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MarrowMyth · Norse Reference Engine
THE WORLDENGINE
Powered by Materia
VERSION 1.00
Try:
Pick a focus: the first three give you accurate, sourced reference. Ask Calder lets you talk with the character himself, fully in his voice.
Enter World—
Vol75
Hurt—
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Heal—
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Rest—
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Safe—
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Button Hover—
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Narrator Message—
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Background Music—
Vol40
Ambient Sound—
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Haven Music—
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Title / Hub Music—
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Text Size100%
Response
Typewriter
Auto-Compress Memory
When a story gets long (about 55,000 tokens), the app automatically condenses the older part of the story into a summary, so the narrator stops forgetting details and contradicting itself. Your visible chat history does not change — only the narrator’s hidden working memory is shortened, and it happens quietly with no pop-ups. On: this is done for you automatically. Off: you must press the Compress button yourself when the token warning appears.
Fullscreen
Your API key is stored locally in your browser and never transmitted to our servers.
The Norse Codex is a working reference tool for the history, mythology, and language of the Norse and the wider Viking Age. It is built for accuracy first: it marks what is attested in the sources, what is debated among scholars, and what is modern invention — and it will tell you when the record is simply silent rather than invent an answer.
It is not a game, a story engine, or a roleplay world. It is a specialist you can consult — and, when you choose, a Viking you can speak to directly.
Getting Started
Assistance Prompt
Describe what you are working on — a novel, a role, an essay, a translation. The Codex keeps it as context and tailors its depth and examples to it. You can also leave it blank and simply ask questions.
Focus
Pick what the Codex specializes in. The first three are rigorous reference: Norse History (real societies, raiding, trade, daily life), Norse Mythology (the gods, the cosmology, the myths and where they are attested), and Norse Language (Old Norse and the runes — pronunciation, meaning, grammar, transliteration). Ask Calder is different — see below. Your focus stays on for every question until you change it, and you can change it any time, even in the middle of a session.
API Key
The Codex runs on an AI model you supply. Paste your own key (Grok, OpenAI, or Gemini) in Settings. Your key stays in your browser and is sent only to the provider you choose.
Inside a Session
Asking
Type any question and send it. Answers lead with the direct answer, then the evidence, then the caveats — citing the actual sources (the Eddas, a named saga, a runic inscription, archaeology) wherever it matters.
Topic Buttons
The row of subjects — Every Day Life, War, Hierarchy, Law, Religion, Art, Culture, Family, Love, Curses & Insults, Compliments, Trauma, Trade, Agriculture, Food — each aim the answer at one subject. Press one on its own for an in-depth lesson on that topic, or type a question first and press a topic to ask about that subject only. They do not change your standing focus.
Highlights
Select any text in an answer and a Highlight button appears — click it to save that passage to the Highlights panel. Highlights stay with the session and can be exported.
Images
The Images panel pulls relevant pictures as you go — artifacts, runestones, manuscripts — and an “Open in Google Images” button opens a full web search for the current topic.
My Notebook
A private notepad for your own notes. The model never sees it. Kept with the session and exportable.
Continue · Save · Load · Export · Compress
Continue elaborates on the last answer with no new question. Save and Load keep your whole Codex (every session) as a file. Export saves a single session as plain text. Compress condenses a long session’s memory so it stays fast and your costs stay low.
Ask Calder
Choose this focus to speak directly with Calder Coldwater — a Norse raider and father living through the Fimbulwinter, the long winter before Ragnarök. He answers entirely in character, in his own voice, from the lived belief of a man of his age — not as a modern scholar. It is a plain conversation: no narration, no stage directions, just him talking. Built for an actor or writer who wants to understand the character and his world from the inside. Ask him about the gods, his wife, his son, raiding, or death — and his temper shifts with the subject.
Accuracy & Honesty
This is a reference tool, not a final authority. The AI can still be wrong. For anything that matters, check it against the primary sources and scholarship it points you to.
In the three reference focuses it is built to flag uncertainty and to debunk popular myth-about-the-myth. In Ask Calder you are talking to a character — what he “knows” is the belief of his time, not modern fact.
Compatibility
Built and tuned for Grok. Output quality may vary with other models or providers.
All original content, design, systems, and materials created for the Norse Codex are the sole property of MarrowMyth & F.C. Marrow. All rights reserved.
Calder Coldwater is an original character created by F.C. Marrow for use by Fanward, Mighty Morning Coffee, and Austin St. John. The character — his story, voice, and likeness — remains the property of F.C. Marrow; all rights reserved.
The Norse Codex is a reference and study tool for Norse history, mythology, and language. It is an independent educational utility and is not affiliated with, endorsed by, or connected to any third-party institution, publisher, or rights-holder whose works may be referenced within it.
