NPCs that hold grudges. Ghosts that get lonely. JSON files with anxiety.

You write this:

{
  "essence": "Lonely ghost",
  "dialogue": {
    "intro": [{ "lang": { "en": "Why am I alone?" } }]
  }
}

Result:

• Ghost spawns ✅
• Ghost speaks its dialogue ✅
• Ghost gets lonelier over time ✅
• Ghost eventually fades away ✅

You wrote zero code.

Yeah. In any language you want.

{
  "dialogue": {
    "intro": [{
      "lang": {
        "en": "You see me, but do you remember me?",
        "th": "เธอเห็นฉัน... แต่เธอจำฉันได้ไหม?",
        "ja": "見えているのか…それとも、思い出しているのか？"
      }
    }]
  }
}

It auto-detects browser language. Falls back to English. No translation library needed.

{
  "emotion": {
    "transitions": [
      {
        "trigger": "player.attack",
        "to": "anger",
        "intensity": 0.9
      }
    ]
  },
  "dialogue": {
    "onPlayerAttack": [{
      "lang": { "en": "So you strike your own shadow?" }
    }]
  }
}

What happens:

1. Player attacks
2. Entity gets angry (emotion.valence = -0.54)
3. Entity says the dialogue
4. Entity remembers being attacked

Forever.

Start here: 3-Minute Overview

npm install @v1b3x0r/mds-core

Or CDN (no install):

<script type="module">
  import { World } from 'https://esm.sh/@v1b3x0r/mds-core'
</script>

if (player.near(npc)) {
  if (npc.remembers(player)) {
    if (player.attackedBefore) {
      npc.mood = "angry"
      npc.say(getAngryDialogue(npc.language))
    }
  }
}

Next chapter? NPC forgot everything.

{
  "essence": "NPC who remembers violence",
  "emotion": {
    "transitions": [
      { "trigger": "player.attack", "to": "anger" }
    ]
  },
  "dialogue": {
    "onPlayerClose": [{
      "lang": { "en": "I remember what you did." }
    }]
  }
}

Next chapter? NPC still remembers. Forever.

See heroblind.mdm — a fully functional entity with:

• ✅ Multilingual dialogue (EN, TH, JA, ES, ZH)
• ✅ Emotion triggers (anger, curiosity, fear)
• ✅ Self-monologue (internal thoughts)
• ✅ Event-driven responses
• ✅ Memory of interactions

277 lines of JSON. Zero code.

Ages 12+ | Minecraft players | Students | Artists | Game devs | Researchers

You don't need to code. Just describe what something IS, and behavior emerges.

When you describe an entity, you automatically get:

🧠 Memory

• Entities remember interactions
• Memories decay over time (Ebbinghaus curve)
• Important events stick longer

💚 Emotion

• PAD model (Pleasure, Arousal, Dominance)
• Emotional contagion (entities affect each other)
• Trigger-based transitions

💬 Dialogue

• Multilingual support (any language)
• Event-driven phrases
• Auto-detects user language

🎓 Learning

• Entities learn from rewards
• Skills improve with practice
• Q-learning built-in

🌍 Physics

• Entities move based on similarity
• Info-physics (meaning creates gravity)
• Environmental effects

💾 Save/Load

• Full world state serialization
• Memories survive page refresh
• Deterministic replay

• 📖 3-Minute Overview
• 📚 Full Documentation
• 💻 API Reference
• 🤯 Philosophy
• 💬 Discussions
• 🐛 Issues

"I wanted NPCs that remember I quicksaved before killing them. Now they do."

Made in Chiang Mai, Thailand 🇹🇭 | MIT License