From e9254f11e3969063085e51afac68ee9e212c385d Mon Sep 17 00:00:00 2001
From: Ciaran Ryan-Anderson <ciaranra@gmail.com>
Date: Sat, 12 Jul 2025 13:44:11 -0600
Subject: [PATCH 1/6] Minimal Rust wrapper for PCG

---
 Cargo.lock                                    |  8 +++
 Cargo.toml                                    |  2 +
 .../tests/simple_determinism_test.rs          |  2 +-
 crates/pecos-clib-pcg/Cargo.toml              | 20 ++++++++
 crates/pecos-clib-pcg/README.md               | 33 ++++++++++++
 crates/pecos-clib-pcg/build.rs                | 29 +++++++++++
 crates/pecos-clib-pcg/src/lib.rs              | 51 +++++++++++++++++++
 crates/pecos/Cargo.toml                       |  1 +
 crates/pecos/src/prelude.rs                   |  6 +++
 python/pecos-rslib/rust/src/lib.rs            |  2 +
 python/pecos-rslib/rust/src/pcg_bindings.rs   | 49 ++++++++++++++++++
 .../src/pecos/engines/cvm/rng_model.py        |  9 +++-
 12 files changed, 209 insertions(+), 3 deletions(-)
 create mode 100644 crates/pecos-clib-pcg/Cargo.toml
 create mode 100644 crates/pecos-clib-pcg/README.md
 create mode 100644 crates/pecos-clib-pcg/build.rs
 create mode 100644 crates/pecos-clib-pcg/src/lib.rs
 create mode 100644 python/pecos-rslib/rust/src/pcg_bindings.rs

diff --git a/Cargo.lock b/Cargo.lock
index 7e2697500..86686d115 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1167,6 +1167,7 @@ name = "pecos"
 version = "0.1.1"
 dependencies = [
  "log",
+ "pecos-clib-pcg",
  "pecos-core",
  "pecos-engines",
  "pecos-phir",
@@ -1189,6 +1190,13 @@ dependencies = [
  "serde_json",
 ]
 
+[[package]]
+name = "pecos-clib-pcg"
+version = "0.1.1"
+dependencies = [
+ "cc",
+]
+
 [[package]]
 name = "pecos-core"
 version = "0.1.1"
diff --git a/Cargo.toml b/Cargo.toml
index 48ea11978..a64deadf9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -49,6 +49,7 @@ tempfile = "3"
 assert_cmd = "2"
 wasmtime = "33"
 serial_test = "3"
+cc = "1"
 
 pecos-core = { version = "0.1.1", path = "crates/pecos-core" }
 pecos-qsim = { version = "0.1.1", path = "crates/pecos-qsim" }
@@ -57,6 +58,7 @@ pecos-phir = { version = "0.1.1", path = "crates/pecos-phir" }
 pecos-engines = { version = "0.1.1", path = "crates/pecos-engines" }
 pecos-qir = { version = "0.1.1", path = "crates/pecos-qir" }
 pecos-qec = { version = "0.1.1", path = "crates/pecos-qec" }
+pecos-clib-pcg = { version = "0.1.1", path = "crates/pecos-clib-pcg" }
 pecos = { version = "0.1.1", path = "crates/pecos" }
 pecos-cli = { version = "0.1.1", path = "crates/pecos-cli" }
 pecos-rslib = { version = "0.1.1", path = "python/pecos-rslib/rust" }
diff --git a/crates/pecos-cli/tests/simple_determinism_test.rs b/crates/pecos-cli/tests/simple_determinism_test.rs
index e315e4aa5..f7330d3c7 100644
--- a/crates/pecos-cli/tests/simple_determinism_test.rs
+++ b/crates/pecos-cli/tests/simple_determinism_test.rs
@@ -254,7 +254,7 @@ fn test_noise_impact_on_determinism() -> Result<(), Box<dyn std::error::Error>>
 ///
 /// NOTE: Currently skipped as worker count determinism is an open issue in PECOS
 #[test]
-#[ignore]
+#[ignore = "worker count determinism is an open issue in PECOS"]
 fn test_worker_count_consistency() -> Result<(), Box<dyn std::error::Error>> {
     let manifest_dir = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
     let phir_path = manifest_dir.join("../../examples/phir/simple_test.json");
diff --git a/crates/pecos-clib-pcg/Cargo.toml b/crates/pecos-clib-pcg/Cargo.toml
new file mode 100644
index 000000000..efa86a6b1
--- /dev/null
+++ b/crates/pecos-clib-pcg/Cargo.toml
@@ -0,0 +1,20 @@
+[package]
+name = "pecos-clib-pcg"
+version.workspace = true
+edition.workspace = true
+authors.workspace = true
+homepage.workspace = true
+repository.workspace = true
+license.workspace = true
+keywords.workspace = true
+categories.workspace = true
+description = "PCG RNG C library wrapper for PECOS"
+readme = "README.md"
+
+[dependencies]
+
+[build-dependencies]
+cc.workspace = true
+
+[lints]
+workspace = true
diff --git a/crates/pecos-clib-pcg/README.md b/crates/pecos-clib-pcg/README.md
new file mode 100644
index 000000000..7d359a4e0
--- /dev/null
+++ b/crates/pecos-clib-pcg/README.md
@@ -0,0 +1,33 @@
+# pecos-clib-pcg
+
+Rust wrapper for the PCG C library used in PECOS.
+
+This crate provides safe Rust bindings to the PCG random number generator implementation in C.
+
+## Features
+
+- `pcg32_random()` - Generate a 32-bit random number
+- `pcg32_boundedrand(bound)` - Generate a random number in range [0, bound)
+- `pcg32_frandom()` - Generate a random floating-point number in [0, 1)
+- `pcg32_srandom(seed)` - Set the random seed
+
+## Usage
+
+This crate is primarily used internally by PECOS and exposed through the main `pecos` crate's prelude.
+
+```rust
+use pecos_clib_pcg::{random, boundedrand, frandom, srandom};
+
+// Set seed for reproducibility
+srandom(12345);
+
+// Generate random values
+let r1 = random();           // 32-bit random number
+let r2 = boundedrand(100);   // Random number in [0, 100)
+let r3 = frandom();          // Random float in [0, 1)
+```
+
+## Implementation
+
+This crate uses the `cc` build dependency to compile the existing C implementation from `clibs/pecos-rng/src/rng_pcg.c`
+and provides safe Rust wrappers around the unsafe FFI functions.
diff --git a/crates/pecos-clib-pcg/build.rs b/crates/pecos-clib-pcg/build.rs
new file mode 100644
index 000000000..e06496d1a
--- /dev/null
+++ b/crates/pecos-clib-pcg/build.rs
@@ -0,0 +1,29 @@
+use cc::Build;
+use std::env;
+use std::path::PathBuf;
+
+fn main() {
+    let clib_path = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap())
+        .parent()
+        .unwrap()
+        .parent()
+        .unwrap()
+        .join("clibs")
+        .join("pecos-rng");
+
+    let src_path = clib_path.join("src");
+
+    println!(
+        "cargo:rerun-if-changed={}",
+        src_path.join("rng_pcg.c").display()
+    );
+    println!(
+        "cargo:rerun-if-changed={}",
+        src_path.join("rng_pcg.h").display()
+    );
+
+    Build::new()
+        .file(src_path.join("rng_pcg.c"))
+        .include(&src_path)
+        .compile("pecos_pcg");
+}
diff --git a/crates/pecos-clib-pcg/src/lib.rs b/crates/pecos-clib-pcg/src/lib.rs
new file mode 100644
index 000000000..f44696de9
--- /dev/null
+++ b/crates/pecos-clib-pcg/src/lib.rs
@@ -0,0 +1,51 @@
+// FFI bindings to the C PCG library
+unsafe extern "C" {
+    fn pcg32_random() -> u32;
+    fn pcg32_boundedrand(bound: u32) -> u32;
+    fn pcg32_frandom() -> f64;
+    fn pcg32_srandom(seq: u64);
+}
+
+// Rust wrapper functions with safe interfaces
+#[must_use]
+pub fn random() -> u32 {
+    unsafe { pcg32_random() }
+}
+
+#[must_use]
+pub fn boundedrand(bound: u32) -> u32 {
+    unsafe { pcg32_boundedrand(bound) }
+}
+
+#[must_use]
+pub fn frandom() -> f64 {
+    unsafe { pcg32_frandom() }
+}
+
+pub fn srandom(seq: u64) {
+    unsafe { pcg32_srandom(seq) }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_pcg_functions() {
+        // Set seed
+        srandom(12345);
+
+        // Test basic random
+        let r1 = random();
+        assert!(r1 > 0);
+
+        // Test bounded random
+        let bound = 100;
+        let r2 = boundedrand(bound);
+        assert!(r2 < bound);
+
+        // Test float random
+        let r3 = frandom();
+        assert!((0.0..1.0).contains(&r3));
+    }
+}
diff --git a/crates/pecos/Cargo.toml b/crates/pecos/Cargo.toml
index 8f47df46c..8aa18be77 100644
--- a/crates/pecos/Cargo.toml
+++ b/crates/pecos/Cargo.toml
@@ -22,6 +22,7 @@ pecos-engines.workspace = true
 pecos-qasm.workspace = true
 pecos-phir.workspace = true
 pecos-qir.workspace = true
+pecos-clib-pcg.workspace = true
 log.workspace = true
 serde_json.workspace = true
 
