What is worldanvil-mcp CLAUDE.md?

Repository instructions for developing worldanvil-mcp, a server that connects coding agents to World Anvil, a worldbuilding platform. The repository is a monorepo, meaning one repository contains multiple packages, and the main package is in a subdirectory.

Use it when changing, testing, running, or deploying the World Anvil MCP server and its optional Cloudflare proxy.

It tells developers where the actual package lives, which commands to run, and how its server, tools, handlers, API client, and tests are organized.

How wlcarden/worldanvil-mcp configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to wlcarden/worldanvil-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/wlcarden/worldanvil-mcp/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/wlcarden/worldanvil-mcp

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/wlcarden/worldanvil-mcp/claude-md/github.svg)](https://agentmods.dev/instructions/wlcarden/worldanvil-mcp/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/wlcarden/worldanvil-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/wlcarden/worldanvil-mcp/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/wlcarden/worldanvil-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/wlcarden/worldanvil-mcp/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 908 This file is loaded in full into every session.

When invoked 908 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00908	$0.00908
Opus 5.5	$0.00363	$0.00363
Sonnet 5.5	$0.00182	$0.00182
Haiku 4.5	$0.00091	$0.00091

Measured 2mo ago against content hash 150b6979850e, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

worldanvil-mcp CLAUDE.md 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 2mo 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.

CLAUDE.md · 75 lines

How it starts

The opening of the file, as written. The whole thing — 75 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Repository Structure

This is a monorepo. The actual MCP server package lives at plugins/worldbuilding/worldanvil-mcp/. All development commands run from that subdirectory.

plugins/worldbuilding/worldanvil-mcp/   ← main package (npm: worldanvil-mcp)
  index.js                              ← entry point, starts stdio transport
  src/
    server.js                           ← MCP server factory
    tools.js                            ← tool schema definitions (90+ tools)
    handlers.js                         ← tool call dispatch (switch on tool name)
    api-client.js                       ← WorldAnvilClient HTTP wrapper
    utils.js                            ← Markdown→BBCode conversion
  test/                                 ← vitest tests
  cloudflare-worker/                    ← optional proxy deployment (Wrangler)
  CLAUDE.md                             ← worldbuilding guidance for MCP users (not devs)

Commands

All commands run from plugins/worldbuilding/worldanvil-mcp/:

npm start            # run the MCP server
npm run dev          # run with --watch (auto-restart on changes)
npm test             # run all tests
npm run test:watch   # run tests in watch mode
npm run test:coverage  # run tests with coverage report

To run a single test file:

npx vitest run test/utils.test.js

Tests load credentials from .env in the package directory (use dotenv). Integration tests hit the real WorldAnvil API and require WA_AUTH_TOKEN to be set.

Environment Variables

Variable	Required	Purpose
`WA_AUTH_TOKEN`	Always	User's WorldAnvil auth token
`WA_APP_KEY`	Optional	Direct API mode; if omitted, uses default public proxy
`WA_PROXY_URL`	Optional	Custom Cloudflare Worker proxy URL
`WA_TOOL_GROUPS`	Optional	Comma-separated tool groups or preset to load (default: all). Groups: core, content, images, campaign, maps, timeline, blocks, manuscripts, canvas, variables, social, rpg. Presets: all, standard, worldbuilding, writing, gamemaster

Read the full file on GitHub · 75 lines

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.

2mo ago First seen · 75 lines · 908 tokens per session scan A 150b6979850e

Subscribe to this mod's changes

worldanvil-mcp CLAUDE.md is an instructions file published in the GitHub repository wlcarden/worldanvil-mcp (14 stars, last pushed 5mo ago), licensed MIT. It adds 908 tokens to every session, about $0.0036 per session on Opus 5.5. 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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worldanvil-mcp: Instructions file for Claude Code