Connectors and Integration Patterns

Understanding Connectors

Connectors are the building blocks of Logic Apps integration. They provide pre-built access to hundreds of services, both in the cloud and on-premises.

Microsoft Reference: Connectors overview

Connector Types

Built-in Connectors

Built-in connectors run natively within the Logic Apps runtime with no external dependencies. They offer the best performance and lowest latency.

Connector	Description
HTTP	Call any REST API endpoint
HTTP + Webhook	Register/unregister webhook callbacks
Request	Receive HTTP requests (trigger)
Response	Return HTTP responses
Schedule	Recurrence and sliding window triggers
Compose	Data manipulation and transformation
Parse JSON	Schema-based JSON parsing
Variables	Initialize, set, increment, append
Condition/Switch	Conditional branching
For Each / Until	Looping constructs
Scope	Group actions for error handling
Terminate	End workflow with status
Batch	Send and receive batched messages
Inline Code	Execute JavaScript snippets (Consumption only)

Standard Plan Built-in Connectors

Standard (single-tenant) Logic Apps includes additional built-in connectors with better performance:

Connector	Description
Azure Service Bus	Queues, topics, and subscriptions
Azure Blob Storage	Blob operations without managed connector overhead
Azure Cosmos DB	Document database operations
Azure Event Hubs	Event streaming
Azure Table Storage	Table operations
Azure Queue Storage	Queue operations
SQL Server	Database operations
IBM MQ	Enterprise messaging
SMTP / POP3 / IMAP	Email protocols

Microsoft Reference: Built-in connectors for Standard

Managed Connectors

Managed connectors are hosted and managed by Microsoft. They run in Azure and connect to external services via APIs.

Standard Managed Connectors

Connector	Service
Azure SQL	Azure SQL Database
Azure Blob Storage	Blob storage operations
SharePoint	SharePoint Online lists and libraries
Outlook.com / Office 365	Email, calendar, contacts
OneDrive	File storage
Dynamics 365	CRM operations
Azure DevOps	Work items, pipelines, repos
Azure Key Vault	Secret management
Azure Service Bus	Messaging (Consumption plan)
Azure Event Grid	Event routing
Teams	Posts, channels, adaptive cards

Enterprise Managed Connectors

Enterprise connectors provide access to enterprise systems at a higher per-execution cost:

Connector	Service
SAP	SAP ERP and S/4HANA
IBM 3270	Mainframe terminal access
IBM DB2	DB2 database
IBM MQ	Enterprise messaging (Consumption)
Oracle Database	Oracle DB operations

Microsoft Reference: Managed connectors list

Custom Connectors

Create your own connectors to wrap any REST or SOAP API:

1. Define the API — Import an OpenAPI (Swagger) specification, Postman collection, or build from scratch
2. Configure authentication — API Key, OAuth 2.0, Basic Auth, or Azure AD
3. Define actions and triggers — Map API operations to connector actions
4. Set policies — Transform requests/responses with policy templates
5. Share — Use within your organisation or publish to the connector ecosystem

{
  "swagger": "2.0",
  "info": {
    "title": "Order Management API",
    "version": "1.0"
  },
  "host": "api.example.com",
  "basePath": "/v1",
  "schemes": ["https"],
  "paths": {
    "/orders": {
      "get": {
        "operationId": "GetOrders",
        "summary": "Get all orders",
        "parameters": [
          {
            "name": "status",
            "in": "query",
            "type": "string",
            "enum": ["pending", "processing", "completed"]
          }
        ],
        "responses": {
          "200": {
            "description": "Success",
            "schema": {
              "type": "array",
              "items": { "$ref": "#/definitions/Order" }
            }
          }
        }
      }
    }
  }
}

Microsoft Reference: Create custom connectors

On-Premises Data Gateway

Connect Logic Apps to on-premises data sources through a secure gateway.

How It Works

Logic Apps (Cloud)
  ↕ HTTPS (outbound only from gateway)
On-Premises Data Gateway (installed on a server in your network)
  ↕ Native protocols
On-Premises Data Sources (SQL Server, Oracle, file systems, SAP)

Supported On-Premises Connectors

Connector	Protocol
SQL Server	TDS
Oracle Database	ODP.NET
File System	SMB
SAP	RFC/BAPI
SharePoint Server	CSOM
IBM DB2	DRDA
IBM Informix	DRDA
MySQL	MySQL protocol
PostgreSQL	PostgreSQL protocol

Gateway Installation

1. Download from the Microsoft Download Centre
2. Install on a Windows server within your network
3. Register with your Azure AD tenant
4. Create a gateway resource in Azure
5. Reference in your Logic App connections

Best Practices for On-Premises Gateway

• Install on a dedicated server (not a domain controller or database server)
• Use a gateway cluster for high availability (up to 7 members)
• Place the gateway close to the data source to minimise network latency
• Configure Windows Firewall to allow outbound HTTPS (port 443) to Azure Service Bus
• Use a service account with appropriate permissions
• Monitor gateway health via the on-premises data gateway app

Microsoft Reference: On-premises data gateway

Integration Service Environment (ISE) — Deprecated

ISE provided a dedicated environment for Logic Apps but is deprecated. Migrate to Standard Logic Apps with VNET integration for equivalent functionality.