diff --git a/crates/pecos/src/prelude.rs b/crates/pecos/src/prelude.rs
index 129de05da..cd15fed83 100644
--- a/crates/pecos/src/prelude.rs
+++ b/crates/pecos/src/prelude.rs
@@ -65,3 +65,9 @@ pub use pecos_qir::setup_qir_engine;
 
 // Re-export run_sim from pecos-engines
 pub use pecos_engines::run_sim;
+
+// Re-export PCG RNG functions
+pub use pecos_clib_pcg::{
+    boundedrand as pcg32_boundedrand, frandom as pcg32_frandom, random as pcg32_random,
+    srandom as pcg32_srandom,
+};
diff --git a/python/pecos-rslib/rust/src/lib.rs b/python/pecos-rslib/rust/src/lib.rs
index 41d5644d4..1afde6542 100644
--- a/python/pecos-rslib/rust/src/lib.rs
+++ b/python/pecos-rslib/rust/src/lib.rs
@@ -18,6 +18,7 @@
 
 mod byte_message_bindings;
 mod engine_bindings;
+mod pcg_bindings;
 pub mod phir_bridge;
 mod sparse_sim;
 mod sparse_stab_bindings;
@@ -43,5 +44,6 @@ fn _pecos_rslib(_py: Python<'_>, m: &Bound<'_, PyModule>) -> PyResult<()> {
     m.add_class::<PyByteMessageBuilder>()?;
     m.add_class::<PyStateVecEngine>()?;
     m.add_class::<PySparseStabEngine>()?;
+    pcg_bindings::create_pcg_module(m)?;
     Ok(())
 }
diff --git a/python/pecos-rslib/rust/src/pcg_bindings.rs b/python/pecos-rslib/rust/src/pcg_bindings.rs
new file mode 100644
index 000000000..04e977022
--- /dev/null
+++ b/python/pecos-rslib/rust/src/pcg_bindings.rs
@@ -0,0 +1,49 @@
+// Copyright 2025 The PECOS Developers
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+// in compliance with the License.You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software distributed under the License
+// is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+// or implied. See the License for the specific language governing permissions and limitations under
+// the License.
+
+use pecos::prelude::*;
+use pyo3::prelude::*;
+
+#[pyfunction]
+#[pyo3(name = "pcg32_random")]
+pub fn py_pcg32_random() -> u32 {
+    pcg32_random()
+}
+
+#[pyfunction]
+#[pyo3(name = "pcg32_boundedrand")]
+pub fn py_pcg32_boundedrand(bound: u32) -> u32 {
+    pcg32_boundedrand(bound)
+}
+
+#[pyfunction]
+#[pyo3(name = "pcg32_frandom")]
+pub fn py_pcg32_frandom() -> f64 {
+    pcg32_frandom()
+}
+
+#[pyfunction]
+#[pyo3(name = "pcg32_srandom")]
+pub fn py_pcg32_srandom(seq: u64) {
+    pcg32_srandom(seq);
+}
+
+/// Create a submodule for PCG functions
+pub fn create_pcg_module(m: &Bound<'_, PyModule>) -> PyResult<()> {
+    let pcg_module = PyModule::new(m.py(), "pcg")?;
+    pcg_module.add_function(wrap_pyfunction!(py_pcg32_random, &pcg_module)?)?;
+    pcg_module.add_function(wrap_pyfunction!(py_pcg32_boundedrand, &pcg_module)?)?;
+    pcg_module.add_function(wrap_pyfunction!(py_pcg32_frandom, &pcg_module)?)?;
+    pcg_module.add_function(wrap_pyfunction!(py_pcg32_srandom, &pcg_module)?)?;
+    m.add_submodule(&pcg_module)?;
+    Ok(())
+}
diff --git a/python/quantum-pecos/src/pecos/engines/cvm/rng_model.py b/python/quantum-pecos/src/pecos/engines/cvm/rng_model.py
index de760a639..dfd08a5cd 100644
--- a/python/quantum-pecos/src/pecos/engines/cvm/rng_model.py
+++ b/python/quantum-pecos/src/pecos/engines/cvm/rng_model.py
@@ -1,10 +1,15 @@
 """This Module is responsible for keeping track of the state for generating a sequence of random numbers.
 
-It handles RNG platform function calls that that are handled by the pcg_rng library.
+It handles RNG platform function calls that are handled by the pcg_rng library.
 
