Custom Connectors Overview
Custom Connectors Overview
Microsoft Power Platform provides many ready-made connectors for popular services such as Microsoft 365, SharePoint, Dataverse, Outlook, Teams, Salesforce, SQL Server, and many other systems. However, sometimes a business needs to connect Power Apps, Power Automate, Copilot Studio, or Azure Logic Apps with a system that does not have a prebuilt connector. In that case, a Custom Connector can be created.
Microsoft documentation explains that Azure Logic Apps, Microsoft Power Automate, Microsoft Power Apps, and Microsoft Copilot Studio offer over 1,000 connectors to connect to Microsoft and verified services, but users may want to communicate with services that are not available as prebuilt connectors. Custom connectors address this scenario by allowing users to create and share a connector with its own triggers and actions. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
In simple words, a Custom Connector is a reusable connector created for a custom API or service. It allows Power Platform solutions to communicate with external systems in a low-code way.
1. What is a Custom Connector?
A Custom Connector is a user-created connector that allows Power Platform products to connect with an API or system that is not available as a ready-made connector. Microsoft documentation defines a custom connector as a wrapper around a REST API that allows Logic Apps, Power Automate, Power Apps, or Copilot Studio to communicate with that REST or SOAP API. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
| Concept | Simple Meaning | Example |
|---|---|---|
| Custom Connector | A reusable connector created for a custom API or service. | Connector for company HR API. |
| REST API | A web API that uses HTTP requests. | GET employee details from an API. |
| SOAP API | A web service style that can also be supported in some scenarios. | Legacy enterprise system web service. |
| Action | An operation exposed by the connector. | Get Employee, Create Ticket, Update Order. |
| Trigger | An event that can start a workflow. | When a new order is created in external system. |
2. Why Custom Connectors are Needed
Custom connectors are needed when a business system does not have a prebuilt connector or when the available connector does not meet specific requirements. Microsoft Learn training explains that custom connectors help app and flow makers connect to other apps, data, and devices in the cloud, and the training path covers using custom connectors with Power Apps, Power Automate, and Azure Logic Apps. [2](https://learn.microsoft.com/en-us/training/paths/build-custom-connectors/)
| Need | Explanation | Example |
|---|---|---|
| No Prebuilt Connector | The required API or service is not available in the connector list. | Internal payroll API. |
| Internal Business System | Company-specific systems often expose custom APIs. | Employee verification system. |
| Third-Party API | Some third-party services may not have official connectors. | Local courier tracking API. |
| Reusable Integration | One connector can be reused in multiple apps and flows. | HR connector used in onboarding app and leave app. |
| Low-Code API Usage | Makers can use connector actions instead of writing full API code. | Power Automate action calls an API endpoint. |
3. Where Custom Connectors Can Be Used
Microsoft documentation states that a custom connector can allow Logic Apps, Power Automate, Power Apps, or Copilot Studio to communicate with a REST or SOAP API. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
| Power Platform Product | How Custom Connector is Used | Example |
|---|---|---|
| Power Apps | Use custom connector actions to retrieve or submit external data. | Display employee profile from HR API. |
| Power Automate | Use custom connector actions or triggers in cloud flows. | Create external ticket when Dataverse row is created. |
| Copilot Studio | Extend agent capabilities by connecting to external services. | Agent retrieves order status using custom connector. |
| Azure Logic Apps | Use custom connector in enterprise workflow automation. | Connect enterprise integration workflow to custom API. |
4. Custom Connector and API Relationship
A custom connector does not replace an API. Instead, it wraps the API in a Power Platform-friendly format. The API provides the actual business operation, while the connector exposes that operation as an action or trigger inside Power Apps, Power Automate, Copilot Studio, or Logic Apps.
