450ad9c3b1da563fb6948a8e0fb0fb9269711c9c73d9ea1de5058c79c8d643a"
 dependencies = [
  "bitflags",
 ]
@@ -1772,9 +1817,9 @@ dependencies = [
 
 [[package]]
 name = "rustls"
-version = "0.23.37"
+version = "0.23.38"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "758025cb5fccfd3bc2fd74708fd4682be41d99e5dff73c377c0646c6012c73a4"
+checksum = "69f9466fb2c14ea04357e91413efb882e2a6d4a406e625449bc0a5d360d53a21"
 dependencies = [
  "log",
  "once_cell",
@@ -1796,9 +1841,9 @@ dependencies = [
 
 [[package]]
 name = "rustls-webpki"
-version = "0.103.10"
+version = "0.103.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "df33b2b81ac578cabaf06b89b0631153a3f416b0a886e8a7a1707fb51abbd1ef"
+checksum = "61c429a8649f110dddef65e2a5ad240f747e85f7758a6bccc7e5777bd33f756e"
 dependencies = [
  "ring",
  "rustls-pki-types",
@@ -1988,7 +2033,7 @@ dependencies = [
  "approx",
  "nalgebra",
  "num-traits",
- "rand 0.8.5",
+ "rand 0.8.6",
 ]
 
 [[package]]
@@ -2177,9 +2222,9 @@ checksum = "5d99f8c9a7727884afe522e9bd5edbfc91a3312b36a77b5fb8926e4c31a41801"
 
 [[package]]
 name = "typenum"
-version = "1.19.0"
+version = "1.20.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "562d481066bde0658276a35467c4af00bdc6ee726305698a55b86e61d7ad82bb"
+checksum = "40ce102ab67701b8526c123c1bab5cbe42d7040ccfd0f64af1a385808d2f43de"
 
 [[package]]
 name = "unarray"
@@ -2278,9 +2323,9 @@ checksum = "b6c140620e7ffbb22c2dee59cafe6084a59b5ffc27a8859a5f0d494b5d52b6be"
 
 [[package]]
 name = "uuid"
-version = "1.23.0"
+version = "1.23.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5ac8b6f42ead25368cf5b098aeb3dc8a1a2c05a3eee8a9a1a68c640edbfc79d9"
+checksum = "ddd74a9687298c6858e9b88ec8935ec45d22e8fd5e6394fa1bd4e99a87789c76"
 dependencies = [
  "getrandom 0.4.2",
  "js-sys",
@@ -2326,11 +2371,11 @@ checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
 
 [[package]]
 name = "wasip2"
-version = "1.0.2+wasi-0.2.9"
+version = "1.0.3+wasi-0.2.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9517f9239f02c069db75e65f174b3da828fe5f5b945c4dd26bd25d89c03ebcf5"
+checksum = "20064672db26d7cdc89c7798c48a0fdfac8213434a1186e5ef29fd560ae223d6"
 dependencies = [
- "wit-bindgen",
+ "wit-bindgen 0.57.1",
 ]
 
 [[package]]
@@ -2339,14 +2384,14 @@ version = "0.4.0+wasi-0.3.0-rc-2026-01-06"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5428f8bf88ea5ddc08faddef2ac4a67e390b88186c703ce6dbd955e1c145aca5"
 dependencies = [
- "wit-bindgen",
+ "wit-bindgen 0.51.0",
 ]
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.117"
+version = "0.2.118"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0551fc1bb415591e3372d0bc4780db7e587d84e2a7e79da121051c5c4b89d0b0"
+checksum = "0bf938a0bacb0469e83c1e148908bd7d5a6010354cf4fb73279b7447422e3a89"
 dependencies = [
  "cfg-if",
  "once_cell",
@@ -2357,9 +2402,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.117"
+version = "0.2.118"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7fbdf9a35adf44786aecd5ff89b4563a90325f9da0923236f6104e603c7e86be"
+checksum = "eeff24f84126c0ec2db7a449f0c2ec963c6a49efe0698c4242929da037ca28ed"
 dependencies = [
  "quote",
  "wasm-bindgen-macro-support",
@@ -2367,9 +2412,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.117"
+version = "0.2.118"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dca9693ef2bab6d4e6707234500350d8dad079eb508dca05530c85dc3a529ff2"
+checksum = "9d08065faf983b2b80a79fd87d8254c409281cf7de75fc4b773019824196c904"
 dependencies = [
  "bumpalo",
  "proc-macro2",
@@ -2380,9 +2425,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.117"
+version = "0.2.118"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "39129a682a6d2d841b6c429d0c51e5cb0ed1a03829d8b3d1e69a011e62cb3d3b"
+checksum = "5fd04d9e306f1907bd13c6361b5c6bfc7b3b3c095ed3f8a9246390f8dbdee129"
 dependencies = [
  "unicode-ident",
 ]
@@ -2423,9 +2468,9 @@ dependencies = [
 
 [[package]]
 name = "web-sys"
-version = "0.3.94"
+version = "0.3.95"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cd70027e39b12f0849461e08ffc50b9cd7688d942c1c8e3c7b22273236b4dd0a"
+checksum = "4f2dfbb17949fa2088e5d39408c48368947b86f7834484e87b73de55bc14d97d"
 dependencies = [
  "js-sys",
  "wasm-bindgen",
@@ -2433,9 +2478,9 @@ dependencies = [
 
 [[package]]
 name = "webpki-root-certs"
-version = "1.0.6"
+version = "1.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "804f18a4ac2676ffb4e8b5b5fa9ae38af06df08162314f96a68d2a363e21a8ca"
+checksum = "f31141ce3fc3e300ae89b78c0dd67f9708061d1d2eda54b8209346fd6be9a92c"
 dependencies = [
  "rustls-pki-types",
 ]
@@ -2446,14 +2491,14 @@ version = "0.26.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "521bc38abb08001b01866da9f51eb7c5d647a19260e00054a8c7fd5f9e57f7a9"
 dependencies = [
- "webpki-roots 1.0.6",
+ "webpki-roots 1.0.7",
 ]
 
 [[package]]
 name = "webpki-roots"
-version = "1.0.6"
+version = "1.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "22cfaf3c063993ff62e73cb4311efde4db1efb31ab78a3e5c457939ad5cc0bed"
+checksum = "52f5ee44c96cf55f1b349600768e3ece3a8f26010c05265ab73f945bb1a2eb9d"
 dependencies = [
  "rustls-pki-types",
 ]
@@ -2702,6 +2747,12 @@ dependencies = [
  "wit-bindgen-rust-macro",
 ]
 
+[[package]]
+name = "wit-bindgen"
+version = "0.57.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1ebf944e87a7c253233ad6766e082e3cd714b5d03812acc24c318f549614536e"
+
 [[package]]
 name = "wit-bindgen-core"
 version = "0.51.0"
diff --git a/Cargo.toml b/Cargo.toml
index 1b56066..8e28563 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,14 +2,14 @@
 members = [
     "crates/ci-core",
     "crates/ci-python",
-    "crates/ci-r",
+    "crates/cir/src/rust",
     "crates/ci-js",
 ]
 resolver = "2"
 
 [workspace.dependencies]
 anyhow = "1"
-ndarray = "0.17"
+ndarray = "0.16"
 statrs = { version = "0.18.0"}
 
 
diff --git a/crates/ci-core/Cargo.toml b/crates/ci-core/Cargo.toml
index bd94090..07339aa 100644
--- a/crates/ci-core/Cargo.toml
+++ b/crates/ci-core/Cargo.toml
@@ -20,13 +20,13 @@ rand = "0.9"
 libm = "0.2.16"
 
 [target.'cfg(target_os = "linux")'.dependencies]
-ndarray-linalg = { version = "0.18.1", features = ["openblas-system"] }
+ndarray-linalg = { version = "0.17", features = ["openblas-system"] }
 
 [target.'cfg(target_os = "macos")'.dependencies]
-ndarray-linalg = { version = "0.18.1", features = ["openblas-system"] }
+ndarray-linalg = { version = "0.17", features = ["openblas-system"] }
 
 [target.'cfg(windows)'.dependencies]
-ndarray-linalg = { version = "0.18.1", features = ["intel-mkl-static"] }
+ndarray-linalg = { version = "0.17", features = ["intel-mkl-static"] }
 