Scholarly works, translations, editions, and any third-party materials referenced remain the property of their respective authors and publishers. The Codex points you toward sources; it does not reproduce or claim them.
The Materia engine itself — its code, architecture, and systems, and the engine concept in all its forms (World, Story, and Practical engines, and Web Experiences) — is the exclusive, proprietary property of MarrowMyth and F.C. Marrow. A commissioned engine is yours to use, run, host, and share, along with everything you create in it; the technology that powers it is not transferred to you. The engine’s underlying code and systems may not be reverse-engineered, decompiled, repurposed, or used to build another engine without the express written permission of MarrowMyth.
Accuracy & Use
Everything the Codex outputs is AI-generated. It is designed to be accurate and to mark what is attested, debated, or modern invention — but it can still be mistaken, incomplete, or out of date. Treat it as a knowledgeable starting point, not a citation of record: verify anything that matters against the primary sources and scholarship it names. “Ask Calder” is a fictional character voice, not a historical source.
You supply your own AI-provider API key, and it — along with your sessions, highlights, and notes — stays only in your own browser and any files you choose to export. We keep no accounts and run no servers that store it. Your requests go directly to your chosen provider and are governed by that provider’s own terms and acceptable-use policies. This tool is provided as-is, without warranty, and MarrowMyth and F.C. Marrow accept no liability for generated content or its use.
A reference tool, not a final authority. It can still err — verify anything that matters against the cited primary sources and scholarship.
Enter to send · Shift+Enter for new line
Change Focus
Pick the area the Codex specializes in. This stays on for every question until you pick a different one.
Ask Through a Topic
Press a topic on its own for an in-depth lesson on it — or type a question first, then press a topic to ask about that subject only. Either way, this does not change the focus you picked above.
Debauchery
Level0
Pure as snow — not a sinful thought in sight
Narrator Nudge
Ask the Codex something, or type a search above — images appear here automatically as you go.
Inline thumbnails: Wikimedia Commons (free, mostly public-domain / historical). The button opens full results on Google Images in a new tab.
Approximation — an Icelandic voice (the closest living tongue) stands in for reconstructed Old Norse. For the most authentic result, install an Icelandic voice on your device: • Windows: Settings › Time & Language › Language & region › Add a language › Íslenska, then add its speech pack. • Mac / iPhone: Settings › Accessibility › Spoken Content › Voices (or System Voice) › add Icelandic. • Android: Settings › Accessibility › Text-to-speech › install an Icelandic voice. Without one, a default voice is used.
Runes are an alphabet, not a language — this transliterates your letters into the chosen futhark. A rough guide, not a scholarly spelling.
Reconstructed values — scholarly, not recorded sound.
The Æsir & Vanir
Óðinn — Allfather; war, wisdom, poetry, death.
Þórr — thunder; guards Midgard; hammer Mjöllnir.
Loki — trickster, shape-shifter; kin to gods and giants.
Freyja (Vanir) — love, war, seiðr, half the slain.
Freyr (Vanir) — fertility, peace, plenty.
Frigg — Óðinn’s wife; foreknowledge.
Týr — war, oaths, justice.
Baldr — light, beloved; his death triggers Ragnarök.
Heimdallr — watchman of the Bifröst bridge.
Njörðr (Vanir) — sea, wind, wealth.
Yggdrasil & the Nine Worlds
Yggdrasil — the world-ash that binds all realms.
Asgard — the Æsir · Vanaheim — the Vanir
Álfheim — light elves · Midgard — humans
Jötunheim — giants · Svartálfheim — dwarves
Múspellsheim — fire (Surtr) · Niflheim — ice & mist
Hel — the dead below.
The lists vary by source — there was never one fixed canon.
HealthHEALTHY
THE WORLD
Settings
🔞 Adult Content
Fullscreen
Sound
MythUI Settings
AI Connection
Choose who powers your story and paste your key. Your key is stored only in this browser — it is never sent to us.
Audio
Add your own sounds and music — all optional. Upload a file for a moment (a hit, a heal, entering a safe room) and it plays at that moment. Volumes are remembered.
Mute everything
Display & Reading
Tune how the story looks and how long each response runs.
Edit Character
Edits apply to this story only — they ride along if you compress & continue, and a new story starts fresh. Leave a field blank to keep the default.
Replace — edit the current description and bio directly.
Gifts or actions matching a like nudge their bond up (+1).
Gifts or actions matching a dislike nudge their bond down (-1).
Character
Appearance
Profile
Additional
Likes
Dislikes
Bug Report
Describe the issue and it will be sent directly to the developer.
⚠︎ You need an API key first
This engine runs on your own AI key. One key works in every world engine — you set it up once.
