diff --git a/PaperlessREST/Features/BatchProcessing/Presentation/Dto/AccessReportDto.cs b/Paperless.Contracts/BatchProcessing/AccessReportDto.cs
similarity index 84%
rename from PaperlessREST/Features/BatchProcessing/Presentation/Dto/AccessReportDto.cs
rename to Paperless.Contracts/BatchProcessing/AccessReportDto.cs
index c89da53..c8eeda3 100644
--- a/PaperlessREST/Features/BatchProcessing/Presentation/Dto/AccessReportDto.cs
+++ b/Paperless.Contracts/BatchProcessing/AccessReportDto.cs
@@ -1,4 +1,7 @@
-namespace PaperlessREST.Features.BatchProcessing.Presentation.Dto;
+using System.Diagnostics.CodeAnalysis;
+using System.Xml.Serialization;
+
+namespace Paperless.Contracts.BatchProcessing;
 
 [XmlRoot("accessReport")]
 [ExcludeFromCodeCoverage(Justification = "DTO record - XML serialization tested via ReportProcessor tests")]
diff --git a/Paperless.Contracts/DocumentManagement/DocumentDtos.cs b/Paperless.Contracts/DocumentManagement/DocumentDtos.cs
new file mode 100644
index 0000000..f6b4e57
--- /dev/null
+++ b/Paperless.Contracts/DocumentManagement/DocumentDtos.cs
@@ -0,0 +1,133 @@
+using System.ComponentModel;
+using System.ComponentModel.DataAnnotations;
+using Paperless.Contracts.Validation;
+
+namespace Paperless.Contracts.DocumentManagement;
+
+/// <summary>
+///     Query parameters for paginated document listing.
+/// </summary>
+/// <remarks>
+///     Uses cursor-based pagination with GUIDv7 (time-ordered) document IDs.
+///     Pass the last document's ID as <see cref="Cursor"/> to get the next page.
+/// </remarks>
+public sealed record PaginationQuery
+{
+	[Range(PaginationConstraints.MinPageSize, PaginationConstraints.MaxPageSize,
+		ErrorMessage = "Page size must be between 1 and 100")]
+	[Description("Number of documents to return per page")]
+	public int PageSize { get; init; } = PaginationConstraints.DefaultPageSize;
+
+	[Description("Cursor for pagination (last document ID from previous page)")]
+	public Guid? Cursor { get; init; }
+}
+
+/// <summary>
+///     Query parameters for document search.
+/// </summary>
+public sealed record SearchQuery
+{
+	[StringLength(SearchConstraints.QueryMaxLength, MinimumLength = SearchConstraints.QueryMinLength,
+		ErrorMessage = "Search query must be between 1 and 100 characters")]
+	[Description("Search text to find in documents")]
+	public required string Query { get; init; }
+
+	[Range(1, SearchConstraints.MaxResultLimit, ErrorMessage = "Limit must be between 1 and 100")]
+	[Description("Maximum number of results to return")]
+	public int Limit { get; init; } = SearchConstraints.DefaultResultLimit;
+}
+
+/// <summary>
+///     Represents document metadata returned by the API.
+/// </summary>
+public sealed record DocumentDto
+{
+	[Description("Unique document identifier")]
+	public required Guid Id { get; init; }
+
+	[Description("Original PDF filename")] public required string FileName { get; init; }
+
+	[Description("Processing status (Pending, Completed, Failed)")]
+	public required string Status { get; init; }
+
+	[Description("Upload timestamp (UTC)")]
+	public required DateTimeOffset CreatedAt { get; init; }
+
+	[Description("Processing completion timestamp (UTC)")]
+	public DateTimeOffset? ProcessedAt { get; init; }
+
+	[Description("OCR extracted text content")]
+	public string? Content { get; init; }
+
+	[Description("AI-generated summary")] public string? Summary { get; init; }
+
+	[Description("Timestamp when summary was generated (UTC)")]
+	public DateTimeOffset? SummaryGeneratedAt { get; init; }
+}
+
+/// <summary>
+///     Response returned after successfully uploading a document.
+/// </summary>
+public sealed record CreateDocumentResponse
+{
+	[Description("Unique document identifier")]
+	public required Guid Id { get; init; }
+
+	[Description("Original PDF filename")] public required string FileName { get; init; }
+
+	[Description("Processing status")] public required string Status { get; init; }
+
+	[Description("Upload timestamp (UTC)")]
+	public required DateTimeOffset CreatedAt { get; init; }
+}
+
+/// <summary>
+///     Represents a document search result with relevant fields.
+/// </summary>