Microsoft documentation states that to create a custom connector, you must describe the API you want to connect to so the connector understands the API’s operations and data structures. [3](https://learn.microsoft.com/en-us/connectors/custom-connectors/define-openapi-definition)
| Layer | Purpose | Example |
|---|---|---|
| API | Provides business operation or data. | GET /employees/{id} |
| Custom Connector | Wraps API operation for Power Platform use. | Get Employee Details action. |
| Power App / Flow | Uses connector action in business solution. | Show employee data in app or send notification. |
5. Custom Connector Lifecycle
Microsoft custom connector documentation describes a lifecycle that includes building the API and securing the API. It explains that custom connectors can work with public APIs visible on the internet and private APIs visible only to a network. It also states that for private APIs, Microsoft offers on-premises data connectivity through an on-premises data gateway. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
| Lifecycle Stage | Meaning | Example |
|---|---|---|
| Build or Identify API | Decide which API the connector will use. | HR Employee API. |
| Secure API | Choose authentication and access control. | OAuth 2.0 or API Key. |
| Describe API | Define operations, parameters, and data structure. | OpenAPI definition. |
| Create Connector | Create reusable connector in Power Platform. | Employee API Connector. |
| Use Connector | Use connector in apps, flows, agents, or Logic Apps. | Power App calls Get Employee action. |
| Maintain Connector | Update connector when API changes. | Add new action for Get Department. |
6. Public API vs Private API
Microsoft documentation explains that APIs used by custom connectors can be public, meaning visible on the public internet, or private, meaning visible only to a network. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
| API Type | Description | Example |
|---|---|---|
| Public API | API visible on the public internet. | Public weather API or public service API. |
| Private API | API visible only inside a company network or private environment. | Internal payroll API. |
| Private API with Gateway | Private API can be accessed through on-premises data connectivity where applicable. | Internal system accessed using on-premises data gateway. |
7. Authentication in Custom Connectors
Authentication is one of the most important parts of custom connector design. Microsoft documentation lists standard authentication methods for APIs and connectors, including Generic OAuth 2.0, OAuth 2.0 for specific services including Microsoft Entra ID, Dropbox, GitHub, and Salesforce, Basic authentication, and API Key. It also states that Microsoft Entra ID is recommended. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
| Authentication Type | Meaning | Example |
|---|---|---|
| API Key | A secret key is sent with API requests. | x-api-key header. |
| Basic Authentication | Username and password based access. | Legacy API authentication. |
| OAuth 2.0 | Token-based authentication. | Third-party SaaS API login. |
| Microsoft Entra ID | Microsoft identity-based authentication. | Enterprise API protected by Entra ID. |
8. Actions in Custom Connectors
Actions are operations exposed by the custom connector. For example, if an API has endpoints for getting employee details, creating tickets, or updating orders, each endpoint can be represented as a custom connector action. Microsoft documentation states that custom connectors allow users to create connectors with their own triggers and actions. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
| API Endpoint | Custom Connector Action | Business Use |
|---|---|---|
| GET /employees/{id} | Get Employee Details | Show employee information in Power App. |
| POST /tickets | Create Support Ticket | Create ticket from Power Automate flow. |
| PATCH /orders/{id} | Update Order Status | Update external order after approval. |
| GET /shipments/{trackingNo} | Get Shipment Status | Display delivery status in app. |
9. Triggers in Custom Connectors
Custom connectors can also support trigger definitions where a system needs to respond to changes in underlying data or services. Microsoft Learn training explains that custom connector functionality can be expanded with trigger definitions in Power Automate and Azure Logic Apps when a system needs to respond to changes in underlying data or services. [2](https://learn.microsoft.com/en-us/training/paths/build-custom-connectors/)
| Trigger Example | Meaning | Business Scenario |
|---|---|---|
| When a new order is created | Flow starts when external system creates an order. | Notify warehouse team. |
| When shipment status changes | Flow starts when delivery status changes. | Send customer delivery update. |
| When employee record is updated | Flow starts when HR API reports a change. | Update Dataverse employee table. |
10. OpenAPI / Swagger in Custom Connectors
OpenAPI helps describe an API in a machine-readable format. Microsoft documentation explains that one way to create custom connectors for Microsoft Copilot Studio, Azure Logic Apps, Microsoft Power Automate, or Microsoft Power Apps is to provide an OpenAPI definition file. It also explains that an OpenAPI definition file is a language-agnostic, machine-readable document that describes API operations and parameters. [4](https://make.powerautomate.com/documentation/customapi-how-to-swagger/)
Microsoft documentation also states that when creating a custom connector from an OpenAPI definition, the OpenAPI definition must be less than 1 MB and in OpenAPI 2.0, formerly known as Swagger, format. [3](https://learn.microsoft.com/en-us/connectors/custom-connectors/define-openapi-definition)
| Term | Meaning | Why It Matters |
|---|---|---|
| OpenAPI | Machine-readable API description. | Helps custom connector understand API operations. |
| Swagger | Former name commonly associated with OpenAPI 2.0. | Many APIs provide Swagger documentation. |
| Operation | API action described in the definition. | Get Employee, Create Order. |
| Parameter | Input required by an API operation. | Employee ID, Order Number. |
11. Custom Connector Architecture
A custom connector architecture usually includes a Power Platform app or flow, the custom connector, authentication, the API endpoint, and the external system. The connector acts as a reusable bridge between Power Platform and the API.