 [dev-dependencies]
 criterion = { workspace = true }
diff --git a/crates/ci-core/src/ci_tests/chi_squared.rs b/crates/ci-core/src/ci_tests/chi_squared.rs
index d32ec3c..9106d7d 100644
--- a/crates/ci-core/src/ci_tests/chi_squared.rs
+++ b/crates/ci-core/src/ci_tests/chi_squared.rs
@@ -10,6 +10,7 @@ pub struct ChiSquared {
 }
 
 impl ChiSquared {
+    #[must_use]
     pub fn new(boolean: bool, significance_level: f64) -> Self {
         Self {
             boolean,
diff --git a/crates/ci-core/src/ci_tests/cressie_read.rs b/crates/ci-core/src/ci_tests/cressie_read.rs
index 9ce61f8..47ffb16 100644
--- a/crates/ci-core/src/ci_tests/cressie_read.rs
+++ b/crates/ci-core/src/ci_tests/cressie_read.rs
@@ -10,6 +10,7 @@ pub struct CressieRead {
 }
 
 impl CressieRead {
+    #[must_use]
     pub fn new(boolean: bool, significance_level: f64) -> Self {
         Self {
             boolean,
diff --git a/crates/ci-core/src/ci_tests/freeman_tukey.rs b/crates/ci-core/src/ci_tests/freeman_tukey.rs
index b4474bc..27c018c 100644
--- a/crates/ci-core/src/ci_tests/freeman_tukey.rs
+++ b/crates/ci-core/src/ci_tests/freeman_tukey.rs
@@ -10,6 +10,7 @@ pub struct FreemanTukey {
 }
 
 impl FreemanTukey {
+    #[must_use]
     pub fn new(boolean: bool, significance_level: f64) -> Self {
         Self {
             boolean,
diff --git a/crates/ci-core/src/ci_tests/log_likelihood.rs b/crates/ci-core/src/ci_tests/log_likelihood.rs
index 0d443b2..296437f 100644
--- a/crates/ci-core/src/ci_tests/log_likelihood.rs
+++ b/crates/ci-core/src/ci_tests/log_likelihood.rs
@@ -10,6 +10,7 @@ pub struct LogLikelihood {
 }
 
 impl LogLikelihood {
+    #[must_use]
     pub fn new(boolean: bool, significance_level: f64) -> Self {
         Self {
             boolean,
diff --git a/crates/ci-core/src/ci_tests/mod.rs b/crates/ci-core/src/ci_tests/mod.rs
index e7efdd0..0f53b52 100644
--- a/crates/ci-core/src/ci_tests/mod.rs
+++ b/crates/ci-core/src/ci_tests/mod.rs
@@ -1,10 +1,10 @@
-mod chi_squared;
-mod cressie_read;
-mod freeman_tukey;
-mod log_likelihood;
-mod modified_likelihood;
-mod pearson_correlation;
-mod pearson_equivalence;
+pub mod chi_squared;
+pub mod cressie_read;
+pub mod freeman_tukey;
+pub mod log_likelihood;
+pub mod modified_likelihood;
+pub mod pearson_correlation;
+pub mod pearson_equivalence;
 
 use chi_squared::ChiSquared;
 use cressie_read::CressieRead;
@@ -16,6 +16,9 @@ use pearson_equivalence::PearsonEquivalence;
 
 use crate::registry::Registry;
 
+/// # Panics
+///
+/// Panics if any test name is already registered (indicates a duplicate registration bug).
 pub fn register_all_tests(registry: &mut Registry) {
     registry
         .add_to_registry("chi_square", ChiSquared::new(true, 0.05))
diff --git a/crates/ci-core/src/ci_tests/modified_likelihood.rs b/crates/ci-core/src/ci_tests/modified_likelihood.rs
index ed97967..4ca950e 100644
--- a/crates/ci-core/src/ci_tests/modified_likelihood.rs
+++ b/crates/ci-core/src/ci_tests/modified_likelihood.rs
@@ -10,6 +10,7 @@ pub struct ModifiedLikelihood {
 }
 
 impl ModifiedLikelihood {
+    #[must_use]
     pub fn new(boolean: bool, significance_level: f64) -> Self {
         Self {
             boolean,
diff --git a/crates/ci-core/src/ci_tests/pearson_correlation.rs b/crates/ci-core/src/ci_tests/pearson_correlation.rs
index 34b8576..1214b7a 100644
--- a/crates/ci-core/src/ci_tests/pearson_correlation.rs
+++ b/crates/ci-core/src/ci_tests/pearson_correlation.rs
@@ -21,6 +21,7 @@ pub struct PearsonCorrelation {
 }
 
 impl PearsonCorrelation {
+    #[must_use]
     pub fn new(boolean: bool, significance_level: f64) -> Self {
         Self {
             boolean,
@@ -84,6 +85,7 @@ impl CITest for PearsonCorrelation {
 }
 
 /// Construct the appropriate [`TestResult`] variant based on the `boolean` flag.
+#[must_use]
 pub fn wrap_result(
     boolean: bool,
     p_value: f64,
diff --git a/crates/ci-core/src/ci_tests/pearson_equivalence.rs b/crates/ci-core/src/ci_tests/pearson_equivalence.rs
index b3010c6..4b44b11 100644
--- a/crates/ci-core/src/ci_tests/pearson_equivalence.rs
+++ b/crates/ci-core/src/ci_tests/pearson_equivalence.rs
@@ -11,6 +11,7 @@ pub struct PearsonEquivalence {
 }
 
 impl PearsonEquivalence {
+    #[must_use]
     pub fn new(boolean: bool, significance_level: f64, delta_threshold: f64) -> Self {
         Self {
             boolean,
@@ -87,6 +88,7 @@ impl CITest for PearsonEquivalence {
     }
 }
 
