SCode

Hand-coding tools for classic ciphers — as an app, an API, and a library.

Encode and decode messages with Enigma, Morse, Polybius, Vigenère, Bacon, and more. Built for cryptography enthusiasts, learners, and developers who want to embed ciphers into their own projects.

Web app · API · Docs · npm

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What is SCode

SCode is a monorepo with four pieces that share one core:

Piece	What it is	Who it's for
web/	A React app for encoding/decoding in the browser.	Anyone curious about ciphers.
npm/	@zyther/scode-core — the cipher engine as a TypeScript library.	Developers embedding ciphers in JS/TS projects.
api/	A Next.js HTTP API wrapping the core.	Apps in any language that need ciphers over HTTP.
cli/	@zyther/scode-cli — the scd command-line tool.	Terminal users, shell scripts, CI pipelines.

Every cipher runs entirely client-side in the web app, and statelessly in the API. No accounts, no tracking, no data stored between requests.

Try it

• Web app → scode.zyther.dev
• API playground → api.scode.zyther.dev/docs
• Install the library → npm install @zyther/scode-core
• Install the CLI → npm install -g @zyther/scode-cli

Encode via API

curl -X POST https://api.scode.zyther.dev/api/encode \
  -H "Content-Type: application/json" \
  -d '{"message": "hello world", "pattern": "¬"}'

Encode via library

import { encode, decode, format_str } from "@zyther/scode-core"

const { encrypted, config, pattern } = encode({
  message: format_str("hello world"),
  pattern: "¬",       // Morse
})

const { message } = decode({ encrypted, pattern, config })
// → "HELLOWORLD"

Encode via CLI

scd encode "hello world" --pattern "¬"
# → -.-. .... . .-.. .-.. ---

The pattern system

What makes SCode different from "just another cipher library": ciphers compose.

A pattern is a string of cipher symbols applied in sequence. Chain them to layer encryption:

encode({ message: "meet me at dawn", pattern: "?|" })
//                                             ││
//                              Enigma ────────┘│
//                              Vigenère ───────┘

Patterns are applied right-to-left (last symbol = innermost encoding), so decoding reverses the order automatically. The response includes a config string with whatever parameters are needed to decode — pass it back verbatim.

Symbol	Cipher		Symbol	Cipher
$	SCSimply (key)		|	Vigenère
¢	SCSimply (key_m)		§	Frama
@	SCSimply (a_num)		₢	Bacon
¬	Morse		&	Mutation — reciprocity
£	Binary		~	Mutation — decalation
#	Polybius		:	Order — reverse
*	Navajo		°	Order — random
?	Enigma

Symbols @, *, # are restricted — they only work at the end of a pattern.

Repository structure

scode/
├── web/          React app (Vite + Tailwind)
├── npm/          @zyther/scode-core — the cipher engine
├── api/          Next.js HTTP wrapper around the core
├── cli/          @zyther/scode-cli — the `scd` command
└── ...

The core is the source of truth for every cipher. The web app and the API both consume it — no duplicated logic.

Tech stack

	Web	Core	API	CLI
Framework	React 18 + Vite	TypeScript	Next.js 15	commander
Styling	Tailwind	—	Tailwind	picocolors
Validation	—	—	Zod	—
Build	Vite	tsup	Next	tsup
Docs	—	—	Scalar (OpenAPI)	--help

Contributing

Contributions are welcome — new ciphers, docs, bug reports, anything.

1. Fork the repo
2. Create a branch (git checkout -b feat/my-cipher)
3. Commit your changes (git commit -m 'feat: add X cipher')
4. Push (git push origin feat/my-cipher)
5. Open a Pull Request

Please follow Conventional Commits.

License

MIT © Zyther Dev

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Built with ♥ for cryptography.