| Architecture Component | Purpose | Example |
|---|---|---|
| Power App / Flow | Uses the custom connector. | Employee onboarding app. |
| Custom Connector | Wraps API operations into reusable actions/triggers. | HR API Connector. |
| Authentication | Secures the API call. | OAuth 2.0 or API Key. |
| External API | Provides data or operation. | Payroll API. |
| External System | System behind the API. | HRMS, ERP, CRM, logistics system. |
12. Common Use Cases for Custom Connectors
| Use Case | API / System | Example |
|---|---|---|
| Employee Lookup | Internal HR API | Power App shows employee manager and department. |
| Order Tracking | Courier API | Flow retrieves shipment status. |
| Payment Verification | Payment Gateway API | Flow checks whether payment is successful. |
| ERP Integration | Legacy ERP API | Power Automate sends approved invoice data. |
| Customer Validation | External verification API | App validates customer tax number. |
| Copilot Extension | Business API | Copilot agent retrieves order status. |
13. Custom Connector vs HTTP Action
Power Automate can call APIs directly using HTTP actions, but a custom connector is better when the same API needs to be reused in multiple apps or flows. Microsoft documentation supports the idea that custom connectors create a reusable connector with its own triggers and actions for services not available as prebuilt connectors. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
| Comparison | HTTP Action | Custom Connector |
|---|---|---|
| Usage | Used directly inside a flow. | Reusable across apps, flows, agents, and Logic Apps. |
| Reusability | Less reusable if repeated manually in many flows. | More reusable because actions are defined once. |
| User Experience | Flow maker works directly with URL, headers, and body. | Maker uses named actions such as Get Employee Details. |
| Best For | Simple one-time API calls. | Reusable and governed API integration. |
14. Custom Connector Licensing Consideration
Custom connectors are generally treated as a premium capability in Power Platform licensing discussions. Because licensing can change and depends on tenant, product, and user rights, always confirm the current licensing requirements before using custom connectors in production. This is a practical recommendation for solution planning.
| Planning Area | Why It Matters | Example |
|---|---|---|
| User Licensing | Users may need appropriate Power Platform rights to use apps or flows with custom connectors. | Power App using HR custom connector. |
| Environment Governance | Admins may control where custom connectors can be created or used. | Allow custom connectors only in approved environments. |
| DLP Policy | Custom connectors may need governance classification. | Classify HR API connector as business connector. |
15. Security Best Practices for Custom Connectors
| Best Practice | Explanation | Example |
|---|---|---|
| Use secure authentication | Use suitable authentication method such as OAuth 2.0, API key, Basic authentication, or Microsoft Entra ID where applicable. | Use Entra ID for internal enterprise API. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/) |
| Use HTTPS | API communication should be encrypted. | Use HTTPS endpoint for payroll API. |
| Follow least privilege | Connector credentials should have only required access. | Read-only connector for lookup scenario. |
| Protect secrets | Do not expose API keys or tokens in app screens or documentation. | Do not hardcode API key in visible app formulas. |
| Review access | Only approved users should use sensitive connectors. | Restrict payroll connector to HR solution. |
16. Best Practices for Designing Custom Connectors
| Best Practice | Explanation | Example |
|---|---|---|
| Use clear action names | Actions should be easy for makers to understand. | Get Employee Details instead of GET Emp API. |
| Use meaningful descriptions | Descriptions help makers understand operation purpose. | “Returns employee details by employee ID.” |
| Define request and response schemas | Power Apps and flows need predictable input and output structure. | Employee ID input and employee details output. |
| Use OpenAPI where available | OpenAPI describes API operations and parameters in machine-readable format. | Import Swagger file for connector. [4](https://make.powerautomate.com/documentation/customapi-how-to-swagger/) |
| Test every operation | Validate authentication, input, output, and error handling. | Test Get Order Status with valid and invalid order numbers. |
| Document the connector | Maintain details for future support and governance. | Document API base URL, auth type, actions, owner, and use cases. |
17. Common Mistakes in Custom Connectors
| Mistake | Problem | Better Approach |
|---|---|---|
| No clear API documentation | Connector actions may be wrongly configured. | Understand endpoint, method, parameters, headers, and response. |
| Ignoring authentication | Connector fails or exposes data insecurely. | Configure authentication correctly. |
| Poor action names | Makers cannot understand what actions do. | Use business-friendly action names. |
| No response schema | App or flow cannot easily use returned data. | Define response schema during connector design. |
| Hardcoding secrets | Security and maintenance risk. | Use approved secure authentication pattern. |
| No version planning | API changes may break apps and flows. | Plan connector versioning and document changes. |
| No governance review | Connector may be used in unsafe or unsupported scenarios. | Review DLP, environment, and access policies. |
18. Real-Life Example: HR Employee API Connector
Imagine a company has an internal HR API that stores employee details. There is no prebuilt connector for this API, so the organization creates a custom connector.