+#[must_use]
 pub fn wrap_result(
     boolean: bool,
     p_value: f64,
diff --git a/crates/ci-core/src/lib.rs b/crates/ci-core/src/lib.rs
index 3294e97..abc87ef 100644
--- a/crates/ci-core/src/lib.rs
+++ b/crates/ci-core/src/lib.rs
@@ -1,4 +1,4 @@
-mod ci_tests;
+pub mod ci_tests;
 pub mod registry;
 pub mod strategy;
 pub mod utils;
diff --git a/crates/ci-r/Cargo.toml b/crates/ci-r/Cargo.toml
deleted file mode 100644
index 13b8caf..0000000
--- a/crates/ci-r/Cargo.toml
+++ /dev/null
@@ -1,16 +0,0 @@
-[package]
-name = "ci_r"
-version = "0.1.0"
-edition = "2021"
-authors = ["Your Team <team@example.com>"]
-license = ""
-description = "extendr bindings for Conditional Independence Testing"
-repository = ""
-
-[dependencies]
-ci_core = { path = "../ci-core" }
-
-[lints]
-workspace = true
-
-[lib]
diff --git a/crates/ci-r/README.md b/crates/ci-r/README.md
deleted file mode 100644
index 41e4a99..0000000
--- a/crates/ci-r/README.md
+++ /dev/null
@@ -1 +0,0 @@
-extendr bindings
\ No newline at end of file
diff --git a/crates/ci-r/src/lib.rs b/crates/ci-r/src/lib.rs
deleted file mode 100644
index 8b13789..0000000
--- a/crates/ci-r/src/lib.rs
+++ /dev/null
@@ -1 +0,0 @@
-
diff --git a/crates/cir/.Rbuildignore b/crates/cir/.Rbuildignore
new file mode 100644
index 0000000..a020d1a
--- /dev/null
+++ b/crates/cir/.Rbuildignore
@@ -0,0 +1,6 @@
+^\.vscode$
+^src/\.cargo$
+^src/rust/vendor$
+^src/rust/target$
+^src/Makevars$
+^src/Makevars\.win$
diff --git a/crates/cir/.gitignore b/crates/cir/.gitignore
new file mode 100644
index 0000000..20cff42
--- /dev/null
+++ b/crates/cir/.gitignore
@@ -0,0 +1,3 @@
+src/rust/vendor
+src/Makevars
+src/Makevars.win
diff --git a/crates/cir/.vscode/settings.json b/crates/cir/.vscode/settings.json
new file mode 100644
index 0000000..a0fd38b
--- /dev/null
+++ b/crates/cir/.vscode/settings.json
@@ -0,0 +1,15 @@
+{
+  "rust-analyzer.linkedProjects": [
+    "${workspaceFolder}/src/rust/Cargo.toml"
+  ],
+  "files.associations": {
+    "Makevars": "makefile",
+    "Makevars.in": "makefile",
+    "Makevars.win": "makefile",
+    "Makevars.win.in": "makefile",
+    "configure": "shellscript",
+    "configure.win": "shellscript",
+    "cleanup": "shellscript",
+    "cleanup.win": "shellscript"
+  }
+}
diff --git a/crates/cir/DESCRIPTION b/crates/cir/DESCRIPTION
new file mode 100644
index 0000000..3f20518
--- /dev/null
+++ b/crates/cir/DESCRIPTION
@@ -0,0 +1,22 @@
+Package: cir
+Title: Conditional Independence Testing
+Version: 0.0.0.9000
+Authors@R:
+    person("GIP", "House", email = "giphouse@example.com", role = c("aut", "cre"))
+Description: R bindings for a collection of conditional independence tests
+    implemented in Rust. Supports discrete, continuous, and mixed data via
+    chi-squared, log-likelihood, Cressie-Read, Freeman-Tukey, Pearson
+    correlation, modified log-likelihood, and Pearson equivalence tests.
+License: MIT
+Encoding: UTF-8
+Roxygen: list(markdown = TRUE)
+RoxygenNote: 7.3.3
+Config/rextendr/version: 0.5.0
+SystemRequirements: Cargo (Rust's package manager), rustc >= 1.65.0, xz
+Depends:
+    R (>= 4.2)
+Suggests:
+    devtools,
+    rextendr,
+    testthat (>= 3.0.0)
+Config/testthat/edition: 3
diff --git a/crates/cir/NAMESPACE b/crates/cir/NAMESPACE
new file mode 100644
index 0000000..5d83515
--- /dev/null
+++ b/crates/cir/NAMESPACE
@@ -0,0 +1,3 @@
+# Generated by roxygen2: do not edit by hand
+
+useDynLib(cir, .registration = TRUE)
diff --git a/crates/cir/R/extendr-wrappers.R b/crates/cir/R/extendr-wrappers.R
new file mode 100644
index 0000000..02e79f9
--- /dev/null
+++ b/crates/cir/R/extendr-wrappers.R
@@ -0,0 +1,31 @@
+# Generated by extendr: Do not edit by hand
+# nolint start
+
+#' @usage NULL
+#' @useDynLib cir, .registration = TRUE
+NULL
+
+#' Returns a sorted vector of all registered CI test names.
+list_ci_tests <- function() .Call(wrap__list_ci_tests)
+
+#' Returns a sorted vector of CI test names compatible with the given data type.
+#'
+#' `data_type` must be one of `"discrete"`, `"continuous"`, or `"mixed"` (case-insensitive).
+#' Returns an error for any other value.
+list_ci_tests_for <- function(data_type) .Call(wrap__list_ci_tests_for, data_type)
+
+chi_squared_test <- function(x_values, y_values, z, boolean, significance_level) .Call(wrap__chi_squared_test, x_values, y_values, z, boolean, significance_level)
+
+log_likelihood_test <- function(x_values, y_values, z, boolean, significance_level) .Call(wrap__log_likelihood_test, x_values, y_values, z, boolean, significance_level)
+
+cressie_read_test <- function(x_values, y_values, z, boolean, significance_level) .Call(wrap__cressie_read_test, x_values, y_values, z, boolean, significance_level)
+
+pearson_correlation_test <- function(x_values, y_values, z, boolean, significance_level) .Call(wrap__pearson_correlation_test, x_values, y_values, z, boolean, significance_level)
+
+freeman_tukey_test <- function(x_values, y_values, z, boolean, significance_level) .Call(wrap__freeman_tukey_test, x_values, y_values, z, boolean, significance_level)
+
+modified_likelihood_test <- function(x_values, y_values, z, boolean, significance_level) .Call(wrap__modified_likelihood_test, x_values, y_values, z, boolean, significance_level)
+
+pearson_equivalence_test <- function(x_values, y_values, z, boolean, significance_level) .Call(wrap__pearson_equivalence_test, x_values, y_values, z, boolean, significance_level)
+
+# nolint end
diff --git a/crates/cir/README.md b/crates/cir/README.md
new file mode 100644
index 0000000..b49d77a
--- /dev/null
+++ b/crates/cir/README.md
@@ -0,0 +1,35 @@
+extendr bindings
+
+## Usage
+
+Install R, then open an R session:
+
+```sh
+R
+```
+
+Install `pak` (the modern R package manager that handles system dependencies automatically):
+
+```r
+install.packages("pak", repos = "https://cloud.r-project.org")
+```
+
+Install dev dependencies:
+
+```r
+pak::pak(c("devtools", "rextendr"))
+```
+
+### Regenerate bindings
+
+```r
+setwd("crates/cir")
+rextendr::document()  # regenerates R wrappers and compiles Rust
+```
+
+### Load and test
+
+```r
+devtools::load_all()  # compiles Rust + loads the package
+devtools::test()      # run all tests
+```
diff --git a/crates/cir/cleanup b/crates/cir/cleanup
new file mode 100644
index 0000000..e346d71
--- /dev/null
+++ b/crates/cir/cleanup
@@ -0,0 +1 @@
+rm -f src/Makevars
diff --git a/crates/cir/cleanup.win b/crates/cir/cleanup.win
new file mode 100644
index 0000000..a182174
--- /dev/null
+++ b/crates/cir/cleanup.win
@@ -0,0 +1 @@
+rm -f src/Makevars.win
diff --git a/crates/cir/configure b/crates/cir/configure
