@imakeinternet/door-sdk

Write a BBS door game in JavaScript and run it locally — no board required.

The SDK + CLI from iMakeInternet for authoring doors — the small text games a bulletin board hands a player's terminal to. You write plain, synchronous code against a typed Host API; the runtime sandboxes it (quickjs-emscripten, deny-by-default — no fs, no net, no timers) and the gateway streams your ANSI to the player and feeds you their input.

Install

npm install -g @imakeinternet/door-sdk   # puts the `bbs-door` CLI on your PATH

Requires Node.js ≥ 20. Prefer no global install? Use npx @imakeinternet/door-sdk <command>.

Quick start

bbs-door new my-door     # scaffold ./my-door  (door.json + my-door.door.js)
bbs-door dev my-door     # play it in your terminal; hot-reloads on every save

new writes a runnable door you can edit immediately. dev runs it in the same sandbox a board uses, so what you see locally is exactly what players get — no board, no account, no network needed.

Write a door

A door is a folder with a *.door.js entry plus a door.json manifest. The entry default-exports door({ name, play }). Your play(ctx) runs synchronously — input reads look blocking because the host transparently suspends the sandbox while it waits. No async, no await, no promises.

// hello.door.js
import { door } from "@imakeinternet/door-sdk";

export default door({
  name: "Hello",
  summary: "The smallest possible door.",
  play(ctx) {
    ctx.screen.clear();
    ctx.screen.color("  Welcome!\r\n\r\n", "bold", "cyan");

    const name = ctx.input.line("  Your name? ");           // reads as if it blocks
    const pick = ctx.menu("Pick one", ["Gold", "Glory"]);   // returns the chosen index

    ctx.player.score = (ctx.player.score || 0) + (pick === 0 ? 10 : 5);
    ctx.player.save();                                       // persists per (player, door)

    ctx.screen.say(`\r\n  Nice to meet you, ${name}. Score: ${ctx.player.score}.`);
  },
});

A fuller example — menu loop, save, leaderboard, broadcast

The bundled examples/dice door: a menu loop, a numeric save field that feeds the world leaderboard, and a board-wide broadcast on a big win. (Math.random inside the sandbox is host-seeded, so games stay fair and reproducible.)

import { door } from "@imakeinternet/door-sdk";

const d6 = () => 1 + Math.floor(Math.random() * 6);

export default door({
  name: "High Roller",
  summary: "Roll against the house.",
  play(ctx) {
    ctx.player.wins = ctx.player.wins || 0;

    while (true) {
      ctx.screen.clear();
      ctx.screen.color("  H I G H   R O L L E R\r\n\r\n", "bold", "yellow");
      ctx.screen.say(`  Wins: ${ctx.player.wins}\r\n`);

      const choice = ctx.menu("What now?", ["Roll the dice", "Leaderboard", "Cash out"]);
      if (choice === 2) break;                              // Cash out

      if (choice === 1) {                                   // Leaderboard
        const top = ctx.world.leaderboard({ field: "wins", limit: 5 });
        top.forEach((row, i) => ctx.screen.say(`   ${i + 1}. ${row.handle} — ${row.score}`));
        ctx.input.key();                                    // "press any key"
        continue;
      }

      const you = d6() + d6();
      const house = d6() + d6();
      ctx.screen.say(`\r\n  You rolled ${you}; the house rolled ${house}.`);

      if (you > house) {
        ctx.player.wins += 1;
        ctx.player.save();
        ctx.screen.color("  You win!\r\n", "bold", "green");
        if (you === 12) ctx.world.broadcast(`${ctx.player.handle} rolled boxcars in High Roller!`);
      } else {
        ctx.screen.color("  The house takes it.\r\n", "red");
      }
      ctx.input.key();
    }
  },
});

