feat: add tiff file support (#741)

Author: cristian-groza

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "uipath-langchain"
-version = "0.9.17"
+version = "0.9.18"
 description = "Python SDK that enables developers to build and deploy LangGraph agents to the UiPath Cloud Platform"
 readme = { file = "README.md", content-type = "text/markdown" }
 requires-python = ">=3.11"
@@ -22,6 +22,7 @@ dependencies = [
     "jsonpath-ng>=1.7.0",
     "mcp==1.26.0",
     "langchain-mcp-adapters==0.2.1",
+    "pillow>=12.1.1",
 ]
 
 classifiers = [

src/uipath_langchain/agent/multimodal/__init__.py

@@ -1,19 +1,27 @@
 """Multimodal LLM input handling (images, PDFs, etc.)."""
 
 from .invoke import (
-    build_file_content_block,
+    build_file_content_blocks_for,
     llm_call_with_files,
 )
-from .types import IMAGE_MIME_TYPES, FileInfo
-from .utils import download_file_base64, is_image, is_pdf, sanitize_filename
+from .types import IMAGE_MIME_TYPES, TIFF_MIME_TYPES, FileInfo
+from .utils import (
+    download_file_base64,
+    is_image,
+    is_pdf,
+    is_tiff,
+    sanitize_filename,
+)
 
 __all__ = [
     "FileInfo",
     "IMAGE_MIME_TYPES",
-    "build_file_content_block",
+    "TIFF_MIME_TYPES",
+    "build_file_content_blocks_for",
     "download_file_base64",
     "is_image",
     "is_pdf",
+    "is_tiff",
     "llm_call_with_files",
     "sanitize_filename",
 ]

src/uipath_langchain/agent/multimodal/invoke.py

@@ -13,47 +13,61 @@
 from langchain_core.messages.content import create_file_block, create_image_block
 
 from .types import MAX_FILE_SIZE_BYTES, FileInfo
-from .utils import download_file_base64, is_image, is_pdf, sanitize_filename
+from .utils import (
+    download_file_base64,
+    is_image,
+    is_pdf,
+    is_tiff,
+    sanitize_filename,
+    stream_tiff_to_content_blocks,
+)
 
 logger = logging.getLogger("uipath")
 
 
-async def build_file_content_block(
+async def build_file_content_blocks_for(
     file_info: FileInfo,
     *,
     max_size: int = MAX_FILE_SIZE_BYTES,
-) -> DataContentBlock:
-    """Build a LangChain content block for a file attachment.
+) -> list[DataContentBlock]:
+    """Build LangChain content blocks for a single file attachment.
 
-    Downloads the file with size enforcement and creates the content block.
-    Size validation happens during download (via Content-Length check and
-    streaming guard) to avoid loading oversized files into memory.
+    Handles all supported MIME types in one place: images, PDFs, and
+    TIFFs (multi-page, converted to individual PNG blocks).
 
     Args:
         file_info: File URL, name, and MIME type.
         max_size: Maximum allowed raw file size in bytes. LLM providers
             enforce payload limits; base64 encoding adds ~30% overhead.
 
     Returns:
-        A DataContentBlock for the file (image or PDF).
+        A list of DataContentBlock instances for the file.
 
     Raises:
         ValueError: If the MIME type is not supported or the file exceeds
             the size limit for LLM payloads.
     """
+    if is_tiff(file_info.mime_type):
+        try:
+            return await stream_tiff_to_content_blocks(file_info.url, max_size=max_size)
+        except ValueError as exc:
+            raise ValueError(f"File '{file_info.name}': {exc}") from exc
+
     try:
         base64_file = await download_file_base64(file_info.url, max_size=max_size)
     except ValueError as exc:
         raise ValueError(f"File '{file_info.name}': {exc}") from exc
 
     if is_image(file_info.mime_type):
-        return create_image_block(base64=base64_file, mime_type=file_info.mime_type)
+        return [create_image_block(base64=base64_file, mime_type=file_info.mime_type)]
     if is_pdf(file_info.mime_type):
-        return create_file_block(
-            base64=base64_file,
-            mime_type=file_info.mime_type,
-            filename=sanitize_filename(file_info.name),
-        )
+        return [
+            create_file_block(
+                base64=base64_file,
+                mime_type=file_info.mime_type,
+                filename=sanitize_filename(file_info.name),
+            )
+        ]
 
     raise ValueError(f"Unsupported mime_type={file_info.mime_type}")
 
