Resources

Everything you need to learn, connect, and run SESL: user guides, connection details, quickstart commands, FAQs, and release notes.

Documentation

Open the user guides directly from here.

SESL Overview - High-level introduction to SESL and its product capabilities

Open Product Overview

SESL Command Line Interface - CLI commands, online mode, and batch automation

Open CLI User Guide

SESL Language and Engine - Language syntax, rule structure, engine behaviour, and examples

Open Language User Guide

Connecting to SESL MCP

Connecting from OpenAI ChatGPT

Use the following API call to connect to SESL:

TBA

Quickstart

More details can be found in the User Guides above.

# Run a file
sesl rules.sesl

# Start an online session
sesl --online

# Run a batch job
sesl --batch model.sesl

# Show help without starting an online session
sesl --batch help

# Set a persistent variable
sesl --batch "options test=Testing123"
sesl --batch options
sesl --batch "options delete test"
sesl --batch options

FAQ

What is SESL?

SESL (Simple Expert System Language) is a deterministic, rule-based expert system. You express decisions as structured rules and scenarios, and SESL’s engine evaluates them the same way every time—no randomness and no hallucinations. It pairs readable models with an explainable rule trace so you can show exactly how each conclusion was reached.

What does SESL do?

SESL turns documents, policies, or business logic into executable rules that produce consistent answers. It supports forward-chaining evaluation, priorities, linting for safety, dependency graphs, and rich monitoring outputs. Typical uses include eligibility checks, compliance and policy enforcement, pricing and discounts, risk scoring, routing decisions, and any workflow where repeatable, auditable logic matters.

How does SESL differ from LLMs?

SESL is a deterministic rules engine: the same inputs always yield the same outputs, with a full explanation of which rules fired. Large Language Models generate probabilistic text and can hallucinate; SESL does not. You can pair SESL with LLMs (for example, to draft rules), but SESL is the source of truth for the decision logic and evidence trail.

Changelog

v0.0.1 — 2025-12-05: Initial public site release and documentation links.