Bayesian Python Packages

arviz

Exploratory analysis of Bayesian models with Python

pyro-ppl

Deep universal probabilistic programming with Python and PyTorch

pydlm

A python library for Bayesian time series modeling

orbit-ml

A Python package for Bayesian forecasting with object-oriented design and probabilistic models under the hood.

lightweight-mmm

LightweightMMM 🦇 is a lightweight Bayesian Marketing Mix Modeling (MMM) library that allows users to easily train MMMs and obtain channel attribution information.

nested-fit

Bayesian data analysis code for evidence and probability distribution calculation based on nested sampling algorithm

gempy

GemPy is an open-source, Python-based 3-D structural geological modeling software, which allows the implicit (i.e. automatic) creation of complex geological models from interface and orientation data. It also offers support for stochastic modeling to address parameter and model uncertainties.

aelfrice

Bayesian memory that learns from feedback for LLM agents

changepoint

A toolkit for Bayesian change point detection

bsts-causalimpact

Bayesian CausalImpact for Python — R-compatible Gibbs sampler in Rust (PyO3), 30x faster, no TensorFlow

btrack

Bayesian multi-object tracking

pygpgo

Bayesian optimization for Python

posteriordb

Database with posteriors of interest for Bayesian inference

ipsos-credibility-interval

Calculate Bayesian credibility intervals for online polling using the Ipsos method

bocd

Bayesian Changepoint Detection

fastrvm

[fastrvm] Relevance Vector Machine in Python with a C++ core

argus-debate-ai

Debate-native multi-agent AI framework that eliminates LLM hallucination, overconfidence, and opacity. Structures knowledge evaluation as adversarial multi-round debates over a Conceptual Debate Graph (C-DAG) with Bayesian aggregation, CRUX protocol, 8 novel Evolution extensions, 27+ LLM providers, 50+ tools, and W3C-compliant provenance tracking.

lampe

Likelihood-free AMortized Posterior Estimation with PyTorch

brmspy

Python-first access to R’s brms with proper parameter names, ArviZ support, and cmdstanr performance. The easiest way to run brms models from Python.

clairvoyance-feature-selection

AutoML simultaneous bayesian hyperparameter optimization and feature selection

lirisimpact

IMPACT framework, an interpretable multi-target framework for ordinal outputs

bayesian-cage

Bayesian Cage

biolith

Bayesian Ecological Modeling in Python

nous-state

Probabilistic agent state layer. Bayesian belief tracking, surprise-driven updates, and delta logs for AI agents. Paper: arXiv:2606.22030