# dealcode

> Collision-free, random-looking codes from a counter — FF1 format-preserving
> encryption (NIST SP 800-38G) with one normative spec and seven bit-identical
> implementations: Python, TypeScript/JavaScript, Go, Java, Rust, C, C++.
> Same key + config produces the same code in every language. Not encryption
> for secrecy; codes are not auth tokens.

Everything in one file: https://algorix-hq.github.io/dealcode/llms-full.txt

## Docs

- [Getting started](https://algorix-hq.github.io/dealcode/getting-started/):
  install + quickstart in all seven languages
- [Configuration](https://algorix-hq.github.io/dealcode/guide/configuration/):
  alphabets, domains, lengths, key rules, the frozen-config rule, and the
  fixed-length cycling mode
- [Database integration](https://algorix-hq.github.io/dealcode/guide/database/):
  sequence → encode → UNIQUE tripwire; decode is parsing, not proof of
  existence
- [Security model](https://algorix-hq.github.io/dealcode/guide/security/):
  what the key does and doesn't protect

## Reference

- [Specification (normative)](https://raw.githubusercontent.com/algorix-hq/dealcode/main/SPEC.md):
  format v1 + the v1c cycling mode, exact algorithms and constraints
- [Test vectors](https://github.com/algorix-hq/dealcode/tree/main/testvectors):
  NIST FF1 samples + cross-language conformance vectors

## Optional

- Agent skill for coding assistants: `npx skills add algorix-hq/dealcode`
  (installs the `using-dealcode` usage rules)

- [Why dealcode exists](https://algorix-hq.github.io/dealcode/philosophy/)
- [Design decisions](https://algorix-hq.github.io/dealcode/design/)
- [Contributing](https://raw.githubusercontent.com/algorix-hq/dealcode/main/CONTRIBUTING.md)