🚀 [AI Agent]Build a Twitter Auto-Posting Bot with n8n, GPT, FastAPI & Tweepy

[Full Guide] How to Build an AI Twitter Agent with n8n, FastAPI, Tweepy & GPT

Introduction: Automate Your Twitter Strategy with AI

Managing a Twitter account can be time-consuming — thinking of tweet ideas, composing text within 280 characters, and scheduling posts. What if we could automate the entire process from content creation to publishing using AI?

This article will show you how to build a fully automated Twitter agent that:

• Generates tweet content using OpenAI GPT

• Posts tweets through a FastAPI endpoint using Tweepy

• Orchestrates the entire flow using the no-code automation tool n8n

1. Tools & Requirements

1.1 Tech Stack Overview

You’ll be using:

• FastAPI to handle HTTP requests

• Tweepy to interact with the Twitter API

• OpenAI API to generate tweets using GPT

• n8n to automate the workflow with no code

1.2 Twitter API Keys

1. Go to Twitter Developer Portal

2. Create a new App

3. Get the following credentials:

• API Key

• API Secret Key

• Access Token

• Access Token Secret

2. Set Up a Tweet Posting API with FastAPI

2.1 FastAPI + Tweepy Script

from fastapi import FastAPI, Request
import tweepy
import os
from dotenv import load_dotenv

load_dotenv()

auth = tweepy.OAuthHandler(os.getenv("API_KEY"), os.getenv("API_SECRET"))
auth.set_access_token(os.getenv("ACCESS_TOKEN"), os.getenv("ACCESS_SECRET"))
api = tweepy.API(auth)

app = FastAPI()

@app.post("/tweet")
async def post_tweet(request: Request):
    body = await request.json()
    content = body.get("text", "")
    try:
        api.update_status(content)
        return {"status": "success", "message": "Tweet posted"}
    except Exception as e:
        return {"status": "error", "message": str(e)}

Start the server:

uvicorn main:app --reload

3. Generate Tweets Automatically with GPT

You can prompt GPT to write short, engaging tweets. Example prompt:

Using OpenAI’s API:

import openai

openai.api_key = os.getenv("OPENAI_API_KEY")

response = openai.ChatCompletion.create(
    model="gpt-4",
    messages=[
        {"role": "user", "content": "Write a 140-character tweet about artificial intelligence in everyday life."}
    ]
)

tweet_text = response.choices[0].message['content']

4. Use n8n to Automate the Workflow

4.1 What is n8n?

n8n is an open-source automation tool that allows you to create custom workflows. It supports HTTP requests, GPT integration, and Twitter posting.

4.2 Workflow Outline

1. OpenAI Node: Sends a prompt to GPT to generate a tweet

2. HTTP Request Node: Sends the tweet to your FastAPI /tweet endpoint

3. Scheduler Node: Runs the workflow daily or hourly

HTTP Node config example:

• Method: POST

• URL: http://localhost:8000/tweet

• Body:

{
  "text": {{$json["choices"][0]["message"]["content"]}}
}

5. Final Result

When the workflow runs, GPT generates a tweet and sends it through FastAPI to be posted on Twitter via Tweepy — all without manual input. The system is scalable, efficient, and highly customizable.

Conclusion

By combining FastAPI, Tweepy, OpenAI GPT, and n8n, you can create a robust and dynamic AI Twitter bot that writes and posts tweets automatically. Whether for personal branding, marketing, or content automation, this workflow saves time and maintains consistent engagement.