 """
 
-from pecos_pcg import pecos_rng
+from __future__ import annotations
+
+try:
+    from pecos_pcg import pecos_rng
+except ImportError:
+    from pecos_rslib._pecos_rslib import pcg as pecos_rng
 
 from pecos.engines.cvm.binarray import BinArray
 

From cfac02b76120f8d1d4afa37ad7eff81cafb4bc20 Mon Sep 17 00:00:00 2001
From: Ciaran Ryan-Anderson <ciaranra@gmail.com>
Date: Sat, 12 Jul 2025 13:45:54 -0600
Subject: [PATCH 2/6] Add TODO to the rng_model.py

---
 python/quantum-pecos/src/pecos/engines/cvm/rng_model.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/python/quantum-pecos/src/pecos/engines/cvm/rng_model.py b/python/quantum-pecos/src/pecos/engines/cvm/rng_model.py
index dfd08a5cd..028acc8e7 100644
--- a/python/quantum-pecos/src/pecos/engines/cvm/rng_model.py
+++ b/python/quantum-pecos/src/pecos/engines/cvm/rng_model.py
@@ -4,6 +4,8 @@
 
 """
 
+# TODO: A Rust version of this RNGModel should be created for Rust side usage and then exposed via pecos-rslib/PyO3
+
 from __future__ import annotations
 
 try:

From fdda8ea55a52c2bf908cd6542034754536a3bee7 Mon Sep 17 00:00:00 2001
From: Ciaran Ryan-Anderson <ciaranra@gmail.com>
Date: Sat, 12 Jul 2025 13:52:03 -0600
Subject: [PATCH 3/6] Renaming clibs/ to clib/ since a library is already a
 collection of things

---
 Makefile                                      | 38 +++++++++----------
 {clibs => clib}/pecos-rng/CMakeLists.txt      |  0
 {clibs => clib}/pecos-rng/README.md           |  0
 .../pecos-rng/pecos_pcg/__init__.py           |  0
 {clibs => clib}/pecos-rng/pyproject.toml      |  0
 {clibs => clib}/pecos-rng/src/rng_pcg.c       |  0
 {clibs => clib}/pecos-rng/src/rng_pcg.h       |  0
 {clibs => clib}/pecos-rng/src/wrapper.cpp     |  0
 crates/pecos-clib-pcg/README.md               |  2 +-
 crates/pecos-clib-pcg/build.rs                |  2 +-
 ruff.toml                                     |  2 +-
 11 files changed, 22 insertions(+), 22 deletions(-)
 rename {clibs => clib}/pecos-rng/CMakeLists.txt (100%)
 rename {clibs => clib}/pecos-rng/README.md (100%)
 rename {clibs => clib}/pecos-rng/pecos_pcg/__init__.py (100%)
 rename {clibs => clib}/pecos-rng/pyproject.toml (100%)
 rename {clibs => clib}/pecos-rng/src/rng_pcg.c (100%)
 rename {clibs => clib}/pecos-rng/src/rng_pcg.h (100%)
 rename {clibs => clib}/pecos-rng/src/wrapper.cpp (100%)

diff --git a/Makefile b/Makefile
index d94150ed7..144fdf4b0 100644
--- a/Makefile
+++ b/Makefile
@@ -23,7 +23,7 @@ installreqs: ## Install Python project requirements to root .venv
 buildrng:
 	@echo "Building and installing RNG library..."
 	uv pip install nanobind
-	cd clibs/pecos-rng && CC=gcc CXX=g++ uv pip install --python $(shell uv run which python) -e .
+	cd clib/pecos-rng && CC=gcc CXX=g++ uv pip install --python $(shell uv run which python) -e .
 
 # Building development environments
 # ---------------------------------
@@ -155,12 +155,12 @@ clean-unix:
 	@find . -type d -name "junit" -exec rm -rf {} +
 	@find python -name "*.so" -delete
 	@find python -name "*.pyd" -delete
-	@# Clean clibs build artifacts
-	@find clibs -type d -name "build" -exec rm -rf {} +
-	@find clibs -type d -name "dist" -exec rm -rf {} +
-	@find clibs -type d -name "*.egg-info" -exec rm -rf {} +
-	@find clibs -type d -name ".venv" -exec rm -rf {} +
-	@find clibs -name "uv.lock" -delete
+	@# Clean clib build artifacts
+	@find clib -type d -name "build" -exec rm -rf {} +
+	@find clib -type d -name "dist" -exec rm -rf {} +
+	@find clib -type d -name "*.egg-info" -exec rm -rf {} +
+	@find clib -type d -name ".venv" -exec rm -rf {} +
+	@find clib -name "uv.lock" -delete
 	@# Clean all target directories in crates (in case they were built independently)
 	@find crates -type d -name "target" -exec rm -rf {} +
 	@find python -type d -name "target" -exec rm -rf {} +
@@ -182,12 +182,12 @@ clean-windows-ps:
 	@powershell -Command "Get-ChildItem -Path . -Recurse -Directory -Filter '.hypothesis' | Remove-Item -Recurse -Force -ErrorAction SilentlyContinue"
 	@powershell -Command "Get-ChildItem -Path . -Recurse -Directory -Filter 'junit' | Remove-Item -Recurse -Force -ErrorAction SilentlyContinue"
 	@powershell -Command "Get-ChildItem -Path python -Recurse -File -Include '*.so','*.pyd' | Remove-Item -Force -ErrorAction SilentlyContinue"
-	@# Clean clibs build artifacts
-	@powershell -Command "Get-ChildItem -Path clibs -Recurse -Directory -Filter 'build' | Remove-Item -Recurse -Force -ErrorAction SilentlyContinue"
-	@powershell -Command "Get-ChildItem -Path clibs -Recurse -Directory -Filter 'dist' | Remove-Item -Recurse -Force -ErrorAction SilentlyContinue"
-	@powershell -Command "Get-ChildItem -Path clibs -Recurse -Directory -Filter '*.egg-info' | Remove-Item -Recurse -Force -ErrorAction SilentlyContinue"
-	@powershell -Command "Get-ChildItem -Path clibs -Recurse -Directory -Filter '.venv' | Remove-Item -Recurse -Force -ErrorAction SilentlyContinue"
-	@powershell -Command "Get-ChildItem -Path clibs -Recurse -File -Filter 'uv.lock' | Remove-Item -Force -ErrorAction SilentlyContinue"
+	@# Clean clib build artifacts
+	@powershell -Command "Get-ChildItem -Path clib -Recurse -Directory -Filter 'build' | Remove-Item -Recurse -Force -ErrorAction SilentlyContinue"
+	@powershell -Command "Get-ChildItem -Path clib -Recurse -Directory -Filter 'dist' | Remove-Item -Recurse -Force -ErrorAction SilentlyContinue"
+	@powershell -Command "Get-ChildItem -Path clib -Recurse -Directory -Filter '*.egg-info' | Remove-Item -Recurse -Force -ErrorAction SilentlyContinue"
+	@powershell -Command "Get-ChildItem -Path clib -Recurse -Directory -Filter '.venv' | Remove-Item -Recurse -Force -ErrorAction SilentlyContinue"
+	@powershell -Command "Get-ChildItem -Path clib -Recurse -File -Filter 'uv.lock' | Remove-Item -Force -ErrorAction SilentlyContinue"
 	@# Clean all target directories in crates
 	@powershell -Command "Get-ChildItem -Path crates -Recurse -Directory -Filter 'target' | Remove-Item -Recurse -Force -ErrorAction SilentlyContinue"
 	@powershell -Command "Get-ChildItem -Path python -Recurse -Directory -Filter 'target' | Remove-Item -Recurse -Force -ErrorAction SilentlyContinue"
@@ -208,12 +208,12 @@ clean-windows-cmd:
 	-@for /f "delims=" %%d in ('dir /s /b /ad .hypothesis 2^>nul') do @rd /s /q "%%d" 2>nul
 	-@for /f "delims=" %%d in ('dir /s /b /ad junit 2^>nul') do @rd /s /q "%%d" 2>nul
 	-@for /f "delims=" %%f in ('dir /s /b python\*.so python\*.pyd 2^>nul') do @del "%%f" 2>nul
-	-@REM Clean clibs build artifacts
-	-@for /f "delims=" %%d in ('dir /s /b /ad clibs\build 2^>nul') do @rd /s /q "%%d" 2>nul
-	-@for /f "delims=" %%d in ('dir /s /b /ad clibs\dist 2^>nul') do @rd /s /q "%%d" 2>nul
-	-@for /f "delims=" %%d in ('dir /s /b /ad clibs\*.egg-info 2^>nul') do @rd /s /q "%%d" 2>nul
-	-@for /f "delims=" %%d in ('dir /s /b /ad clibs\.venv 2^>nul') do @rd /s /q "%%d" 2>nul
-	-@for /f "delims=" %%f in ('dir /s /b clibs\uv.lock 2^>nul') do @del "%%f" 2>nul
+	-@REM Clean clib build artifacts
+	-@for /f "delims=" %%d in ('dir /s /b /ad clib\build 2^>nul') do @rd /s /q "%%d" 2>nul
+	-@for /f "delims=" %%d in ('dir /s /b /ad clib\dist 2^>nul') do @rd /s /q "%%d" 2>nul
+	-@for /f "delims=" %%d in ('dir /s /b /ad clib\*.egg-info 2^>nul') do @rd /s /q "%%d" 2>nul
+	-@for /f "delims=" %%d in ('dir /s /b /ad clib\.venv 2^>nul') do @rd /s /q "%%d" 2>nul
+	-@for /f "delims=" %%f in ('dir /s /b clib\uv.lock 2^>nul') do @del "%%f" 2>nul
 	-@REM Clean all target directories in crates
 	-@for /f "delims=" %%d in ('dir /s /b /ad crates\target 2^>nul') do @rd /s /q "%%d" 2>nul
 	-@for /f "delims=" %%d in ('dir /s /b /ad python\target 2^>nul') do @rd /s /q "%%d" 2>nul
diff --git a/clibs/pecos-rng/CMakeLists.txt b/clib/pecos-rng/CMakeLists.txt
similarity index 100%
rename from clibs/pecos-rng/CMakeLists.txt
rename to clib/pecos-rng/CMakeLists.txt
diff --git a/clibs/pecos-rng/README.md b/clib/pecos-rng/README.md
similarity index 100%
rename from clibs/pecos-rng/README.md
rename to clib/pecos-rng/README.md
diff --git a/clibs/pecos-rng/pecos_pcg/__init__.py b/clib/pecos-rng/pecos_pcg/__init__.py
similarity index 100%
rename from clibs/pecos-rng/pecos_pcg/__init__.py
rename to clib/pecos-rng/pecos_pcg/__init__.py
diff --git a/clibs/pecos-rng/pyproject.toml b/clib/pecos-rng/pyproject.toml
similarity index 100%
rename from clibs/pecos-rng/pyproject.toml
rename to clib/pecos-rng/pyproject.toml
diff --git a/clibs/pecos-rng/src/rng_pcg.c b/clib/pecos-rng/src/rng_pcg.c
similarity index 100%
rename from clibs/pecos-rng/src/rng_pcg.c
rename to clib/pecos-rng/src/rng_pcg.c
diff --git a/clibs/pecos-rng/src/rng_pcg.h b/clib/pecos-rng/src/rng_pcg.h
similarity index 100%
rename from clibs/pecos-rng/src/rng_pcg.h
rename to clib/pecos-rng/src/rng_pcg.h
diff --git a/clibs/pecos-rng/src/wrapper.cpp b/clib/pecos-rng/src/wrapper.cpp
similarity index 100%
rename from clibs/pecos-rng/src/wrapper.cpp
rename to clib/pecos-rng/src/wrapper.cpp
diff --git a/crates/pecos-clib-pcg/README.md b/crates/pecos-clib-pcg/README.md
index 7d359a4e0..dbed9a341 100644
--- a/crates/pecos-clib-pcg/README.md
+++ b/crates/pecos-clib-pcg/README.md
@@ -29,5 +29,5 @@ let r3 = frandom();          // Random float in [0, 1)
 
