diff --git a/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/DoclingServeConvertApi.java b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/DoclingServeConvertApi.java
index 91ff50b1..7e5bea62 100644
--- a/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/DoclingServeConvertApi.java
+++ b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/DoclingServeConvertApi.java
@@ -46,7 +46,7 @@ default ConvertDocumentResponse convertFiles(Path... files) {
    * If the request is null, default conversion options are applied.
    *
    * @param request an optional {@link ConvertDocumentRequest} specifying conversion settings and parameters
-   * @param files an array of {@link Path} objects representing the file paths to be converted
+   * @param files   an array of {@link Path} objects representing the file paths to be converted
    * @return a {@link ConvertDocumentResponse} containing the processed document data, any errors encountered,
    *         and additional processing metadata
    * @throws ai.docling.serve.api.validation.ValidationException If request validation fails for any reason.
@@ -148,8 +148,7 @@ default CompletionStage<ConvertDocumentResponse> convertFilesAsync(@Nullable Con
   private ConvertDocumentRequest createRequest(@Nullable ConvertDocumentRequest request, Path... files) {
     ValidationUtils.ensureNotEmpty(files, "files");
 
-    var builder = Optional.ofNullable(request)
-        .map(ConvertDocumentRequest::toBuilder)
+    var builder = Optional.ofNullable(request).<ConvertDocumentRequest.Builder<?, ?>>map(ConvertDocumentRequest::toBuilder)
         .orElseGet(ConvertDocumentRequest::builder);
 
     FileUtils.createFileSources(files)
diff --git a/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/chunk/request/ChunkDocumentRequest.java b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/chunk/request/ChunkDocumentRequest.java
index d03f4187..e8d08936 100644
--- a/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/chunk/request/ChunkDocumentRequest.java
+++ b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/chunk/request/ChunkDocumentRequest.java
@@ -1,35 +1,18 @@
 package ai.docling.serve.api.chunk.request;
 
-import java.util.List;
-
-import org.jspecify.annotations.Nullable;
-
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
-import com.fasterxml.jackson.annotation.JsonSetter;
-import com.fasterxml.jackson.annotation.Nulls;
 
 import ai.docling.serve.api.convert.request.options.ConvertDocumentOptions;
-import ai.docling.serve.api.convert.request.source.Source;
-import ai.docling.serve.api.convert.request.target.Target;
+import ai.docling.serve.api.request.DocumentRequest;
 
 @JsonInclude(JsonInclude.Include.NON_EMPTY)
 @tools.jackson.databind.annotation.JsonDeserialize(builder = ChunkDocumentRequest.ChunkDocumentRequestBuilder.class)
 @lombok.experimental.SuperBuilder(toBuilder = true)
 @lombok.Getter
-@lombok.ToString
-public sealed abstract class ChunkDocumentRequest permits HierarchicalChunkDocumentRequest, HybridChunkDocumentRequest {
-  /**
-   * List of input document sources to process.
-   *
-   * @param sources the list of document sources
-   * @return the list of document sources
-   */
-  @JsonProperty("sources")
-  @JsonSetter(nulls = Nulls.AS_EMPTY)
-  @lombok.Singular
-  private List<Source> sources;
-
+@lombok.ToString(callSuper = true)
+public sealed abstract class ChunkDocumentRequest extends DocumentRequest
+    permits HierarchicalChunkDocumentRequest, HybridChunkDocumentRequest {
   /**
    * Conversion options.
    *
@@ -41,16 +24,6 @@ public sealed abstract class ChunkDocumentRequest permits HierarchicalChunkDocum
   @lombok.Builder.Default
   private ConvertDocumentOptions options = ConvertDocumentOptions.builder().build();
 
-  /**
-   * Specification for the type of output target.
-   *
-   * @param target the output target specification, or null if not specified
-   * @return the output target specification, or null if not specified
-   */
-  @JsonProperty("target")
-  @Nullable
-  private Target target;
-
   /**
    * If true, the output will include both the chunks and the converted document.
    *
@@ -61,7 +34,6 @@ public sealed abstract class ChunkDocumentRequest permits HierarchicalChunkDocum
   private boolean includeConvertedDoc;
 