The hello and dice examples ship inside the package (and live in the repo). With a local install you can play one straight away:

bbs-door dev node_modules/@imakeinternet/door-sdk/examples/dice

Types & editor support

Doors ship as .js, but the bundled .d.ts gives you full autocomplete and type-checking. door<S>() types ctx.player as your own save shape plus the read-only handle and save():

import { door } from "@imakeinternet/door-sdk";

type Save = { wins: number };

export default door<Save>({
  name: "High Roller",
  play(ctx) {
    ctx.player.wins ??= 0;        // typed as number
    ctx.player.save();            // ctx.player.handle is readonly
  },
});

The Host API (ctx)

Area	Methods
ctx.screen	write(text) · say(text?) · clear() · art(name) · color(text, …styles) · paint/sgr(…styles)
ctx.input	key() · line(prompt?) · number(prompt?, fallback?) · confirm(prompt?)
ctx.menu(prompt, options)	renders a lightbar; returns the chosen index (0-based)
ctx.player	your save blob + save() and a read-only handle
ctx.world	broadcast(text) (board-wide, rate-limited) · leaderboard({ field, limit }) → { handle, score }[]
conveniences	ctx.say · ctx.write · ctx.clear · ctx.log · ctx.door ({ slug, name, handle })

Styles for color / paint / sgr: bold dim underline reverse, the eight foreground colors (red green yellow blue magenta cyan white black) and their bg… background variants.

Limits enforced by the runtime + host: a per-turn CPU deadline, a memory cap, an output flood cap, a 16 KB save-blob cap, and broadcast rate limiting. A door that loops, floods, or crashes is killed without touching the gateway or other players.

The manifest (door.json)

{
  "slug": "my-door",          // required — ^[a-z0-9][a-z0-9-]*$, the folder + registry key
  "name": "My Door",          // required — display name
  "entry": "my-door.door.js", // optional — defaults to <slug>.door.js
  "summary": "One line.",     // optional — shown in listings
  "description": "Longer.",   // optional — store detail page
  "author": "you",            // optional
  "version": "1.0.0",         // semver — REQUIRED to publish
  "apiVersion": 1,            // Host API major — REQUIRED to publish (see below)
  "category": "rpg",          // optional — coarse store grouping
  "tags": ["lord", "rpg"],    // optional
  "license": "MIT",           // optional — SPDX id
  "homepage": "https://..."   // optional
}

The schema lives in door.schema.json (Draft-07) — point your editor at it for autocomplete and validation.

Host API version

apiVersion is the Host API major your door targets; this SDK exports the one it speaks as HOST_API_VERSION. A board refuses to launch a door whose major doesn't match — a clean "needs a board update" message instead of a mid-game crash. Build against the HOST_API_VERSION your SDK ships and you're compatible with any board on that major.

CLI reference

bbs-door new <name>         # scaffold a door folder (door.json + <slug>.door.js)
bbs-door dev <path>         # play locally with hot-reload (no board)
bbs-door validate <path>    # check the manifest + that the entry loads
bbs-door pack <path>        # build a distributable <slug>-<version>.door (+ sha256)
bbs-door publish <path>     # pack and upload to a catalog
bbs-door help

Command	Useful flags
dev	--handle <name> — play as a given handle (default devuser)
validate	--publish — also require version + apiVersion (store-publish rules)
pack	--out <dir> — where to write the .door (default: the door folder)
publish	--registry <url> (required) · --token <token> (or BBS_CATALOG_TOKEN) · --changelog <text>

Package & publish

bbs-door validate ./my-door --publish       # manifest + entry + version/apiVersion
bbs-door pack ./my-door                      # → my-door-1.0.0.door  (+ sha256)
bbs-door publish ./my-door \
  --registry https://your-board.example \
  --token "$BBS_CATALOG_TOKEN" \
  --changelog "First release"

A .door is a gzipped tar of the door's files (door.json, *.door.js, *.ans, README*) — the unit a board's door store installs. A sysop can install one directly (bbs:door:install my-door-1.0.0.door) or browse a store and install from there. The publish token is issued by the catalog operator; the CLI never prints it.

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Made by Mike Wojcik under the iMakeInternet brand · MIT licensed · Changelog