Fermi
PRE: Probabilistic Reasoning Engine for uncertainty quantification in agentic systems
synopsis
Fermi is a Probabilistic Reasoning Engine (PRE) designed to bring rigorous uncertainty quantification to agentic systems. Named after Enrico Fermi's approach to estimation under uncertainty, the engine provides a domain-specific language — the Forecasting Programming Language (FPL) — for expressing probabilistic models, defining confidence intervals, and composing Fermi-style estimations that decompose complex questions into tractable sub-problems with quantified uncertainty at every stage.
At its core, Fermi is the reasoning substrate that powers the Agent Bestiary's forecasting capabilities. Each agent in the bestiary uses FPL to structure its reasoning, calibrate its confidence, and produce evidence-weighted outputs. The engine handles distribution arithmetic, sensitivity analysis, gas-fee accounting for computational cost, and multi-model execution — enabling agents to reason probabilistically about everything from market dynamics to biological system behavior. Fermi transforms agents from black-box predictors into transparent, auditable reasoning machines.
key capabilities
architecture
related research
tags
FPL Language Spec
Complete language specification for the Forecasting Programming Language (FPL), including grammar, distribution primitives, composition operators, sensitivity directives, and gas-fee annotations. Reference implementation in Rust with examples covering common estimation patterns from market sizing to biological system modeling.