new file mode 100755
index 0000000..c608b11
--- /dev/null
+++ b/crates/cir/configure
@@ -0,0 +1,3 @@
+#!/usr/bin/env sh
+: "${R_HOME=`R RHOME`}"
+"${R_HOME}/bin/Rscript" tools/config.R 
diff --git a/crates/cir/configure.win b/crates/cir/configure.win
new file mode 100644
index 0000000..57eb255
--- /dev/null
+++ b/crates/cir/configure.win
@@ -0,0 +1,2 @@
+#!/usr/bin/env sh
+"${R_HOME}/bin${R_ARCH_BIN}/Rscript.exe" tools/config.R
diff --git a/crates/cir/src/.gitignore b/crates/cir/src/.gitignore
new file mode 100644
index 0000000..24e51fc
--- /dev/null
+++ b/crates/cir/src/.gitignore
@@ -0,0 +1,8 @@
+*.o
+*.so
+*.dll
+target
+.cargo
+rust/vendor
+Makevars
+Makevars.win
diff --git a/crates/cir/src/Makevars.in b/crates/cir/src/Makevars.in
new file mode 100644
index 0000000..a687d41
--- /dev/null
+++ b/crates/cir/src/Makevars.in
@@ -0,0 +1,52 @@
+TARGET_DIR = ./rust/target
+LIBDIR = $(TARGET_DIR)/@LIBDIR@
+STATLIB = $(LIBDIR)/libcir.a
+PKG_LIBS = -L$(LIBDIR) -lcir
+
+all: $(SHLIB) rust_clean
+
+.PHONY: $(STATLIB)
+
+$(SHLIB): $(STATLIB)
+
+CARGOTMP = $(CURDIR)/.cargo
+VENDOR_DIR = $(CURDIR)/vendor
+
+
+# RUSTFLAGS appends --print=native-static-libs to ensure that 
+# the correct linkers are used. Use this for debugging if need. 
+#
+# CRAN note: Cargo and Rustc versions are reported during
+# configure via tools/msrv.R.
+#
+# If a vendor directory exists, it is used for offline compilation. Otherwise if
+# vendor.tar.xz exists, it is unzipped and used for offline compilation.
+$(STATLIB):
+
+	if [ -d ./vendor ]; then \
+		echo "=== Using offline vendor directory ==="; \
+		mkdir -p $(CARGOTMP) && \
+		cp rust/vendor-config.toml $(CARGOTMP)/config.toml; \
+	elif [ -f ./rust/vendor.tar.xz ]; then \
+		echo "=== Using offline vendor tarball ==="; \
+		tar xf rust/vendor.tar.xz && \
+		mkdir -p $(CARGOTMP) && \
+		cp rust/vendor-config.toml $(CARGOTMP)/config.toml; \
+	fi
+
+	export CARGO_HOME=$(CARGOTMP) && \
+	export PATH="$(PATH):$(HOME)/.cargo/bin" && \
+	@PANIC_EXPORTS@RUSTFLAGS="$(RUSTFLAGS) --print=native-static-libs" cargo build @CRAN_FLAGS@ --lib @PROFILE@ --manifest-path=./rust/Cargo.toml --target-dir $(TARGET_DIR) @TARGET@
+
+	export CARGO_HOME=$(CARGOTMP) && \
+	export PATH="$(PATH):$(HOME)/.cargo/bin" && \
+	cargo run @CRAN_FLAGS@ --bin document --manifest-path=./rust/Cargo.toml --target-dir $(TARGET_DIR) @TARGET@
+
+	# Always clean up CARGOTMP
+	rm -Rf $(CARGOTMP);
+
+rust_clean: $(SHLIB)
+	rm -Rf $(CARGOTMP) $(VENDOR_DIR) @CLEAN_TARGET@
+
+clean:
+	rm -Rf $(SHLIB) $(STATLIB) $(OBJECTS) $(TARGET_DIR) $(VENDOR_DIR)
diff --git a/crates/cir/src/Makevars.win.in b/crates/cir/src/Makevars.win.in
new file mode 100644
index 0000000..6f72063
--- /dev/null
+++ b/crates/cir/src/Makevars.win.in
@@ -0,0 +1,51 @@
+TARGET = $(subst 64,x86_64,$(subst 32,i686,$(WIN)))-pc-windows-gnu
+
+TARGET_DIR = ./rust/target
+LIBDIR = $(TARGET_DIR)/$(TARGET)/@LIBDIR@
+STATLIB = $(LIBDIR)/libcir.a
+PKG_LIBS = -L$(LIBDIR) -lcir -lws2_32 -ladvapi32 -luserenv -lbcrypt -lntdll
+
+all: $(SHLIB) rust_clean
+
+.PHONY: $(STATLIB)
+
+$(SHLIB): $(STATLIB)
+
+CARGOTMP = $(CURDIR)/.cargo
+VENDOR_DIR = vendor
+
+$(STATLIB):
+	mkdir -p $(TARGET_DIR)/libgcc_mock
+	touch $(TARGET_DIR)/libgcc_mock/libgcc_eh.a
+
+  # If a vendor directory exists, it is used for offline compilation. Otherwise if
+  # vendor.tar.xz exists, it is unzipped and used for offline compilation.
+	if [ -d ./vendor ]; then \
+		echo "=== Using offline vendor directory ==="; \
+		mkdir -p $(CARGOTMP) && \
+		cp rust/vendor-config.toml $(CARGOTMP)/config.toml; \
+	elif [ -f ./rust/vendor.tar.xz ]; then \
+		echo "=== Using offline vendor tarball ==="; \
+		tar xf rust/vendor.tar.xz && \
+		mkdir -p $(CARGOTMP) && \
+		cp rust/vendor-config.toml $(CARGOTMP)/config.toml; \
+	fi
+
+	# Build the project using Cargo with additional flags
+	export CARGO_HOME=$(CARGOTMP) && \
+	export LIBRARY_PATH="$(LIBRARY_PATH);$(CURDIR)/$(TARGET_DIR)/libgcc_mock" && \
+	RUSTFLAGS="$(RUSTFLAGS) --print=native-static-libs" cargo build @CRAN_FLAGS@ --target=$(TARGET) --lib @PROFILE@ --manifest-path=rust/Cargo.toml --target-dir=$(TARGET_DIR)
+
+	# Generate wrappers
+	export CARGO_HOME=$(CARGOTMP) && \
+	export PATH="$(PATH):$(HOME)/.cargo/bin" && \
+	cargo run @CRAN_FLAGS@ --bin document --target $(TARGET) --manifest-path=./rust/Cargo.toml --target-dir $(TARGET_DIR)
+
+	# Always clean up CARGOTMP
+	rm -Rf $(CARGOTMP);
+
+rust_clean: $(SHLIB)
+	rm -Rf $(CARGOTMP) $(VENDOR_DIR) @CLEAN_TARGET@
+
+clean:
+	rm -Rf $(SHLIB) $(STATLIB) $(OBJECTS) $(TARGET_DIR) $(VENDOR_DIR)
diff --git a/crates/cir/src/cir-win.def b/crates/cir/src/cir-win.def
new file mode 100644
index 0000000..6fe96d6
--- /dev/null
+++ b/crates/cir/src/cir-win.def
@@ -0,0 +1,2 @@
+EXPORTS
+R_init_cir
diff --git a/crates/cir/src/entrypoint.c b/crates/cir/src/entrypoint.c
new file mode 100644
index 0000000..fc87ffb
--- /dev/null
+++ b/crates/cir/src/entrypoint.c
@@ -0,0 +1,10 @@
+// We need to forward routine registration from C to Rust
+// to avoid the linker removing the static library.
+
+void R_init_cir_extendr(void *dll);
+void register_extendr_panic_hook(void);
+
+void R_init_cir(void *dll) {
+    register_extendr_panic_hook();
+    R_init_cir_extendr(dll);
+}
diff --git a/crates/cir/src/rust/Cargo.toml b/crates/cir/src/rust/Cargo.toml
new file mode 100644
index 0000000..f0b3dbb
--- /dev/null
+++ b/crates/cir/src/rust/Cargo.toml
@@ -0,0 +1,23 @@
+[package]
+name = 'cir'
+publish = false
+version = '0.1.0'
+edition = '2021'
+rust-version = '1.65'
+
+[lib]
+crate-type = [ 'rlib', 'staticlib' ]
+name = 'cir'
+
+[[bin]]
+name = 'document'
+path = 'document.rs'
+
+[dependencies]
+ci_core = { path = "../../../ci-core" }
+anyhow = "1"
+extendr-api = { version = '0.9.0', features = ['ndarray'] }
+
+[profile.release]
+lto = true
+codegen-units = 1
diff --git a/crates/cir/src/rust/document.rs b/crates/cir/src/rust/document.rs
new file mode 100644
index 0000000..ef5b73f
--- /dev/null
+++ b/crates/cir/src/rust/document.rs
@@ -0,0 +1,20 @@
+// Generated by extendr: Do not edit by hand
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let wrapper_path = "../R/extendr-wrappers.R";
+    let header = "\
+        # Generated by extendr: Do not edit by hand\n\
+        # nolint start\n\
+        \n\
+        #' @usage NULL\n\
+        #' @useDynLib cir, .registration = TRUE\n\
+        NULL\n\
+        \n\
+    ";
+    let footer = "# nolint end\n";
+    let wrappers = cir::get_cir_metadata()
+        .make_r_wrappers(true, "cir")
+        .map_err(|e| format!("failed to generate wrappers: {e}"))?;
