Copilot · Nov 6, 2026 · Nov 6, 2026 · Nov 6, 2026
diff --git a/README.md b/README.md
@@ -70,6 +70,17 @@ Time            : 4/26/2021 9:00:45 AM
 Type            : com.example.object.deleted.v2
 ```
 
+Use the optional `-DataSchema` absolute URI parameter on `New-CloudEvent`,
+`Set-CloudEventData`, or `Set-CloudEventJsonData` to specify the schema for the
+event data:
+
+```powershell
+$cloudEvent | Set-CloudEventJsonData -Data @{ 'Foo' = 'Hello'; 'Bar' = 'World' } -DataSchema 'https://example.com/schema.json'
+```
+
+Omitting `-DataSchema` when setting data preserves any schema already set on the
+event.
+
 ### Set **XML Data** to a CloudEvent object
 ```powershell
 $cloudEvent | Set-CloudEventXmlData -Data @{

diff --git a/src/CloudEventsPowerShell/CloudEvents.Sdk.psm1 b/src/CloudEventsPowerShell/CloudEvents.Sdk.psm1
@@ -29,6 +29,9 @@ function New-CloudEvent {
    .PARAMETER Time
    Specifies the 'time' attribute of the cloud event.
 
+   .PARAMETER DataSchema
+   Specifies the absolute URI of the schema that the cloud event 'data' adheres to.
+
    .EXAMPLE
    New-CloudEvent -Type 'com.example.object.deleted.v2' -Source 'mailto:cncf-wg-serverless@lists.cncf.io' -Id '6e8bc430-9c3a-11d9-9669-0800200c9a66' -Time (Get-Date)
 
@@ -55,7 +58,13 @@ function New-CloudEvent {
         [Parameter(Mandatory = $false)]
         [ValidateNotNullOrEmpty()]
         [DateTime]
-        $Time
+        $Time,
+
+        [Parameter(Mandatory = $false)]
+        [ValidateNotNullOrEmpty()]
+        [ValidateScript({ $_.IsAbsoluteUri })]
+        [System.Uri]
+        $DataSchema
     )
 
     PROCESS {
@@ -68,6 +77,10 @@ function New-CloudEvent {
             $Time,
             @())
 
+        if ($PSBoundParameters.ContainsKey('DataSchema')) {
+            $cloudEvent.DataSchema = $DataSchema
+        }
+
         Write-Output $cloudEvent
     }
 }
@@ -90,6 +103,10 @@ function Set-CloudEventData {
    .PARAMETER DataContentType
    Specifies the 'datacontenttype' attribute of the cloud event.
 
+   .PARAMETER DataSchema
+   Specifies the absolute URI of the schema that the cloud event 'data' adheres to.
+   If omitted, the existing 'dataschema' attribute is preserved.
+
 
    .EXAMPLE
    $cloudEvent = New-CloudEvent -Type 'com.example.object.deleted.v2' -Source 'mailto:cncf-wg-serverless@lists.cncf.io' -Id '6e8bc430-9c3a-11d9-9669-0800200c9a66' -Time (Get-Date)
@@ -118,7 +135,14 @@ function Set-CloudEventData {
         [Parameter(Mandatory = $false,
             ValueFromPipeline = $false)]
         [string]
-        $DataContentType)
+        $DataContentType,
+
+        [Parameter(Mandatory = $false,
+            ValueFromPipeline = $false)]
+        [ValidateNotNullOrEmpty()]
+        [ValidateScript({ $_.IsAbsoluteUri })]
+        [System.Uri]
+        $DataSchema)
 
     PROCESS {
 
@@ -130,6 +154,10 @@ function Set-CloudEventData {
         $cloudEvent.Data = $Data
         $cloudEvent.DataContentType = $dataContentType
 
+        if ($PSBoundParameters.ContainsKey('DataSchema')) {
+            $cloudEvent.DataSchema = $DataSchema
+        }
+
         Write-Output $CloudEvent
     }
 
@@ -155,6 +183,10 @@ function Set-CloudEventJsonData {
    This parameter is passed on the `-Depth` parameter of the `ConvertTo-Json` cmdlet.
    The default value is 3
 
+   .PARAMETER DataSchema
+   Specifies the absolute URI of the schema that the cloud event 'data' adheres to.
+   If omitted, the existing 'dataschema' attribute is preserved.
+
 