   @tools.jackson.databind.annotation.JsonPOJOBuilder(withPrefix = "")
-  public static abstract class ChunkDocumentRequestBuilder<C extends ChunkDocumentRequest, B extends ChunkDocumentRequestBuilder<C, B>> {
-    // Lombok's @SuperBuilder generates the actual implementation
+  public abstract static class ChunkDocumentRequestBuilder<C extends ChunkDocumentRequest, B extends ChunkDocumentRequestBuilder<C, B>> extends DocumentRequest.DocumentRequestBuilder<C, B> {
   }
 }
diff --git a/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/chunk/response/ChunkDocumentResponse.java b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/chunk/response/ChunkDocumentResponse.java
index 199f1121..9785bb10 100644
--- a/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/chunk/response/ChunkDocumentResponse.java
+++ b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/chunk/response/ChunkDocumentResponse.java
@@ -7,11 +7,15 @@
 import com.fasterxml.jackson.annotation.JsonSetter;
 import com.fasterxml.jackson.annotation.Nulls;
 
+import ai.docling.serve.api.response.ProcessedDocumentResponse;
+
 /**
  * Response returned by the Chunk API for a single conversion request.
  *
  * <p>Serialization uses {@link JsonInclude.Include#NON_EMPTY}, so nulls and empty
  * collections/strings are omitted from JSON output.</p>
+ *
+ * @see ProcessedDocumentResponse
  */
 @JsonInclude(JsonInclude.Include.NON_EMPTY)
 @tools.jackson.databind.annotation.JsonDeserialize(builder = ChunkDocumentResponse.Builder.class)
@@ -19,7 +23,7 @@
 @lombok.Builder(toBuilder = true)
 @lombok.Getter
 @lombok.ToString
-public class ChunkDocumentResponse {
+public final class ChunkDocumentResponse extends ProcessedDocumentResponse {
 
   /**
    * List of document chunks.
@@ -55,17 +59,18 @@ public class ChunkDocumentResponse {
   /**
    * Builder for creating {@link ChunkDocumentResponse} instances.
    * Generated by Lombok's {@code @Builder} annotation.
-   * 
+   *
    * <p>Builder methods:
    * <ul>
-   *   <li>{@code chunk(Chunk)} - Add a single chunk (use with @Singular)</li>
-   *   <li>{@code chunks(List<Chunk>)} - Set the list of chunks</li>
-   *   <li>{@code document(Document)} - Add a single document (use with @Singular)</li>
-   *   <li>{@code documents(List<Document>)} - Set the list of converted documents</li>
-   *   <li>{@code processingTime(Double)} - Set the processing time in seconds</li>
+   * <li>{@code chunk(Chunk)} - Add a single chunk (use with @Singular)</li>
+   * <li>{@code chunks(List<Chunk>)} - Set the list of chunks</li>
+   * <li>{@code document(Document)} - Add a single document (use with @Singular)</li>
+   * <li>{@code documents(List<Document>)} - Set the list of converted documents</li>
+   * <li>{@code processingTime(Double)} - Set the processing time in seconds</li>
    * </ul>
    */
   @tools.jackson.databind.annotation.JsonPOJOBuilder(withPrefix = "")
-  public static class Builder { }
+  public static class Builder {
+  }
 
 }
diff --git a/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/convert/request/BatchConvertDocumentRequest.java b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/convert/request/BatchConvertDocumentRequest.java
index ec5d55ba..1d0e1648 100644
--- a/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/convert/request/BatchConvertDocumentRequest.java
+++ b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/convert/request/BatchConvertDocumentRequest.java
@@ -1,6 +1,7 @@
 package ai.docling.serve.api.convert.request;
 
 import java.util.List;
+import java.util.Objects;
 
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
@@ -8,49 +9,30 @@
 import com.fasterxml.jackson.annotation.Nulls;
 
 import ai.docling.serve.api.convert.request.options.ConvertDocumentOptions;
-import ai.docling.serve.api.convert.request.source.Source;
 import ai.docling.serve.api.convert.request.target.Target;
+import ai.docling.serve.api.request.DocumentRequest;
 
