feat: add implicit document conversion support

- Discovered that the Nutrient API automatically converts Office documents (DOCX, XLSX, PPTX) to PDF
- Added convert_to_pdf method that leverages implicit conversion
- Updated all Direct API method documentation to reflect Office document support
- Updated SUPPORTED_OPERATIONS.md with comprehensive documentation of the discovery
- All methods now accept both PDFs and Office documents seamlessly
- Updated examples to show mixing PDFs and Office documents in operations like merge

This is a significant improvement to the library's capabilities, as users can now:
- Convert Office documents to PDF without explicit conversion steps
- Use any processing operation (rotate, OCR, watermark, etc.) directly on Office files
- Mix PDFs and Office documents in merge operations

Author: jdrhyne

SUPPORTED_OPERATIONS.md

@@ -2,27 +2,64 @@
 
 This document lists all operations currently supported by the Nutrient DWS API through this Python client.
 
+## 🎯 Important Discovery: Implicit Document Conversion
+
+The Nutrient DWS API automatically converts Office documents (DOCX, XLSX, PPTX) to PDF when processing them. This means:
+
+- **No explicit conversion needed** - Just pass your Office documents to any method
+- **All methods accept Office documents** - `rotate_pages()`, `ocr_pdf()`, etc. work with DOCX files
+- **Seamless operation chaining** - Convert and process in one API call
+
+### Example:
+```python
+# This automatically converts DOCX to PDF and rotates it!
+client.rotate_pages("document.docx", degrees=90)
+
+# Merge PDFs and Office documents together
+client.merge_pdfs(["file1.pdf", "file2.docx", "spreadsheet.xlsx"])
+```
+
 ## Direct API Methods
 
 The following methods are available on the `NutrientClient` instance:
 
-### 1. `flatten_annotations(input_file, output_path=None)`
+### 1. `convert_to_pdf(input_file, output_path=None)`
+Converts Office documents to PDF format using implicit conversion.
+
+**Parameters:**
+- `input_file`: Office document (DOCX, XLSX, PPTX)
+- `output_path`: Optional path to save output
+
+**Example:**
+```python
+# Convert DOCX to PDF
+client.convert_to_pdf("document.docx", "document.pdf")
+
+# Convert and get bytes
+pdf_bytes = client.convert_to_pdf("spreadsheet.xlsx")
+```
+
+**Note:** HTML files are not currently supported.
+
+### 2. `flatten_annotations(input_file, output_path=None)`
 Flattens all annotations and form fields in a PDF, converting them to static page content.
 
 **Parameters:**
-- `input_file`: PDF file (path, bytes, or file-like object)
+- `input_file`: PDF or Office document
 - `output_path`: Optional path to save output
 
 **Example:**
 ```python
 client.flatten_annotations("document.pdf", "flattened.pdf")
+# Works with Office docs too!
+client.flatten_annotations("form.docx", "flattened.pdf")
 ```
 
-### 2. `rotate_pages(input_file, output_path=None, degrees=0, page_indexes=None)`
-Rotates pages in a PDF.
+### 3. `rotate_pages(input_file, output_path=None, degrees=0, page_indexes=None)`
+Rotates pages in a PDF or converts Office document to PDF and rotates.
 
 **Parameters:**
-- `input_file`: PDF file
+- `input_file`: PDF or Office document
 - `output_path`: Optional output path
 - `degrees`: Rotation angle (90, 180, 270, or -90)
 - `page_indexes`: Optional list of page indexes to rotate (0-based)
@@ -32,15 +69,18 @@ Rotates pages in a PDF.
 # Rotate all pages 90 degrees
 client.rotate_pages("document.pdf", "rotated.pdf", degrees=90)
 