    .EXAMPLE
    $cloudEvent = New-CloudEvent -Type 'com.example.object.deleted.v2' -Source 'mailto:cncf-wg-serverless@lists.cncf.io' -Id '6e8bc430-9c3a-11d9-9669-0800200c9a66' -Time (Get-Date)
@@ -180,7 +212,14 @@ function Set-CloudEventJsonData {
         [Parameter(Mandatory = $false,
             ValueFromPipeline = $false)]
         [int]
-        $Depth = 3)
+        $Depth = 3,
+
+        [Parameter(Mandatory = $false,
+            ValueFromPipeline = $false)]
+        [ValidateNotNullOrEmpty()]
+        [ValidateScript({ $_.IsAbsoluteUri })]
+        [System.Uri]
+        $DataSchema)
 
     PROCESS {
 
@@ -193,6 +232,10 @@ function Set-CloudEventJsonData {
         $cloudEvent.DataContentType = $dataContentType
         $cloudEvent.Data = ConvertTo-Json -InputObject $Data -Depth $Depth
 
+        if ($PSBoundParameters.ContainsKey('DataSchema')) {
+            $cloudEvent.DataSchema = $DataSchema
+        }
+
         Write-Output $CloudEvent
     }
 

diff --git a/test/unit/New-CloudEvent.Tests.ps1 b/test/unit/New-CloudEvent.Tests.ps1
@@ -22,6 +22,7 @@ Describe "New-CloudEvent Function Tests" {
          $actual.Type | Should -Be $expectedType
          $actual.Source | Should -Be $expectedSource
          $actual.Id | Should -Be $expectedId
+         $actual.DataSchema | Should -BeNullOrEmpty
       }
 
       It 'Create CloudEvent with all possible parameters' {
@@ -30,20 +31,36 @@ Describe "New-CloudEvent Function Tests" {
          $expectedSource  = 'urn:test'
          $expectedId  = 'test-id-1'
          $expectedTime  = Get-Date -Year 2021 -Month 1 -Day 18 -Hour 12 -Minute 30 -Second 0
+         $expectedDataSchema = 'https://example.com/schema.json'
 
          # Act
          $actual = New-CloudEvent `
                   -Type $expectedType `
                   -Source $expectedSource `
                   -Id $expectedId `
-                  -Time $expectedTime
+                  -Time $expectedTime `
+                  -DataSchema $expectedDataSchema
 
          # Assert
          $actual | Should -Not -Be $null
          $actual.Type | Should -Be $expectedType
          $actual.Source | Should -Be $expectedSource
          $actual.Id | Should -Be $expectedId
          $actual.Time | Should -Be $expectedTime
+         $actual.DataSchema | Should -BeOfType ([System.Uri])
+         $actual.DataSchema | Should -Be $expectedDataSchema
+      }
+
+      It 'Rejects invalid DataSchema values' -TestCases @(
+         @{ DataSchema = $null }
+         @{ DataSchema = '' }
+         @{ DataSchema = 'schema.json' }
+         @{ DataSchema = 'http://[invalid' }
+      ) {
+         param($DataSchema)
+
+         { New-CloudEvent -Type test -Source 'urn:test' -Id 'test-id' -DataSchema $DataSchema } |
+            Should -Throw
       }
    }
 }
diff --git a/test/unit/Set-CloudEventData.Tests.ps1 b/test/unit/Set-CloudEventData.Tests.ps1
@@ -26,6 +26,7 @@ Describe "Set-CloudEventData Function Tests" {
          $actual | Should -Not -Be $null
          $actual.DataContentType.ToString() | Should -Be $expectedDataContentType
          $actual.Data | Should -Be $expectedData
+         $actual.DataSchema | Should -BeNullOrEmpty
       }
 
       It 'Sets xml text data' {
@@ -53,6 +54,41 @@ Describe "Set-CloudEventData Function Tests" {
    }
 