 /**
  * Represents a request to batch convert document sources. The batch endpoint processes multiple
  * documents asynchronously and returns a task ID for tracking progress. Sources can be HTTP URLs
  * or S3 buckets, and results are delivered to a presigned URL or S3 target.
  *
+ * <p>Unlike {@link ConvertDocumentRequest}, the {@linkplain #getTarget() target} is required
+ * for batch requests — it must be either a
+ * {@link ai.docling.serve.api.convert.request.target.PresignedUrlTarget} or
+ * {@link ai.docling.serve.api.convert.request.target.S3Target}.
+ *
  * <p>This class is serialized into JSON to conform to the API specification using
  * {@link JsonProperty} annotations. Fields with {@code null} values or empty collections
  * are omitted from the serialized JSON using {@link JsonInclude}.
  */
 @JsonInclude(JsonInclude.Include.NON_EMPTY)
-@tools.jackson.databind.annotation.JsonDeserialize(builder = BatchConvertDocumentRequest.Builder.class)
+@tools.jackson.databind.annotation.JsonDeserialize(builder = BatchConvertDocumentRequest.BuilderImpl.class)
 @lombok.extern.jackson.Jacksonized
-@lombok.Builder(toBuilder = true)
+@lombok.experimental.SuperBuilder(toBuilder = true)
 @lombok.Getter
-@lombok.ToString
-public class BatchConvertDocumentRequest {
-  /**
-   * List of document sources to be converted.
-   * Each source can be an HTTP URL or S3 reference.
-   *
-   * @param sources the list of document sources
-   * @return the list of document sources
-   */
-  @JsonProperty("sources")
-  @JsonSetter(nulls = Nulls.AS_EMPTY)
-  @lombok.Singular
-  private List<Source> sources;
-
-  /**
-   * Target specification for where the converted documents should be delivered.
-   * Must be either a {@link ai.docling.serve.api.convert.request.target.PresignedUrlTarget}
-   * or {@link ai.docling.serve.api.convert.request.target.S3Target}.
-   *
-   * @param target the output target
-   * @return the output target
-   */
-  @JsonProperty("target")
-  @lombok.NonNull
-  private Target target;
-
+@lombok.ToString(callSuper = true)
+public final class BatchConvertDocumentRequest extends DocumentRequest {
   /**
    * Options controlling the document conversion process.
    * Includes settings for OCR, output formats, processing pipelines, and more.
@@ -75,19 +57,16 @@ public class BatchConvertDocumentRequest {
   private List<CallbackSpec> callbacks;
 
   /**
-   * Builder for creating {@link BatchConvertDocumentRequest} instances.
-   * Generated by Lombok's {@code @Builder} annotation.
+   * Returns the output target, which is required for batch requests.
    *
-   * <p>Builder methods:
-   * <ul>
-   *   <li>{@code source(Source)} - Add a single document source</li>
-   *   <li>{@code sources(List<Source>)} - Set the list of document sources</li>
-   *   <li>{@code target(Target)} - Set the output target</li>
-   *   <li>{@code options(ConvertDocumentOptions)} - Set the conversion options</li>
-   *   <li>{@code callback(CallbackSpec)} - Add a single callback specification</li>
-   *   <li>{@code callbacks(List<CallbackSpec>)} - Set the list of callback specifications</li>
-   * </ul>
+   * @return the output target, never null
    */
+  @Override
+  public Target getTarget() {
+    return Objects.requireNonNull(super.getTarget(), "target is marked non-null but is null");
+  }
+
   @tools.jackson.databind.annotation.JsonPOJOBuilder(withPrefix = "")
-  public static class Builder { }
+  public abstract static class BatchConvertDocumentRequestBuilder<C extends BatchConvertDocumentRequest, B extends BatchConvertDocumentRequestBuilder<C, B>> extends DocumentRequest.DocumentRequestBuilder<C, B> {
+  }
 }
diff --git a/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/convert/request/ConvertDocumentRequest.java b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/convert/request/ConvertDocumentRequest.java
index dc83c306..d2a73812 100644
--- a/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/convert/request/ConvertDocumentRequest.java
+++ b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/convert/request/ConvertDocumentRequest.java
@@ -1,17 +1,10 @@
 package ai.docling.serve.api.convert.request;
 
-import java.util.List;
-
-import org.jspecify.annotations.Nullable;
-
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
-import com.fasterxml.jackson.annotation.JsonSetter;
-import com.fasterxml.jackson.annotation.Nulls;
 
 import ai.docling.serve.api.convert.request.options.ConvertDocumentOptions;
-import ai.docling.serve.api.convert.request.source.Source;
-import ai.docling.serve.api.convert.request.target.Target;
+import ai.docling.serve.api.request.DocumentRequest;
 
