What is exploreyc CLAUDE.md?

A project-specific instruction file for ExploreYC, a web app that collects and analyzes Y Combinator company data. It documents the app's technologies, services, and development commands.

Orienting agents when developing, running, or deploying the ExploreYC frontend, backend, database, and connected services.

It gives a coding agent the project background and the commands needed to work on the repository consistently.

How KonstantinMB/exploreyc configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to KonstantinMB/exploreyc. 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/KonstantinMB/exploreyc/master/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/KonstantinMB/exploreyc

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/konstantinmb/exploreyc/claude-md/github.svg)](https://agentmods.dev/instructions/konstantinmb/exploreyc/claude-md)

Your own site

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

Per session 1,153 This file is loaded in full into every session.

When invoked 1,153 The same file — it is already loaded in full.

Security scan A 1 finding. 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	$0.01153	$0.01153
Opus 5.5	$0.00461	$0.00461
Sonnet 5.5	$0.00231	$0.00231
Haiku 4.5	$0.00115	$0.00115

Measured 1mo ago against content hash e4ecb5318908, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

exploreyc CLAUDE.md scanned grade A with 1 finding 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 1mo 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -X POST http://localhost:8000/api/scrape \

CLAUDE.md · 99 lines

How it starts

The opening of the file, as written. The whole thing — 99 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

ExploreYC — a full-stack web app that scrapes Y Combinator's Algolia API for company data and provides analytics, AI-powered tools (idea validation, success prediction), interactive maps/charts, email digests, and a hiring board.

Tech Stack

Frontend: React 19 + Vite 8 + TypeScript + Tailwind CSS (monospace/hacker theme with YC orange #FF6600)
Backend: FastAPI (Python 3.11) — nearly all endpoints live in backend/main.py
Database: SQLite locally, PostgreSQL (Supabase) in production — chosen via database_factory.py based on DATABASE_URL
Deployment: Vercel (frontend + API rewrites to api.exploreyc.com) + Railway (backend; render.yaml is vestigial) + GitHub Actions (cron)
Key integrations: OpenAI (idea validation/embeddings), Perplexity AI (research), CoreSignal (company enrichment), Resend (email), Algolia (YC data source)

Development Commands

# Frontend dev server (proxies /api and /ws to localhost:8000)
cd frontend && npm install && npm run dev

# Backend dev server
cd backend && python3 -m venv venv && source venv/bin/activate && pip install -r requirements.txt && python3 -m uvicorn main:app --reload

# Production frontend build (from repo root)
npm run build

# Run backend tests (from backend/)
python -m pytest test_email_digest.py
python -m pytest test_pagination.py

No frontend test suite exists. Backend tests are integration-focused (test_*.py files in backend/).

Seeding local data: With DATABASE_URL unset the backend uses SQLite (backend/yc_companies.db, auto-created). Scrape YC data from the public Algolia API (no keys needed):

# Seed last 3 batches (with backend running)
curl -X POST http://localhost:8000/api/scrape \
  -H "Content-Type: application/json" \
  -d '{"batch": ["Winter 2025", "Summer 2024", "Winter 2024"], "hits_per_page": 1000, "max_pages": 20}'

# Check progress
curl http://localhost:8000/api/scrape/status/1

Read the full file on GitHub · 99 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.

1mo ago Changed · +9 tokens per session e4ecb5318908
2mo ago First seen · 99 lines · 1,144 tokens per session scan A bea9647c95c4

Subscribe to this mod's changes

exploreyc CLAUDE.md is an instructions file published in the GitHub repository KonstantinMB/exploreyc (47 stars, last pushed 1mo ago), licensed MIT. It adds 1,153 tokens to every session, about $0.0046 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

React Research fastapi full-stack idea-validator open-source openai

exploreyc CLAUDE.md next to 6 instructions from other repositories
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exploreyc: Instructions file for Claude Code