Tenor is a formal contract language for declaring provably correct business logic. You write a single .tenor file that specifies every entity, authority boundary, rule, and workflow in a domain. The evaluator computes deterministic verdicts and action spaces from that specification, and static analysis proves properties of your contracts before they ever run.

This documentation covers the open-source language and toolchain.

Documentation Sections

Getting Started

Install the CLI, write your first contract, and run the evaluator.

• Installation -- CLI and evaluator setup
• First Contract -- Write and evaluate a contract from scratch
• Evaluator -- How deterministic evaluation works

Language Reference

Complete reference for every construct in the Tenor language.

• Overview -- Language structure and concepts
• Symbols, Facts, Entities, Personas -- Data model primitives
• Rules, Operations, Flows -- Decision and workflow logic
• Types, Sources, Systems -- Type system, external data, system integration
• Parallel Composition -- Composing multiple contracts

Guides

Conceptual guides, tutorials, and deep dives.

• What Is Tenor? -- Conceptual introduction
• The Tenor Narrative -- Why Tenor exists and the problems it solves
• Author Guide -- How to write contracts effectively
• Minimal Kernel -- The smallest possible Tenor contract
• Migration Guide -- Migrating existing systems to Tenor
• Trust and Signing -- Cryptographic guarantees and contract integrity
• Source Declarations -- Connecting contracts to external data

SDKs

Client libraries for integrating Tenor into application code.

• Overview -- SDK design principles and common patterns
• TypeScript -- @tenor/sdk for Node.js and browser
• Python -- tenor-sdk for Python applications
• Go -- tenor-go for Go services

CLI Reference

All 26 commands in the tenor CLI with flags, options, and example output.

Reference

Configuration, error codes, static analysis checks, and executor obligations.

• Configuration -- .tenorrc, environment variables, project config
• Errors -- Error codes and diagnostic messages
• Static Analysis -- The eight formal checks (S1--S8)
• Executor Obligations -- What executors must guarantee

Domain Contracts

Six validated domain contracts demonstrating Tenor in production scenarios.

Specification

The full formal Tenor language specification.

Where to Start

New to Tenor? Begin with Getting Started. Install the CLI, write a contract, and see evaluation in action within minutes.

Writing contracts? Read the Author Guide for practical patterns, then use the Language Reference as you write.

Integrating with code? The SDK Overview covers client libraries for TypeScript, Python, and Go. Pick your language and start calling the evaluator from application code.

Open Source

The Tenor language, evaluator, CLI, and static analysis tools are open source. You can write contracts, evaluate them, and run static analysis entirely locally.