 /**
  * Represents a request to convert a document. The request includes the source(s) of the document,
@@ -22,24 +15,12 @@
  * are omitted from the serialized JSON using {@link JsonInclude}.
  */
 @JsonInclude(JsonInclude.Include.NON_EMPTY)
-@tools.jackson.databind.annotation.JsonDeserialize(builder = ConvertDocumentRequest.Builder.class)
+@tools.jackson.databind.annotation.JsonDeserialize(builder = ConvertDocumentRequest.BuilderImpl.class)
 @lombok.extern.jackson.Jacksonized
-@lombok.Builder(toBuilder = true)
+@lombok.experimental.SuperBuilder(toBuilder = true)
 @lombok.Getter
-@lombok.ToString
-public class ConvertDocumentRequest {
-  /**
-   * List of document sources to be converted.
-   * Each source can be a file (base64-encoded) or an HTTP URL.
-   *
-   * @param sources the list of document sources
-   * @return the list of document sources
-   */
-  @JsonProperty("sources")
-  @JsonSetter(nulls = Nulls.AS_EMPTY)
-  @lombok.Singular
-  private List<Source> sources;
-
+@lombok.ToString(callSuper = true)
+public final class ConvertDocumentRequest extends DocumentRequest {
   /**
    * Options controlling the document conversion process.
    * Includes settings for OCR, output formats, processing pipelines, and more.
@@ -52,29 +33,7 @@ public class ConvertDocumentRequest {
   @lombok.Builder.Default
   private ConvertDocumentOptions options = ConvertDocumentOptions.builder().build();
 
-  /**
-   * Target specification for where the converted document should be delivered.
-   * If not specified, the result is returned in the response body.
-   *
-   * @param target the output target, or null if not specified
-   * @return the output target, or null if not specified
-   */
-  @JsonProperty("target")
-  @Nullable
-  private Target target;
-
-  /**
-   * Builder for creating {@link ConvertDocumentRequest} instances.
-   * Generated by Lombok's {@code @Builder} annotation.
-   * 
-   * <p>Builder methods:
-   * <ul>
-   *   <li>{@code source(Source)} - Add a single document source (use with @Singular)</li>
-   *   <li>{@code sources(List<Source>)} - Set the list of document sources</li>
-   *   <li>{@code options(ConvertDocumentOptions)} - Set the conversion options</li>
-   *   <li>{@code target(Target)} - Set the output target</li>
-   * </ul>
-   */
   @tools.jackson.databind.annotation.JsonPOJOBuilder(withPrefix = "")
-  public static class Builder { }
+  public abstract static class ConvertDocumentRequestBuilder<C extends ConvertDocumentRequest, B extends ConvertDocumentRequestBuilder<C, B>> extends DocumentRequest.DocumentRequestBuilder<C, B> {
+  }
 }
diff --git a/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/convert/response/ConvertDocumentResponse.java b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/convert/response/ConvertDocumentResponse.java
index 58233051..2172bbff 100644
--- a/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/convert/response/ConvertDocumentResponse.java
+++ b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/convert/response/ConvertDocumentResponse.java
@@ -3,6 +3,7 @@
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
+import ai.docling.serve.api.response.ProcessedDocumentResponse;
 import ai.docling.serve.api.serialization.Jackson2ConvertDocumentResponseDeserializer;
 import ai.docling.serve.api.serialization.Jackson3ConvertDocumentResponseDeserializer;
 
