diff --git a/src/Runner.Worker/ExecutionContext.cs b/src/Runner.Worker/ExecutionContext.cs
index d835682a4..b5947338e 100644
--- a/src/Runner.Worker/ExecutionContext.cs
+++ b/src/Runner.Worker/ExecutionContext.cs
@@ -902,6 +902,10 @@ namespace GitHub.Runner.Worker
                         jobContext[pair.Key] = pair.Value;
                     }
                 }
+
+                // Derive workflow_repository and workflow_file_path from workflow_ref
+                // if the server sent workflow_ref but not the decomposed fields
+                jobContext.DeriveWorkflowRefComponents();
             }
             ExpressionValues["job"] = jobContext;
 
diff --git a/src/Runner.Worker/JobContext.cs b/src/Runner.Worker/JobContext.cs
index 09f3296de..0ce869011 100644
--- a/src/Runner.Worker/JobContext.cs
+++ b/src/Runner.Worker/JobContext.cs
@@ -82,5 +82,103 @@ namespace GitHub.Runner.Worker
                 }
             }
         }
+
+        public string WorkflowRef
+        {
+            get
+            {
+                if (this.TryGetValue("workflow_ref", out var value) && value is StringContextData str)
+                {
+                    return str.Value;
+                }
+                return null;
+            }
+            set
+            {
+                this["workflow_ref"] = value != null ? new StringContextData(value) : null;
+            }
+        }
+
+        public string WorkflowSha
+        {
+            get
+            {
+                if (this.TryGetValue("workflow_sha", out var value) && value is StringContextData str)
+                {
+                    return str.Value;
+                }
+                return null;
+            }
+            set
+            {
+                this["workflow_sha"] = value != null ? new StringContextData(value) : null;
+            }
+        }
+
+        public string WorkflowRepository
+        {
+            get
+            {
+                if (this.TryGetValue("workflow_repository", out var value) && value is StringContextData str)
+                {
+                    return str.Value;
+                }
+                return null;
+            }
+            set
+            {
+                this["workflow_repository"] = value != null ? new StringContextData(value) : null;
+            }
+        }
+
+        public string WorkflowFilePath
+        {
+            get
+            {
+                if (this.TryGetValue("workflow_file_path", out var value) && value is StringContextData str)
+                {
+                    return str.Value;
+                }
+                return null;
+            }
+            set
+            {
+                this["workflow_file_path"] = value != null ? new StringContextData(value) : null;
+            }
+        }
+
+        /// <summary>
+        /// Parses a composite workflow_ref (e.g. "owner/repo/.github/workflows/file.yml@refs/heads/main")
+        /// and populates workflow_repository and workflow_file_path if they are not already set.
+        /// </summary>
+        public void DeriveWorkflowRefComponents()
+        {
+            var workflowRef = WorkflowRef;
+            if (string.IsNullOrEmpty(workflowRef))
+            {
+                return;
+            }
+
+            // Format: owner/repo/path/to/file.yml@ref
+            var atIndex = workflowRef.IndexOf('@');
+            var pathPart = atIndex >= 0 ? workflowRef.Substring(0, atIndex) : workflowRef;
+
+            // Split into owner/repo and file path at the .github/ boundary
+            var githubDirIndex = pathPart.IndexOf("/.github/");
+            if (githubDirIndex < 0)
+            {
+                return;
+            }
+
+            if (WorkflowRepository == null)
+            {
+                WorkflowRepository = pathPart.Substring(0, githubDirIndex);
+            }
+
+            if (WorkflowFilePath == null)
+            {
+                WorkflowFilePath = pathPart.Substring(githubDirIndex + 1); // skip leading '/'
+            }
+        }
     }
 }
diff --git a/src/Test/L0/Worker/ExecutionContextL0.cs b/src/Test/L0/Worker/ExecutionContextL0.cs
index 2f28f797f..e72e8f9d3 100644
--- a/src/Test/L0/Worker/ExecutionContextL0.cs
+++ b/src/Test/L0/Worker/ExecutionContextL0.cs
@@ -1239,6 +1239,124 @@ namespace GitHub.Runner.Common.Tests.Worker
             }
         }
 
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void InitializeJob_HydratesJobContextWithWorkflowIdentity()
