Ghost Cofounder

Quick Start (TL;DR)

• pip install -r requirements.txt
• ./install.sh
• Total install time ~60 seconds

Uses (Claude Code Subagents) to provide alternative perspectives and contrarian analysis by consulting the OpenRouter API. I like using Moonshot Kimi K2 for this! This model thinks very differently than Claude, often in a complementary way.

Built for Solo Founders & Indie Hackers

Stop making critical decisions in an echo chamber. ghost-cofounder is the co-founder you don't have—constantly challenging your assumptions about product, architecture, and market.

"It’s like having a brutally honest co-founder who never needs equity or sleep!"

I appreciate a star if you find this useful!

ghost-cofounder analyzing itself—brutal honesty included.

Features

• Easily configurable model and system prompt via config.json
• Secure API key loading with .env
• Ready-to-use Bash install script for agent setup
• Compatible with Claude sub-agent workflows

Requirements

• Claude Code (https://claude.ai/claude-code)
• Python 3.7+
• pip (Python package manager)
• An OpenRouter API key (get one here)

Default Model info

You can use any model from OpenRouter. I highly recommend you check your Openrouter settings > Privacy and > Paid Models and turn OFF "Enable providers that may train on inputs". Otherwise you may be routed to a provider that does train on your inputs without your explicit consent. More info here

Setup Instructions

1. Clone or Download This Repository

2. Install Python Dependencies

   pip install -r requirements.txt

3. Configure Your API Key

   • Copy .env.example to .env and add your OpenRouter API key:

     cp .env.example .env
     # Edit .env and set your key

4. Configure Model and System Prompt

   • Copy config.example.json to config.json:

     cp config.example.json config.json

   • Edit config.json to choose your preferred model and customize the system prompt.
   • Example:

     {
       "model": "moonshotai/kimi-k2:moonshotai",
       "system_prompt": "You are a constructive deviation agent. For any proposal, surface 2–3 concretely different approaches (not just criticisms) and finish with a 1-sentence recommendation on which trade-off is most pragmatic given current constraints. Stay ≤ 300 words."
     }

5. Install the Agent for Claude Code

   Run the install script to copy the agent files to your Claude agents directory and automatically bake in the correct script path:

   bash install.sh

   This will:

   • Copy ghost-cofounder.md to ~/.claude/agents/
   • Replace SCRIPT_DIR in ghost-cofounder.md with the absolute path to your cloned project, so the agent always finds the correct script location.

Usage

To get a contrarian response, simply ask Claude Code for a second opinion. You don't necessarily have to ask a specific question, Claude Code will take your current context into account and ask for a second opinion based on that. The subagent will use the OpenRouter API to provide alternative perspectives.

Files

• ghost_cofounder.py — Main script for querying OpenRouter API
• config.json — Model and prompt configuration (copy from config.example.json if missing)
• config.example.json — Example config for onboarding
• .env.example — API key storage example file
• requirements.txt — Python dependencies
• install.sh — Installs subagent and bakes in the script path for Claude
• ghost-cofounder.md — Documentation and agent definition for the ghost cofounder workflow

Troubleshooting

If you see errors about config.json not being found or invalid:

• Make sure you have copied config.example.json to config.json in your project directory.
• Ensure your config.json is valid JSON (no trailing commas, proper quotes, etc.).
• Edit config.json to set your desired model and prompt.

License

MIT