+    std::fs::write(wrapper_path, format!("{header}{wrappers}{footer}"))
+        .map_err(|e| format!("failed to write {wrapper_path}: {e}"))?;
+    Ok(())
+}
diff --git a/crates/cir/src/rust/src/lib.rs b/crates/cir/src/rust/src/lib.rs
new file mode 100644
index 0000000..8cd84db
--- /dev/null
+++ b/crates/cir/src/rust/src/lib.rs
@@ -0,0 +1,97 @@
+//! R bindings for the conditional independence testing library.
+//!
+//! Exposes CI test functions and registry queries to R via the `extendr` framework.
+//! Each CI test accepts paired observation vectors and a conditioning matrix, returning
+//! a named R list whose shape depends on whether the test runs in boolean or numeric mode.
+
+use ci_core::ci_tests::{
+    chi_squared::ChiSquared, cressie_read::CressieRead, freeman_tukey::FreemanTukey,
+    log_likelihood::LogLikelihood, modified_likelihood::ModifiedLikelihood,
+    pearson_correlation::PearsonCorrelation,
+};
+use ci_core::registry::Registry;
+use ci_core::strategy::{CITest, CITestDataType};
+use extendr_api::prelude::*;
+use ndarray::{ArrayView1, ArrayView2};
+mod util;
+
+/// Generates an R-callable wrapper for a [`CITest`] implementation.
+///
+/// The generated function signature is:
+/// ```text
+/// fn $fn_name(x_values, y_values, z, boolean, significance_level) -> Robj
+/// ```
+/// - `x_values` / `y_values`: paired observation vectors.
+/// - `z`: conditioning matrix; pass a 0-column matrix for unconditional tests.
+/// - `boolean`: when `true`, returns only an independence verdict at `significance_level`
+///   instead of the raw test statistic and p-value.
+/// - `significance_level`: threshold used only when `boolean` is `true`.
+macro_rules! r_ci_test {
+    ($fn_name:ident, $inner:ty) => {
+        #[extendr]
+        fn $fn_name(
+            x_values: ArrayView1<f64>,
+            y_values: ArrayView1<f64>,
+            z: ArrayView2<f64>,
+            boolean: bool,
+            significance_level: f64,
+        ) -> anyhow::Result<Robj> {
+            let citest = <$inner>::new(boolean, significance_level);
+            let result = citest.run_test(x_values.to_owned(), y_values.to_owned(), z.to_owned())?;
+            Ok(util::test_result_to_robj(result))
+        }
+    };
+}
+
+/// Returns a sorted vector of all registered CI test names.
+#[extendr]
+fn list_ci_tests() -> anyhow::Result<Vec<String>> {
+    let registry = Registry::new();
+    let mut tests: Vec<String> = registry.all_tests()?.map(String::from).collect();
+    tests.sort();
+    Ok(tests)
+}
+
+/// Returns a sorted vector of CI test names compatible with the given data type.
+///
+/// `data_type` must be one of `"discrete"`, `"continuous"`, or `"mixed"` (case-insensitive).
+/// Returns an error for any other value.
+#[extendr]
+fn list_ci_tests_for(data_type: &str) -> anyhow::Result<Vec<String>> {
+    let dt = match data_type.to_lowercase().as_str() {
+        "discrete" => CITestDataType::Discrete,
+        "continuous" => CITestDataType::Continuous,
+        "mixed" => CITestDataType::Mixed,
+        _ => anyhow::bail!(
+            "Unknown data type: '{data_type}'. Use 'discrete', 'continuous', or 'mixed'."
+        ),
+    };
+    let registry = Registry::new();
+    let mut tests: Vec<String> = registry
+        .tests_with_data_type(&dt)?
+        .map(String::from)
+        .collect();
+    tests.sort();
+    Ok(tests)
+}
+
+r_ci_test!(chi_squared_test, ChiSquared);
+r_ci_test!(log_likelihood_test, LogLikelihood);
+r_ci_test!(cressie_read_test, CressieRead);
+r_ci_test!(pearson_correlation_test, PearsonCorrelation);
+r_ci_test!(freeman_tukey_test, FreemanTukey);
+r_ci_test!(modified_likelihood_test, ModifiedLikelihood);
+//r_ci_test!(pearson_equivalence_test, PearsonEquivalence);
+
+extendr_module! {
+    mod cir;
+    fn list_ci_tests;
+    fn list_ci_tests_for;
+    fn chi_squared_test;
+    fn log_likelihood_test;
+    fn cressie_read_test;
+    fn pearson_correlation_test;
+    fn freeman_tukey_test;
+    fn modified_likelihood_test;
+    //fn pearson_equivalence_test;
+}
diff --git a/crates/cir/src/rust/src/util.rs b/crates/cir/src/rust/src/util.rs
new file mode 100644
index 0000000..4804aaa
--- /dev/null
+++ b/crates/cir/src/rust/src/util.rs
@@ -0,0 +1,26 @@
+//! Conversion utilities from core result types to R objects.
+
+use ci_core::strategy::TestResult;
+use extendr_api::prelude::*;
+
+/// Converts a [`TestResult`] into a named R list.
+///
+/// The returned list always contains a `kind` field identifying the variant:
+/// - `"pvalue"` — also contains `p_value` and `coefficient`.
+/// - `"statistic"` — also contains `statistic`, `p_value`, and `df` (degrees of freedom).
+/// - `"boolean"` — also contains `independent` (logical).
+pub fn test_result_to_robj(r: TestResult) -> Robj {
+    match r {
+        TestResult::PValue(p, coef) => {
+            list!(kind = "pvalue", p_value = p, coefficient = coef,).into()
+        }
+        TestResult::Statistic(p, stat, df) => list!(
+            kind = "statistic",
+            statistic = stat,
+            p_value = p,
+            df = df as i32,
+        )
+        .into(),
+        TestResult::Boolean(b) => list!(kind = "boolean", independent = b,).into(),
+    }
+}
diff --git a/crates/cir/tests/testthat/test-chi_squared.R b/crates/cir/tests/testthat/test-chi_squared.R
new file mode 100644
index 0000000..3672e30
--- /dev/null
+++ b/crates/cir/tests/testthat/test-chi_squared.R
@@ -0,0 +1,45 @@
+library(cir)
+
+test_that("independent data is not rejected", {
+    x = c(1.0, 1.0, 2.0, 2.0, 1.0, 1.0, 2.0, 2.0)
+    y = c(1.0, 2.0, 1.0, 2.0, 1.0, 2.0, 1.0, 2.0)
+    z = matrix(0, nrow = 8, ncol = 0)
+
+    result = chi_squared_test(x, y, z, FALSE, 0.05)
+    expect_equal(result$kind, "statistic")
+    expect_true(result$statistic < 1e-9)
+    expect_true(result$p_value >= 0.99)
+    expect_equal(result$df, 1)
+  })
+
+test_that("dependent data is rejected", {
+    x = c(1., 1., 1., 1., 2., 2., 2., 2.)
+    y = c(1., 1., 1., 1., 2., 2., 2., 2.)
+    z = matrix(0, nrow = 8, ncol = 0)
+
+    result = chi_squared_test(x, y, z, FALSE, 0.05)
+    expect_equal(result$kind, "statistic")
+    expect_true(abs(result$statistic - 8.0) < 1e-9)
+    expect_true(abs(result$p_value - 0.004677734981047276) < 1e-12)
+    expect_equal(result$df, 1)
+  })
+
+test_that("boolean mode returns independent=TRUE for independent data", {
+    x = c(1.0, 1.0, 2.0, 2.0, 1.0, 1.0, 2.0, 2.0)
+    y = c(1.0, 2.0, 1.0, 2.0, 1.0, 2.0, 1.0, 2.0)
+    z = matrix(0, nrow = 8, ncol = 0)
+
+    result = chi_squared_test(x, y, z, TRUE, 0.05)