+        {
+            using (TestHostContext hc = CreateTestContext())
+            {
+                // Arrange: Create a job request message with the feature flag enabled
+                var variables = new Dictionary<string, VariableValue>()
+                {
+                    [Constants.Runner.Features.AddCheckRunIdToJobContext] = new VariableValue("true"),
+                };
+                var jobRequest = new Pipelines.AgentJobRequestMessage(new TaskOrchestrationPlanReference(), new TimelineReference(), Guid.NewGuid(), "some job name", "some job name", null, null, null, variables, new List<MaskHint>(), new Pipelines.JobResources(), new Pipelines.ContextData.DictionaryContextData(), new Pipelines.WorkspaceOptions(), new List<Pipelines.ActionStep>(), null, null, null, null, null);
+                var pagingLogger = new Moq.Mock<IPagingLogger>();
+                var jobServerQueue = new Moq.Mock<IJobServerQueue>();
+                hc.EnqueueInstance(pagingLogger.Object);
+                hc.SetSingleton(jobServerQueue.Object);
+                var ec = new Runner.Worker.ExecutionContext();
+                ec.Initialize(hc);
+
+                // Arrange: Add workflow identity to the job context
+                var jobContext = new Pipelines.ContextData.DictionaryContextData();
+                jobContext["workflow_ref"] = new StringContextData("my-org/my-repo/.github/workflows/reusable.yml@refs/heads/main");
+                jobContext["workflow_sha"] = new StringContextData("abc123def456");
+                jobRequest.ContextData["job"] = jobContext;
+                jobRequest.ContextData["github"] = new Pipelines.ContextData.DictionaryContextData();
+
+                // Act
+                ec.InitializeJob(jobRequest, CancellationToken.None);
+
+                // Assert: direct properties from server
+                Assert.NotNull(ec.JobContext);
+                Assert.Equal("my-org/my-repo/.github/workflows/reusable.yml@refs/heads/main", ec.JobContext.WorkflowRef);
+                Assert.Equal("abc123def456", ec.JobContext.WorkflowSha);
+
+                // Assert: derived properties
+                Assert.Equal("my-org/my-repo", ec.JobContext.WorkflowRepository);
+                Assert.Equal(".github/workflows/reusable.yml", ec.JobContext.WorkflowFilePath);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void InitializeJob_WorkflowIdentityNotSet_WhenFeatureFlagDisabled()
+        {
+            using (TestHostContext hc = CreateTestContext())
+            {
+                // Arrange: Create a job request message with the feature flag disabled
+                var variables = new Dictionary<string, VariableValue>()
+                {
+                    [Constants.Runner.Features.AddCheckRunIdToJobContext] = new VariableValue("false"),
+                };
+                var jobRequest = new Pipelines.AgentJobRequestMessage(new TaskOrchestrationPlanReference(), new TimelineReference(), Guid.NewGuid(), "some job name", "some job name", null, null, null, variables, new List<MaskHint>(), new Pipelines.JobResources(), new Pipelines.ContextData.DictionaryContextData(), new Pipelines.WorkspaceOptions(), new List<Pipelines.ActionStep>(), null, null, null, null, null);
+                var pagingLogger = new Moq.Mock<IPagingLogger>();
+                var jobServerQueue = new Moq.Mock<IJobServerQueue>();
+                hc.EnqueueInstance(pagingLogger.Object);
+                hc.SetSingleton(jobServerQueue.Object);
+                var ec = new Runner.Worker.ExecutionContext();
+                ec.Initialize(hc);
+
+                // Arrange: Add workflow identity to the job context
+                var jobContext = new Pipelines.ContextData.DictionaryContextData();
+                jobContext["workflow_ref"] = new StringContextData("my-org/my-repo/.github/workflows/reusable.yml@refs/heads/main");
+                jobContext["workflow_sha"] = new StringContextData("abc123def456");
+                jobRequest.ContextData["job"] = jobContext;
+                jobRequest.ContextData["github"] = new Pipelines.ContextData.DictionaryContextData();
+
+                // Act
+                ec.InitializeJob(jobRequest, CancellationToken.None);
+
+                // Assert: properties should not be populated when flag is off
+                Assert.NotNull(ec.JobContext);