@@ -14,12 +15,14 @@
  *
  * <p>Serialization uses {@link JsonInclude.Include#NON_EMPTY}, so nulls and empty
  * collections/strings are omitted from JSON output.</p>
+ *
+ * @see ProcessedDocumentResponse
  */
 @JsonInclude(JsonInclude.Include.NON_EMPTY)
 @com.fasterxml.jackson.databind.annotation.JsonDeserialize(using = Jackson2ConvertDocumentResponseDeserializer.class)
 @tools.jackson.databind.annotation.JsonDeserialize(using = Jackson3ConvertDocumentResponseDeserializer.class)
-public abstract sealed class ConvertDocumentResponse permits InBodyConvertDocumentResponse, PreSignedUrlConvertDocumentResponse,
-    PreSignedUrlConvertResponse, ZipArchiveConvertDocumentResponse {
+public abstract sealed class ConvertDocumentResponse extends ProcessedDocumentResponse permits InBodyConvertDocumentResponse,
+    PreSignedUrlConvertDocumentResponse, PreSignedUrlConvertResponse, ZipArchiveConvertDocumentResponse {
   /**
    * Type of response
    *
diff --git a/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/request/DocumentRequest.java b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/request/DocumentRequest.java
new file mode 100644
index 00000000..10e51c6e
--- /dev/null
+++ b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/request/DocumentRequest.java
@@ -0,0 +1,69 @@
+package ai.docling.serve.api.request;
+
+import java.util.List;
+
+import org.jspecify.annotations.Nullable;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonSetter;
+import com.fasterxml.jackson.annotation.Nulls;
+
+import ai.docling.serve.api.chunk.request.ChunkDocumentRequest;
+import ai.docling.serve.api.convert.request.BatchConvertDocumentRequest;
+import ai.docling.serve.api.convert.request.ConvertDocumentRequest;
+import ai.docling.serve.api.convert.request.source.Source;
+import ai.docling.serve.api.convert.request.target.Target;
+
+/**
+ * Abstract base class for all document processing requests. Provides the common fields shared
+ * across conversion, chunking, and batch conversion requests: document {@linkplain #getSources()
+ * sources} and an optional output {@linkplain #getTarget() target}.
+ *
+ * <p>This is a {@code sealed} class — the only permitted subtypes are
+ * {@link ConvertDocumentRequest}, {@link BatchConvertDocumentRequest}, and
+ * {@link ChunkDocumentRequest} — enabling exhaustive pattern matching:
+ *
+ * <pre>{@code
+ * switch (request) {
+ *   case ConvertDocumentRequest r    -> client.convertSource(r);
+ *   case BatchConvertDocumentRequest r -> client.convertSourceBatch(r);
+ *   case HierarchicalChunkDocumentRequest r -> client.chunkSourceWithHierarchicalChunker(r);
+ *   case HybridChunkDocumentRequest r       -> client.chunkSourceWithHybridChunker(r);
+ * }
+ * }</pre>
+ */
+@JsonInclude(JsonInclude.Include.NON_EMPTY)
+@tools.jackson.databind.annotation.JsonDeserialize(builder = DocumentRequest.DocumentRequestBuilder.class)
+@lombok.experimental.SuperBuilder(toBuilder = true)
+@lombok.Getter
+@lombok.ToString
+public abstract sealed class DocumentRequest
+    permits ConvertDocumentRequest, BatchConvertDocumentRequest, ChunkDocumentRequest {
+  /**
+   * List of document sources to be processed.
+   * Each source can be a file (base64-encoded), an HTTP URL, or an S3 reference.
+   *
+   * @param sources the list of document sources
+   * @return the list of document sources
+   */
+  @JsonProperty("sources")
+  @JsonSetter(nulls = Nulls.AS_EMPTY)
+  @lombok.Singular
+  private List<Source> sources;
+
+  /**
+   * Specification for the type of output target.
+   * If not specified, the result is returned in the response body.
+   *
+   * @param target the output target specification, or null if not specified
+   * @return the output target specification, or null if not specified
+   */
+  @JsonProperty("target")
+  @Nullable
+  private Target target;
+
+  @tools.jackson.databind.annotation.JsonPOJOBuilder(withPrefix = "")
+  public abstract static class DocumentRequestBuilder<C extends DocumentRequest, B extends DocumentRequestBuilder<C, B>> {
+  }
+}
diff --git a/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/request/package-info.java b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/request/package-info.java
new file mode 100644
index 00000000..43e09b77
--- /dev/null
+++ b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/request/package-info.java
@@ -0,0 +1,4 @@
+@NullMarked
+package ai.docling.serve.api.request;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/response/ProcessedDocumentResponse.java b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/response/ProcessedDocumentResponse.java
new file mode 100644
index 00000000..7c67a71b
--- /dev/null
+++ b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/response/ProcessedDocumentResponse.java
@@ -0,0 +1,30 @@
+package ai.docling.serve.api.response;
+
+import ai.docling.serve.api.chunk.response.ChunkDocumentResponse;
+import ai.docling.serve.api.convert.response.ConvertDocumentResponse;
+
+/**
+ * Abstract base class for all document processing responses. Provides a common type for
+ * conversion and chunking responses, enabling polymorphism when working with different
+ * response types.
+ *
+ * <p>This is a {@code sealed} class — the only permitted subtypes are
+ * {@link ConvertDocumentResponse} (which is itself sealed with four further subtypes)
+ * and {@link ChunkDocumentResponse} — enabling exhaustive pattern matching:
+ *
+ * <pre>{@code
+ * switch (response) {
+ *   case InBodyConvertDocumentResponse r           -> handleInBody(r);
+ *   case PreSignedUrlConvertDocumentResponse r     -> handlePreSignedUrl(r);
+ *   case PreSignedUrlConvertResponse r             -> handlePreSignedUrlResponse(r);
+ *   case ZipArchiveConvertDocumentResponse r       -> handleZipArchive(r);
+ *   case ChunkDocumentResponse r                   -> handleChunk(r);
+ * }
+ * }</pre>
+ *
+ * @see ConvertDocumentResponse
+ * @see ChunkDocumentResponse
+ */
+public abstract sealed class ProcessedDocumentResponse
+    permits ConvertDocumentResponse, ChunkDocumentResponse {
+}
diff --git a/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/response/package-info.java b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/response/package-info.java
new file mode 100644
index 00000000..2b683edf
--- /dev/null
+++ b/docling-serve/docling-serve-api/src/main/java/ai/docling/serve/api/response/package-info.java
@@ -0,0 +1,4 @@
+@NullMarked
+package ai.docling.serve.api.response;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/docling-serve/docling-serve-api/src/main/java/module-info.java b/docling-serve/docling-serve-api/src/main/java/module-info.java
index 4243e573..06678ac3 100644
--- a/docling-serve/docling-serve-api/src/main/java/module-info.java
+++ b/docling-serve/docling-serve-api/src/main/java/module-info.java
@@ -12,6 +12,8 @@
 