+    expect_equal(result$kind, "boolean")
+    expect_true(result$independent)
+  })
+
+test_that("boolean mode returns independent=FALSE for dependent data", {
+    x = c(1., 1., 1., 1., 2., 2., 2., 2.)
+    y = c(1., 1., 1., 1., 2., 2., 2., 2.)
+    z = matrix(0, nrow = 8, ncol = 0)
+
+    result = chi_squared_test(x, y, z, TRUE, 0.05)
+    expect_equal(result$kind, "boolean")
+    expect_false(result$independent)
+  })
diff --git a/crates/cir/tests/testthat/test-cressie_read.R b/crates/cir/tests/testthat/test-cressie_read.R
new file mode 100644
index 0000000..ad8d20c
--- /dev/null
+++ b/crates/cir/tests/testthat/test-cressie_read.R
@@ -0,0 +1,78 @@
+library(cir)
+
+test_that("unconditional independent data is not rejected", {
+    x = c(1.0, 1.0, 2.0, 2.0, 1.0, 1.0, 2.0, 2.0)
+    y = c(1.0, 2.0, 1.0, 2.0, 1.0, 2.0, 1.0, 2.0)
+    z = matrix(0, nrow = 8, ncol = 0)
+
+    result = cressie_read_test(x, y, z, FALSE, 0.05)
+    expect_equal(result$kind, "statistic")
+    expect_true(result$statistic < 1e-9)
+    expect_true(result$p_value > 0.99)
+    expect_equal(result$df, 1)
+  })
+
+test_that("unconditional boolean accepts independent data", {
+    x = c(1.0, 1.0, 2.0, 2.0, 1.0, 1.0, 2.0, 2.0)
+    y = c(1.0, 2.0, 1.0, 2.0, 1.0, 2.0, 1.0, 2.0)
+    z = matrix(0, nrow = 8, ncol = 0)
+
+    result = cressie_read_test(x, y, z, TRUE, 0.05)
+    expect_equal(result$kind, "boolean")
+    expect_true(result$independent)
+  })
+
+test_that("unconditional dependent data is rejected", {
+    x = c(1., 1., 1., 1., 2., 2., 2., 2.)
+    y = c(1., 1., 1., 1., 2., 2., 2., 2.)
+    z = matrix(0, nrow = 8, ncol = 0)
+
+    result = cressie_read_test(x, y, z, FALSE, 0.05)
+    expect_equal(result$kind, "statistic")
+    expect_true(result$statistic > 5.0)
+    expect_true(result$p_value < 0.05)
+    expect_equal(result$df, 1)
+  })
+
+test_that("unconditional boolean rejects dependent data", {
+    x = c(1., 1., 1., 1., 2., 2., 2., 2.)
+    y = c(1., 1., 1., 1., 2., 2., 2., 2.)
+    z = matrix(0, nrow = 8, ncol = 0)
+
+    result = cressie_read_test(x, y, z, TRUE, 0.05)
+    expect_equal(result$kind, "boolean")
+    expect_false(result$independent)
+  })
+
+test_that("conditional independent data is not rejected", {
+    x = c(1.0, 1.0, 2.0, 2.0, 1.0, 1.0, 2.0, 2.0)
+    y = c(1.0, 2.0, 1.0, 2.0, 1.0, 2.0, 1.0, 2.0)
+    z = matrix(c(0., 0., 0., 0., 1., 1., 1., 1.), nrow = 8, ncol = 1)
+
+    result = cressie_read_test(x, y, z, FALSE, 0.05)
+    expect_equal(result$kind, "statistic")
+    expect_true(result$statistic < 1e-9)
+    expect_true(result$p_value > 0.99)
+    expect_equal(result$df, 2)
+  })
+
+test_that("conditional boolean accepts conditionally independent data", {
+    x = c(1.0, 1.0, 2.0, 2.0, 1.0, 1.0, 2.0, 2.0)
+    y = c(1.0, 2.0, 1.0, 2.0, 1.0, 2.0, 1.0, 2.0)
+    z = matrix(c(0., 0., 0., 0., 1., 1., 1., 1.), nrow = 8, ncol = 1)
+
+    result = cressie_read_test(x, y, z, TRUE, 0.05)
+    expect_equal(result$kind, "boolean")
+    expect_true(result$independent)
+  })
+
+test_that("conditional dependent data is rejected", {
+    x = c(1., 1., 2., 2., 1., 1., 2., 2.)
+    y = c(1., 1., 2., 2., 1., 1., 2., 2.)
+    z = matrix(c(0., 0., 0., 0., 1., 1., 1., 1.), nrow = 8, ncol = 1)
+
+    result = cressie_read_test(x, y, z, FALSE, 0.05)
+    expect_equal(result$kind, "statistic")
+    expect_true(result$statistic > 5.0)
+    expect_true(result$p_value < 0.05)
+  })
diff --git a/crates/cir/tests/testthat/test-freeman_tukey.R b/crates/cir/tests/testthat/test-freeman_tukey.R
new file mode 100644
index 0000000..b02b2d8
--- /dev/null
+++ b/crates/cir/tests/testthat/test-freeman_tukey.R
@@ -0,0 +1,35 @@
+library(cir)
+
+test_that("independent data is not rejected", {
+    x = c(1.0, 1.0, 2.0, 2.0, 1.0, 1.0, 2.0, 2.0)
+    y = c(1.0, 2.0, 1.0, 2.0, 1.0, 2.0, 1.0, 2.0)
+    z = matrix(0, nrow = 8, ncol = 0)
+
+    result = freeman_tukey_test(x, y, z, FALSE, 0.05)
+    expect_equal(result$kind, "statistic")
+    expect_true(result$statistic < 1e-9)
+    expect_true(result$p_value >= 0.99)
+    expect_equal(result$df, 1)
+  })
+
+test_that("dependent data is rejected", {
+    x = c(1., 1., 1., 1., 1., 1., 2., 2., 2., 2., 2., 2.)
+    y = c(1., 1., 1., 1., 1., 2., 1., 2., 2., 2., 2., 2.)
+    z = matrix(0, nrow = 12, ncol = 0)
+
+    result = freeman_tukey_test(x, y, z, FALSE, 0.05)
+    expect_equal(result$kind, "statistic")
+    expect_true(abs(result$statistic - 6.319453539579289) < 1e-9)
+    expect_true(abs(result$p_value - 0.011942042564347121) < 1e-12)
+    expect_equal(result$df, 1)
+  })
+
+test_that("boolean mode returns independent=TRUE for independent data", {
+    x = c(1.0, 1.0, 2.0, 2.0, 1.0, 1.0, 2.0, 2.0)
+    y = c(1.0, 2.0, 1.0, 2.0, 1.0, 2.0, 1.0, 2.0)
+    z = matrix(0, nrow = 8, ncol = 0)
+
+    result = freeman_tukey_test(x, y, z, TRUE, 0.05)
+    expect_equal(result$kind, "boolean")
+    expect_true(result$independent)
+  })
diff --git a/crates/cir/tests/testthat/test-log_likelihood.R b/crates/cir/tests/testthat/test-log_likelihood.R
new file mode 100644
index 0000000..58cad3d
--- /dev/null
+++ b/crates/cir/tests/testthat/test-log_likelihood.R
@@ -0,0 +1,35 @@
+library(cir)
+
+test_that("independent data is not rejected", {
+    x = c(1.0, 1.0, 2.0, 2.0, 1.0, 1.0, 2.0, 2.0)
+    y = c(1.0, 2.0, 1.0, 2.0, 1.0, 2.0, 1.0, 2.0)
+    z = matrix(0, nrow = 8, ncol = 0)
+
+    result = log_likelihood_test(x, y, z, FALSE, 0.05)
+    expect_equal(result$kind, "statistic")
+    expect_true(result$statistic < 1e-9)
+    expect_true(result$p_value >= 0.99)
+    expect_equal(result$df, 1)
+  })
+
+test_that("dependent data is rejected", {
+    x = c(1., 1., 1., 1., 1., 1., 2., 2., 2., 2., 2., 2.)
+    y = c(1., 1., 1., 1., 1., 2., 1., 2., 2., 2., 2., 2.)
+    z = matrix(0, nrow = 12, ncol = 0)
+
+    result = log_likelihood_test(x, y, z, FALSE, 0.05)
+    expect_equal(result$kind, "statistic")
+    expect_true(abs(result$statistic - 5.822063320647374) < 1e-9)
+    expect_true(abs(result$p_value - 0.015826368796540195) < 1e-12)
+    expect_equal(result$df, 1)
+  })
+
+test_that("boolean mode returns independent=FALSE for dependent data", {
+    x = c(1., 1., 1., 1., 1., 1., 2., 2., 2., 2., 2., 2.)
+    y = c(1., 1., 1., 1., 1., 2., 1., 2., 2., 2., 2., 2.)
+    z = matrix(0, nrow = 12, ncol = 0)
+
+    result = log_likelihood_test(x, y, z, TRUE, 0.05)
+    expect_equal(result$kind, "boolean")
+    expect_false(result$independent)
+  })
diff --git a/crates/cir/tests/testthat/test-modified_likelihood.R b/crates/cir/tests/testthat/test-modified_likelihood.R