+public sealed record DocumentSearchResultDto
+{
+	[Description("Unique document identifier")]
+	public required Guid Id { get; init; }
+
+	[Description("Original PDF filename")] public required string FileName { get; init; }
+
+	[Description("OCR extracted content")] public string? Content { get; init; }
+
+	[Description("AI-generated summary")] public string? Summary { get; init; }
+
+	[Description("Upload timestamp (UTC)")]
+	public required DateTimeOffset CreatedAt { get; init; }
+
+	[Description("Processing status")] public required string Status { get; init; }
+}
+
+/// <summary>
+///     Response containing a document summary.
+/// </summary>
+public sealed record SummaryDto
+{
+	[Description("AI-generated summary of the document content")]
+	public string? Summary { get; init; }
+}
+
+/// <summary>
+///     Paginated response wrapper for document listings.
+/// </summary>
+/// <remarks>
+///     Uses cursor-based pagination for efficient traversal of large datasets.
+///     The <see cref="NextCursor"/> is null when there are no more pages.
+/// </remarks>
+public sealed record PaginatedDocumentsResponse
+{
+	[Description("List of documents in this page")]
+	public required List<DocumentDto> Items { get; init; }
+
+	[Description("Cursor for the next page (null if no more pages)")]
+	public Guid? NextCursor { get; init; }
+
+	[Description("Whether more documents exist after this page")]
+	public required bool HasMore { get; init; }
+
+	[Description("Number of documents in this response")]
+	public int Count => Items.Count;
+}
diff --git a/Paperless.Contracts/Paperless.Contracts.csproj b/Paperless.Contracts/Paperless.Contracts.csproj
new file mode 100644
index 0000000..d7dbfaa
--- /dev/null
+++ b/Paperless.Contracts/Paperless.Contracts.csproj
@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+	<PropertyGroup>
+		<TargetFramework>net10.0</TargetFramework>
+		<LangVersion>preview</LangVersion>
+		<Nullable>enable</Nullable>
+		<ImplicitUsings>enable</ImplicitUsings>
+		<RootNamespace>Paperless.Contracts</RootNamespace>
+	</PropertyGroup>
+
+</Project>
diff --git a/Paperless.Contracts/Validation/Constraints.cs b/Paperless.Contracts/Validation/Constraints.cs
new file mode 100644
index 0000000..a34fd3d
--- /dev/null
+++ b/Paperless.Contracts/Validation/Constraints.cs
@@ -0,0 +1,34 @@
+namespace Paperless.Contracts.Validation;
+
+/// <summary>
+/// Search query validation constraints applied at the HTTP boundary.
+/// </summary>
+public static class SearchConstraints
+{
+	/// <summary>Maximum query string length for DTO validation.</summary>
+	public const int QueryMaxLength = 100;
+
+	/// <summary>Minimum query string length.</summary>
+	public const int QueryMinLength = 1;
+
+	/// <summary>Maximum results that can be requested.</summary>
+	public const int MaxResultLimit = 100;
+
+	/// <summary>Default number of results returned.</summary>
+	public const int DefaultResultLimit = 10;
+}
+
+/// <summary>
+/// Pagination constraints for document listing applied at the HTTP boundary.
+/// </summary>
+public static class PaginationConstraints
+{
+	/// <summary>Default page size when not specified.</summary>
+	public const int DefaultPageSize = 20;
+
+	/// <summary>Maximum page size allowed.</summary>
+	public const int MaxPageSize = 100;
+
+	/// <summary>Minimum page size allowed.</summary>
+	public const int MinPageSize = 1;
+}
diff --git a/Paperless.slnx b/Paperless.slnx
index af09639..22e5342 100644
--- a/Paperless.slnx
+++ b/Paperless.slnx
@@ -1,4 +1,5 @@
 <Solution>
+  <Project Path="Paperless.Contracts/Paperless.Contracts.csproj" />
   <Project Path="PaperlessREST/PaperlessREST.csproj" />
   <Project Path="PaperlessServices/PaperlessServices.csproj" />
   <Project Path="PaperlessREST.Tests/PaperlessREST.Tests.csproj" />
diff --git a/PaperlessREST.Tests/GlobalUsings.cs b/PaperlessREST.Tests/GlobalUsings.cs
index 7951ddd..13e9a53 100644
--- a/PaperlessREST.Tests/GlobalUsings.cs
+++ b/PaperlessREST.Tests/GlobalUsings.cs
@@ -83,6 +83,11 @@
 global using PaperlessREST.Features.DocumentManagement.Presentation.Dto;
 global using PaperlessREST.Features.DocumentManagement.Presentation.Endpoints;
 
