Many modern AI projects use prebuilt APIs and external libraries to handle tasks. However, building an AI agent on your own can give you a deeper understanding of the process. It also allows you greater control over how your agent behaves.
Creating an AI agent from scratch provides flexibility and customization that no-code or low-code platforms may not offer, especially for developers who want to fine-tune every aspect of their solution.
In this guide, we will show you how to create an autonomous AI agent using Python and Flask, with natural language processing (NLP) provided by the Natural Language Toolkit (NLTK).ingecko
Our AI agent is simple but powerful, it can
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Display real-time market data (prices, market cap, trading volume, OHLC)
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Fetch top gainers and losers in the last 24 hours
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Recommend coins with similar market cap and trade volume
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Predict prices using a basic linear regression model
Today’s article is intended for beginners and intermediate developers who want to try building an AI agent without relying on too many third-party solutions. We will go through setting up your environment, writing the code, testing the agent, and adding some extra features along the way.

Prerequisites
Before getting started, make sure you have the following ready:
- CoinGecko API for crypto prices and market data, especially the /market and /market_chart endpoints. The free demo plan is enough for this project. If you don't already have one, create an account to try it out.
- Python 3.x: Install Python 3 from the official website to run and test your code seamlessly.
- Basic Python Knowledge: Familiarity with functions, loops, and data types is essential for understanding and writing the code
- Command-line Familiarity: The ability to navigate directories and execute commands in a terminal is necessary for running scripts
- A Code Editor: Use editors like Visual Studio Code, PyCharm, or Notepad++ to write and manage your project efficiently
We will also explore additional endpoints to enhance our AI agent:
- Trending Coins: Use /search/trending to fetch the top trending cryptocurrencies
- Global Market Data: Use /global to retrieve global cryptocurrency market statistics such as total market cap and volume
- Supported Currencies: Use /simple/supported_vs_currencies to get a list of all supported fiat and cryptocurrency currencies
- Exchange Rates: Use /exchange_rates to access current conversion rates for numerous currencies
- OHLC Range: Use /coins/{id}/ohlc to fetch historical OHLC (Open, High, Low, Close) data for cryptocurrencies over a specified time range
We will also be using the following libraries:
- Flask: Flask is a lightweight web framework for Python. It is ideal for creating APIs, serving web pages, and managing HTTP requests.
- NLTK: The Natural Language Toolkit (NLTK) provides tools for processing and analyzing human language data. It includes libraries for tokenization, parsing, and more, which help create AI chatbots.
- Requests: The requests library helps send HTTP requests in Python. It is commonly used for interacting with APIs, such as retrieving real-time cryptocurrency prices.
- Scikit-learn: Scikit-learn is a complete machine learning library. It includes tools for data analysis, preprocessing, and modelling, such as linear regression for price predictions.
Step 1: Setting Up Your Environment
Let’s start by preparing your project environment.
Creating a Project Directory
Open your terminal or command prompt.
Create a new folder for your project:
mkdir ai_agent_project
cd ai_agent_projectSetting Up a Virtual Environment
Using a virtual environment helps manage packages without affecting your system-wide Python installation.
py -m venv venv
Activate the virtual environment:
On Windows:
venv\Scripts\activateOn macOS or Linux:
source venv/bin/activateInstalling Dependencies
Create a file named requirements.txt in your project folder and add these lines:
nltk
requests
scikit-learn
python-dotenv

Now install all the dependencies by running:
pip install -r requirements.txt
Downloading NLTK Data
Some NLTK functions require additional datasets for proper functionality. For instance, the punkt tokenizer, commonly used for breaking text into sentences or words, must be downloaded. Open a Python shell and run:
nltk.download('punkt')
This ensures the required data is available locally for seamless text processing in your projects.
Step 2: Organizing Your Project Structure
Creating a clear and organized project structure is required for proper development and debugging. Below is the recommended folder structure for our AI Agent project:
ai_agent_project/
├── app.py # Main Flask application file that handles routes and backend logic
├── requirements.txt # Lists all the Python dependencies required to run the project
├── .env # Stores sensitive environment variables (like API keys), keeping them secure
├── templates/
│ └── index.html # HTML file for the chatbot interface viewed by the user
└── static/
└── css/
└── style.css # CSS file to define the styling for the user interface
app.py: This is the core file containing the Flask server and logic. It connects the front end to the back end and processes user requests.
requirements.txt: Having all the dependencies listed here allows others to install them with a single command (pip install -r requirements.txt), ensuring reproducibility.
.env: If your application uses API keys or other sensitive credentials, this file keeps them private and outside of the main codebase.