Microsoft Reference: ISE deprecation and migration

Connector Authentication

Authentication Methods

Method	Use Case
OAuth 2.0	Microsoft 365, Dynamics 365, third-party SaaS
API Key	Custom APIs, third-party services
Basic Auth	Legacy APIs, on-premises systems
Managed Identity	Azure services (Key Vault, SQL, Storage, Service Bus)
Certificate	mTLS, SAP, enterprise systems
Raw	Custom authentication headers

Managed Identity Authentication

Use managed identity to authenticate to Azure services without storing credentials:

{
  "HTTP": {
    "type": "Http",
    "inputs": {
      "method": "GET",
      "uri": "https://management.azure.com/subscriptions/{subscription-id}/resourceGroups?api-version=2021-04-01",
      "authentication": {
        "type": "ManagedServiceIdentity",
        "identity": "SystemAssigned",
        "audience": "https://management.azure.com/"
      }
    }
  }
}

API Connection Security

For managed connectors, connections store credentials as Azure resources:

resource apiConnection 'Microsoft.Web/connections@2016-06-01' = {
  name: 'sql-connection'
  location: location
  properties: {
    displayName: 'SQL Server Connection'
    api: {
      id: subscriptionResourceId('Microsoft.Web/locations/managedApis', location, 'sql')
    }
    parameterValues: {
      server: sqlServer.properties.fullyQualifiedDomainName
      database: 'OrderDB'
      authType: 'windows'
      username: '@Microsoft.KeyVault(SecretUri=${keyVault::sqlUsername.properties.secretUri})'
      password: '@Microsoft.KeyVault(SecretUri=${keyVault::sqlPassword.properties.secretUri})'
    }
  }
}

Integration Patterns

Request-Reply

The most common pattern — receive a request and return a response:

HTTP Request Trigger
  → Validate Input
  → Process Data
  → Return HTTP Response (200 OK with result)

Publish-Subscribe

Distribute events to multiple subscribers:

Event Grid Trigger (e.g., Blob created)
  → Parallel Branch 1: Process image → Store in Cosmos DB
  → Parallel Branch 2: Send notification → Teams
  → Parallel Branch 3: Update index → Azure Search

Scatter-Gather

Call multiple services in parallel and aggregate results:

HTTP Request Trigger
  → Parallel Branch 1: Call Service A
  → Parallel Branch 2: Call Service B
  → Parallel Branch 3: Call Service C
  → Compose: Aggregate all results
  → Return HTTP Response

Content-Based Router

Route messages to different handlers based on content:

Service Bus Trigger
  → Switch on message type:
    → "order": Process Order workflow
    → "invoice": Process Invoice workflow
    → "return": Process Return workflow
    → default: Send to dead letter queue

Message Enrichment

Augment incoming data with additional information:

HTTP Trigger (receive order)
  → Get Customer Details (CRM)
  → Get Product Details (Catalogue API)
  → Get Shipping Rates (Carrier API)
  → Compose: Merge all data
  → Send Enriched Order to ERP

Claim Check

For large payloads, store the content and pass a reference:

HTTP Trigger (large payload)
  → Upload Body to Blob Storage
  → Send message to Service Bus with blob URL (claim check)
  → Return 202 Accepted

Separate workflow:
  → Service Bus Trigger (receives claim check)
  → Download from Blob Storage
  → Process large payload
  → Delete blob

Connecting to API Management

Logic Apps integrates with Azure API Management for governed API access:

Logic App → API Management Gateway → Backend API

Benefits

• Centralised security — JWT validation, OAuth, subscription keys
• Rate limiting — Protect backend services
• Transformation — Request/response manipulation
• Monitoring — Unified API analytics
• Versioning — Multiple API versions through APIM

Configuration

1. Import your API into APIM
2. In the Logic App, use the HTTP action to call the APIM gateway URL
3. Pass the subscription key via Ocp-Apim-Subscription-Key header
4. Or use Managed Identity with validate-jwt in APIM

Hybrid Integration

Azure Relay

For scenarios where the on-premises data gateway is not suitable, use Azure Relay for direct hybrid connections:

Logic App → Azure Relay Hybrid Connection → On-premises endpoint

Azure Arc-Enabled Logic Apps

Run Logic Apps on Kubernetes anywhere — on-premises, multi-cloud, or edge:

Azure Arc-enabled Kubernetes cluster
  └── Logic Apps extension
        └── Standard Logic App workflows
              └── Built-in connectors (Service Bus, SQL, etc.)

Microsoft Reference: Azure Arc-enabled Logic Apps

Best Practices

1. Use built-in connectors over managed connectors where possible for better performance and lower cost
2. Use managed identity instead of connection strings for Azure service authentication
3. Implement connection access policies to control who can use API connections
4. Monitor connector throttling — each connector has its own limits (typically 100–600 calls per connection per minute)
5. Use batching for high-volume scenarios to reduce connector calls
6. Cache frequently accessed data to avoid unnecessary connector calls
7. Use custom connectors to standardise access to internal APIs
8. Deploy gateway clusters for on-premises high availability
9. Keep connectors updated — Microsoft regularly adds features and fixes

Official Microsoft Resources

• Connectors overview
• Connector reference for Logic Apps
• Custom connectors documentation
• On-premises data gateway
• Managed identity authentication
• Logic Apps limits and configuration