Azure Logic Apps

Azure Logic Apps — Comprehensive Reference

Azure Logic Apps is a cloud platform for automating workflows and integrating apps, data, and services via a visual designer and JSON-based Workflow Definition Language (WDL).

1. Hosting Models

Choose Consumption for low-volume, spiky workloads. Choose Standard for high-volume, VNet requirements, multi-workflow apps, or local development needs.

ISE is retired (end of life August 31, 2024 — it depended on Azure Cloud Services classic). It is no longer selectable for new deployments; the column above is kept only to map legacy ISE features onto their Standard equivalents. Migrate any remaining ISE workloads to Logic Apps Standard.

2. Triggers

Every workflow starts with exactly one trigger.

Recurrence

"Recurrence": {
  "type": "Recurrence",
  "recurrence": { "frequency": "Hour", "interval": 4, "startTime": "2024-01-01T08:00:00Z", "timeZone": "Eastern Standard Time" }
}

HTTP (Request) — exposes a POST webhook URL

"manual": {
  "type": "Request", "kind": "Http",
  "inputs": {
    "schema": {
      "type": "object",
      "properties": { "orderId": { "type": "string" }, "amount": { "type": "number" } },
      "required": ["orderId"]
    }
  }
}

Retrieve callback URL: listCallbackUrl() expression or Portal → Overview.

Service Bus (poll-based)

"When_message_received": {
  "type": "ApiConnection",
  "inputs": {
    "host": { "connection": { "name": "@parameters('$connections')['servicebus']['connectionId']" } },
    "method": "get",
    "path": "/@{encodeURIComponent('myqueue')}/messages/head",
    "queries": { "queueType": "Main" }
  },
  "recurrence": { "frequency": "Minute", "interval": 1 }
}

Event Grid (webhook-based)

Use ApiConnectionWebhook type; Logic Apps registers/deregisters subscriptions automatically. Filter by includedEventTypes (e.g., Microsoft.Storage.BlobCreated).

Blob Storage

Uses ApiConnection with polling recurrence; returns up to maxFileCount changed blobs per cycle.

Manual / HTTP Webhook

Request kind triggers wait for a callback; useful for approval flows and async patterns.

3. Actions

HTTP

"Call_API": {
  "type": "Http",
  "inputs": {
    "method": "POST", "uri": "https://api.example.com/orders",
    "headers": { "Content-Type": "application/json", "x-api-key": "@parameters('apiKey')" },
    "body": { "orderId": "@triggerBody()?['orderId']", "amount": "@triggerBody()?['amount']" },
    "retryPolicy": { "type": "exponential", "count": 4, "interval": "PT7S", "maximumInterval": "PT1H" }
  }
}

Condition (If/Else)

"Check_Amount": {
  "type": "If",
  "expression": { "and": [{ "greater": ["@triggerBody()?['amount']", 1000] }] },
  "actions": { "Send_Approval": {} },
  "else": { "actions": { "Auto_Approve": {} } },
  "runAfter": {}
}

For-Each Loop

"Process_Items": {
  "type": "Foreach", "foreach": "@body('Get_Items')?['value']",
  "actions": { "Insert_Row": {} },
  "runtimeConfiguration": { "concurrency": { "repetitions": 10 } },
  "runAfter": { "Get_Items": ["Succeeded"] }
}

Default is sequential (repetitions=1). Max 50 for Consumption.

Until Loop

"Poll_Until_Done": {
  "type": "Until",
  "expression": "@equals(body('Check_Status')?['status'], 'completed')",
  "limit": { "count": 20, "timeout": "PT2H" },
  "actions": {
    "Check_Status": { "type": "Http", "inputs": { "method": "GET", "uri": "https://api.example.com/status/@{variables('jobId')}" } },
    "Wait": { "type": "Wait", "inputs": { "interval": { "count": 30, "unit": "Second" } }, "runAfter": { "Check_Status": ["Succeeded"] } }
  }
}

Switch, Scope, Variables

"Route_By_Type": {
  "type": "Switch", "expression": "@triggerBody()?['eventType']",
  "cases": {
    "OrderCreated":   { "case": "OrderCreated",   "actions": {} },
    "OrderCancelled": { "case": "OrderCancelled", "actions": {} }
  },
  "default": { "actions": {} }
}

Variables: InitializeVariable, SetVariable, IncrementVariable, AppendToArrayVariable. Scope: wraps a group of actions — foundation for try-catch (see §6).