@@ -75,8 +89,8 @@ async def build_file_content_blocks(files: list[FileInfo]) -> list[DataContentBl
 
     file_content_blocks: list[DataContentBlock] = []
     for file in files:
-        block = await build_file_content_block(file)
-        file_content_blocks.append(block)
+        blocks = await build_file_content_blocks_for(file)
+        file_content_blocks.extend(blocks)
     return file_content_blocks
 
 
@@ -111,8 +125,8 @@ async def llm_call_with_files(
 
     content_blocks: list[Any] = []
     for file_info in files:
-        content_block = await build_file_content_block(file_info)
-        content_blocks.append(content_block)
+        blocks = await build_file_content_blocks_for(file_info)
+        content_blocks.extend(blocks)
 
     file_message = HumanMessage(content_blocks=content_blocks)
     all_messages = list(messages) + [file_message]

src/uipath_langchain/agent/multimodal/types.py

@@ -11,6 +11,11 @@
     "image/webp",
 }
 
+TIFF_MIME_TYPES: set[str] = {
+    "image/tiff",
+    "image/x-tiff",
+}
+
 
 @dataclass
 class FileInfo:

src/uipath_langchain/agent/multimodal/utils.py

@@ -1,13 +1,16 @@
 """Utility functions for multimodal file handling."""
 
 import base64
+import io
 import re
 from collections.abc import AsyncIterator
+from contextlib import asynccontextmanager
 
 import httpx
+from langchain_core.messages import DataContentBlock
 from uipath._utils._ssl_context import get_httpx_client_kwargs
 
-from .types import IMAGE_MIME_TYPES
+from .types import IMAGE_MIME_TYPES, TIFF_MIME_TYPES
 
 
 def sanitize_filename(filename: str) -> str:
@@ -37,6 +40,11 @@ def is_image(mime_type: str) -> bool:
     return mime_type.lower() in IMAGE_MIME_TYPES
 
 
+def is_tiff(mime_type: str) -> bool:
+    """Check if the MIME type represents a TIFF image."""
+    return mime_type.lower() in TIFF_MIME_TYPES
+
+
 def _format_mb(size_bytes: int, decimals: int = 1) -> str:
     """Format a byte count as MB.
 
@@ -97,22 +105,28 @@ async def encode_streamed_base64(
     return result
 
 
-async def download_file_base64(url: str, *, max_size: int = 0) -> str:
-    """Download a file from a URL and return its content as a base64 string.
+@asynccontextmanager
+async def _stream_download(url: str, *, max_size: int = 0):
+    """Stream an HTTP download with size enforcement.
+
+    Yields the validated response object. Checks Content-Length upfront
+    and raises ValueError if the file is known to exceed the limit.
 
     Args:
         url: The URL to download from.
         max_size: Maximum allowed file size in bytes. 0 means unlimited.
 