| Requirement | Custom Connector Action | Purpose |
|---|---|---|
| Find employee by ID | Get Employee Details | Show employee name, email, manager, department. |
| Check employment status | Get Employment Status | Confirm whether employee is active. |
| Submit onboarding request | Create Onboarding Request | Send new employee request to HR system. |
19. Real-Life Example: Courier Tracking Connector
A business may need to track shipments from a courier API. If no prebuilt connector exists, a custom connector can expose the courier API as reusable actions.
| API Endpoint | Custom Connector Action | Business Use |
|---|---|---|
| GET /tracking/{trackingNumber} | Get Shipment Status | Power App shows current shipment status. |
| POST /pickup | Create Pickup Request | Flow schedules courier pickup after order confirmation. |
| GET /delivery-estimate | Get Delivery Estimate | App displays estimated delivery date. |
20. Mini Project: Build a Custom Connector Concept for Order Status
Project Objective
Design a custom connector concept that connects Power Platform to an external order tracking API.
| Component | Design | Example |
|---|---|---|
| External API | Order tracking API | https://api.example.com/orders |
| Authentication | API Key or OAuth 2.0 | Authorization token. |
| Action 1 | Get Order Status | Input: Order Number; Output: Status. |
| Action 2 | Update Order Notes | Input: Order Number and Notes. |
| Power App Use | User checks order status. | Customer service app. |
| Power Automate Use | Flow sends status update email. | Notify customer when order is shipped. |
Learning Outcome
- Students understand why custom connectors are used.
- Students learn how APIs become reusable Power Platform actions.
- Students understand the role of authentication, OpenAPI, actions, and response schemas.
- Students learn how Power Apps and Power Automate can reuse the same connector.
21. Interview Questions and Answers
Q1. What is a custom connector?
A custom connector is a connector created to communicate with a service that is not available as a prebuilt connector. Microsoft documentation defines a custom connector as a wrapper around a REST API that allows Logic Apps, Power Automate, Power Apps, or Copilot Studio to communicate with that REST or SOAP API. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
Q2. Why do we need custom connectors?
Custom connectors are needed when a required service is not available as a prebuilt connector. Microsoft documentation states that custom connectors address scenarios where users want to communicate with services that are not available as prebuilt connectors. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
Q3. Which products can use custom connectors?
Microsoft documentation states that custom connectors can be used with Azure Logic Apps, Microsoft Power Automate, Microsoft Power Apps, and Microsoft Copilot Studio. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
Q4. What type of APIs can custom connectors connect to?
Microsoft documentation states that custom connectors can wrap REST APIs, and Logic Apps also supports SOAP APIs. It also states that APIs can be public or private. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
Q5. What authentication methods can be used with custom connectors?
Microsoft documentation lists Generic OAuth 2.0, OAuth 2.0 for specific services, Basic authentication, and API Key. It also states that Microsoft Entra ID is recommended. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
Q6. What is OpenAPI in custom connectors?