+# Works with Office documents too!
+client.rotate_pages("presentation.pptx", "rotated.pdf", degrees=180)
+
 # Rotate specific pages
 client.rotate_pages("document.pdf", "rotated.pdf", degrees=180, page_indexes=[0, 2])
 ```
 
-### 3. `ocr_pdf(input_file, output_path=None, language="english")`
-Applies OCR to make a PDF searchable.
+### 4. `ocr_pdf(input_file, output_path=None, language="english")`
+Applies OCR to make a PDF searchable. Converts Office documents to PDF first if needed.
 
 **Parameters:**
-- `input_file`: PDF file
+- `input_file`: PDF or Office document
 - `output_path`: Optional output path
 - `language`: OCR language - supported values:
   - `"english"` or `"eng"` - English
@@ -49,13 +89,15 @@ Applies OCR to make a PDF searchable.
 **Example:**
 ```python
 client.ocr_pdf("scanned.pdf", "searchable.pdf", language="english")
+# Convert DOCX to searchable PDF
+client.ocr_pdf("document.docx", "searchable.pdf", language="eng")
 ```
 
-### 4. `watermark_pdf(input_file, output_path=None, text=None, image_url=None, width=200, height=100, opacity=1.0, position="center")`
-Adds a watermark to all pages of a PDF.
+### 5. `watermark_pdf(input_file, output_path=None, text=None, image_url=None, width=200, height=100, opacity=1.0, position="center")`
+Adds a watermark to all pages of a PDF. Converts Office documents to PDF first if needed.
 
 **Parameters:**
-- `input_file`: PDF file
+- `input_file`: PDF or Office document
 - `output_path`: Optional output path
 - `text`: Text for watermark (either text or image_url required)
 - `image_url`: URL of image for watermark
@@ -78,38 +120,46 @@ client.watermark_pdf(
 )
 ```
 
-### 5. `apply_redactions(input_file, output_path=None)`
-Applies redaction annotations to permanently remove content.
+### 6. `apply_redactions(input_file, output_path=None)`
+Applies redaction annotations to permanently remove content. Converts Office documents to PDF first if needed.
 
 **Parameters:**
-- `input_file`: PDF file with redaction annotations
+- `input_file`: PDF or Office document with redaction annotations
 - `output_path`: Optional output path
 
 **Example:**
 ```python
 client.apply_redactions("document_with_redactions.pdf", "redacted.pdf")
 ```
 
-### 6. `merge_pdfs(input_files, output_path=None)`
-Merges multiple PDF files into one.
+### 7. `merge_pdfs(input_files, output_path=None)`
+Merges multiple files into one PDF. Automatically converts Office documents to PDF before merging.
 
 **Parameters:**
-- `input_files`: List of PDF files to merge
+- `input_files`: List of files to merge (PDFs and/or Office documents)
 - `output_path`: Optional output path
 
 **Example:**
 ```python
+# Merge PDFs only
 client.merge_pdfs(
     ["document1.pdf", "document2.pdf", "document3.pdf"],
     "merged.pdf"
 )
+
+# Mix PDFs and Office documents - they'll be converted automatically!
+client.merge_pdfs(
+    ["report.pdf", "spreadsheet.xlsx", "presentation.pptx"],
+    "combined.pdf"
+)
 ```
 
 ## Builder API
 
-The Builder API allows chaining multiple operations:
+The Builder API allows chaining multiple operations. Like the Direct API, it automatically converts Office documents to PDF when needed:
 
 ```python
+# Works with PDFs
 client.build(input_file="document.pdf") \
     .add_step("rotate-pages", {"degrees": 90}) \
     .add_step("ocr-pdf", {"language": "english"}) \
@@ -121,6 +171,12 @@ client.build(input_file="document.pdf") \
     }) \
     .add_step("flatten-annotations") \
     .execute(output_path="processed.pdf")
+
+# Also works with Office documents!
+client.build(input_file="report.docx") \
+    .add_step("watermark-pdf", {"text": "CONFIDENTIAL", "width": 300, "height": 150}) \
+    .add_step("flatten-annotations") \
+    .execute(output_path="watermarked_report.pdf")
 ```
 
 ### Supported Builder Actions
@@ -135,7 +191,7 @@ client.build(input_file="document.pdf") \
 
 The following operations are **NOT** currently supported by the API:
 
-- Document conversion (Office to PDF, HTML to PDF)
+- HTML to PDF conversion (only Office documents are supported)
 - PDF to image export
 - PDF splitting
 - Form filling

src/nutrient/api/direct.py

@@ -18,7 +18,8 @@ class DirectAPIMixin:
     These methods provide a simplified interface to common document
     processing operations. They internally use the Build API.
     
