Building a Pen API with The Product API: A Complete Guide

Introduction to Pens

Pens are essential writing instruments found in every office, school, and home. From reliable ballpoint pens for everyday writing to elegant fountain pens for special occasions, finding the right pen with the right specifications is crucial for writing comfort and style. Whether you're stocking an office supply store, building a stationery marketplace, or creating a writing instrument catalog, having structured pen product data is essential.

Imagine being able to search for pens and instantly get detailed information about each pen - from pen type to ink color. This is exactly what a specialized Pen Product API can provide.

What Makes a Pen API Special?

A Pen Product API goes beyond basic product listings. It understands the unique characteristics that matter to pen buyers:

• Pen Type: The writing mechanism - ballpoint, gel, fountain, rollerball, marker, or felt tip
• Ink Color: The color of the ink - black, blue, red, green, or multi-color

With this structured data, you can build powerful features like filtering by pen type, comparing ink colors, or recommending pens based on writing preferences.

Try It Out: Search for Pens

Use the search bar below to search for pens. Try queries like "Pilot G2 gel pen", "ballpoint pen blue", or "fountain pen black". The results will include detailed specifications automatically extracted from product information across the web.

How It Works: Technical Implementation

Now that you've seen the API in action, let's dive into how it's implemented. This specialized Pen API is built on top of The Product API which is an AI-based product search API that works with any product and any type of query. It responds with structured JSON and supports custom structured responses, allowing you to build specialized APIs for any product category.

The Product API's powerful custom_data_schema feature allows you to define additional structured fields specific to your product category, enabling you to create category-specific APIs like this Pen API. For more details on how the API works, see the full documentation.

Understanding APIs for Product Data

An API (Application Programming Interface) enables different software applications to communicate. For product data:

• Input: You send a search query (e.g., "pen Pilot G2 gel")
• Processing: The API searches across multiple sources and uses AI to extract relevant information
• Output: You receive structured product data in JSON format

The flexibility of a product API means you can customize it for specific categories by defining additional data fields through JSON Schema.

Creating a Pen-Specific JSON Schema to pass as custom_data_schema of search request

Here's the JSON Schema we use for pen products:

{
  "type": "object",
  "properties": {
    "pen_type": {
      "type": "string",
      "enum": ["ballpoint", "gel", "fountain", "rollerball", "marker", "felt_tip"],
      "description": "Type of pen"
    },
    "ink_color": {
      "type": "string",
      "description": "Ink color (e.g., 'black', 'blue', 'red', 'green', 'multi-color')"
    }
  },
  "required": ["pen_type"]
}

Using the Category Prefix

When searching for pens, we prefix the search query with "pen" to help the AI understand the context and return more relevant results.

Example Search Queries:

• pen Pilot G2 gel
• pen ballpoint blue
• pen fountain black
• pen gel multi-color

The prefix "pen" ensures the API understands you're looking specifically for pens and not other products.

Complete Example: Making a Request

Here's how to make a request to The Product API with a pen-specific schema. For complete API reference including authentication, endpoints, and all parameters, see the documentation:

const response = await fetch('https://api.example.com/api?search=pen%20Pilot%20G2%20gel&with_image=true', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'Authorization': 'Bearer YOUR_API_KEY'
  },
  body: JSON.stringify({
    custom_data_schema: {
      type: "object",
      properties: {
        pen_type: {
          type: "string",
          enum: ["ballpoint", "gel", "fountain", "rollerball", "marker", "felt_tip"],
          description: "Type of pen"
        },
        ink_color: {
          type: "string",
          description: "Ink color"
        }
      },
      required: ["pen_type"]
    }
  })
});

const data = await response.json();
console.log(data.products);
Show more (27 lines)

Expected Response

The API will return products with standard fields plus your custom custom_data field:

{
  "status": "success",
  "products": [
    {
      "name": "Pilot G2 Gel Pen",
      "description": "The Pilot G2 is a smooth-writing gel pen with vibrant ink...",
      "brand": "Pilot",
      "image": "https://example.com/image.jpg",
      "custom_data": {
        "pen_type": "gel",
        "ink_color": "black"
      }
    }
  ]
}

Conclusion

By combining the flexible Product API with a pen-specific JSON Schema, you can create a powerful, specialized API for pen products. The key is:

1. Define your schema based on what pen data matters to your application
2. Use category prefixes in search queries for better context
3. Leverage the custom_data field to build rich, category-specific features

The same approach works for any product category - you just need to define the right schema for your needs!

Ready to get started? Create your own product API on The Product API and start building your own category-specific APIs today!

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Ready to build your own category-specific API? Check out our other API preset guides for chairs, keyboards, books, and more!