Microsoft documentation explains that an OpenAPI definition file is a language-agnostic, machine-readable document that describes API operations and parameters. [4](https://make.powerautomate.com/documentation/customapi-how-to-swagger/)
Q7. Why is OpenAPI useful?
OpenAPI is useful because it describes API operations and parameters in a machine-readable way, helping the connector understand the API structure. Microsoft documentation states that to create a custom connector, the API must be described so the connector understands operations and data structures. [3](https://learn.microsoft.com/en-us/connectors/custom-connectors/define-openapi-definition)
Q8. What is the difference between a custom connector and an HTTP action?
An HTTP action is usually configured directly inside a flow for a specific API call. A custom connector wraps API operations as reusable actions and can be used in Power Apps, Power Automate, Copilot Studio, and Logic Apps. This explanation follows Microsoft’s definition of a custom connector as a reusable wrapper around REST or SOAP APIs. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
Q9. Can custom connectors have triggers?
Yes. Microsoft Learn training states that custom connector functionality can be extended with trigger definitions where a system needs to respond to changes in underlying data or services. [2](https://learn.microsoft.com/en-us/training/paths/build-custom-connectors/)
Q10. Give a real-life example of a custom connector.
A company can create a custom connector for an internal HR API. The connector can expose actions such as Get Employee Details, Get Employment Status, or Create Onboarding Request, allowing Power Apps and Power Automate to use HR data in business processes.
22. Student-Friendly Summary
| Concept | Easy Meaning | Example |
|---|---|---|
| Custom Connector | A connector created for a custom API. | HR API connector. |
| API | A way for systems to communicate. | Order tracking API. |
| Action | A task exposed by the connector. | Get Order Status. |
| Trigger | An event that can start a flow. | When shipment status changes. |
| Authentication | Security for API access. | OAuth 2.0 or API Key. |
| OpenAPI | Machine-readable API description. | Swagger file for connector creation. |
23. Quick Revision Points
- Custom connectors are used when a required service is not available as a prebuilt connector. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
- A custom connector is a wrapper around a REST API that allows Power Apps, Power Automate, Copilot Studio, or Logic Apps to communicate with the API. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
- Logic Apps also supports SOAP APIs in custom connector scenarios. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
- APIs used with custom connectors can be public or private. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
- For private APIs, Microsoft offers on-premises data connectivity through an on-premises data gateway. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
- Authentication methods include OAuth 2.0, Basic authentication, API Key, and Microsoft Entra ID-based options. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
- OpenAPI definitions describe API operations and parameters. [4](https://make.powerautomate.com/documentation/customapi-how-to-swagger/)
- When creating a connector from OpenAPI, Microsoft documentation states that the definition must be less than 1 MB and in OpenAPI 2.0 format. [3](https://learn.microsoft.com/en-us/connectors/custom-connectors/define-openapi-definition)
- Custom connectors can include actions and triggers. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)[2](https://learn.microsoft.com/en-us/training/paths/build-custom-connectors/)
- Custom connectors should be designed with security, documentation, governance, testing, and maintainability in mind.
Conclusion
Custom Connectors are an important integration feature in Microsoft Power Platform. They allow Power Apps, Power Automate, Copilot Studio, and Azure Logic Apps to communicate with APIs and services that are not available as prebuilt connectors.
Microsoft documentation defines a custom connector as a wrapper around a REST API that allows Logic Apps, Power Automate, Power Apps, or Copilot Studio to communicate with that REST or SOAP API. It also explains that custom connectors can be used with public APIs and private APIs, and that private APIs can use on-premises data connectivity through an on-premises data gateway. [1](https://learn.microsoft.com/en-us/connectors/custom-connectors/)
Custom connectors can expose API operations as actions and can also support triggers where the external system needs to respond to changes. OpenAPI definitions can be used to describe API operations and parameters in a machine-readable format, helping the connector understand the API structure. [4](https://make.powerautomate.com/documentation/customapi-how-to-swagger/)[2](https://learn.microsoft.com/en-us/training/paths/build-custom-connectors/)
In real-world projects, custom connectors are useful for internal APIs, third-party services, legacy systems, ERP integrations, HR systems, payment gateways, courier tracking APIs, and specialized business platforms. A good custom connector should have secure authentication, meaningful action names, clear request and response schemas, proper testing, documentation, governance, and lifecycle planning.