Add source_url to MCP get_document_by_url output

src/Elastic.Markdown/Exporters/Elasticsearch/ElasticsearchMarkdownExporter.Export.cs

@@ -7,6 +7,7 @@
 using Elastic.Documentation;
 using Elastic.Documentation.AppliesTo;
 using Elastic.Documentation.Configuration.Inference;
+using Elastic.Documentation.Extensions;
 using Elastic.Documentation.Navigation;
 using Elastic.Documentation.Search;
 using Elastic.Ingest.Elasticsearch.Indices;
@@ -157,6 +158,19 @@
 			}).ToArray()
 			: null;
 
+		var gitHubRepo = fileContext.BuildContext.Git.GitHubRepository;
+		var branch = fileContext.BuildContext.Git.Branch;
+		if (gitHubRepo is not null
+			&& fileContext.BuildContext.Git != GitCheckoutInformation.Unavailable
+			&& fileContext.BuildContext.DocumentationCheckoutDirectory is { } checkoutDirectory)
+		{
+			var relativeSourcePath = Path.GetRelativePath(
+				checkoutDirectory.FullName,
+				fileContext.BuildContext.DocumentationSourceDirectory.FullName);
+			var path = UrlPath.Join(relativeSourcePath, file.RelativePath);
+			doc.SourceUrl = $"https://github.com/{gitHubRepo}/blob/{branch}/{path}";
+		}
+
 		CommonEnrichments(doc, currentNavigation);
 		AssignContentHash(doc);
 		AssignDocumentMetadata(doc);

src/api/Elastic.Documentation.Mcp.Remote/Gateways/DocumentGateway.cs

@@ -47,6 +47,7 @@ public class DocumentGateway(
 					e => e.AiQuestions,
 					e => e.AiUseCases,
 					e => e.LastUpdated,
+					e => e.SourceUrl,
 					e => e.Product,
 					e => e.RelatedProducts
 				))),
@@ -79,6 +80,7 @@ public class DocumentGateway(
 				AiQuestions = doc.AiQuestions,
 				AiUseCases = doc.AiUseCases,
 				LastUpdated = doc.LastUpdated,
+				SourceUrl = doc.SourceUrl,
 				Product = doc.Product?.Id != null ? new DocumentProduct
 				{
 					Id = doc.Product.Id,

src/api/Elastic.Documentation.Mcp.Remote/Gateways/IDocumentGateway.cs

@@ -36,6 +36,7 @@ public record DocumentResult
 	public string[]? AiQuestions { get; init; }
 	public string[]? AiUseCases { get; init; }
 	public DateTimeOffset? LastUpdated { get; init; }
+	public string? SourceUrl { get; init; }
 	public DocumentParent[] Parents { get; init; } = [];
 	public string[] Headings { get; init; } = [];
 	public string[] Links { get; init; } = [];

src/api/Elastic.Documentation.Mcp.Remote/Responses/McpResponses.cs

@@ -110,6 +110,7 @@ public sealed record DocumentResponse
 	public string[]? AiQuestions { get; init; }
 	public string[]? AiUseCases { get; init; }
 	public DateTimeOffset? LastUpdated { get; init; }
+	public string? SourceUrl { get; init; }
 	public required List<ParentDto> Parents { get; init; }
 	public required List<string> Headings { get; init; }
 	public ProductDto? Product { get; init; }

src/api/Elastic.Documentation.Mcp.Remote/Tools/DocumentTools.cs

@@ -68,6 +68,7 @@ public async Task<string> GetDocumentByUrl(
 				AiQuestions = result.AiQuestions,
 				AiUseCases = result.AiUseCases,
 				LastUpdated = result.LastUpdated,
+				SourceUrl = result.SourceUrl,
 				Parents = result.Parents.Select(p => new ParentDto
 				{
 					Title = p.Title,

tests-integration/Mcp.Remote.IntegrationTests/DocumentToolsIntegrationTests.cs

@@ -72,6 +72,33 @@
 		Output.WriteLine($"Error message: {errorResponse.Error}");
 	}
 