 
+   Context "Sets DataSchema" {
+      It 'Sets or preserves DataSchema' -TestCases @(
+         @{ Parameters = @{ DataSchema = 'https://example.com/schema.json' }; ExpectedDataSchema = 'https://example.com/schema.json' }
+         @{ Parameters = @{ DataSchema = [System.Uri]'urn:test:schema' }; ExpectedDataSchema = 'urn:test:schema' }
+         @{ Parameters = @{}; ExpectedDataSchema = 'https://example.com/original.json' }
+      ) {
+         param($Parameters, $ExpectedDataSchema)
+
+         $cloudEvent = New-CloudEvent -Type test -Source 'urn:test' -Id 'test-id'
+         $cloudEvent.DataSchema = [System.Uri]'https://example.com/original.json'
+
+         $actual = $cloudEvent | Set-CloudEventData -Data '{"a":"b"}' -DataContentType 'application/json' @Parameters
+
+         $actual | Should -Be $cloudEvent
+         $actual.DataSchema | Should -BeOfType ([System.Uri])
+         $actual.DataSchema | Should -Be $ExpectedDataSchema
+         $actual.Data | Should -Be '{"a":"b"}'
+         $actual.DataContentType.ToString() | Should -Be 'application/json'
+      }
+
+      It 'Rejects invalid DataSchema values' -TestCases @(
+         @{ DataSchema = $null }
+         @{ DataSchema = '' }
+         @{ DataSchema = 'schema.json' }
+         @{ DataSchema = 'http://[invalid' }
+      ) {
+         param($DataSchema)
+
+         $cloudEvent = New-CloudEvent -Type test -Source 'urn:test' -Id 'test-id'
+
+         { $cloudEvent | Set-CloudEventData -Data '{}' -DataContentType 'application/json' -DataSchema $DataSchema } |
+            Should -Throw
+      }
+   }
+
    Context "Errors on invalid data content type" {
       It 'Throws error on invalid MIME content type' {
          # Arrange
@@ -85,7 +121,7 @@ Describe "Set-CloudEventData Function Tests" {
                -CloudEvent $cloudEvent `
                -Data '1' `
                -DataContentType $invalidContentType } | `
-         Should -Throw "*The parameter 'contentType' cannot be an empty string*"
+         Should -Throw "*cannot be an empty string*"
       }
 
       It 'Throws error on null content type' {
@@ -102,7 +138,7 @@ Describe "Set-CloudEventData Function Tests" {
                -CloudEvent $cloudEvent `
                -Data '1' `
                -DataContentType $invalidContentType } | `
-         Should -Throw "*The parameter 'contentType' cannot be an empty string*"
+         Should -Throw "*cannot be an empty string*"
       }
    }
 }
diff --git a/test/unit/Set-CloudEventJsonData.Tests.ps1 b/test/unit/Set-CloudEventJsonData.Tests.ps1
@@ -4,6 +4,41 @@
 # **************************************************************************
 
 Describe "Set-CloudEventJsonData Function Tests" {
+   Context "Sets DataSchema" {
+      It 'Sets or preserves DataSchema' -TestCases @(
+         @{ Parameters = @{ DataSchema = 'https://example.com/schema.json' }; ExpectedDataSchema = 'https://example.com/schema.json' }
+         @{ Parameters = @{ DataSchema = [System.Uri]'urn:test:schema' }; ExpectedDataSchema = 'urn:test:schema' }
+         @{ Parameters = @{}; ExpectedDataSchema = 'https://example.com/original.json' }
+      ) {
+         param($Parameters, $ExpectedDataSchema)
+
+         $cloudEvent = New-CloudEvent -Type test -Source 'urn:test' -Id 'test-id'
+         $cloudEvent.DataSchema = [System.Uri]'https://example.com/original.json'
+
+         $actual = $cloudEvent | Set-CloudEventJsonData -Data @{ 'a' = 'b' } @Parameters
+
+         $actual | Should -Be $cloudEvent
+         $actual.DataSchema | Should -BeOfType ([System.Uri])
+         $actual.DataSchema | Should -Be $ExpectedDataSchema
+         ($actual.Data | ConvertFrom-Json).a | Should -Be 'b'
+         $actual.DataContentType.ToString() | Should -Be 'application/json'
+      }
+
+      It 'Rejects invalid DataSchema values' -TestCases @(
+         @{ DataSchema = $null }
+         @{ DataSchema = '' }
+         @{ DataSchema = 'schema.json' }
+         @{ DataSchema = 'http://[invalid' }
+      ) {
+         param($DataSchema)
+
+         $cloudEvent = New-CloudEvent -Type test -Source 'urn:test' -Id 'test-id'
+
+         { $cloudEvent | Set-CloudEventJsonData -Data @{} -DataSchema $DataSchema } |
+            Should -Throw
+      }
+   }
+
    Context "Sets Json Data" {
       It 'Sets json data with depth 1' {
          # Arrange
@@ -25,6 +60,7 @@ Describe "Set-CloudEventJsonData Function Tests" {
          $actual | Should -Not -Be $null
          $actual.DataContentType.ToString() | Should -Be 'application/json'
          $actual.Data | Should -Be $expectedJson
+         $actual.DataSchema | Should -BeNullOrEmpty
       }
 
       It 'Sets json data with depth 4' {