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I Built an AI That Auto-Replies to Your Instagram DMs (No Login Required)

Managing Instagram DMs is a full-time job. Whether you are a small business owner, a content creator, or just someone who gets too many messages, you have probably missed important replies because you could not keep up.

So I built InstaReply Bot: an open-source Android app that watches your Instagram notifications and replies with AI-generated messages. Automatically. In the background. Without your Instagram password.

Here is how it works, why I built it, and what I learned.

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The Problem

Instagram does not have an official API for sending DMs to personal accounts. Most automation tools either:

Require your login credentials (security risk) #

Use fragile web scraping (breaks when Instagram updates) #

Need the screen on (not practical for background automation)

I wanted something different: a solution that works entirely through Android notification system, with zero credential sharing.

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The Solution: Notification Listener + AI

InstaReply Bot uses Android Notification Listener API to read incoming Instagram DM notifications. When a new message arrives, the app:

Extracts the sender name and message text from the notification #

Matches the message against user-defined rules (keyword patterns, regex, specific contacts) #

Generates a reply using an AI provider (Groq, Gemini, OpenRouter, or any OpenAI-compatible API) #

Sends the reply through Instagram own notification Reply action, exactly like tapping Reply in your notification shade, but automated

The key insight: Instagram notification already includes a Reply action. InstaReply Bot just automates clicking that button.

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Why No Login Is Needed

Most Instagram bots need your username and password. That is a dealbreaker for me because:

Security risk: Credentials stored on someone else server #

Account ban: Instagram actively detects and bans automation accounts #

Privacy: I do not want to trust anyone with my Instagram session

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InstaReply Bot never touches your Instagram credentials. It works with Android notification system, a system-level API that Google designed for exactly this kind of use case.

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Free AI Models Included

I did not want cost to be a barrier, so InstaReply Bot supports free AI providers:

Groq (Free Tier)

- openai/gpt-oss-20b: Fast, great for quick replies
- llama-3.3-70b-versatile: Better conversational quality
- qwen/qwen3.6-27b: Multilingual support

OpenCode Zen (Free Tier)

- opencode/deepseek-v4-flash-free: Lightweight, fast
- opencode/mimo-v2.5-free: Context-aware responses

Google Gemini (Free Tier Available)

- gemini-3.6-flash: Google latest

No credit card required for any of these. You can also use paid providers like OpenRouter, NVIDIA, or OpenAI if you want more power.

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Technical Architecture

The app is built with Kotlin and follows modern Android development practices:

Key decisions:

Room Database for local storage: rules, contacts, and reply logs stay on your device #

OkHttp for API calls: lightweight and reliable #

Material Design: native Android look and feel #

Kotlin Coroutines: efficient background processing

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The One-Reply Guarantee

One of the hardest problems was ensuring exactly one reply per message. Instagram sometimes re-posts notifications while the AI is still generating, which could cause duplicate replies.

InstaReply Bot solves this with three layers:

60-second deduplication: Same sender + message text within 60 seconds is ignored #

Persisted log check: Successful replies are stored for 10 minutes (survives app restarts) #

Send discipline: The AI text is typed once, Send is clicked at most once

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What I Learned

1. Notification APIs Are Powerful

Android Notification Listener API is underutilized. It is a legitimate system API that can transform how apps interact with notifications, no hacking required.

2. Free AI Is Real

Groq and OpenCode Zen offer genuinely useful free tiers. For a personal auto-reply bot, free models work perfectly.

3. Deduplication Is Hard

What seems simple: reply to each message once, is actually complex when notifications can arrive multiple times and the AI takes a few seconds to respond.

4. Users Care About Privacy

Every person I showed this to asked: Does it need my password? When I say no, the reaction is always relief. Privacy-first design matters.

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Try It The app is open source and available on GitHub:

[github.com/nandandas2407-web/InstaReplyBot](https://github.com/nandandas2407-web/InstaReplyBot)

- Download the APK from Releases:
[https://github.com/nandandas2407-web/InstaReplyBot/releases/latest](https://github.com/nandandas2407-web/InstaReplyBot/releases/latest)

• Grant Notification Access
• Configure a free AI provider (Groq takes 2 minutes)
• Create your reply rules

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What Is Next

• Support for Instagram Story mentions

• Multi-language reply templates

• Webhook integration for business workflows

• iOS support (if there is interest)

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Open to Contributions

This is a side project, but I am open to contributions. If you want to help:

• Check the issue tracker for open issues

• Read the contributing guidelines

• Submit a PR: I review within 24 hours Built with Kotlin for Android. Free AI models included. No Instagram login required.

source & further reading

dev.to — original article Engrava 0.5.0: a first-class MCP server Bridging the AI Cutoff: Teaching Coding Agents Every Dart Feature from 1.0 to 3.14 Everyone is hyping Claude Code. I used Google Jules to build and ship a phone tracking app—entirely from my phone on the beach.