 ## Implementation
 
-This crate uses the `cc` build dependency to compile the existing C implementation from `clibs/pecos-rng/src/rng_pcg.c`
+This crate uses the `cc` build dependency to compile the existing C implementation from `clib/pecos-rng/src/rng_pcg.c`
 and provides safe Rust wrappers around the unsafe FFI functions.
diff --git a/crates/pecos-clib-pcg/build.rs b/crates/pecos-clib-pcg/build.rs
index e06496d1a..551a248f1 100644
--- a/crates/pecos-clib-pcg/build.rs
+++ b/crates/pecos-clib-pcg/build.rs
@@ -8,7 +8,7 @@ fn main() {
         .unwrap()
         .parent()
         .unwrap()
-        .join("clibs")
+        .join("clib")
         .join("pecos-rng");
 
     let src_path = clib_path.join("src");
diff --git a/ruff.toml b/ruff.toml
index 36fffc649..dab0d7f43 100644
--- a/ruff.toml
+++ b/ruff.toml
@@ -91,7 +91,7 @@ ignore = [
     "ANN",
     "D",
 ]
-"clibs/pecos-rng/pecos_pcg/__init__.py" = ["TID252"]
+"clib/pecos-rng/pecos_pcg/__init__.py" = ["TID252"]
 
 
 [lint.pycodestyle]

From 95a6ddbdf85ad7bcf8b9133aa2552f3f1ae7da84 Mon Sep 17 00:00:00 2001
From: Ciaran Ryan-Anderson <ciaranra@gmail.com>
Date: Sat, 12 Jul 2025 14:16:54 -0600
Subject: [PATCH 4/6] Fixing more clibs to clib references

---
 .github/workflows/python-release.yml | 4 ++--
 .github/workflows/python-test.yml    | 2 +-
 .gitignore                           | 4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/python-release.yml b/.github/workflows/python-release.yml
index be09eca8b..09ba7451d 100644
--- a/.github/workflows/python-release.yml
+++ b/.github/workflows/python-release.yml
@@ -204,7 +204,7 @@ jobs:
 
       - name: Build PECOS RNG
         run: |
-          cd clibs/pecos-rng && mkdir build && cd build/ && cmake ..
+          cd clib/pecos-rng && mkdir build && cd build/ && cmake ..
           make && cd .. && pip install .
         env:
             NANOBIND_DIR: python -m nanobind --include_dir
@@ -261,7 +261,7 @@ jobs:
 
