Build a Low-Code API Using Power Automate and SharePoint or Dataverse

Overview

In many organizations, different teams and even external partners often need to interact with the same set of business data. Building a secure, reusable API is a powerful way to facilitate this—but not every use case requires a full-scale backend system.

With Microsoft Power Automate, SharePoint Lists, and Dataverse, you can design lightweight API interfaces that allow internal or external users to insert, update, and query data with no server infrastructure. This approach is fast to implement, cost-effective, and entirely maintainable by a business operations team.

This article walks you through how to set up such a solution—complete with authentication, routing, and dynamic responses—using low-code tools.

Digging Deeper

1. Set Up Your Data Source

Before creating an API, you need somewhere to store and manage your data. Power Automate integrates seamlessly with:

Start by designing your table or list structure to fit the needs of the users calling your API. Think through the fields they’ll need to provide and what outputs they’ll expect in return.

2. Create an Instant Cloud Flow

In Power Automate, build a new Instant Cloud Flow triggered by an HTTP Request. This essentially turns your flow into an API endpoint. Once the trigger is set, Power Automate will generate a unique HTTP POST URL. This is what your end users (or external systems) will use to send API calls.

3. Share the Endpoint and Configure Access

After saving your flow, copy the HTTP POST URL. You’ll share this URL with the users or systems that will call your API.

When configuring your HTTP trigger’s authentication:

  • Internal Access: Select “Any user in my organization” to limit access to users within your Microsoft 365 tenant.
  • External Access: Choose “Anyone with the link” and implement your own authentication (discussed next) to secure it.

4. Implement Simple Authentication with Headers

While Power Automate’s HTTP trigger can accept anonymous requests, you should implement basic validation using custom headers. Instruct your users to include a username and password as key-value pairs in their request headers.

ChatGPT Image Generation Example:

Project 5a Image

You can then validate these values inside the flow to ensure only authorized callers can proceed.

To manage access, maintain a list of valid credentials in a secure SharePoint List, Dataverse table, or Azure Key Vault.

5. Support Multiple Actions with a call_type Header

If your API needs to support multiple operations (e.g., insert, query, update), add another header like call_type.

Example:

Project 5b Image

This makes your API flexible and scalable—callers can use a single endpoint for a variety of functions.

6. Create an Instant Cloud Flow

In Power Automate, build a new Instant Cloud Flow triggered by an HTTP Request. This essentially turns your flow into an API endpoint. Once the trigger is set, Power Automate will generate a unique HTTP POST URL. This is what your end users (or external systems) will use to send API calls.

7. Create an Instant Cloud Flow

In Power Automate, build a new Instant Cloud Flow triggered by an HTTP Request. This essentially turns your flow into an API endpoint. Once the trigger is set, Power Automate will generate a unique HTTP POST URL. This is what your end users (or external systems) will use to send API calls.

8. Create an Instant Cloud Flow

In Power Automate, build a new Instant Cloud Flow triggered by an HTTP Request. This essentially turns your flow into an API endpoint. Once the trigger is set, Power Automate will generate a unique HTTP POST URL. This is what your end users (or external systems) will use to send API calls.

Tech Stack

Key Features

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Lessons Learned

Working through the full stack of design, hosting, and backend integration gave me a holistic view of web development and reinforced my comfort with AWS and frontend design systems like Tailwind.