new file mode 100644
index 0000000..9204669
--- /dev/null
+++ b/crates/cir/tests/testthat/test-modified_likelihood.R
@@ -0,0 +1,35 @@
+library(cir)
+
+test_that("independent data is not rejected", {
+    x = c(1.0, 1.0, 2.0, 2.0, 1.0, 1.0, 2.0, 2.0)
+    y = c(1.0, 2.0, 1.0, 2.0, 1.0, 2.0, 1.0, 2.0)
+    z = matrix(0, nrow = 8, ncol = 0)
+
+    result = modified_likelihood_test(x, y, z, FALSE, 0.05)
+    expect_equal(result$kind, "statistic")
+    expect_true(result$statistic < 1e-9)
+    expect_true(result$p_value >= 0.99)
+    expect_equal(result$df, 1)
+  })
+
+test_that("dependent data is rejected", {
+    x = c(1., 1., 1., 1., 1., 1., 2., 2., 2., 2., 2., 2.)
+    y = c(1., 1., 1., 1., 1., 2., 1., 2., 2., 2., 2., 2.)
+    z = matrix(0, nrow = 12, ncol = 0)
+
+    result = modified_likelihood_test(x, y, z, FALSE, 0.05)
+    expect_equal(result$kind, "statistic")
+    expect_true(abs(result$statistic - 7.053439978825427) < 1e-9)
+    expect_true(abs(result$p_value - 0.007911317670556329) < 1e-12)
+    expect_equal(result$df, 1)
+  })
+
+test_that("boolean mode returns independent=FALSE for dependent data", {
+    x = c(1., 1., 1., 1., 1., 1., 2., 2., 2., 2., 2., 2.)
+    y = c(1., 1., 1., 1., 1., 2., 1., 2., 2., 2., 2., 2.)
+    z = matrix(0, nrow = 12, ncol = 0)
+
+    result = modified_likelihood_test(x, y, z, TRUE, 0.05)
+    expect_equal(result$kind, "boolean")
+    expect_false(result$independent)
+  })
diff --git a/crates/cir/tests/testthat/test-pearson_correlation.R b/crates/cir/tests/testthat/test-pearson_correlation.R
new file mode 100644
index 0000000..707f160
--- /dev/null
+++ b/crates/cir/tests/testthat/test-pearson_correlation.R
@@ -0,0 +1,134 @@
+library(cir)
+N = 1000
+
+test_that("unconditional independent data is not rejected", {
+    set.seed(42)
+    x = rnorm(N)
+    y = rnorm(N)
+    z = matrix(0, nrow = N, ncol = 0)
+
+    result = pearson_correlation_test(x, y, z, FALSE, 0.05)
+    expect_equal(result$kind, "pvalue")
+    expect_true(result$p_value > 0.05)
+    expect_true(abs(result$coefficient) < 0.1)
+  })
+
+test_that("unconditional boolean accepts independent data", {
+    set.seed(42)
+    x = rnorm(N)
+    y = rnorm(N)
+    z = matrix(0, nrow = N, ncol = 0)
+
+    result = pearson_correlation_test(x, y, z, TRUE, 0.05)
+    expect_equal(result$kind, "boolean")
+    expect_true(result$independent)
+  })
+
+test_that("unconditional dependent data is rejected", {
+    set.seed(42)
+    x     = rnorm(N)
+    noise = rnorm(N, sd = 0.1)
+    y     = 3 * x + noise
+    z     = matrix(0, nrow = N, ncol = 0)
+
+    result = pearson_correlation_test(x, y, z, FALSE, 0.05)
+    expect_equal(result$kind, "pvalue")
+    expect_true(result$p_value < 0.05)
+    expect_true(abs(result$coefficient) > 0.9)
+  })
+
+test_that("unconditional boolean rejects dependent data", {
+    set.seed(42)
+    x     = rnorm(N)
+    noise = rnorm(N, sd = 0.1)
+    y     = 3 * x + noise
+    z     = matrix(0, nrow = N, ncol = 0)
+
+    result = pearson_correlation_test(x, y, z, TRUE, 0.05)
+    expect_equal(result$kind, "boolean")
+    expect_false(result$independent)
+  })
+
+test_that("conditional independent data is not rejected", {
+    set.seed(42)
+    z_col   = rnorm(N)
+    noise_x = rnorm(N, sd = 0.1)
+    noise_y = rnorm(N, sd = 0.1)
+    x = 3 * z_col + noise_x
+    y = 2 * z_col + noise_y
+    z = matrix(z_col, nrow = N, ncol = 1)
+
+    result = pearson_correlation_test(x, y, z, FALSE, 0.05)
+    expect_equal(result$kind, "pvalue")
+    expect_true(result$p_value > 0.05)
+    expect_true(abs(result$coefficient) < 0.1)
+  })
+
+test_that("conditional boolean accepts conditionally independent data", {
+    set.seed(42)
+    z_col   = rnorm(N)
+    noise_x = rnorm(N, sd = 0.1)
+    noise_y = rnorm(N, sd = 0.1)
+    x = 3 * z_col + noise_x
+    y = 2 * z_col + noise_y
+    z = matrix(z_col, nrow = N, ncol = 1)
+
+    result = pearson_correlation_test(x, y, z, TRUE, 0.05)
+    expect_equal(result$kind, "boolean")
+    expect_true(result$independent)
+  })
+
+test_that("conditional dependent data (v-structure collider) is rejected", {
+    set.seed(42)
+    x     = rnorm(N)
+    y     = rnorm(N)
+    noise = rnorm(N, sd = 0.1)
+    z_col = 2 * x + 2 * y + noise
+    z     = matrix(z_col, nrow = N, ncol = 1)
+
+    result = pearson_correlation_test(x, y, z, FALSE, 0.05)
+    expect_equal(result$kind, "pvalue")
+    expect_true(result$p_value < 0.05)
+    expect_true(abs(result$coefficient) > 0.9)
+  })
+
+test_that("conditional boolean rejects dependent data (v-structure collider)", {
+    set.seed(42)
+    x     = rnorm(N)
+    y     = rnorm(N)
+    noise = rnorm(N, sd = 0.1)
+    z_col = 2 * x + 2 * y + noise
+    z     = matrix(z_col, nrow = N, ncol = 1)
+
+    result = pearson_correlation_test(x, y, z, TRUE, 0.05)
+    expect_equal(result$kind, "boolean")
+    expect_false(result$independent)
+  })
+
+test_that("conditional independent data with multiple conditioning variables is not rejected", {
+    set.seed(42)
+    z1      = rnorm(N)
+    z2      = rnorm(N)
+    z3      = rnorm(N)
+    noise_x = rnorm(N, sd = 0.1)
+    noise_y = rnorm(N, sd = 0.1)
+    x = 0.5 * z1 + 0.5 * z2 + 0.5 * z3 + noise_x
+    y = 0.5 * z1 + 0.5 * z2 + 0.5 * z3 + noise_y
+    z = cbind(z1, z2, z3)
+
+    result = pearson_correlation_test(x, y, z, FALSE, 0.05)
+    expect_equal(result$kind, "pvalue")
+    expect_true(result$p_value >= 0.05)
+    expect_true(abs(result$coefficient) <= 0.1)
+  })
+
+test_that("minimum input (n=3) with perfect correlation returns coefficient near 1", {
+    x = c(1.0, 2.0, 3.0)
+    y = c(1.0, 2.0, 3.0)
+    z = matrix(0, nrow = 3, ncol = 0)
+
+    result = pearson_correlation_test(x, y, z, FALSE, 0.05)
+    expect_equal(result$kind, "pvalue")
+    expect_true(abs(result$coefficient - 1.0) < 1e-10)
+    expect_true(result$p_value < 0.05)
+  })
diff --git a/crates/cir/tests/testthat/test-pearson_equivalence.R b/crates/cir/tests/testthat/test-pearson_equivalence.R
new file mode 100644
index 0000000..e69de29
diff --git a/crates/cir/tools/config.R b/crates/cir/tools/config.R
new file mode 100644
index 0000000..06d57cd
--- /dev/null
+++ b/crates/cir/tools/config.R
@@ -0,0 +1,112 @@
+# Note: Any variables prefixed with `.` are used for text
+# replacement in the Makevars.in and Makevars.win.in
+
+# check the packages MSRV first
+source("tools/msrv.R")
+
+# check DEBUG and NOT_CRAN environment variables
+env_debug <- Sys.getenv("DEBUG")
+env_not_cran <- Sys.getenv("NOT_CRAN")
+
+# check if the vendored zip file exists