   exports ai.docling.serve.api;
   exports ai.docling.serve.api.health;
+  exports ai.docling.serve.api.request;
+  exports ai.docling.serve.api.response;
   exports ai.docling.serve.api.util;
 
   // Chunking API
@@ -42,5 +44,6 @@
 
   // SPI
   exports ai.docling.serve.api.spi;
+
   uses ai.docling.serve.api.spi.DoclingServeApiBuilderFactory;
 }
diff --git a/docling-serve/docling-serve-api/src/test/java/ai/docling/serve/api/request/DocumentRequestTests.java b/docling-serve/docling-serve-api/src/test/java/ai/docling/serve/api/request/DocumentRequestTests.java
new file mode 100644
index 00000000..dc2a180e
--- /dev/null
+++ b/docling-serve/docling-serve-api/src/test/java/ai/docling/serve/api/request/DocumentRequestTests.java
@@ -0,0 +1,127 @@
+package ai.docling.serve.api.request;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+import java.net.URI;
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+import ai.docling.serve.api.chunk.request.HierarchicalChunkDocumentRequest;
+import ai.docling.serve.api.chunk.request.HybridChunkDocumentRequest;
+import ai.docling.serve.api.convert.request.BatchConvertDocumentRequest;
+import ai.docling.serve.api.convert.request.ConvertDocumentRequest;
+import ai.docling.serve.api.convert.request.source.HttpSource;
+import ai.docling.serve.api.convert.request.target.InBodyTarget;
+import ai.docling.serve.api.convert.request.target.ZipTarget;
+
+/**
+ * Unit tests for the {@link DocumentRequest} sealed hierarchy.
+ */
+class DocumentRequestTests {
+  private static final HttpSource HTTP_SOURCE = HttpSource.builder()
+      .url(URI.create("http://example.com/doc.pdf"))
+      .build();
+
+  @Test
+  void sourcesAndTargetAccessibleThroughBaseType() {
+    var target = InBodyTarget.builder().build();
+
+    DocumentRequest request = ConvertDocumentRequest.builder()
+        .sources(List.of(HTTP_SOURCE))
+        .target(target)
+        .build();
+
+    assertThat(request.getSources())
+        .singleElement()
+        .isEqualTo(HTTP_SOURCE);
+
+    assertThat(request.getTarget()).isSameAs(target);
+  }
+
+  @Test
+  void targetIsNullByDefault() {
+    DocumentRequest request = ConvertDocumentRequest.builder()
+        .source(HTTP_SOURCE)
+        .build();
+
+    assertThat(request.getTarget()).isNull();
+  }
+
+  @Test
+  void sourcesDefaultToEmptyList() {
+    DocumentRequest request = ConvertDocumentRequest.builder().build();
+
+    assertThat(request.getSources()).isEmpty();
+  }
+
+  @Test
+  void allConcreteSubtypesAreDistinguishableViaInstanceOf() {
+    List<DocumentRequest> requests = List.of(
+        ConvertDocumentRequest.builder().source(HTTP_SOURCE).build(), BatchConvertDocumentRequest.builder().source(HTTP_SOURCE).target(ZipTarget.builder().build())
+            .build(), HierarchicalChunkDocumentRequest.builder().source(HTTP_SOURCE).build(), HybridChunkDocumentRequest.builder().source(HTTP_SOURCE).build()
+    );
+
+    var results = requests.stream()
+        .map(DocumentRequestTests::classifyRequest)
+        .toList();
+
+    assertThat(results).containsExactly("convert", "batch", "hierarchical-chunk", "hybrid-chunk");
+  }
+
+  @Test
+  void toBuilderPreservesSourcesAndTarget() {
+    var target = InBodyTarget.builder().build();
+
+    ConvertDocumentRequest original = ConvertDocumentRequest.builder()
+        .source(HTTP_SOURCE)
+        .target(target)
+        .build();
+
+    ConvertDocumentRequest copy = original.toBuilder().build();
+
+    assertThat(copy.getSources())
+        .isEqualTo(original.getSources());
+
+    assertThat(copy.getTarget()).isSameAs(original.getTarget());
+  }
+
+  @Test
+  void batchConvertGetTargetThrowsWhenTargetIsNull() {
+    BatchConvertDocumentRequest request = BatchConvertDocumentRequest.builder()
+        .source(HTTP_SOURCE)
+        .build();
+
+    assertThatThrownBy(request::getTarget)
+        .isInstanceOf(NullPointerException.class);
+  }
+
+  @Test
+  void toStringIncludesSourcesAndTarget() {
+    ConvertDocumentRequest request = ConvertDocumentRequest.builder()
+        .source(HTTP_SOURCE)
+        .target(InBodyTarget.builder().build())
+        .build();
+
+    assertThat(request.toString())
+        .contains("sources")