+                Assert.Null(ec.JobContext.WorkflowRef);
+                Assert.Null(ec.JobContext.WorkflowSha);
+                Assert.Null(ec.JobContext.WorkflowRepository);
+                Assert.Null(ec.JobContext.WorkflowFilePath);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void InitializeJob_WorkflowIdentityDerived_WhenServerSendsAllFields()
+        {
+            using (TestHostContext hc = CreateTestContext())
+            {
+                // Arrange: Server sends all 4 fields explicitly
+                var variables = new Dictionary<string, VariableValue>()
+                {
+                    [Constants.Runner.Features.AddCheckRunIdToJobContext] = new VariableValue("true"),
+                };
+                var jobRequest = new Pipelines.AgentJobRequestMessage(new TaskOrchestrationPlanReference(), new TimelineReference(), Guid.NewGuid(), "some job name", "some job name", null, null, null, variables, new List<MaskHint>(), new Pipelines.JobResources(), new Pipelines.ContextData.DictionaryContextData(), new Pipelines.WorkspaceOptions(), new List<Pipelines.ActionStep>(), null, null, null, null, null);
+                var pagingLogger = new Moq.Mock<IPagingLogger>();
+                var jobServerQueue = new Moq.Mock<IJobServerQueue>();
+                hc.EnqueueInstance(pagingLogger.Object);
+                hc.SetSingleton(jobServerQueue.Object);
+                var ec = new Runner.Worker.ExecutionContext();
+                ec.Initialize(hc);
+
+                // Arrange: Server sends all fields, derivation should not overwrite
+                var jobContext = new Pipelines.ContextData.DictionaryContextData();
+                jobContext["workflow_ref"] = new StringContextData("my-org/my-repo/.github/workflows/reusable.yml@refs/heads/main");
+                jobContext["workflow_sha"] = new StringContextData("abc123def456");
+                jobContext["workflow_repository"] = new StringContextData("explicit-org/explicit-repo");
+                jobContext["workflow_file_path"] = new StringContextData(".github/workflows/explicit.yml");
+                jobRequest.ContextData["job"] = jobContext;
+                jobRequest.ContextData["github"] = new Pipelines.ContextData.DictionaryContextData();
+
+                // Act
+                ec.InitializeJob(jobRequest, CancellationToken.None);
+
+                // Assert: explicit values should be preserved, not overwritten by derivation
+                Assert.Equal("explicit-org/explicit-repo", ec.JobContext.WorkflowRepository);
+                Assert.Equal(".github/workflows/explicit.yml", ec.JobContext.WorkflowFilePath);
+            }
+        }
+
         private bool ExpressionValuesAssertEqual(DictionaryContextData expect, DictionaryContextData actual)
         {
             foreach (var key in expect.Keys.ToList())
diff --git a/src/Test/L0/Worker/JobContextL0.cs b/src/Test/L0/Worker/JobContextL0.cs
index 87e334379..1a2206ab0 100644
--- a/src/Test/L0/Worker/JobContextL0.cs
+++ b/src/Test/L0/Worker/JobContextL0.cs
@@ -34,5 +34,165 @@ namespace GitHub.Runner.Common.Tests.Worker
             ctx.CheckRunId = null;
             Assert.Null(ctx.CheckRunId);
         }
+
+        [Fact]
+        public void WorkflowRef_SetAndGet_WorksCorrectly()
+        {
+            var ctx = new JobContext();
+            ctx.WorkflowRef = "owner/repo/.github/workflows/ci.yml@refs/heads/main";
+            Assert.Equal("owner/repo/.github/workflows/ci.yml@refs/heads/main", ctx.WorkflowRef);
+            Assert.True(ctx.TryGetValue("workflow_ref", out var value));
+            Assert.IsType<StringContextData>(value);
+        }
+
+        [Fact]
+        public void WorkflowRef_NotSet_ReturnsNull()
+        {
+            var ctx = new JobContext();
+            Assert.Null(ctx.WorkflowRef);
+        }
+
+        [Fact]
+        public void WorkflowRef_SetNull_ClearsValue()
+        {
+            var ctx = new JobContext();
+            ctx.WorkflowRef = "owner/repo/.github/workflows/ci.yml@refs/heads/main";
+            ctx.WorkflowRef = null;
+            Assert.Null(ctx.WorkflowRef);
+        }
+
+        [Fact]
+        public void WorkflowSha_SetAndGet_WorksCorrectly()
+        {
+            var ctx = new JobContext();
+            ctx.WorkflowSha = "abc123def456";
+            Assert.Equal("abc123def456", ctx.WorkflowSha);
+            Assert.True(ctx.TryGetValue("workflow_sha", out var value));