4. Connectors

Built-in (in-process, free in Standard)

HTTP, Request, Schedule, Control (Condition/Loop/Switch/Scope/Terminate), Variables, Data Operations (Compose, Parse JSON, Filter Array, Select, Join), Date/Time, Inline Code (JS in Consumption; C#/JS in Standard), Azure Functions, Liquid/XML transforms.

Managed (shared service, billed per call)

• Standard: Office 365, SharePoint, Dynamics 365, Salesforce, Slack, Twilio, SQL Azure
• Enterprise: SAP, IBM MQ, IBM 3270, IBM DB2
• On-premises (via Data Gateway): SQL Server, Oracle, File System, SharePoint on-prem

Custom Connectors

Import from OpenAPI 2.0 (Swagger) or Postman collection. Shared across Logic Apps, Power Automate, and Power Apps within the same tenant.

5. Expressions & WDL Functions

All expressions begin with @; embed in strings as @{...}.

# Trigger / action output
@triggerBody()                          -- parsed trigger JSON payload
@triggerBody()?['field']               -- safe navigation (null if missing)
@triggerOutputs()?['headers']['x-id']  -- trigger HTTP header
@body('ActionName')                    -- body of a named action
@outputs('ActionName')?['statusCode']  -- HTTP status code of action
@result('ScopeName')?[0]?['error']?['message']  -- scope/action error detail

# Strings
@concat('Order-', triggerBody()?['id'])
@toLower(triggerBody()?['email'])  |  @toUpper(variables('code'))
@replace(body('A')?['text'], 'old', 'new')
@substring('Hello World', 6, 5)    -- 'World'
@split(triggerBody()?['csv'], ',') -- string → array
@trim('  spaces  ')

# JSON / encoding
@json('{"key":"val"}')             -- parse string to object
@string(body('Parse_JSON'))        -- serialize object to string
@base64(body('Action'))
@base64ToString(triggerBody()?['data'])
@xml(body('Compose'))
@xpath(xml(body('XML')), 'string(//OrderId)')

# Arrays
@first(body('Get')?['value'])  |  @last(...)  |  @length(...)
@union(arr1, arr2)  |  @intersection(arr1, arr2)
@skip(array, 2)    |  @take(array, 5)

# Math
@add(variables('counter'), 1)
@mul(triggerBody()?['qty'], triggerBody()?['price'])
@div(variables('total'), 100)  |  @mod(variables('i'), 10)

# Date/Time
@utcNow()  |  @utcNow('yyyy-MM-ddTHH:mm:ssZ')
@addDays(utcNow(), 7)  |  @addHours(utcNow(), -5)
@formatDateTime(utcNow(), 'yyyy-MM-dd')
@convertTimeZone(utcNow(), 'UTC', 'Eastern Standard Time')
@ticks(utcNow())                   -- Int64 ticks, useful for unique IDs

# Workflow metadata
@workflow().run.id                 -- current run ID
@workflow().name                   -- workflow name
@parameters('paramName')
@variables('varName')

# Conditionals
@if(greater(triggerBody()?['amount'], 1000), 'high', 'normal')
@coalesce(triggerBody()?['opt'], 'default')
@empty(body('Get')?['value'])
@not(empty(triggerBody()?['email']))

6. Error Handling

Retry Policies (per action)

"retryPolicy": { "type": "exponential", "count": 4, "interval": "PT7S", "maximumInterval": "PT1H", "minimumInterval": "PT5S" }

Types: exponential (default, 4 retries), fixed, none.

runAfter — execution dependency

"runAfter": { "Previous_Action": ["Succeeded", "Failed", "Skipped", "TimedOut"] }

