worldbuilding

worldbuilding is a skill for Claude Code, Codex from inkeep/open-knowledge-skills. It costs 107 tokens per session (668 once invoked), scanned A, original, MIT.

A set of rules for maintaining a fiction encyclopedia, where characters, places, groups, themes, and lore are stored as linked entries.

In plain words
What is it for?
Use it to add or update characters, settings, factions, and lore, or to check whether story details remain consistent.
Why use it?
It keeps fictional details organized and helps reveal contradictions as the world grows.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/inkeep/open-knowledge-skills/worldbuilding
Any agent
npx skills add inkeep/open-knowledge-skills --skill worldbuilding
Clone the repo
git clone --depth 1 https://github.com/inkeep/open-knowledge-skills

Made for: Claude Code, Codex.

Its marketplace also offers this one on its own, as the plugin worldbuilding/plugin install worldbuilding after adding the marketplace above.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for worldbuilding

README.md
[![agentmods](https://agentmods.dev/badge/skills/inkeep/open-knowledge-skills/worldbuilding.svg)](https://agentmods.dev/skills/inkeep/open-knowledge-skills/worldbuilding)
Your own site
<a href="https://agentmods.dev/skills/inkeep/open-knowledge-skills/worldbuilding"><img src="https://agentmods.dev/badge/skills/inkeep/open-knowledge-skills/worldbuilding.svg" alt="Measured on agentmods" height="20"></a>
Per session 107 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 668 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00107 $0.00668
Opus 5 $0.00053 $0.00334
Sonnet 5 $0.00021 $0.00134
Haiku 4.5 $0.00011 $0.00067

Measured 4d ago against content hash 84acdede0fcc, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

worldbuilding scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/starter-packs/worldbuilding/worldbuilding/SKILL.md · 34 lines

How it starts

The opening of the file, as written. The whole thing — 34 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Worldbuilding pack — how to work here

This project is a fiction encyclopedia. The graph is the product: characters, settings, themes, factions, and lore that link to each other. The agent's main jobs are auto-stubbing new entities as they're mentioned and flagging contradictions. This skill holds those behaviors so templates and folder descriptions stay clean.

This skill is pack guidance. The platform /open-knowledge skill (read/write/preview/linking/grounding rules) still governs every markdown operation — this layers the worldbuilding conventions on top.

Folders

  • characters/ — one file per character (PC + NPC); frontmatter carries type, status, faction, first appearance.
  • settings/ — locations, regions, world-rules; frontmatter carries region, controlling faction, danger level. The "where" of the story.
  • themes/ — recurring narrative concerns (love, betrayal, identity). The "why." Themes work via opposition; each entry captures the theme and its tension.
  • factions/ — political, social, criminal, magical, religious groups. Ships faction, political-faction, and religion templates.
  • lore/ — history, mythology, cosmology, magic systems. Ships lore, magic-system, and historical-event templates.

Agent behaviors (the core value)

  • Auto-stub on mention. When a chapter, session log, or existing entry references a name not yet captured, stub a file in the right folder with backlinks to where it was mentioned.
  • Flag contradictions. When a character's faction (or any field) contradicts their actions in narrative, or a setting is described two ways, surface the conflict — in fiction a contradiction is itself a story-shaping detail worth noting, not silently "fixing."
  • Thread the graph. Link characters ↔ factions ↔ settings ↔ lore so each entry becomes a hub for everywhere it appears.
  • Do NOT add TTRPG stat-block fields (xp_awarded, etc.) — those belong in a future TTRPG variant.

Templates

Create with write({ document: { path, template: "<name>" } }). Templates carry only structure; section meaning is described here, not inside the document body.

Read the full file on GitHub · 34 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 4d ago First seen · 34 lines · 107 tokens per session scan A 84acdede0fcc

Subscribe to this mod's changes

worldbuilding is a skill published in the GitHub repository inkeep/open-knowledge-skills (6 stars, last pushed 2d ago), licensed MIT. It adds 107 tokens to every session and 668 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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