-    Note: Only operations actually supported by the API are included.
+    Note: The API automatically converts supported document formats
+    (DOCX, XLSX, PPTX) to PDF when processing.
     """
 
     def _process_file(
@@ -31,13 +32,42 @@ def _process_file(
         """Process file method that will be provided by NutrientClient."""
         raise NotImplementedError("This method is provided by NutrientClient")
 
+    def convert_to_pdf(
+        self,
+        input_file: FileInput,
+        output_path: Optional[str] = None,
+    ) -> Optional[bytes]:
+        """Convert a document to PDF.
+
+        Converts Office documents (DOCX, XLSX, PPTX) to PDF format.
+        This uses the API's implicit conversion - simply uploading a 
+        non-PDF document returns it as a PDF.
+
+        Args:
+            input_file: Input document (DOCX, XLSX, PPTX, etc).
+            output_path: Optional path to save the output PDF.
+
+        Returns:
+            Converted PDF as bytes, or None if output_path is provided.
+
+        Raises:
+            AuthenticationError: If API key is missing or invalid.
+            APIError: For other API errors (e.g., unsupported format).
+            
+        Note:
+            HTML files are not currently supported by the API.
+        """
+        # Use builder with no actions - implicit conversion happens
+        return self.build(input_file).execute(output_path)  # type: ignore
+
     def flatten_annotations(self, input_file: FileInput, output_path: Optional[str] = None) -> Optional[bytes]:
         """Flatten annotations and form fields in a PDF.
 
         Converts all annotations and form fields into static page content.
+        If input is an Office document, it will be converted to PDF first.
 
         Args:
-            input_file: Input PDF file (path, bytes, or file-like object).
+            input_file: Input file (PDF or Office document).
             output_path: Optional path to save the output file.
 
         Returns:
@@ -59,9 +89,10 @@ def rotate_pages(
         """Rotate pages in a PDF.
 
         Rotate all pages or specific pages by the specified degrees.
+        If input is an Office document, it will be converted to PDF first.
 
         Args:
-            input_file: Input PDF file (path, bytes, or file-like object).
+            input_file: Input file (PDF or Office document).
             output_path: Optional path to save the output file.
             degrees: Rotation angle (90, 180, 270, or -90).
             page_indexes: Optional list of page indexes to rotate (0-based).
@@ -87,10 +118,11 @@ def ocr_pdf(
         """Apply OCR to a PDF to make it searchable.
 
         Performs optical character recognition on the PDF to extract text
-        and make it searchable.
+        and make it searchable. If input is an Office document, it will 
+        be converted to PDF first.
 
         Args:
-            input_file: Input PDF file (path, bytes, or file-like object).
+            input_file: Input file (PDF or Office document).
             output_path: Optional path to save the output file.
             language: OCR language. Supported: "english", "eng", "deu", "german".
                      Default is "english".
@@ -118,9 +150,10 @@ def watermark_pdf(
         """Add a watermark to a PDF.
 
         Adds a text or image watermark to all pages of the PDF.
+        If input is an Office document, it will be converted to PDF first.
 
         Args:
-            input_file: Input PDF file (path, bytes, or file-like object).
+            input_file: Input file (PDF or Office document).
             output_path: Optional path to save the output file.
             text: Text to use as watermark. Either text or image_url required.
             image_url: URL of image to use as watermark.
@@ -164,10 +197,11 @@ def apply_redactions(
         """Apply redaction annotations to permanently remove content.
 
         Applies any redaction annotations in the PDF to permanently remove
-        the underlying content.
+        the underlying content. If input is an Office document, it will 
+        be converted to PDF first.
 
         Args:
-            input_file: Input PDF file (path, bytes, or file-like object).
+            input_file: Input file (PDF or Office document).
             output_path: Optional path to save the output file.
 
         Returns:
@@ -186,10 +220,12 @@ def merge_pdfs(
     ) -> Optional[bytes]:
         """Merge multiple PDF files into one.
 
-        Combines multiple PDF files into a single PDF in the order provided.
+        Combines multiple files into a single PDF in the order provided.
+        Office documents (DOCX, XLSX, PPTX) will be automatically converted 
+        to PDF before merging.
 
         Args:
-            input_files: List of input PDF files (paths, bytes, or file-like objects).
+            input_files: List of input files (PDFs or Office documents).
             output_path: Optional path to save the output file.
 
         Returns:
@@ -199,6 +235,14 @@ def merge_pdfs(
             AuthenticationError: If API key is missing or invalid.
             APIError: For other API errors.
             ValueError: If less than 2 files provided.
+            
+        Example:
+            # Merge PDFs and Office documents
+            client.merge_pdfs([
+                "document1.pdf",
+                "document2.docx",
+                "spreadsheet.xlsx"
+            ], "merged.pdf")
         """
         if len(input_files) < 2:
             raise ValueError("At least 2 files required for merge")