+            Assert.IsType<StringContextData>(value);
+        }
+
+        [Fact]
+        public void WorkflowSha_NotSet_ReturnsNull()
+        {
+            var ctx = new JobContext();
+            Assert.Null(ctx.WorkflowSha);
+        }
+
+        [Fact]
+        public void WorkflowSha_SetNull_ClearsValue()
+        {
+            var ctx = new JobContext();
+            ctx.WorkflowSha = "abc123def456";
+            ctx.WorkflowSha = null;
+            Assert.Null(ctx.WorkflowSha);
+        }
+
+        [Fact]
+        public void WorkflowRepository_SetAndGet_WorksCorrectly()
+        {
+            var ctx = new JobContext();
+            ctx.WorkflowRepository = "owner/repo";
+            Assert.Equal("owner/repo", ctx.WorkflowRepository);
+            Assert.True(ctx.TryGetValue("workflow_repository", out var value));
+            Assert.IsType<StringContextData>(value);
+        }
+
+        [Fact]
+        public void WorkflowRepository_NotSet_ReturnsNull()
+        {
+            var ctx = new JobContext();
+            Assert.Null(ctx.WorkflowRepository);
+        }
+
+        [Fact]
+        public void WorkflowRepository_SetNull_ClearsValue()
+        {
+            var ctx = new JobContext();
+            ctx.WorkflowRepository = "owner/repo";
+            ctx.WorkflowRepository = null;
+            Assert.Null(ctx.WorkflowRepository);
+        }
+
+        [Fact]
+        public void WorkflowFilePath_SetAndGet_WorksCorrectly()
+        {
+            var ctx = new JobContext();
+            ctx.WorkflowFilePath = ".github/workflows/ci.yml";
+            Assert.Equal(".github/workflows/ci.yml", ctx.WorkflowFilePath);
+            Assert.True(ctx.TryGetValue("workflow_file_path", out var value));
+            Assert.IsType<StringContextData>(value);
+        }
+
+        [Fact]
+        public void WorkflowFilePath_NotSet_ReturnsNull()
+        {
+            var ctx = new JobContext();
+            Assert.Null(ctx.WorkflowFilePath);
+        }
+
+        [Fact]
+        public void WorkflowFilePath_SetNull_ClearsValue()
+        {
+            var ctx = new JobContext();
+            ctx.WorkflowFilePath = ".github/workflows/ci.yml";
+            ctx.WorkflowFilePath = null;
+            Assert.Null(ctx.WorkflowFilePath);
+        }
+
+        [Fact]
+        public void DeriveWorkflowRefComponents_PopulatesRepositoryAndFilePath()
+        {
+            var ctx = new JobContext();
+            ctx.WorkflowRef = "my-org/my-repo/.github/workflows/deploy.yml@refs/heads/main";
+            ctx.DeriveWorkflowRefComponents();
+
+            Assert.Equal("my-org/my-repo", ctx.WorkflowRepository);
+            Assert.Equal(".github/workflows/deploy.yml", ctx.WorkflowFilePath);
+        }
+
+        [Fact]
+        public void DeriveWorkflowRefComponents_DoesNotOverwriteExistingValues()
+        {
+            var ctx = new JobContext();
+            ctx.WorkflowRef = "my-org/my-repo/.github/workflows/deploy.yml@refs/heads/main";
+            ctx.WorkflowRepository = "explicit/override";
+            ctx.WorkflowFilePath = ".github/workflows/override.yml";
+            ctx.DeriveWorkflowRefComponents();
+
+            Assert.Equal("explicit/override", ctx.WorkflowRepository);
+            Assert.Equal(".github/workflows/override.yml", ctx.WorkflowFilePath);
+        }
+
+        [Fact]
+        public void DeriveWorkflowRefComponents_NoOp_WhenWorkflowRefIsNull()
+        {
+            var ctx = new JobContext();
+            ctx.DeriveWorkflowRefComponents();
+
+            Assert.Null(ctx.WorkflowRepository);
+            Assert.Null(ctx.WorkflowFilePath);
+        }
+
+        [Fact]
+        public void DeriveWorkflowRefComponents_NoOp_WhenRefHasNoGithubDir()
+        {
+            var ctx = new JobContext();
+            ctx.WorkflowRef = "some/path/without/github/dir@refs/heads/main";
+            ctx.DeriveWorkflowRefComponents();
+
+            Assert.Null(ctx.WorkflowRepository);
+            Assert.Null(ctx.WorkflowFilePath);
+        }
+
+        [Fact]
+        public void DeriveWorkflowRefComponents_HandlesRefWithoutAtSign()
+        {
+            var ctx = new JobContext();
+            ctx.WorkflowRef = "my-org/my-repo/.github/workflows/deploy.yml";
+            ctx.DeriveWorkflowRefComponents();
+
+            Assert.Equal("my-org/my-repo", ctx.WorkflowRepository);
+            Assert.Equal(".github/workflows/deploy.yml", ctx.WorkflowFilePath);
+        }
     }
 }