A fast, general-purpose C++ framework for agent-based epidemiological simulation.

⚡ 150M+ agent·day/sec 📦 Header-only 🧬 Multi-pathogen 🌐 Network-aware

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C++

Freely available on GitHub, including the single header.

R

Available both on GitHub and the Comprehensive R Archive Network (CRAN).

Try It Live

Edit the code below and click ▶ Run to compile and execute it in your browser via Compiler Explorer. No local setup needed!

🧪 Interactive Example ↺ Reset ▶ Run

#include "epiworld.hpp" using namespace epiworld; int main() { // epiworld already comes with a couple // of models, like the SIR epimodels::ModelSIR<> hello( "COVID-19", // Name of the virus 0.01, // Initial prevalence 0.1, // Transmission probability 0.3 // Recovery probability ); // We can simulate agents using a small-world network // with 10,000 individuals, in this case hello.agents_smallworld(10'000, 10, false, 0.01); // Running the model and printing the results // Setting the number of days (100) and seed (122) hello.run(100, 122); hello.print(); }

Output

⚡

Lightning Fast

Over 150 million agent × day simulations per second — built for large-scale studies without sacrificing speed.

🧩

Fully Flexible

Define arbitrary states, viruses, tools, and update rules. Build the exact model you need from composable primitives.

📦

Header-Only

Single-file include with zero external dependencies — just the C++ standard library. Drop it in and go.

🌐

Network-Aware

Simulations run on contact networks with configurable topologies including small-world, scale-free, and custom graphs.

🧬

Multi-Pathogen

Multiple viruses and tools can coexist in one simulation with independent transmission and recovery dynamics.

📊

Rich Analytics

Built-in data collection, reproductive number tracking, generation intervals, and likelihood-free inference (LFMCMC).

Documentation Sections

• Models

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  Browse all built-in compartmental models: SIR, SEIR, SIS, connected population variants, mixing models, and disease-specific models.

  View models

• Examples

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  Explore ready-to-run examples — from a basic Hello World to likelihood-free MCMC — each with an interactive Compiler Explorer playground.

  Browse examples

• Implementation

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  Deep dives into library architecture, performance optimization, extending the library, queueing system, and more.

  Learn more

• API Reference

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  Complete class and function reference generated from the source code via Doxygen.

  API docs

Source Code

The epiworld source code is hosted at UofUEpiBio/epiworld on GitHub.