+    Yields:
+        The httpx response object, ready for streaming via aiter_bytes().
+
     Raises:
-        ValueError: If the file exceeds max_size.
+        ValueError: If the file exceeds max_size (Content-Length check).
         httpx.HTTPStatusError: If the HTTP request fails.
     """
     async with httpx.AsyncClient(**get_httpx_client_kwargs()) as client:
         async with client.stream("GET", url) as response:
             response.raise_for_status()
 
-            # Fast reject via Content-Length before reading the body
             if max_size > 0:
                 content_length = response.headers.get("content-length")
                 if content_length:
@@ -130,6 +144,67 @@ async def download_file_base64(url: str, *, max_size: int = 0) -> str:
                             f" limit for Agent LLM payloads"
                         )
 
-            return await encode_streamed_base64(
-                response.aiter_bytes(), max_size=max_size
-            )
+            yield response
+
+
+async def stream_tiff_to_content_blocks(
+    url: str, *, max_size: int = 0
+) -> list[DataContentBlock]:
+    """Download a TIFF via streaming and convert each page to a content block.
+
+    Streams the HTTP response directly into a buffer for PIL, enforcing
+    size limits as chunks arrive. Each TIFF page is converted to PNG,
+    base64-encoded, and wrapped in a DataContentBlock immediately so
+    the raw PNG bytes can be freed.
+
+    Args:
+        url: The URL to download from.
+        max_size: Maximum allowed file size in bytes. 0 means unlimited.
+
+    Returns:
+        A list of DataContentBlock instances, one per TIFF page.
+
+    Raises:
+        ValueError: If the file exceeds max_size.
+        httpx.HTTPStatusError: If the HTTP request fails.
+    """
+    from langchain_core.messages.content import create_image_block
+    from PIL import Image, ImageSequence
+
+    async with _stream_download(url, max_size=max_size) as response:
+        buf = io.BytesIO()
+        total = 0
+        async for chunk in response.aiter_bytes():
+            total += len(chunk)
+            if max_size > 0 and total > max_size:
+                raise ValueError(
+                    f"File exceeds the {_format_mb(max_size, decimals=0)}"
+                    f" limit for LLM payloads"
+                    f" (downloaded {_format_mb(total)} so far)"
+                )
+            buf.write(chunk)
+
+    buf.seek(0)
+    blocks: list[DataContentBlock] = []
+    with Image.open(buf) as img:
+        for frame in ImageSequence.Iterator(img):
+            png_buf = io.BytesIO()
+            frame.convert("RGBA").save(png_buf, format="PNG")
+            png_b64 = base64.b64encode(png_buf.getvalue()).decode("ascii")
+            blocks.append(create_image_block(base64=png_b64, mime_type="image/png"))
+    return blocks
+
+
+async def download_file_base64(url: str, *, max_size: int = 0) -> str:
+    """Download a file from a URL and return its content as a base64 string.
+
+    Args:
+        url: The URL to download from.
+        max_size: Maximum allowed file size in bytes. 0 means unlimited.
+
+    Raises:
+        ValueError: If the file exceeds max_size.
+        httpx.HTTPStatusError: If the HTTP request fails.
+    """
+    async with _stream_download(url, max_size=max_size) as response:
+        return await encode_streamed_base64(response.aiter_bytes(), max_size=max_size)

src/uipath_langchain/agent/tools/internal_tools/analyze_files_tool.py

@@ -24,7 +24,10 @@
     AgentRuntimeError,
     AgentRuntimeErrorCode,
 )
-from uipath_langchain.agent.multimodal import FileInfo, build_file_content_block
+from uipath_langchain.agent.multimodal import (
+    FileInfo,
+    build_file_content_blocks_for,
+)
 from uipath_langchain.agent.react.jsonschema_pydantic_converter import create_model
 from uipath_langchain.agent.tools.structured_tool_with_argument_properties import (
     StructuredToolWithArgumentProperties,
@@ -182,8 +185,8 @@ async def add_files_to_message(
 
     file_content_blocks: list[DataContentBlock] = []
     for file in files:
-        block = await build_file_content_block(file)
-        file_content_blocks.append(block)
+        blocks = await build_file_content_blocks_for(file)
+        file_content_blocks.extend(blocks)
     return append_content_blocks_to_message(
         message, cast(list[ContentBlock], file_content_blocks)
     )