       - name: Build PECOS RNG
         run: |
-          cd clibs/pecos-rng && mkdir build && cd build/ && cmake ..
+          cd clib/pecos-rng && mkdir build && cd build/ && cmake ..
           make && cd .. && pip install .
         env:
             NANOBIND_DIR: python -m nanobind --include_dir
diff --git a/.github/workflows/python-test.yml b/.github/workflows/python-test.yml
index b374ea298..f3515f73f 100644
--- a/.github/workflows/python-test.yml
+++ b/.github/workflows/python-test.yml
@@ -77,7 +77,7 @@ jobs:
       run: |
         export NANOBIND_CMAKE_DIR=$(uv run -- python -m nanobind --cmake_dir)
         export NANOBIND_DIR=$(uv run -- python -m nanobind --include_dir)
-        cd clibs/pecos-rng && mkdir build && cd build/ && cmake .. -DCMAKE_PREFIX_PATH=$NANOBIND_CMAKE_DIR
+        cd clib/pecos-rng && mkdir build && cd build/ && cmake .. -DCMAKE_PREFIX_PATH=$NANOBIND_CMAKE_DIR
         cmake --build . && cd ..
         uv pip install .
 
diff --git a/.gitignore b/.gitignore
index 147a22cfd..f68be8703 100644
--- a/.gitignore
+++ b/.gitignore
@@ -178,5 +178,5 @@ cython_debug/
 .idea/
 
 # Prevent subdirectory virtual environments
-clibs/*/.venv/
-clibs/*/uv.lock
+clib/*/.venv/
+clib/*/uv.lock

From ae26acfed0cbb5cc07f9d07a6ad96b739615e1a1 Mon Sep 17 00:00:00 2001
From: Ciaran Ryan-Anderson <ciaranra@gmail.com>
Date: Sat, 12 Jul 2025 14:20:20 -0600
Subject: [PATCH 5/6] Resolving maturin build failure due to not including C
 files for sdist

---
 python/pecos-rslib/pyproject.toml | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/python/pecos-rslib/pyproject.toml b/python/pecos-rslib/pyproject.toml
index 51cff5022..733ebe8f5 100644
--- a/python/pecos-rslib/pyproject.toml
+++ b/python/pecos-rslib/pyproject.toml
@@ -22,6 +22,11 @@ features = ["pyo3/extension-module"]
 python-source = "src"
 module-name = "pecos_rslib._pecos_rslib"
 manifest-path = "rust/Cargo.toml"
+sdist-include = [
+    "../../clib/**/*",
+    "../../crates/**/*",
+    "../../Cargo.toml",
+]
 
 [tool.uv.sources]
 pecos-rslib = { workspace = true }

From 2942c70d1a1b94d251eddec59ba77a20dc4b5b9f Mon Sep 17 00:00:00 2001
From: Ciaran Ryan-Anderson <ciaranra@gmail.com>
Date: Sat, 12 Jul 2025 15:52:12 -0600
Subject: [PATCH 6/6] Remove sdist building for pecos-rslib due to external C
 source issues. Users can just use the repo to build from source.

---
 .github/workflows/python-release.yml     |  57 +--
 Cargo.lock                               | 428 ++++++++++++++++++++++-
 crates/pecos-clib-pcg/Cargo.toml         |   1 +
 crates/pecos-clib-pcg/README.md          |   7 +-
 crates/pecos-clib-pcg/build.rs           |  56 ++-
 crates/pecos-clib-pcg/tests/pcg_tests.rs |  89 +++++
 python/pecos-rslib/pyproject.toml        |   5 -
 7 files changed, 559 insertions(+), 84 deletions(-)
 create mode 100644 crates/pecos-clib-pcg/tests/pcg_tests.rs

diff --git a/.github/workflows/python-release.yml b/.github/workflows/python-release.yml
index 09ba7451d..9f5cabe93 100644
--- a/.github/workflows/python-release.yml
+++ b/.github/workflows/python-release.yml
@@ -51,59 +51,6 @@ jobs:
             echo "run=false" >> $GITHUB_OUTPUT
           fi
 
-  build_sdist_pecos_rslib:
-    needs: check_pr_push
-    if: |
-      always() &&
-      (needs.check_pr_push.result == 'success' && needs.check_pr_push.outputs.run == 'true' || needs.check_pr_push.result == 'skipped') &&
-      (github.event_name != 'pull_request' || github.event.pull_request.merged == true || github.event.action == 'opened' || github.event.action == 'synchronize')
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          ref: ${{ inputs.sha || github.sha }}
-
-      - name: Set up Python
-        uses: actions/setup-python@v5
-        with:
-          python-version: ${{ env.PYTHON_VERSION }}
-
-      - name: Remove conflicting README.md
-        run: |
-          if [ -f crates/pecos-python/README.md ]; then
-            mv crates/pecos-python/README.md crates/pecos-python/README.md.bak
-            echo "Moved conflicting README.md to README.md.bak"
-          else
-            echo "No conflicting README.md found"
-          fi
-
-      - name: Build pecos-rslib SDist
-        uses: PyO3/maturin-action@v1
-        with:
-          command: sdist
-          args: --out dist
-          working-directory: python/pecos-rslib
-
-      - name: Restore README.md
-        if: always()
-        run: |
-          if [ -f crates/pecos-python/README.md.bak ]; then
-            mv crates/pecos-python/README.md.bak crates/pecos-python/README.md
-            echo "Restored README.md from backup"
-          else
-            echo "No README.md backup found"
-          fi
-
-      - name: Test pecos-rslib SDist
-        run: |
-          pip install --force-reinstall --verbose python/pecos-rslib/dist/*.tar.gz
-          python -c 'import pecos_rslib; print(pecos_rslib.__version__)'
-
-      - name: Upload pecos-rslib SDist
-        uses: actions/upload-artifact@v4
-        with:
-          name: sdist-pecos-rslib
-          path: python/pecos-rslib/dist/*.tar.gz
 
   build_wheels_pecos_rslib:
     needs: check_pr_push
@@ -173,7 +120,7 @@ jobs:
           path: python/pecos-rslib/dist/*.whl
 
   build_sdist_quantum_pecos:
-    needs: [check_pr_push, build_sdist_pecos_rslib, build_wheels_pecos_rslib]
+    needs: [check_pr_push, build_wheels_pecos_rslib]
     if: |
       always() &&
       (needs.check_pr_push.result == 'success' && needs.check_pr_push.outputs.run == 'true' || needs.check_pr_push.result == 'skipped') &&
@@ -226,7 +173,7 @@ jobs:
           path: python/quantum-pecos/dist/*.tar.gz
 
   build_wheels_quantum_pecos:
-    needs: [check_pr_push, build_wheels_pecos_rslib, build_sdist_quantum_pecos]
+    needs: [check_pr_push, build_wheels_pecos_rslib]
     if: |
       always() &&
       (needs.check_pr_push.result == 'success' && needs.check_pr_push.outputs.run == 'true' || needs.check_pr_push.result == 'skipped') &&
diff --git a/Cargo.lock b/Cargo.lock
index 86686d115..5db70821e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -11,6 +11,12 @@ dependencies = [
  "gimli",
 ]
 
+[[package]]
+name = "adler2"
+version = "2.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "320119579fcad9c21884f5c4861d16174d0e06250625266f50fe6898340abefa"
+
 [[package]]
 name = "aho-corasick"
 version = "1.1.3"
@@ -68,7 +74,7 @@ version = "1.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "79947af37f4177cfead1110013d678905c37501914fba0efea834c3fe9a8d60c"
 dependencies = [
- "windows-sys",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -79,7 +85,7 @@ checksum = "ca3534e77181a9cc07539ad51f2141fe32f6c3ffd4df76db8ad92346b003ae4e"
 dependencies = [
  "anstyle",
  "once_cell",
- "windows-sys",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -600,6 +606,17 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "displaydoc"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "97369cbbc041bc366949bc74d34658d6cda5621039731c6310521892a3a20ae0"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "doc-comment"
 version = "0.3.3"
@@ -675,7 +692,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "33d852cb9b869c2a9b3df2f71a3074817f01e1844f839a144f5fcef059a4eb5d"
 dependencies = [
  "libc",
- "windows-sys",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -690,12 +707,31 @@ version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "37909eebbb50d72f9059c3b6d82c0463f2ff062c9e95845c43a6c9c0355411be"
 
