# KPN++

A C++20 [Kahn Process Network](https://en.wikipedia.org/wiki/Kahn_process_networks) library. Each node wraps a plain function and runs concurrently, communicating with downstream nodes via bounded FIFO channels. Includes Python bindings via nanobind.

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## Why KPN++?

- **Zero boilerplate** — wrap any callable as a node; types flow automatically from the function signature
- **Bounded channels** — backpressure is structural, not bolted on
- **Observable** — per-node and network-level callbacks for overflow and stop events; diagnostics snapshots; optional web UI
- **Composable** — `Network` for runtime wiring, `StaticNetwork` for compile-time topology with zero overhead

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## Quick example

```cpp
#include <kpn/kpn.hpp>
using namespace kpn;

--8<-- "examples/01_hello_pipeline/main.cpp:basic_node_fns"

int main() {
--8<-- "examples/01_hello_pipeline/main.cpp:network_build"
}
```

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## Install & build

```bash
cmake -B build
cmake --build build --parallel
ctest --test-dir build          # unit tests + example smoke tests
```

See [Getting Started](getting-started.md) for full build options.