+// Project namespaces - Paperless.Contracts (transport boundary)
+global using Paperless.Contracts.BatchProcessing;
+global using Paperless.Contracts.DocumentManagement;
+global using Paperless.Contracts.Validation;
+
 // ErrorOr for result pattern
 global using ErrorOr;
 
diff --git a/PaperlessREST.Tests/PaperlessREST.Tests.csproj b/PaperlessREST.Tests/PaperlessREST.Tests.csproj
index 5ad79fb..fe6afbc 100644
--- a/PaperlessREST.Tests/PaperlessREST.Tests.csproj
+++ b/PaperlessREST.Tests/PaperlessREST.Tests.csproj
@@ -68,6 +68,7 @@
 
 	<ItemGroup>
 		<ProjectReference Include="..\PaperlessREST\PaperlessREST.csproj"/>
+		<ProjectReference Include="..\Paperless.Contracts\Paperless.Contracts.csproj"/>
 	</ItemGroup>
 
 
diff --git a/PaperlessREST/Configuration/Constraints.cs b/PaperlessREST/Configuration/Constraints.cs
index a3f33ef..d7977ad 100644
--- a/PaperlessREST/Configuration/Constraints.cs
+++ b/PaperlessREST/Configuration/Constraints.cs
@@ -13,39 +13,13 @@ public static class FileUploadConstraints
 }
 
 /// <summary>
-/// Search query validation constraints.
+/// Server-side search constants that don't belong on the public contract.
+/// Boundary-level <see cref="Paperless.Contracts.Validation.SearchConstraints"/> covers query / limit ranges.
 /// </summary>
-public static class SearchConstraints
+public static class SearchServiceConstraints
 {
-	/// <summary>Maximum query string length for DTO validation.</summary>
-	public const int QueryMaxLength = 100;
-
-	/// <summary>Minimum query string length.</summary>
-	public const int QueryMinLength = 1;
-
 	/// <summary>Maximum query length at service layer (truncation threshold).</summary>
 	public const int ServiceQueryMaxLength = 1000;
-
-	/// <summary>Maximum results that can be requested.</summary>
-	public const int MaxResultLimit = 100;
-
-	/// <summary>Default number of results returned.</summary>
-	public const int DefaultResultLimit = 10;
-}
-
-/// <summary>
-/// Pagination constraints for document listing.
-/// </summary>
-public static class PaginationConstraints
-{
-	/// <summary>Default page size when not specified.</summary>
-	public const int DefaultPageSize = 20;
-
-	/// <summary>Maximum page size allowed.</summary>
-	public const int MaxPageSize = 100;
-
-	/// <summary>Minimum page size allowed.</summary>
-	public const int MinPageSize = 1;
 }
 