+[[package]]
+name = "flate2"
+version = "1.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4a3d7db9596fecd151c5f638c0ee5d5bd487b6e0ea232e5dc96d5250f6f94b1d"
+dependencies = [
+ "crc32fast",
+ "miniz_oxide",
+]
+
 [[package]]
 name = "foldhash"
 version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d9c4f5dac5e15c24eb999c26181a6ca40b39fe946cbe4c263c7209467bc83af2"
 
+[[package]]
+name = "form_urlencoded"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e13624c2627564efccf4934284bdd98cbaa14e79b0b5a141218e507b3a823456"
+dependencies = [
+ "percent-encoding",
+]
+
 [[package]]
 name = "funty"
 version = "2.0.0"
@@ -877,12 +913,119 @@ version = "2.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9a3a5bfb195931eeb336b2a7b4d761daec841b97f947d34394601737a7bba5e4"
 
+[[package]]
+name = "icu_collections"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "200072f5d0e3614556f94a9930d5dc3e0662a652823904c3a75dc3b0af7fee47"
+dependencies = [
+ "displaydoc",
+ "potential_utf",
+ "yoke",
+ "zerofrom",
+ "zerovec",
+]
+
+[[package]]
+name = "icu_locale_core"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0cde2700ccaed3872079a65fb1a78f6c0a36c91570f28755dda67bc8f7d9f00a"
+dependencies = [
+ "displaydoc",
+ "litemap",
+ "tinystr",
+ "writeable",
+ "zerovec",
+]
+
+[[package]]
+name = "icu_normalizer"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "436880e8e18df4d7bbc06d58432329d6458cc84531f7ac5f024e93deadb37979"
+dependencies = [
+ "displaydoc",
+ "icu_collections",
+ "icu_normalizer_data",
+ "icu_properties",
+ "icu_provider",
+ "smallvec",
+ "zerovec",
+]
+
+[[package]]
+name = "icu_normalizer_data"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "00210d6893afc98edb752b664b8890f0ef174c8adbb8d0be9710fa66fbbf72d3"
+
+[[package]]
+name = "icu_properties"
+version = "2.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "016c619c1eeb94efb86809b015c58f479963de65bdb6253345c1a1276f22e32b"
+dependencies = [
+ "displaydoc",
+ "icu_collections",
+ "icu_locale_core",
+ "icu_properties_data",
+ "icu_provider",
+ "potential_utf",
+ "zerotrie",
+ "zerovec",
+]
+
+[[package]]
+name = "icu_properties_data"
+version = "2.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "298459143998310acd25ffe6810ed544932242d3f07083eee1084d83a71bd632"
+
+[[package]]
+name = "icu_provider"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "03c80da27b5f4187909049ee2d72f276f0d9f99a42c306bd0131ecfe04d8e5af"
+dependencies = [
+ "displaydoc",
+ "icu_locale_core",
+ "stable_deref_trait",
+ "tinystr",
+ "writeable",
+ "yoke",
+ "zerofrom",
+ "zerotrie",
+ "zerovec",
+]
+
 [[package]]
 name = "id-arena"
 version = "2.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "25a2bc672d1148e28034f176e01fffebb08b35768468cc954630da77a1449005"
 
+[[package]]
+name = "idna"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "686f825264d630750a544639377bae737628043f20d38bbc029e8f29ea968a7e"
+dependencies = [
+ "idna_adapter",
+ "smallvec",
+ "utf8_iter",
+]
+
+[[package]]
+name = "idna_adapter"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3acae9609540aa318d1bc588455225fb2085b9ed0c4f6bd0d9d5bcd86f1a0344"
+dependencies = [
+ "icu_normalizer",
+ "icu_properties",
+]
+
 [[package]]
 name = "indexmap"
 version = "2.9.0"
@@ -1028,6 +1171,12 @@ version = "0.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cd945864f07fe9f5371a27ad7b52a172b4b499999f1d97574c9fa68373937e12"
 
+[[package]]
+name = "litemap"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "241eaef5fd12c88705a01fc1066c48c4b36e0dd4377dcdc7ec3942cea7a69956"
+
 [[package]]
 name = "lock_api"
 version = "0.4.12"
@@ -1077,6 +1226,15 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "miniz_oxide"
+version = "0.8.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1fa76a2c86f704bdb222d66965fb3d63269ce38518b83cb0575fca855ebb6316"
+dependencies = [
+ "adler2",
+]
+
 [[package]]
 name = "num-bigint"
 version = "0.4.6"
@@ -1195,6 +1353,7 @@ name = "pecos-clib-pcg"
 version = "0.1.1"
 dependencies = [
  "cc",
+ "ureq",
 ]
 
 [[package]]
@@ -1295,6 +1454,12 @@ dependencies = [
  "pyo3-build-config",
 ]
 
+[[package]]
+name = "percent-encoding"
+version = "2.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e3148f5046208a5d56bcfc03053e3ca6334e51da8dfb19b6cdc8b306fae3283e"
+
 [[package]]
 name = "pest"
 version = "2.8.0"
@@ -1404,6 +1569,15 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "potential_utf"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e5a7c30837279ca13e7c867e9e40053bc68740f988cb07f7ca6df43cc734b585"
+dependencies = [
+ "zerovec",
+]
+
 [[package]]
 name = "ppv-lite86"
 version = "0.2.20"
@@ -1670,6 +1844,20 @@ version = "0.8.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2b15c43186be67a4fd63bee50d0303afffcef381492ebe2c5d87f324e1b8815c"
 
+[[package]]
+name = "ring"
+version = "0.17.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4689e6c2294d81e88dc6261c768b63bc4fcdb852be6d1352498b114f61383b7"
+dependencies = [
+ "cc",
+ "cfg-if",
+ "getrandom 0.2.16",
+ "libc",
+ "untrusted",
+ "windows-sys 0.52.0",
+]
+
 [[package]]
 name = "rustc-demangle"
 version = "0.1.24"
@@ -1692,7 +1880,7 @@ dependencies = [
  "errno",
  "libc",
  "linux-raw-sys 0.4.15",
- "windows-sys",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -1705,7 +1893,42 @@ dependencies = [
  "errno",
  "libc",
  "linux-raw-sys 0.9.4",
- "windows-sys",
+ "windows-sys 0.59.0",
+]
+
+[[package]]
+name = "rustls"
+version = "0.23.29"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2491382039b29b9b11ff08b76ff6c97cf287671dbb74f0be44bda389fffe9bd1"
+dependencies = [
+ "log",
+ "once_cell",
+ "ring",
+ "rustls-pki-types",
+ "rustls-webpki",
+ "subtle",
+ "zeroize",
+]
+
+[[package]]
+name = "rustls-pki-types"
+version = "1.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "229a4a4c221013e7e1f1a043678c5cc39fe5171437c88fb47151a21e6f5b5c79"
+dependencies = [
+ "zeroize",
+]
+
+[[package]]
+name = "rustls-webpki"
+version = "0.103.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0a17884ae0c1b773f1ccd2bd4a8c72f16da897310a98b0e84bf349ad5ead92fc"
+dependencies = [
+ "ring",
+ "rustls-pki-types",
+ "untrusted",
 ]
 
