Reddit AI Auto-Replier

An intelligent Reddit bot that monitors subreddits or specific users and generates contextual replies using LLM APIs (OpenAI, Anthropic Claude, or local models via Ollama).

Features

• AI-Powered Replies — Generates context-aware responses using GPT-4, Claude, or local LLMs via Ollama
• Dual Monitoring Modes — Track specific users or monitor entire subreddits by keyword
• Multi-Account Rotation — Distribute replies across multiple Reddit accounts to respect rate limits
• Customizable Prompts — Define system prompts and reply templates per subreddit or topic
• Rate Limit Handling — Exponential backoff with configurable retry logic
• Duplicate Prevention — Tracks replied comments to avoid double-posting
• Persistent State — Saves last run timestamp to resume without reprocessing old comments

Architecture

┌─────────────────┐     ┌──────────────────┐     ┌─────────────────┐
│  Reddit API     │────▶│  Comment Monitor  │────▶│  Reply Filter   │
│  (PRAW)         │     │  (User/Subreddit) │     │  (Keyword/Time) │
└─────────────────┘     └──────────────────┘     └────────┬────────┘
                                                          │
                                                          ▼
┌─────────────────┐     ┌──────────────────┐     ┌─────────────────┐
│  Reddit Post    │◀────│  Account Rotator  │◀────│  LLM Generator  │
│  (Rate Limited) │     │  (Multi-Account)  │     │  (GPT/Claude/   │
└─────────────────┘     └──────────────────┘     │   Ollama)       │
                                                  └─────────────────┘

Quick Start

1. Clone & Install

git clone https://github.com/miao0044/reddit-AI-replier.git
cd reddit-AI-replier
pip install -r requirements.txt

2. Configure Environment

Copy the example environment file and fill in your credentials:

cp .env.example .env

Edit .env with your Reddit API credentials and LLM API key:

# Reddit credentials (create app at https://www.reddit.com/prefs/apps)
REDDIT_USERNAME=your_username
REDDIT_PASSWORD=your_password
REDDIT_CLIENT_ID=your_client_id
REDDIT_CLIENT_SECRET=your_client_secret

# LLM provider: "openai", "anthropic", or "ollama"
LLM_PROVIDER=openai
OPENAI_API_KEY=sk-...
# ANTHROPIC_API_KEY=sk-ant-...
# OLLAMA_BASE_URL=http://localhost:11434
# OLLAMA_MODEL=llama3

3. Customize the System Prompt

Edit prompts/default.txt to define how the AI should respond:

You are a helpful and knowledgeable Reddit user. Reply to the following 
comment naturally and conversationally. Keep responses concise (2-4 sentences) 
and relevant to the topic. Do not mention that you are an AI or bot.

4. Run

# Monitor a specific user's new comments
python reddit_bot.py --mode user --target USERNAME

# Monitor a subreddit for keyword matches
python reddit_bot.py --mode subreddit --target SUBREDDIT --keywords "python,machine learning"

# Continuous monitoring with 60-second intervals
python reddit_bot.py --mode subreddit --target learnpython --loop --interval 60

Configuration

Parameter	Env Variable	CLI Flag	Default	Description
Reddit Username	REDDIT_USERNAME	—	—	Reddit account username
LLM Provider	LLM_PROVIDER	--llm	openai	AI backend: openai, anthropic, ollama
Monitor Mode	—	--mode	user	user or subreddit
Target	—	--target	—	Username or subreddit name
Keywords	—	--keywords	—	Comma-separated filter keywords
Sleep Duration	SLEEP_DURATION	--interval	30	Seconds between checks
Reply Delay	REPLY_DELAY	--delay	10	Seconds between replies
Max Replies	MAX_REPLIES	--max	10	Max replies per run
Loop Mode	—	--loop	false	Continuous monitoring

Project Structure

reddit-AI-replier/
├── reddit_bot.py          # Main bot entry point with CLI
├── config.py              # Configuration loader (env + CLI)
├── llm_client.py          # Unified LLM interface (OpenAI/Claude/Ollama)
├── monitor.py             # Comment monitoring & filtering
├── replier.py             # Reply posting with account rotation
├── state.py               # Persistent state management
├── prompts/
│   └── default.txt        # Default system prompt
├── requirements.txt
├── .env.example           # Template for environment variables
├── .gitignore
└── LICENSE

Supported LLM Providers

Provider	Model	Local/Cloud	Setup
OpenAI	GPT-4o, GPT-4o-mini	Cloud	Set OPENAI_API_KEY
Anthropic	Claude Sonnet 4.5	Cloud	Set ANTHROPIC_API_KEY
Ollama	Llama 3, Mistral, etc.	Local	Install Ollama, pull model

How It Works

1. Monitor — PRAW streams new comments from target user or subreddit
2. Filter — Comments are checked against keyword filters, time window, and duplicate list
3. Generate — Matching comments are sent to the LLM with the system prompt + comment context
4. Reply — Generated responses are posted via account rotation with rate limit handling
5. Persist — Replied comment IDs and timestamps are saved to prevent duplicates

Rate Limiting & Safety

• Configurable delay between replies (default: 10s)
• Exponential backoff on Reddit API rate limits (up to 3 retries)
• Multi-account rotation distributes load
• Max replies per run cap prevents spam
• Duplicate tracking across sessions

License

MIT License — see LICENSE for details.