Step 3: Creating the AI Agent
The AI agent combines static responses for general queries and dynamic functions for tasks like fetching real-time cryptocurrency prices. Static responses rely on predefined patterns to address predictable user inputs, while dynamic functions connect to data sources, process information, and provide specific answers. Together, they create a responsive and versatile AI system.
Writing the Flask Application
Let's build our first step by programming using Python. Create a file named app.py and add the following code:
Explanation
Imports and Setup: We use Flask for the web server, NLTK for text processing, and Requests for making HTTP calls. Sensitive credentials like API keys are managed using environment variables with dotenv for security.
Static Pairs and Chatbot: NLTK's Chat is used to define basic conversation patterns with static responses. These pairs enable the AI agent to handle common queries, while fallback responses ensure uninterrupted interaction for unrecognized inputs.
Dynamic Functions: The get_crypto_price function sends HTTP GET requests to the CoinGecko API to retrieve current cryptocurrency prices. The get_crypto_ohlc function fetches OHLC data for cryptocurrencies over a specified time range. Both functions extract and return relevant details while gracefully handling errors.
Request Handling: The handle_dynamic_response function distinguishes between dynamic and static queries. Dynamic queries (e.g., "price of Bitcoin" or "ohlc of Bitcoin for 7 days") invoke corresponding functions, while static responses rely on predefined patterns.
Flask Routes: The / route renders the index.html chat interface and the /get_response route processes POST requests. It parses user input, dynamically generates responses, and returns JSON data for seamless frontend integration.
Step 4: Building a User Interface
A simple yet professional user interface makes your AI agent more engaging. We will create two files: one for HTML (index.html) and one for CSS (style.css).
The HTML Template (templates/index.html)
Create a file named index.html in the templates folder with this content:
This HTML code creates a basic chatbot interface. It includes a styled header, a chat box to display messages, and an input area for users to type their queries. When the "Send" button is clicked, a JavaScript function sends the user input to a server endpoint (/get_response) using an AJAX POST request. The user's message and the server's response are dynamically displayed in the chat box, keeping the conversation visible. Additionally, the input field is cleared after sending a message, and the chat box automatically scrolls to the latest response for a smooth user experience.
The CSS File (static/css/style.css)
Create a file named style.css in static/css/ with this content to give your interface a dark, modern look:
Step 5: Testing Your AI Agent
It’s essential to test your AI agent to ensure it functions correctly. Follow these steps:
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Run Your Flask Application:
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Open the terminal and navigate to your project directory. Make sure your virtual environment is activated. Run
python app.py -
This will start your Flask server, which usually runs on http://127.0.0.1:5000/
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Interact with the Chat Interface:
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Open a web browser and go to http://127.0.0.1:5000/.
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The chatbot interface should load, showing the input field and chat area
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Test Dynamic Functions:
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Type queries like “price of bitcoin” or “price of ethereum” in the input box
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Observe whether your custom function correctly fetches and displays the real-time cryptocurrency prices
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Type queries like “ohlc of bitcoin for 7 days” to test the OHLC data functionality
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Test Static Responses:
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Ask general questions like “hello” or “how are you?”
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Ensure the predefined static responses from your chatbot appear as expected.
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Step 6: Enhancing Your AI Agent
Once your basic AI agent is working:
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Add More Dynamic Features: Improve the function for cryptocurrency data or add more functions (for example, predicting trends)
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Customize the Static Responses: Adjust the static conversation patterns to cover more use cases
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Improve the User Interface: Update the HTML and CSS to refine the look and add more interactive elements
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Consider Additional Data Sources: If desired, use alternative endpoints from the CoinGecko API to enhance your AI agent, like below
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Derivatives Exchange Data by ID: Use /derivatives/exchanges/{id} to query detailed data about a specific derivatives exchange. This includes information such as the exchange's ID, name, open interest, and more.
- Asset Platforms: Use /asset_platforms to get a list of supported blockchain platforms. This can help users explore tokens and projects on specific blockchains.
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We can also use different machine learning algorithms to improve their accuracy, efficiency, and applicability for specific use cases. Each new feature you add can help improve your agent’s overall usefulness. The goal is to create an evolving, flexible system for your needs.
Conclusion
In this simple guide, you've learned how to build an autonomous AI agent from scratch using Python and Flask. We started by setting up a basic environment, organizing our project, and writing custom code to handle both static and dynamic responses. We then designed a clean and professional user interface using HTML and CSS, and finally, we tested our application locally.
If you enjoyed this article, be sure to check out this one on building an AI Agent with SendAI's Solana Agent Kit
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