Grounding a Custom AI Chatbot or App on SharePoint Content: Three Architectural Options, One Baseline

Introduction

For most organizations, SharePoint is the primary home for unstructured, user-created content, and it is fast becoming the trusted foundation of enterprise knowledge. That raises a natural question. If the knowledge already lives in SharePoint, how do you put it to work inside an AI chatbot that is not SharePoint or Copilot, one built into your own application?

Connecting SharePoint to a non-native AI assistant makes that knowledge available on demand and can meaningfully boost efficiency, and there is more than one way to build the connection.

In this series I walk through three architectural options and, more importantly, the trade-offs between them. To keep the comparison honest, I assess each option against the same set of parameters, so they are measured on a common baseline rather than described in isolation. This first article defines that baseline and introduces the options. The articles that follow take each option in turn and put it through these factors.

The factors I am considering

1. Security. Two things to weigh here. First, what a user can see, meaning whether the solution honors SharePoint’s existing permissions so people only reach content they are already entitled to. Second, the authentication mechanism that carries the user’s identity through to the content.
2. Cost. Three costs shape the decision: licensing and the monthly service bill, one-time implementation cost, and ongoing operations cost.
3. Governance, including auditability and observability. How well the approach fits into enterprise controls, and whether you can see and prove what the agent retrieved and surfaced.
4. Data residency. Where the content actually lives and travels, and whether it ever leaves the tenant boundary.
5. Retrieval quality and citations. How relevant and accurate the returned content is, how much control you have over ranking and chunking, and whether answers come back with trustworthy citations to their source documents.
6. Flexibility. How much control you keep over the model, the orchestration, and the user experience.
7. Scalability. The ability to handle large volumes of content and many sites without running into throttling limits.
8. Data freshness and latency. How quickly a change in SharePoint is reflected in the agent’s answers, and what drives any delay.

The three options at a glance

The three approaches differ mainly in one thing: how much of the pipeline you own. They run from fully managed, where Microsoft does almost everything, to fully custom, where you build and run it yourself.

Work IQ APIs. The most managed option. Microsoft’s own intelligence layer handles retrieval, grounding, and reasoning over your Microsoft 365 content, and your application connects to it over REST, MCP, or A2A. You bring the least and inherit the most, including permission trimming and freshness, straight out of the box.

Copilot Retrieval API plus your own LLM. The middle path. Microsoft returns permission-trimmed, grounded content from the live index, and you bring your own model and orchestration to turn it into an answer. You keep control of the model and the experience without ever having to build or maintain an index of your own.

Custom RAG on Azure AI Search. The most custom option. You extract SharePoint content, build and maintain your own search index, and own the full pipeline end to end, from ingestion to answer. It offers the most control and the widest reach, and it asks the most of you in return.

Each of these earns or loses points differently against the factors above, and the right choice depends on which factors matter most to you.

In the next article I put the first option, Work IQ APIs, the most managed of the three, through all eight factors to see where it shines and where it strains.

Written by Venugopal Reddy P. I write about governance, compliance, AI, and automation for the Property & Casualty insurance world at AK Tech Hub. Views are my own, and product details in this fast-moving space change frequently, so verify current capabilities and pricing before making decisions.