+vendor_exists <- file.exists("src/rust/vendor.tar.xz")
+
+is_not_cran <- env_not_cran != ""
+is_debug <- env_debug != ""
+
+if (is_debug) {
+  # if we have DEBUG then we set not cran to true
+  # CRAN is always release build
+  is_not_cran <- TRUE
+  message("Creating DEBUG build.")
+}
+
+if (!is_not_cran) {
+  message("Building for CRAN.")
+}
+
+# we set cran flags only if NOT_CRAN is empty and if
+# the vendored crates are present.
+.cran_flags <- ifelse(
+  !is_not_cran && vendor_exists,
+  "-j 2 --offline",
+  ""
+)
+
+# when DEBUG env var is present we use `--debug` build
+.profile <- ifelse(is_debug, "", "--release")
+.clean_targets <- ifelse(is_debug, "", "$(TARGET_DIR)")
+
+# We specify this target when building for webR
+webr_target <- "wasm32-unknown-emscripten"
+
+# here we check if the platform we are building for is webr
+is_wasm <- identical(R.version$platform, webr_target)
+
+# print to terminal to inform we are building for webr
+if (is_wasm) {
+  message("Building for WebR")
+}
+
+# we check if we are making a debug build or not
+# if so, the LIBDIR environment variable becomes:
+# LIBDIR = $(TARGET_DIR)/{wasm32-unknown-emscripten}/debug
+# this will be used to fill out the LIBDIR env var for Makevars.in
+target_libpath <- if (is_wasm) "wasm32-unknown-emscripten" else NULL
+cfg <- if (is_debug) "debug" else "release"
+
+# used to replace @LIBDIR@
+.libdir <- paste(c(target_libpath, cfg), collapse = "/")
+
+# use this to replace @TARGET@
+# we specify the target _only_ on webR
+# there may be use cases later where this can be adapted or expanded
+.target <- ifelse(is_wasm, paste0("--target=", webr_target), "")
+
+# add panic exports only for WASM builds
+.panic_exports <- ifelse(
+  is_wasm,
+  "CARGO_PROFILE_DEV_PANIC=\"abort\" CARGO_PROFILE_RELEASE_PANIC=\"abort\" ",
+  ""
+)
+
+# read in the Makevars.in file checking
+is_windows <- .Platform[["OS.type"]] == "windows"
+
+# if windows we replace in the Makevars.win.in
+mv_fp <- ifelse(
+  is_windows,
+  "src/Makevars.win.in",
+  "src/Makevars.in"
+)
+
+# set the output file
+mv_ofp <- ifelse(
+  is_windows,
+  "src/Makevars.win",
+  "src/Makevars"
+)
+
+# delete the existing Makevars{.win/.wasm}
+if (file.exists(mv_ofp)) {
+  message("Cleaning previous `", mv_ofp, "`.")
+  invisible(file.remove(mv_ofp))
+}
+
+# read as a single string
+mv_txt <- readLines(mv_fp)
+
+# replace placeholder values
+new_txt <- gsub("@CRAN_FLAGS@", .cran_flags, mv_txt) |>
+  gsub("@PROFILE@", .profile, x = _) |>
+  gsub("@CLEAN_TARGET@", .clean_targets, x = _) |>
+  gsub("@LIBDIR@", .libdir, x = _) |>
+  gsub("@TARGET@", .target, x = _) |>
+  gsub("@PANIC_EXPORTS@", .panic_exports, x = _)
+
+message("Writing `", mv_ofp, "`.")
+con <- file(mv_ofp, open = "wb")
+writeLines(new_txt, con, sep = "\n")
+close(con)
+
+message("`tools/config.R` has finished.")
diff --git a/crates/cir/tools/msrv.R b/crates/cir/tools/msrv.R
new file mode 100644
index 0000000..59a61ab
--- /dev/null
+++ b/crates/cir/tools/msrv.R
@@ -0,0 +1,116 @@
+# read the DESCRIPTION file
+desc <- read.dcf("DESCRIPTION")
+
+if (!"SystemRequirements" %in% colnames(desc)) {
+  fmt <- c(
+    "`SystemRequirements` not found in `DESCRIPTION`.",
+    "Please specify `SystemRequirements: Cargo (Rust's package manager), rustc`"
+  )
+  stop(paste(fmt, collapse = "\n"))
+}
+
+# extract system requirements
+sysreqs <- desc[, "SystemRequirements"]
+
+# check that cargo and rustc is found
+if (!grepl("cargo", sysreqs, ignore.case = TRUE)) {
+  stop("You must specify `Cargo (Rust's package manager)` in your `SystemRequirements`")
+}
+
+if (!grepl("rustc", sysreqs, ignore.case = TRUE)) {
+  stop("You must specify `Cargo (Rust's package manager), rustc` in your `SystemRequirements`")
+}
+
+# split into parts
+parts <- strsplit(sysreqs, ", ")[[1]]
+
+# identify which is the rustc
+rustc_ver <- parts[grepl("rustc", parts)]
+
+# perform checks for the presence of rustc and cargo on the OS
+no_cargo_msg <- c(
+  "----------------------- [CARGO NOT FOUND]--------------------------",
+  "The 'cargo' command was not found on the PATH. Please install Cargo",
+  "from: https://www.rust-lang.org/tools/install",
+  "",
+  "Alternatively, you may install Cargo from your OS package manager:",
+  " - Debian/Ubuntu: apt-get install cargo",
+  " - Fedora/CentOS: dnf install cargo",
+  " - macOS: brew install rust",
+  "-------------------------------------------------------------------"
+)
+
+no_rustc_msg <- c(
+  "----------------------- [RUST NOT FOUND]---------------------------",
+  "The 'rustc' compiler was not found on the PATH. Please install",
+  paste(rustc_ver, "or higher from:"),
+  "https://www.rust-lang.org/tools/install",
+  "",
+  "Alternatively, you may install Rust from your OS package manager:",
+  " - Debian/Ubuntu: apt-get install rustc",
+  " - Fedora/CentOS: dnf install rustc",
+  " - macOS: brew install rust",
+  "-------------------------------------------------------------------"
+)
+
+# Add {user}/.cargo/bin to path before checking
+new_path <- paste0(
+  Sys.getenv("PATH"),
+  ":",
+  paste0(Sys.getenv("HOME"), "/.cargo/bin")
+)
+
+# set the path with the new path
+Sys.setenv("PATH" = new_path)
+
+# check for rustc installation
+rustc_version <- tryCatch(
+  system("rustc --version", intern = TRUE),
+  error = function(e) {
+    stop(paste(no_rustc_msg, collapse = "\n"))
+  }
+)
+
+# check for cargo installation
+cargo_version <- tryCatch(
+  system("cargo --version", intern = TRUE),
+  error = function(e) {
+    stop(paste(no_cargo_msg, collapse = "\n"))
+  }
+)
+
+# helper function to extract versions
+extract_semver <- function(ver) {
+  if (grepl("\\d+\\.\\d+(\\.\\d+)?", ver)) {
+    sub(".*?(\\d+\\.\\d+(\\.\\d+)?).*", "\\1", ver)
+  } else {
+    NA
+  }
+}
+
+# get the MSRV
+msrv <- extract_semver(rustc_ver)
+
+# extract current version
+current_rust_version <- extract_semver(rustc_version)
+
+# perform check
+if (!is.na(msrv)) {
+  # -1 when current version is later
+  # 0 when they are the same
+  # 1 when MSRV is newer than current
+  is_msrv <- utils::compareVersion(msrv, current_rust_version)
+  if (is_msrv == 1) {
+    fmt <- paste0(
+      "\n------------------ [UNSUPPORTED RUST VERSION]------------------\n",
+      "- Minimum supported Rust version is %s.\n",
+      "- Installed Rust version is %s.\n",
+      "---------------------------------------------------------------"
+    )
+    stop(sprintf(fmt, msrv, current_rust_version))
+  }
+}
+
+# print the versions
+versions_fmt <- "Using %s\nUsing %s"
+message(sprintf(versions_fmt, cargo_version, rustc_version))