+        .contains("target");
+  }
+
+  private static String classifyRequest(DocumentRequest request) {
+    if (request instanceof ConvertDocumentRequest) {
+      return "convert";
+    }
+    else if (request instanceof BatchConvertDocumentRequest) {
+      return "batch";
+    }
+    else if (request instanceof HierarchicalChunkDocumentRequest) {
+      return "hierarchical-chunk";
+    }
+    else if (request instanceof HybridChunkDocumentRequest) {
+      return "hybrid-chunk";
+    }
+    throw new IllegalArgumentException("Unknown request type: " + request.getClass());
+  }
+}
diff --git a/docling-serve/docling-serve-api/src/test/java/ai/docling/serve/api/response/ProcessedDocumentResponseTests.java b/docling-serve/docling-serve-api/src/test/java/ai/docling/serve/api/response/ProcessedDocumentResponseTests.java
new file mode 100644
index 00000000..20224169
--- /dev/null
+++ b/docling-serve/docling-serve-api/src/test/java/ai/docling/serve/api/response/ProcessedDocumentResponseTests.java
@@ -0,0 +1,80 @@
+package ai.docling.serve.api.response;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+import ai.docling.serve.api.chunk.response.ChunkDocumentResponse;
+import ai.docling.serve.api.convert.response.ConvertDocumentResponse;
+import ai.docling.serve.api.convert.response.InBodyConvertDocumentResponse;
+import ai.docling.serve.api.convert.response.PreSignedUrlConvertDocumentResponse;
+import ai.docling.serve.api.convert.response.PreSignedUrlConvertResponse;
+import ai.docling.serve.api.convert.response.ZipArchiveConvertDocumentResponse;
+
+/**
+ * Unit tests for the {@link ProcessedDocumentResponse} sealed hierarchy.
+ */
+class ProcessedDocumentResponseTests {
+
+  @Test
+  void allConcreteSubtypesAreDistinguishableViaInstanceOf() {
+    List<ProcessedDocumentResponse> responses = List.of(
+        InBodyConvertDocumentResponse.builder().build(), PreSignedUrlConvertDocumentResponse.builder().build(), PreSignedUrlConvertResponse.builder()
+            .build(), ZipArchiveConvertDocumentResponse.builder().build(), ChunkDocumentResponse.builder().build());
+
+    var results = responses.stream()
+        .map(ProcessedDocumentResponseTests::classifyResponse)
+        .toList();
+
+    assertThat(results).containsExactly(
+        "in-body", "pre-signed-url", "pre-signed-url-response", "zip-archive", "chunk");
+  }
+
+  @Test
+  void convertDocumentResponseIsAssignableToBase() {
+    ProcessedDocumentResponse response = InBodyConvertDocumentResponse.builder().build();
+
+    assertThat(response)
+        .isInstanceOf(ProcessedDocumentResponse.class)
+        .isInstanceOf(ConvertDocumentResponse.class);
+  }
+
+  @Test
+  void chunkDocumentResponseIsAssignableToBase() {
+    ProcessedDocumentResponse response = ChunkDocumentResponse.builder().build();
+
+    assertThat(response)
+        .isInstanceOf(ProcessedDocumentResponse.class)
+        .isInstanceOf(ChunkDocumentResponse.class);
+  }
+
+  @Test
+  void sealedPermitsOnlyExpectedSubtypes() {
+    var permitted = ProcessedDocumentResponse.class.getPermittedSubclasses();
+
+    assertThat(permitted)
+        .hasSize(2)
+        .containsExactlyInAnyOrder(ConvertDocumentResponse.class, ChunkDocumentResponse.class);
+  }
+
+  private static String classifyResponse(ProcessedDocumentResponse response) {
+    if (response instanceof InBodyConvertDocumentResponse) {
+      return "in-body";
+    }
+    else if (response instanceof PreSignedUrlConvertDocumentResponse) {
+      return "pre-signed-url";
+    }
+    else if (response instanceof PreSignedUrlConvertResponse) {
+      return "pre-signed-url-response";
+    }
+    else if (response instanceof ZipArchiveConvertDocumentResponse) {
+      return "zip-archive";
+    }
+    else if (response instanceof ChunkDocumentResponse) {
+      return "chunk";
+    }
+    throw new IllegalArgumentException("Unknown response type: " + response.getClass());
+  }
+}
diff --git a/docs/src/doc/docs/whats-new.md b/docs/src/doc/docs/whats-new.md
index 87546dde..fa69c7d6 100644
--- a/docs/src/doc/docs/whats-new.md
+++ b/docs/src/doc/docs/whats-new.md
@@ -25,6 +25,11 @@ Docling Java {{ gradle.project_version }} includes important breaking changes, a
 
