What is effect-ontology CLAUDE.md?

A project guide for Effect Ontology, a TypeScript system that turns unstructured text into structured knowledge graphs using defined ontologies, or formal descriptions of concepts and their relationships.

Use it when installing dependencies, building, type-checking, linting, or testing the Effect Ontology project with Bun and Vitest.

It gives the coding agent the repository's commands, development rules, and correct way to run checks and tests.

How mepuka/effect-ontology configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to mepuka/effect-ontology. 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/mepuka/effect-ontology/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/mepuka/effect-ontology

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/mepuka/effect-ontology/claude-md/github.svg)](https://agentmods.dev/instructions/mepuka/effect-ontology/claude-md)

Your own site

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

Per session 2,833 This file is loaded in full into every session.

When invoked 2,833 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	$0.02833	$0.02833
Opus 5.5	$0.01133	$0.01133
Sonnet 5.5	$0.00567	$0.00567
Haiku 4.5	$0.00283	$0.00283

Measured 2mo ago against content hash 2d40e6038013, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

effect-ontology 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 · 310 lines

How it starts

The opening of the file, as written. The whole thing — 310 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.

Project Overview

Effect Ontology is a functional, type-safe system for extracting structured knowledge graphs from unstructured text using ontology-guided LLM prompting. Built entirely with Effect-TS, it implements a mathematically rigorous pipeline based on topological catamorphism and monoid folding over OWL ontologies.

Commands

Development

bun install              # Install dependencies
bun run build            # Build @core-v2 package
bun run check            # TypeScript type checking
bun run test             # Run all tests (vitest)
bun run test:watch       # Run tests in watch mode
bun run lint             # ESLint across the repo
bun run lint-fix         # ESLint with auto-fix

Running Tests

IMPORTANT: Always use bun run test, never bun test directly.

The project uses vitest configured in vitest.config.ts. Using bun test invokes Bun's built-in test runner which has different behavior and will produce incorrect results.

cd packages/@core-v2

# Full test suite (CORRECT)
bun run test

# Single file (CORRECT)
bun run test test/Service/Config.test.ts

# By test name pattern (CORRECT)
bun run test -t "test name pattern"

# Watch mode (CORRECT)
bun run test:watch

# Interactive UI (CORRECT)
bun run test:ui

# WRONG - Do NOT use these:
# bun test                    # Uses Bun's test runner, NOT vitest
# bun test test/...           # Wrong runner

Server & Database

cd packages/@core-v2
bun run serve                  # Start extraction server
bun run serve:postgres         # Start with Postgres (uses .env.postgres)
bun run db:start               # Start Postgres via docker-compose
bun run db:stop                # Stop Postgres
bun run db:psql                # Connect to Postgres shell

Benchmarking

bun run benchmark:smoke        # Quick sanity check (10 samples)
bun run benchmark:quick        # Standard run (100 samples)
bun run benchmark:full         # Full benchmark (all samples)

Read the full file on GitHub · 310 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 · 310 lines · 2,833 tokens per session scan A 2d40e6038013

Subscribe to this mod's changes

effect-ontology CLAUDE.md is an instructions file published in the GitHub repository mepuka/effect-ontology (5 stars, last pushed 10mo ago), licensed MIT. It adds 2,833 tokens to every session, about $0.0113 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.

Data and AI

effect-ontology CLAUDE.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
effect-ontology CLAUDE.mdmepuka/effect-ontology	Instructions file	5	10mo ago	MIT	A	2,833	Claude Code
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	yesterday	MIT	A	7,461	Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	yesterday	MIT	A	4,680	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	274k	2d ago	MIT	A	4,313	Codex, OpenCode

effect-ontology: Instructions file for Claude Code