Try-Catch-Finally Pattern

{
  "Try": {
    "type": "Scope", "runAfter": {},
    "actions": { "Risky_HTTP": { "type": "Http", "inputs": {} } }
  },
  "Catch": {
    "type": "Scope", "runAfter": { "Try": ["Failed", "TimedOut"] },
    "actions": {
      "Log_Error": {
        "type": "Http",
        "inputs": {
          "method": "POST", "uri": "https://logs.example.com/errors",
          "body": { "runId": "@workflow().run.id", "error": "@result('Try')?[0]?['error']?['message']" }
        }
      }
    }
  },
  "Finally": {
    "type": "Scope",
    "runAfter": {
      "Try":   ["Succeeded","Failed","Skipped","TimedOut"],
      "Catch": ["Succeeded","Failed","Skipped","TimedOut"]
    },
    "actions": { "Cleanup": {} }
  }
}

Terminate Action

"Fail_Workflow": {
  "type": "Terminate",
  "inputs": { "runStatus": "Failed", "runError": { "code": "VALIDATION_ERROR", "message": "@concat('Invalid: ', triggerBody()?['orderId'])" } }
}

7. Integration Account & B2B

Required for EDI/transforms in Consumption tier; partially built-in for Standard.

Tiers: Free (dev/test) · Basic (B2B messaging) · Standard (full EDI + maps + schemas)

Artifacts: Partners (business identities) · Agreements (AS2/X12/EDIFACT send/receive rules) · Schemas (XSD for XML validation) · Maps (XSLT or Liquid for transformation) · Certificates (AS2 signing/encryption)

B2B Flow: Receive X12 → Decode X12 → Route by transaction set → Process → Encode X12 → Send

Link in Portal: Logic App → Workflow settings → Integration account.

8. Stateful vs Stateless (Standard only)

Enable stateless: in workflow.json set "operationOptions": "EnableStatelessMode".

9. Managed Identity Authentication

# Enable system-assigned identity
az logic workflow update --resource-group myRG --name myLogicApp --identity-type SystemAssigned

# Grant access to Key Vault
az keyvault set-policy --name myKV --object-id <principalId> --secret-permissions get list

Use in HTTP action:

"authentication": { "type": "ManagedServiceIdentity", "audience": "https://management.azure.com" }

10. Deployment: ARM / Bicep & CLI

ARM Template (Consumption)

{
  "type": "Microsoft.Logic/workflows", "apiVersion": "2019-05-01",
  "name": "[parameters('logicAppName')]", "location": "[parameters('location')]",
  "identity": { "type": "SystemAssigned" },
  "properties": {
    "state": "Enabled",
    "definition": {
      "$schema": "https://schema.management.azure.com/providers/Microsoft.Logic/schemas/2016-06-01/workflowdefinition.json#",
      "contentVersion": "1.0.0.0",
      "triggers": {}, "actions": {}
    }
  }
}

Bicep

resource logicApp 'Microsoft.Logic/workflows@2019-05-01' = {
  name: logicAppName
  location: location
  identity: { type: 'SystemAssigned' }
  properties: { state: 'Enabled', definition: { triggers: {}, actions: {} } }
}

Key CLI Commands

az logic workflow create --resource-group myRG --name myLogicApp --location eastus --definition @def.json
az logic workflow show  --resource-group myRG --name myLogicApp
az logic workflow list  --resource-group myRG --output table
az logic workflow show  --resource-group myRG --name myLogicApp --query properties.definition -o json > def.json
az logic workflow update --resource-group myRG --name myLogicApp --state Disabled
az logic workflow delete --resource-group myRG --name myLogicApp --yes
az logic workflow run list        --resource-group myRG --name myLogicApp --output table
az logic workflow run show        --resource-group myRG --name myLogicApp --run-name <runId>
az logic workflow run action list --resource-group myRG --name myLogicApp --run-name <runId>
az deployment group create --resource-group myRG --template-file azuredeploy.json --parameters logicAppName=myLogicApp

