Wondermail

A JavaScript library for building and reading Wonder Mail passwords from Pokémon Mystery Dungeon: Red Rescue Team / Blue Rescue Team. Other Mystery Dungeon games are currently not supported, although I may choose to support them in the future. Wondermail is dependency-free except for an optional typechecker.

import { buildMission, REWARD_KINDS } from 'wondermail';

const mission = buildMission({
  missionType: 0, // Help me
  dungeon: 0, // Tiny Woods
  floor: 3,
  client: 25, // Pikachu
  reward: { kind: REWARD_KINDS.MONEY_ONLY }
});

mission.password; // "??JNS4+?4P6?2F?864?6P??W"
mission.mailTitle; // "Help!"
mission.mailBody; // ["I don't know how I did it, but I can't exit!", "I feel faint... Please help..."]

Passwords decode back the same way:

import { readMission } from 'wondermail';

readMission('??JNS4+?4P6?2F?864?6P??W');

Features

• No dependencies: the JavaScript ecosystem is not very good (to put it lightly), so I've written this package with no dependencies.
• Deterministic: all fields are generated deterministically, so the same inputs yield the same outputs every time. (Some other websites choose the flavor text randomly each time.)
• Proper rendering of the game's symbols (♂, ♀, …).
• Alphabetical sorting of mission rewards for convenience.

API

See src/index.js for the full surface. The short version:

• buildMission(input) to build a mission and get back { password, passwordDisplay, mailTitle, mailBody, reward, difficulty, ... }.
• readMission(password) decodes a password into the same shape.
• listDungeons(), listItems(), listPokemon(), listFriendAreas() are menu-ready option lists, already filtered down to what's actually legal (some ids in the raw game data are unused engine slots or alternate forms).
• encodePassword / decodePassword is the raw codec, if you already have a mission encoded as a 20-element array.

Testing

npm test

The test suite includes golden fixtures (known inputs -> known passwords) and round-trip checks. The codec and flavor-text logic were additionally cross-checked field-for-field against a reference implementation across thousands of randomized cases during development. Obviously, nothing replaces human testing and inputting the codes into the games yourself.

License

Wondermail is licensed under the MIT license.