 [[package]]
@@ -1878,6 +2101,12 @@ version = "0.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
 
+[[package]]
+name = "subtle"
+version = "2.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
+
 [[package]]
 name = "syn"
 version = "2.0.98"
@@ -1889,6 +2118,17 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "synstructure"
+version = "0.13.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "728a70f3dbaf5bab7f0c4b1ac8d7ae5ea60a4b5549c8a5914361c99147a709d2"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "tap"
 version = "1.0.1"
@@ -1912,7 +2152,7 @@ dependencies = [
  "getrandom 0.3.1",
  "once_cell",
  "rustix 0.38.44",
- "windows-sys",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -1970,6 +2210,16 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "tinystr"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5d4f6d1145dcb577acf783d4e601bc1d76a13337bb54e6233add580b07344c8b"
+dependencies = [
+ "displaydoc",
+ "zerovec",
+]
+
 [[package]]
 name = "tinytemplate"
 version = "1.2.1"
@@ -2068,6 +2318,45 @@ version = "0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7264e107f553ccae879d21fbea1d6724ac785e8c3bfc762137959b5802826ef3"
 
+[[package]]
+name = "untrusted"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ecb6da28b8a351d773b68d5825ac39017e680750f980f3a1a85cd8dd28a47c1"
+
+[[package]]
+name = "ureq"
+version = "2.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "02d1a66277ed75f640d608235660df48c8e3c19f3b4edb6a263315626cc3c01d"
+dependencies = [
+ "base64",
+ "flate2",
+ "log",
+ "once_cell",
+ "rustls",
+ "rustls-pki-types",
+ "url",
+ "webpki-roots 0.26.11",
+]
+
+[[package]]
+name = "url"
+version = "2.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32f8b686cadd1473f4bd0117a5d28d36b1ade384ea9b5069a1c40aefed7fda60"
+dependencies = [
+ "form_urlencoded",
+ "idna",
+ "percent-encoding",
+]
+
+[[package]]
+name = "utf8_iter"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6c140620e7ffbb22c2dee59cafe6084a59b5ffc27a8859a5f0d494b5d52b6be"
+
 [[package]]
 name = "utf8parse"
 version = "0.2.2"
@@ -2287,7 +2576,7 @@ dependencies = [
  "wasmtime-versioned-export-macros",
  "wasmtime-winch",
  "wat",
- "windows-sys",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -2315,7 +2604,7 @@ dependencies = [
  "serde_derive",
  "sha2",
  "toml",
- "windows-sys",
+ "windows-sys 0.59.0",
  "zstd",
 ]
 
@@ -2405,7 +2694,7 @@ dependencies = [
  "rustix 1.0.7",
  "wasmtime-asm-macros",
  "wasmtime-versioned-export-macros",
- "windows-sys",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -2429,7 +2718,7 @@ dependencies = [
  "anyhow",
  "cfg-if",
  "libc",
- "windows-sys",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -2519,6 +2808,24 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "webpki-roots"
+version = "0.26.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "521bc38abb08001b01866da9f51eb7c5d647a19260e00054a8c7fd5f9e57f7a9"
+dependencies = [
+ "webpki-roots 1.0.1",
+]
+
+[[package]]
+name = "webpki-roots"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8782dd5a41a24eed3a4f40b606249b3e236ca61adf1f25ea4d45c73de122b502"
+dependencies = [
+ "rustls-pki-types",
+]
+
 [[package]]
 name = "winapi"
 version = "0.3.9"
@@ -2541,7 +2848,7 @@ version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cf221c93e13a30d793f7645a0e7762c55d169dbb0a49671918a2319d289b10bb"
 dependencies = [
- "windows-sys",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -2569,6 +2876,15 @@ dependencies = [
  "wasmtime-environ",
 ]
 
+[[package]]
+name = "windows-sys"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+dependencies = [
+ "windows-targets",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.59.0"
@@ -2678,6 +2994,12 @@ dependencies = [
  "wasmparser 0.229.0",
 ]
 
+[[package]]
+name = "writeable"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ea2f10b9bb0928dfb1b42b65e1f9e36f7f54dbdf08457afefb38afcdec4fa2bb"
+
 [[package]]
 name = "wyz"
 version = "0.5.1"
@@ -2687,6 +3009,30 @@ dependencies = [
  "tap",
 ]
 
+[[package]]
+name = "yoke"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f41bb01b8226ef4bfd589436a297c53d118f65921786300e427be8d487695cc"
+dependencies = [
+ "serde",
+ "stable_deref_trait",
+ "yoke-derive",
+ "zerofrom",
+]
+
+[[package]]
+name = "yoke-derive"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "38da3c9736e16c5d3c8c597a9aaa5d1fa565d0532ae05e27c24aa62fb32c0ab6"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+ "synstructure",
+]
+
 [[package]]
 name = "zerocopy"
 version = "0.7.35"
@@ -2728,6 +3074,66 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "zerofrom"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "50cc42e0333e05660c3587f3bf9d0478688e15d870fab3346451ce7f8c9fbea5"
+dependencies = [
+ "zerofrom-derive",
+]
+
+[[package]]
+name = "zerofrom-derive"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d71e5d6e06ab090c67b5e44993ec16b72dcbaabc526db883a360057678b48502"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+ "synstructure",
+]
+
+[[package]]
+name = "zeroize"
+version = "1.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ced3678a2879b30306d323f4542626697a464a97c0a07c9aebf7ebca65cd4dde"
+
+[[package]]
+name = "zerotrie"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "36f0bbd478583f79edad978b407914f61b2972f5af6fa089686016be8f9af595"
+dependencies = [
+ "displaydoc",
+ "yoke",
+ "zerofrom",
+]
+
+[[package]]
+name = "zerovec"
+version = "0.11.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4a05eb080e015ba39cc9e23bbe5e7fb04d5fb040350f99f34e338d5fdd294428"
+dependencies = [
+ "yoke",
+ "zerofrom",
+ "zerovec-derive",
+]
+
+[[package]]
+name = "zerovec-derive"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b96237efa0c878c64bd89c436f661be4e46b2f3eff1ebb976f7ef2321d2f58f"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "zstd"
 version = "0.13.3"
diff --git a/crates/pecos-clib-pcg/Cargo.toml b/crates/pecos-clib-pcg/Cargo.toml
index efa86a6b1..6bda9b5b6 100644
--- a/crates/pecos-clib-pcg/Cargo.toml
+++ b/crates/pecos-clib-pcg/Cargo.toml
@@ -15,6 +15,7 @@ readme = "README.md"
 
 [build-dependencies]
 cc.workspace = true
+ureq = "2.9"
 