# Standard tier: zip deploy
cd logic-apps/standard && zip -r ../app.zip .
az logicapp deployment source config-zip --resource-group myRG --name myLogicApp --src ../app.zip

11. CI/CD — GitHub Actions

name: Deploy Logic App
on:
  push:
    branches: [main]
    paths: ['logic-apps/**']

jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: azure/login@v1
        with: { creds: "${{ secrets.AZURE_CREDENTIALS }}" }
      - uses: azure/arm-deploy@v1
        with:
          resourceGroupName: myRG
          template: ./logic-apps/azuredeploy.json
          parameters: logicAppName=myLogicApp

For Standard tier, replace the last step with the az logicapp deployment source config-zip command.

12. Monitoring & Observability

Tracked Properties (custom run metadata)

"Send_Email": {
  "type": "ApiConnection",
  "trackedProperties": { "orderId": "@triggerBody()?['orderId']", "customer": "@triggerBody()?['email']" },
  "inputs": {}
}

Enable Log Analytics Diagnostics

az monitor diagnostic-settings create \
  --resource /subscriptions/<sub>/resourceGroups/myRG/providers/Microsoft.Logic/workflows/myLogicApp \
  --workspace <workspaceResourceId> --name logic-diag \
  --logs '[{"category":"WorkflowRuntime","enabled":true}]' \
  --metrics '[{"category":"AllMetrics","enabled":true}]'

KQL Queries

// Failed runs last 24h
AzureDiagnostics
| where ResourceType == "WORKFLOWS" and status_s == "Failed" and TimeGenerated > ago(24h)
| project TimeGenerated, resource_workflowName_s, error_message_s | order by TimeGenerated desc

// Action failure rate
AzureDiagnostics | where ResourceType == "WORKFLOWS"
| summarize total=count(), failed=countif(status_s=="Failed") by resource_actionName_s
| extend failureRate = round(100.0 * failed / total, 2) | order by failureRate desc

13. Security

IP Restrictions — accessControl.triggers.allowedCallerIpAddresses in workflow properties.

Secure inputs/outputs — hide data from run history:

"runtimeConfiguration": { "secureData": { "properties": ["inputs", "outputs"] } }

Private Endpoints (Standard):

az network private-endpoint create --name myPE --resource-group myRG \
  --vnet-name myVNet --subnet mySubnet \
  --private-connection-resource-id /subscriptions/<sub>/resourceGroups/myRG/providers/Microsoft.Web/sites/myLogicApp \
  --group-id sites --connection-name myConn

az webapp vnet-integration add --resource-group myRG --name myLogicApp --vnet myVNet --subnet mySubnet

Encryption: Data at rest uses Microsoft-managed keys by default; customer-managed keys (CMK) available for Standard. TLS 1.2+ enforced in transit.

14. Performance Patterns

15. Common Patterns

Approval Workflow: HTTP Trigger → Send approval email (O365) → Condition → If approved: proceed; else: notify

Scheduled ETL: Recurrence → Query SQL → For-each row → Transform (Select action) → Upsert target → Email summary

File Processing: Blob Created → Get content → Validate → Move to /processed/ or /errors/ + alert

API Orchestration: Multiple HTTP actions share a step for implicit parallelism. Use Azure Durable Functions for true fan-out/fan-in with joins.

Dead-letter Queue: Service Bus DLQ trigger → Parse → Remediate → Re-enqueue or log/alert

16. Pricing

Consumption (East US approx.)

Standard (East US approx.)

17. References

• Docs: https://learn.microsoft.com/azure/logic-apps/
• WDL functions: https://learn.microsoft.com/azure/logic-apps/workflow-definition-language-functions-reference
• Connector catalog: https://learn.microsoft.com/connectors/
• WDL JSON schema: https://schema.management.azure.com/providers/Microsoft.Logic/schemas/2016-06-01/workflowdefinition.json
• VS Code extension: ms-azuretools.vscode-azurelogicapps
• Pricing calculator: https://azure.microsoft.com/pricing/calculator/