 /// <summary>
diff --git a/PaperlessREST/Features/DocumentManagement/Infrastructure/Search/DocumentSearchService.cs b/PaperlessREST/Features/DocumentManagement/Infrastructure/Search/DocumentSearchService.cs
index e142ed3..85bee1c 100644
--- a/PaperlessREST/Features/DocumentManagement/Infrastructure/Search/DocumentSearchService.cs
+++ b/PaperlessREST/Features/DocumentManagement/Infrastructure/Search/DocumentSearchService.cs
@@ -28,8 +28,8 @@ public async IAsyncEnumerable<T> SearchAsync<T>(string query, int limit = 10,
 	{
 		logger.LogInformation("Searching for query: {Query} (limit: {Limit})", query, limit);
 
-		string searchQuery = query.Length > SearchConstraints.ServiceQueryMaxLength
-			? query[..SearchConstraints.ServiceQueryMaxLength]
+		string searchQuery = query.Length > SearchServiceConstraints.ServiceQueryMaxLength
+			? query[..SearchServiceConstraints.ServiceQueryMaxLength]
 			: query;
 
 		SearchResponse<T> response = await elastic.SearchAsync<T>(
diff --git a/PaperlessREST/Features/DocumentManagement/Presentation/Dto/DTOs.cs b/PaperlessREST/Features/DocumentManagement/Presentation/Dto/DTOs.cs
index 457e8f9..a1b500b 100644
--- a/PaperlessREST/Features/DocumentManagement/Presentation/Dto/DTOs.cs
+++ b/PaperlessREST/Features/DocumentManagement/Presentation/Dto/DTOs.cs
@@ -3,137 +3,13 @@ namespace PaperlessREST.Features.DocumentManagement.Presentation.Dto;
 /// <summary>
 /// Request model for uploading a PDF document.
 /// Validation handled by <see cref="Filters.PdfUploadFilter"/>.
+///
+/// Stays in the API project (rather than Paperless.Contracts) because it carries an
+/// <see cref="IFormFile"/> — an ASP.NET Core input-model concern, not a transport DTO.
+/// All response/query DTOs live in <c>Paperless.Contracts.DocumentManagement</c>.
 /// </summary>
 public sealed record UploadDocumentRequest
 {
 	[Description("PDF file to upload (max 10MB, PDF only)")]
 	public required IFormFile File { get; init; }
 }
-
-/// <summary>
-///     Query parameters for paginated document listing.
-/// </summary>
-/// <remarks>
-///     Uses cursor-based pagination with GUIDv7 (time-ordered) document IDs.
-///     Pass the last document's ID as <see cref="Cursor"/> to get the next page.
-/// </remarks>
-public sealed record PaginationQuery
-{
-	[Range(PaginationConstraints.MinPageSize, PaginationConstraints.MaxPageSize,
-		ErrorMessage = "Page size must be between 1 and 100")]
-	[Description("Number of documents to return per page")]
-	public int PageSize { get; init; } = PaginationConstraints.DefaultPageSize;
-
-	[Description("Cursor for pagination (last document ID from previous page)")]
-	public Guid? Cursor { get; init; }
-}
-
-/// <summary>
-///     Query parameters for document search.
-/// </summary>
-public sealed record SearchQuery
-{
-	[StringLength(SearchConstraints.QueryMaxLength, MinimumLength = SearchConstraints.QueryMinLength,
-		ErrorMessage = "Search query must be between 1 and 100 characters")]
-	[Description("Search text to find in documents")]
-	public required string Query { get; init; }
-
-	[Range(1, SearchConstraints.MaxResultLimit, ErrorMessage = "Limit must be between 1 and 100")]
-	[Description("Maximum number of results to return")]
-	public int Limit { get; init; } = SearchConstraints.DefaultResultLimit;
-}
-
-/// <summary>
-///     Represents document metadata returned by the API.
-/// </summary>
-public sealed record DocumentDto
-{
-	[Description("Unique document identifier")]
-	public required Guid Id { get; init; }
-
-	[Description("Original PDF filename")] public required string FileName { get; init; }
-
-	[Description("Processing status (Pending, Completed, Failed)")]
-	public required string Status { get; init; }
-
-	[Description("Upload timestamp (UTC)")]
-	public required DateTimeOffset CreatedAt { get; init; }
