AlexandrAI AGENTS.md
agents-md

AlexandrAI Tools Caesar Cipher Agent Guide

Agent guide for Caesar shift encoding, decoding, ROT13, case preservation, and non-letter passthrough.

AGENTS.md

Guidance for coding agents working on AlexandrAI Tools Caesar Cipher in the alexandrai-tools project.

Project overview

This guide covers src/tools/caesar-cipher/index.ts. The tool normalizes any shift into the zero through twenty-five range, shifts uppercase and lowercase ASCII letters independently, leaves non-letters unchanged, and exposes rot13 as Caesar shift thirteen.

Primary source files

  • src/tools/caesar-cipher/index.ts defines meta, caesar, and rot13.
  • src/tools/caesar-cipher/index.test.ts covers positive shifts, wrapping, ROT13, decode by inverse shift, non-letter passthrough, identity shifts, mixed case, negative shifts, and ROT13 round trips.
  • src/tools/caesar-cipher/Body.astro owns browser controls.
  • src/tools/caesar-cipher/i18n.ts owns localized copy.
  • src/lib/tools.ts registers metadata.

Setup commands

npm install npm test npm run typecheck npm run build npm run dev

Change rules

  • Normalize shifts with modulo twenty-six.
  • Keep uppercase letters in uppercase output.
  • Keep lowercase letters in lowercase output.
  • Leave non-letters unchanged.
  • Keep rot13 as caesar(text, 13).
  • Do not present Caesar or ROT13 as secure encryption.
  • If non-ASCII alphabets are added, keep current ASCII behavior tested.

Testing

Test wrapping, negative shifts, large shifts, shift zero, shift twenty-six, mixed case, punctuation, digits, spaces, ROT13 self-inverse behavior, and decode by inverse shift.

PR checklist

  • npm test passes for caesar-cipher.
  • Encoding, decoding, and failure behavior remain documented.
  • Browser-local processing and security limits stay clear in UI copy.
  • UI labels, metadata, and tests update together for behavior changes.