 [lints]
 workspace = true
diff --git a/crates/pecos-clib-pcg/README.md b/crates/pecos-clib-pcg/README.md
index dbed9a341..868c39dbf 100644
--- a/crates/pecos-clib-pcg/README.md
+++ b/crates/pecos-clib-pcg/README.md
@@ -29,5 +29,8 @@ let r3 = frandom();          // Random float in [0, 1)
 
 ## Implementation
 
-This crate uses the `cc` build dependency to compile the existing C implementation from `clib/pecos-rng/src/rng_pcg.c`
-and provides safe Rust wrappers around the unsafe FFI functions.
+This crate uses the `cc` build dependency to compile the C implementation of PCG32 (64-bit state, 32-bit output).
+When building from the PECOS workspace, it uses the local C source files. When used as a dependency from crates.io,
+it automatically downloads the C source files from the PECOS GitHub repository.
+
+The PCG implementation is based on the work by Melissa E. O'Neill. For more information, visit http://www.pcg-random.org
diff --git a/crates/pecos-clib-pcg/build.rs b/crates/pecos-clib-pcg/build.rs
index 551a248f1..7bf049bd1 100644
--- a/crates/pecos-clib-pcg/build.rs
+++ b/crates/pecos-clib-pcg/build.rs
@@ -1,9 +1,15 @@
 use cc::Build;
 use std::env;
-use std::path::PathBuf;
+use std::fs;
+use std::path::{Path, PathBuf};
 
+// TODO: Should probably just vendor the C code into the Rust crate...
 fn main() {
-    let clib_path = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap())
+    let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
+    let manifest_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
+
+    // Try local path first (for development)
+    let local_clib_path = manifest_dir
         .parent()
         .unwrap()
         .parent()
@@ -11,19 +17,47 @@ fn main() {
         .join("clib")
         .join("pecos-rng");
 
-    let src_path = clib_path.join("src");
+    let src_path = if local_clib_path.exists() {
+        // Development: use local files
+        let src = local_clib_path.join("src");
+        println!("cargo:rerun-if-changed={}", src.join("rng_pcg.c").display());
+        println!("cargo:rerun-if-changed={}", src.join("rng_pcg.h").display());
+        src
+    } else {
+        // Published crate: download from GitHub
+        let pcg_dir = out_dir.join("pcg");
+        fs::create_dir_all(&pcg_dir).unwrap();
+
+        let commit = "95a6ddbdf85ad7bcf8b9133aa2552f3f1ae7da84";
+        let base_url = format!(
+            "https://raw.githubusercontent.com/PECOS-packages/PECOS/{commit}/clib/pecos-rng/src"
+        );
 
-    println!(
-        "cargo:rerun-if-changed={}",
-        src_path.join("rng_pcg.c").display()
-    );
-    println!(
-        "cargo:rerun-if-changed={}",
-        src_path.join("rng_pcg.h").display()
-    );
+        // Download files if they don't exist
+        download_if_needed(&pcg_dir.join("rng_pcg.c"), &format!("{base_url}/rng_pcg.c"));
+        download_if_needed(&pcg_dir.join("rng_pcg.h"), &format!("{base_url}/rng_pcg.h"));
+
+        pcg_dir
+    };
 
     Build::new()
         .file(src_path.join("rng_pcg.c"))
         .include(&src_path)
         .compile("pecos_pcg");
 }
+
+fn download_if_needed(path: &Path, url: &str) {
+    if !path.exists() {
+        println!("cargo:warning=Downloading {} to {}", url, path.display());
+
+        let response = ureq::get(url)
+            .call()
+            .unwrap_or_else(|e| panic!("Failed to download {url}: {e}"));
+
+        let mut file = fs::File::create(path)
+            .unwrap_or_else(|e| panic!("Failed to create {}: {}", path.display(), e));
+
+        std::io::copy(&mut response.into_reader(), &mut file)
+            .unwrap_or_else(|e| panic!("Failed to write {}: {}", path.display(), e));
+    }
+}
diff --git a/crates/pecos-clib-pcg/tests/pcg_tests.rs b/crates/pecos-clib-pcg/tests/pcg_tests.rs
new file mode 100644
index 000000000..f687ef5b3
--- /dev/null
+++ b/crates/pecos-clib-pcg/tests/pcg_tests.rs
@@ -0,0 +1,89 @@
+use pecos_clib_pcg::{boundedrand, frandom, random, srandom};
+
+#[test]
+fn test_pcg_random_generates_values() {
+    // Test that random() generates different values
+    let val1 = random();
+    let val2 = random();
+
+    // It's extremely unlikely that two consecutive calls return the same value
+    // (probability is 1 in 2^32)
+    assert_ne!(
+        val1, val2,
+        "Two consecutive random() calls should generate different values"
+    );
+}
+
+#[test]
+fn test_pcg_bounded_random() {
+    // Test bounded random with various bounds
+    let bounds = [1, 2, 10, 100, 1000];
+
+    for bound in bounds {
+        for _ in 0..10 {
+            let val = boundedrand(bound);
+            assert!(
+                val < bound,
+                "boundedrand({bound}) returned {val}, which is >= {bound}"
+            );
+        }
+    }
+}
+
+#[test]
+fn test_pcg_frandom_range() {
+    // Test that frandom returns values in [0.0, 1.0)
+    for _ in 0..100 {
+        let val = frandom();
+        assert!(val >= 0.0, "frandom() returned {val}, which is < 0.0");
+        assert!(val < 1.0, "frandom() returned {val}, which is >= 1.0");
+    }
+}
+
+#[test]
+fn test_pcg_seeding() {
+    // Test that seeding produces deterministic sequences
+    // Note: PCG uses global state, so we test determinism directly
+
+    // Test that the same seed produces the same first few values
+    srandom(12345);
+    let first_val_1 = random();
+    let second_val_1 = random();
+
+    srandom(12345);
+    let first_val_2 = random();
+    let second_val_2 = random();
+
+    assert_eq!(
+        first_val_1, first_val_2,
+        "First value after seeding should be deterministic"
+    );
+    assert_eq!(
+        second_val_1, second_val_2,
+        "Second value after seeding should be deterministic"
+    );
+
+    // Test that different seeds produce different values
+    srandom(54321);
+    let different_first = random();
+
+    assert_ne!(
+        first_val_1, different_first,
+        "Different seeds should produce different values"
+    );
+}
+
+#[test]
+fn test_pcg_deterministic_behavior() {
+    // Test that the RNG is deterministic after seeding
+    srandom(999);
+    let first_value = random();
+
+    srandom(999);
+    let second_value = random();
+
+    assert_eq!(
+        first_value, second_value,
+        "First value after seeding should be deterministic"
+    );
+}
diff --git a/python/pecos-rslib/pyproject.toml b/python/pecos-rslib/pyproject.toml
index 733ebe8f5..51cff5022 100644
--- a/python/pecos-rslib/pyproject.toml
+++ b/python/pecos-rslib/pyproject.toml
@@ -22,11 +22,6 @@ features = ["pyo3/extension-module"]
 python-source = "src"
 module-name = "pecos_rslib._pecos_rslib"
 manifest-path = "rust/Cargo.toml"
-sdist-include = [
-    "../../clib/**/*",
-    "../../crates/**/*",
-    "../../Cargo.toml",
-]
 
 [tool.uv.sources]
 pecos-rslib = { workspace = true }