Image Data Extraction API with Structured AI Output - n8n Workflow

Developers needing a serverless OCR API endpoint.
Businesses requiring automated processing of documents, receipts, or ID cards.
Automation specialists looking for advanced n8n templates for AI integration.
Anyone interested in creating sophisticated multimodal n8n workflow solutions.

Extracting structured data from visual documents like receipts, invoices, or ID cards can be challenging. This n8n workflow solves this by acting as a high-performance, customizable API service. When an external application sends a request to the n8n trigger, providing an image URL, the system fetches the image and transforms it into a base64 format.

The core of this n8n automation is the integration with the Gemini AI API, which not only analyzes the image but also adheres to a user-defined JSON schema for the output. This ensures that the result is always clean, structured JSON, making downstream processing easy. This powerful n8n workflow demonstrates how to combine file handling, external HTTP requests, and advanced AI features within a single, reliable system. Deploy this n8n workflow today to streamline data entry and document processing tasks.

This powerful n8n workflow is initiated by an external API call, making it a highly useful automation tool.

1. Webhook Trigger: The automation starts with the Webhook n8n trigger, configured to listen on the path /data-extractor. It expects inputs including the image_url, the Requirement prompt (what data to extract), and the properties schema (defining the required JSON output structure).


2. Fetch Image: The n8n node, Get image from URL (an HTTP Request), downloads the image binary data using the provided URL from the webhook body.


3. Encoding: The Transform image to base64 n8n node converts the binary image file into a Base64 string (data1), which is necessary for embedding the image within the Gemini API request.


4. AI Analysis: The Call Gemini API (Flash Lite) with Image n8n node sends a complex POST request to the Gemini endpoint. This request uses the Base64 image, the extraction Requirement prompt, and crucially, the user-defined JSON schema provided by the webhook input, forcing the AI to return structured data.


5. Clean Output: The Edit fields to output required data alone n8n node extracts the raw JSON text from the AI response, parses it, and assigns it to a single output field named result.


6. Respond: Finally, the Respond to Webhook n8n node returns the extracted, structured data back to the originating client, completing the execution of the n8n workflow.

To deploy and run this sophisticated n8n template, follow these steps:

1. Import: Download the provided JSON code and import it directly into your n8n instance.


2. Credentials: You must set up a credential for the Google Gemini API (labeled as googlePalmApi in the workflow JSON). Ensure you have your Gemini API key configured correctly.


3. Webhook Setup: The Webhook n8n trigger is automatically set up. After activating the n8n workflow, click on the Webhook node and copy the production URL. The expected path is /data-extractor.


4. Testing: Use the sample cURL request provided in the sticky note to test the n8n workflow. Remember to replace your_domain.com with your actual n8n instance domain.

Note: Ensure the API key has the necessary permissions to access the Gemini AI model.

This n8n workflow utilizes several key nodes to manage the data flow and AI integration:

Webhook (n8n trigger): Serves as the API entry point. It receives the image URL, extraction prompt, and the required output schema. Path is set to data-extractor.
Get image from URL (HTTP Request n8n node): Fetches the image specified by the dynamic expression ={{ $json.body.image_url }}.
Transform image to base64 (Extract From File n8n node): Converts the binary data of the downloaded image into a Base64 string, stored in the data1 property, ready for the Gemini API call.
Call Gemini API (Flash Lite) with Image (HTTP Request n8n node): The core processing step. It sends multimodal input (image base64 + text prompt) to the gemini-2.0-flash-lite model. Key configuration includes embedding the input image data ({{$json.data1}}) and defining the responseSchema based on dynamic data from the initial n8n trigger payload.
Edit fields to output required data alone (Set n8n node): Cleans up the complex API response. It uses JSON manipulation (.parseJson()) to isolate the structured AI output and assigns it to the result field.
Respond to Webhook: Sends the final, cleaned JSON output back to the external application instantly.