+	[Fact]
+	public async Task GetDocumentByUrl_SourceUrlIsGitHubBlobUrlWhenPresent()
+	{
+		// Arrange
+		var (documentTools, clientAccessor) = CreateDocumentTools();
+		Assert.SkipUnless(documentTools is not null, "Elasticsearch is not configured");
+		LogDiagnostics(clientAccessor);
+		var canConnect = await clientAccessor!.CanConnect(TestContext.Current.CancellationToken);
+		Assert.SkipUnless(canConnect, "Elasticsearch is not connected");
+
+		// Act
+		var resultJson = await documentTools.GetDocumentByUrl(
+			"/docs/reference/elasticsearch",
+			cancellationToken: TestContext.Current.CancellationToken);
+
+		if (resultJson.Contains("\"error\""))
+			Assert.Skip("Test document not found in index");
+
+		var response = JsonSerializer.Deserialize(resultJson, McpJsonContext.Default.DocumentResponse);
+		response.Should().NotBeNull();
+		Output.WriteLine($"source_url: {response!.SourceUrl ?? "(null — document predates indexing of this field)"}");
+
+		// source_url is null for docs indexed before this field was added; when present it must be a GitHub blob URL
+		if (response.SourceUrl is not null)
+			response.SourceUrl.Should().StartWith("https://github.com/").And.Contain("/blob/");
+	}
+
 	[Fact]
 	public async Task AnalyzeDocumentStructure_ReturnsStructure()
 	{

tests/Mcp.Remote.Tests/DocumentToolsTests.cs

@@ -0,0 +1,63 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+using System.Text.Json;
+using AwesomeAssertions;
+using Elastic.Documentation.Mcp.Remote.Gateways;
+using Elastic.Documentation.Mcp.Remote.Responses;
+using Elastic.Documentation.Mcp.Remote.Tools;
+using Microsoft.Extensions.Logging.Abstractions;
+
+namespace Mcp.Remote.Tests;
+
+public class DocumentToolsTests
+{
+	[Fact]
+	public async Task GetDocumentByUrl_MapsSourceUrlIntoResponse()
+	{
+		const string expectedSourceUrl = "https://github.com/elastic/docs-content/blob/main/docs/some-page.md";
+		var gateway = new StubDocumentGateway(new DocumentResult
+		{
+			Url = "/docs/some-page",
+			Title = "Some Page",
+			Type = "doc",
+			SourceUrl = expectedSourceUrl
+		});
+		var tools = new DocumentTools(gateway, NullLogger<DocumentTools>.Instance);
+
+		var json = await tools.GetDocumentByUrl("/docs/some-page");
+
+		var response = JsonSerializer.Deserialize(json, McpJsonContext.Default.DocumentResponse);
+		response.Should().NotBeNull();
+		response!.SourceUrl.Should().Be(expectedSourceUrl);
+	}
+
+	[Fact]
+	public async Task GetDocumentByUrl_OmitsSourceUrlWhenNull()
+	{
+		var gateway = new StubDocumentGateway(new DocumentResult
+		{
+			Url = "/docs/some-page",
+			Title = "Some Page",
+			Type = "doc",
+			SourceUrl = null
+		});
+		var tools = new DocumentTools(gateway, NullLogger<DocumentTools>.Instance);
+
+		var json = await tools.GetDocumentByUrl("/docs/some-page");
+
+		var response = JsonSerializer.Deserialize(json, McpJsonContext.Default.DocumentResponse);
+		response.Should().NotBeNull();
+		response!.SourceUrl.Should().BeNull();
+	}
+
+	private sealed class StubDocumentGateway(DocumentResult? result) : IDocumentGateway
+	{
+		public Task<DocumentResult?> GetByUrlAsync(string url, CancellationToken ct = default) =>
+			Task.FromResult(result);
+
+		public Task<DocumentStructure?> GetStructureAsync(string url, CancellationToken ct = default) =>
+			Task.FromResult<DocumentStructure?>(null);
+	}
+}