Get a Grok key (recommended):
Go to console.x.ai
Sign in, or make a free account
Click API Keys, then Create API Key
Copy the key. It starts with xai-
Paste it in the API Key box, then press Enter World again
💸 The key runs on tokens (pay-as-you-go) — about $2 gets you hundreds of responses across the world engines.
We make no money from your tokens — they are your fuel to power our engines.
Your key is saved only in your browser. We never see it.
Build a whole world — cast, places, and lore — and export one file your World Engine can load.
Everything you make here is added to a world — it never replaces it.
Load your file into any World Engine and your character, cast, places, and lore drop into that world. The engine's world stays in charge; you're adding your part of the story inside it.
Your World
Set your premise and any world-level lore. Every World Engine already comes with its own world — this feeds into that world's existing lore. All optional.
Your engine already has its world built in. Anything you write here is added to that world's lore — your premise sets up your personal story inside it. It never blanks out or replaces the world the engine provides.
A label for this set of world-lore (also names the file). Optional.
A few sentences setting up your personal story, plus any world-facts you want always true. This is added to the world the engine already has.
Your Character
The character you inhabit and portray. Optional — leave it blank to decide later, or to let other people bring their own.
Portrait: use a square (1:1) image — it shows next to your health bar. You upload it in the engine on the setup screen (the Character Portrait button).
Who they are, their background, what drives them. Your personal story uses this as its starting point.
Main Characters
The world's central cast — built in. Refine their details if you like; they travel with the world.
Named NPCs
Named figures the world can introduce — built in. Refine their details if you like.
This list may include spoilers of who you may meet inside the world engine. If you want to avoid potential spoilers, hit Back.
Emergent Characters
Characters you add, plus any that emerged in play. These are yours to create and edit.
Locations
Places in your world. They're added as spots the story can move to.
Lore
Facts the story should treat as true — history, groups, rules, secrets. Each is sent to the AI only when it comes up, so big lore stays cheap.
Review & Save
Here's your world, and what it costs each turn.
This saves a copy of your world to your device and takes you straight to name and begin a fresh story with it — no uploading. Use Download alone if you just want to keep or share the file.
How to use it: open your World Engine, go to Settings → World, and upload this file where you'd add lore. Your world, character, cast, places, and lore load in — added to whatever world the engine presents. You can re-open this file here any time to edit it.
Sound & Art
Tools that belong to your World Engine itself — they apply to this engine on your device, not to the world file you share.
Put image files in one folder, each named after a character or a location (for example an image named Cloud, or Wutai). Choose that folder and the engine shows the right picture whenever that character or place is in the scene. 1200×1800 (2:3) is the ideal shape — and no images at all is fine, the story still works.
Score the world your way — upload your own clips for the effects and music below. They play in this engine on your device.
Add a character
Only a name is required. Everything else is optional.
Mara Vance · Old Pete · Sister Agnes
Portrait: save an image in your image folder named after this character — their name or any nickname works, capitalization doesn't need to match. A tall 2:3 portrait (about 1200×1800) looks best.
Type one and press Enter. These nudge how they feel about things.
How they feel about you when a story begins — most people start neutral. Set this for an ally, a love interest, or an enemy. It's only a starting point; feelings still shift as the story plays.
Someone can feel strongly before you've ever met — you loathe a tyrant long before you face him. Positive feelings tick “known from start” for you automatically; for fear or hatred, decide it yourself with the toggle below.
Don't introduce them right awayOff = you know them from the start. On = they turn up later when your story reaches them.
Start canonized (permanent cast)On = when this world is loaded into an engine, they join the player’s permanent cast automatically, using the sheet you wrote here.
Other names they go by (optional)
Add nicknames or alternate names so the story recognizes them. A title like the Captain and a real name like Mara can both point to the same character.
Anything extra — private notes, side details, secrets, quirks: whatever the AI should know that isn't the main bio.
Add a location
Only a name is required.
The Old Mill · Riverside · The Chapel
What is this place? Who or what is here?
Whether you can rest and let your guard down here.
Make this a sub-locale of a main location (e.g. a bar inside a slum). Leave blank for a top-level place.
Add a lore entry
Only a name is required.
The Old Order · The Vanishing · House Rules
Type a topic, then press Enter. A topic can be more than one word — the old order works just like a single name.
Always include thisLeave off for almost everything. Only for facts true in every scene (it's sent every turn).
Tie this to a character or place (optional)
Pick characters or locations from your world. This lore appears automatically whenever they're in the scene — no topic word needed.
Draft from your writing
Paste lore you already have — the AI sorts it into characters, places, and lore for you to review.
This uses your own API key. Your pasted text is sent to the AI provider you choose and billed to your key. The key is stored only in this browser.
Review is required. The AI can miss things or make things up. Everything it drafts is marked “review” — open each one, check and fix it, then save. Nothing is final until you do.
Stored only in your browser. Sent only to the provider you pick — never to us.
