You're indexing content with Azure AI Search and you want to recognize and retrieve properties from invoices (such as invoice number, vendor, dates, totals, line items). The Azure service designed for structured information extraction from forms and documents is Azure AI Document Intelligence (formerly Form Recognizer).
In an Azure AI Search enrichment pipeline, you add a skillset. To pull structured fields from invoices, include a skill that invokes Document Intelligence's prebuilt Invoice model. This model already extracts common invoice fields, so you don't have to train anything-meeting the goal of minimal effort. You can wire this in using the built-in Document Intelligence skill for Search, or as a custom Web API skill that calls the Document Intelligence REST API, and then map the extracted fields into your index for retrieval and filtering.
Why the others are not suitable:
* Azure OpenAI is for generative/LLM tasks, not schema-level invoice field extraction.
* Azure AI Immersive Reader improves reading accessibility; it doesn't extract business fields.
* Azure Custom Vision is for image classification/object detection, not form/key-value extraction.
Microsoft References (Azure AI Solution)
* Azure AI Search skillsets - add AI enrichment and custom skills (Web API skill).
* Document Intelligence skill for Azure AI Search (formerly Form Recognizer skill) - integrate extraction into indexing.
* Prebuilt Invoice model - fields extracted (vendor, invoice ID/date, totals, taxes, line items, etc.).
* Azure AI Document Intelligence overview - key-value extraction and table/line-item parsing from documents.