-
-	[Description("Processing completion timestamp (UTC)")]
-	public DateTimeOffset? ProcessedAt { get; init; }
-
-	[Description("OCR extracted text content")]
-	public string? Content { get; init; }
-
-	[Description("AI-generated summary")] public string? Summary { get; init; }
-
-	[Description("Timestamp when summary was generated (UTC)")]
-	public DateTimeOffset? SummaryGeneratedAt { get; init; }
-}
-
-/// <summary>
-///     Response returned after successfully uploading a document.
-/// </summary>
-public sealed record CreateDocumentResponse
-{
-	[Description("Unique document identifier")]
-	public required Guid Id { get; init; }
-
-	[Description("Original PDF filename")] public required string FileName { get; init; }
-
-	[Description("Processing status")] public required string Status { get; init; }
-
-	[Description("Upload timestamp (UTC)")]
-	public required DateTimeOffset CreatedAt { get; init; }
-}
-
-/// <summary>
-///     Represents a document search result with relevant fields.
-/// </summary>
-public sealed record DocumentSearchResultDto
-{
-	[Description("Unique document identifier")]
-	public required Guid Id { get; init; }
-
-	[Description("Original PDF filename")] public required string FileName { get; init; }
-
-	[Description("OCR extracted content")] public string? Content { get; init; }
-
-	[Description("AI-generated summary")] public string? Summary { get; init; }
-
-	[Description("Upload timestamp (UTC)")]
-	public required DateTimeOffset CreatedAt { get; init; }
-
-	[Description("Processing status")] public required string Status { get; init; }
-}
-
-/// <summary>
-///     Response containing a document summary.
-/// </summary>
-public sealed record SummaryDto
-{
-	[Description("AI-generated summary of the document content")]
-	public string? Summary { get; init; }
-}
-
-/// <summary>
-///     Paginated response wrapper for document listings.
-/// </summary>
-/// <remarks>
-///     Uses cursor-based pagination for efficient traversal of large datasets.
-///     The <see cref="NextCursor"/> is null when there are no more pages.
-/// </remarks>
-public sealed record PaginatedDocumentsResponse
-{
-	[Description("List of documents in this page")]
-	public required List<DocumentDto> Items { get; init; }
-
-	[Description("Cursor for the next page (null if no more pages)")]
-	public Guid? NextCursor { get; init; }
-
-	[Description("Whether more documents exist after this page")]
-	public required bool HasMore { get; init; }
-
-	[Description("Number of documents in this response")]
-	public int Count => Items.Count;
-}
diff --git a/PaperlessREST/GlobalUsings.cs b/PaperlessREST/GlobalUsings.cs
index c14d258..57b4b40 100644
--- a/PaperlessREST/GlobalUsings.cs
+++ b/PaperlessREST/GlobalUsings.cs
@@ -68,7 +68,11 @@
 
 // Project namespaces - Batch Processing Feature
 global using PaperlessREST.Features.BatchProcessing.Application;
-global using PaperlessREST.Features.BatchProcessing.Presentation.Dto;
+
+// Project namespaces - Paperless.Contracts (transport boundary)
+global using Paperless.Contracts.BatchProcessing;
+global using Paperless.Contracts.DocumentManagement;
+global using Paperless.Contracts.Validation;
 
 // Project namespaces - Event Processing Feature
 global using PaperlessREST.Features.EventProcessing.Presentation;
diff --git a/PaperlessREST/PaperlessREST.csproj b/PaperlessREST/PaperlessREST.csproj
index 7bfe7fc..2c553e9 100644
--- a/PaperlessREST/PaperlessREST.csproj
+++ b/PaperlessREST/PaperlessREST.csproj
@@ -50,6 +50,10 @@
 		<PackageReference Include="Testably.Abstractions.FileSystem.Interface"/>
 	</ItemGroup>
 
+	<ItemGroup>
+		<ProjectReference Include="..\Paperless.Contracts\Paperless.Contracts.csproj"/>
+	</ItemGroup>
+
 	<ItemGroup>
 		<Content Include="..\.dockerignore">
 			<Link>.dockerignore</Link>