 ### {{ gradle.project_version }}
 
+* **New `DocumentRequest` sealed base class** — `ConvertDocumentRequest`, `BatchConvertDocumentRequest`, and `ChunkDocumentRequest` now extend a common `DocumentRequest` abstract class in the `ai.docling.serve.api.request` package. This enables polymorphism when working with different request types — for example, accepting a `DocumentRequest` and dispatching to the correct endpoint based on the concrete type via pattern matching.
+* **New `ProcessedDocumentResponse` sealed base class** — `ConvertDocumentResponse` and `ChunkDocumentResponse` now extend a common `ProcessedDocumentResponse` abstract class in the `ai.docling.serve.api.response` package. This enables polymorphic handling of document processing responses — for example, using `ProcessedDocumentResponse` as a type bound in generic APIs that work with both conversion and chunking results.
+
+### 0.6.1
+
 * **New batch conversion support** — Added `convertSourceBatch()` and `convertSourceBatchAsync()` methods to `DoclingServeConvertApi` for the new `/v1/convert/source/batch` endpoint. Submit multiple HTTP or S3 sources for batch processing with optional webhook callbacks for progress notifications. Requires docling-serve v1.22.0+.
 * **New `BatchConvertDocumentRequest`** — Request model for batch conversions, supporting `sources` (HTTP or S3), `target` (PresignedUrlTarget or S3Target), conversion `options`, and optional `callbacks` (webhook specifications).
 * **New `CallbackSpec`** — Webhook callback specification for receiving progress notifications during batch processing, with `url`, `headers`, and optional `caCert` fields.