feat: native multimodal file handling; openai responses api

- add input_files parameter to Crew.kickoff(), Flow.kickoff(), Task, and Agent.kickoff()
- add provider-specific file uploaders for OpenAI, Anthropic, Gemini, and Bedrock
- add file type detection, constraint validation, and automatic format conversion
- add URL file source support for multimodal content
- add streaming uploads for large files
- add prompt caching support for Anthropic
- add OpenAI Responses API support

lib/crewai/tests/tools/agent_tools/test_read_file_tool.py

@@ -0,0 +1,122 @@
+"""Unit tests for ReadFileTool."""
+
+import base64
+
+import pytest
+
+from crewai.tools.agent_tools.read_file_tool import ReadFileTool
+from crewai_files import ImageFile, PDFFile, TextFile
+
+
+class TestReadFileTool:
+    """Tests for ReadFileTool."""
+
+    def setup_method(self) -> None:
+        """Set up test fixtures."""
+        self.tool = ReadFileTool()
+
+    def test_tool_metadata(self) -> None:
+        """Test tool has correct name and description."""
+        assert self.tool.name == "read_file"
+        assert "Read content from an input file" in self.tool.description
+
+    def test_run_no_files_available(self) -> None:
+        """Test _run returns message when no files are set."""
+        result = self.tool._run(file_name="any.txt")
+        assert result == "No input files available."
+
+    def test_run_file_not_found(self) -> None:
+        """Test _run returns message when file not found."""
+        self.tool.set_files({"doc.txt": TextFile(source=b"content")})
+
+        result = self.tool._run(file_name="missing.txt")
+
+        assert "File 'missing.txt' not found" in result
+        assert "doc.txt" in result  # Lists available files
+
+    def test_run_text_file(self) -> None:
+        """Test reading a text file returns decoded content."""
+        text_content = "Hello, this is text content!"
+        self.tool.set_files({"readme.txt": TextFile(source=text_content.encode())})
+
+        result = self.tool._run(file_name="readme.txt")
+
+        assert result == text_content
+
+    def test_run_json_file(self) -> None:
+        """Test reading a JSON file returns decoded content."""
+        json_content = '{"key": "value"}'
+        self.tool.set_files({"data.json": TextFile(source=json_content.encode())})
+
+        result = self.tool._run(file_name="data.json")
+
+        assert result == json_content
+
+    def test_run_binary_file_returns_base64(self) -> None:
+        """Test reading a binary file returns base64 encoded content."""
+        # Minimal valid PNG structure for proper MIME detection
+        png_bytes = (
+            b"\x89PNG\r\n\x1a\n"
+            b"\x00\x00\x00\rIHDR"
+            b"\x00\x00\x00\x01\x00\x00\x00\x01\x08\x02\x00\x00\x00"
+            b"\x90wS\xde"
+            b"\x00\x00\x00\x00IEND\xaeB`\x82"
+        )
+        self.tool.set_files({"image.png": ImageFile(source=png_bytes)})
+
+        result = self.tool._run(file_name="image.png")
+
+        assert "[Binary file:" in result
+        assert "image/png" in result
+        assert "Base64:" in result
+
+        # Verify base64 can be decoded
+        b64_part = result.split("Base64: ")[1]
+        decoded = base64.b64decode(b64_part)
+        assert decoded == png_bytes
+
+    def test_run_pdf_file_returns_base64(self) -> None:
+        """Test reading a PDF file returns base64 encoded content."""
+        pdf_bytes = b"%PDF-1.4 some content here"
+        self.tool.set_files({"doc.pdf": PDFFile(source=pdf_bytes)})
+
+        result = self.tool._run(file_name="doc.pdf")
+
+        assert "[Binary file:" in result
+        assert "application/pdf" in result
+
+    def test_set_files_none(self) -> None:
+        """Test setting files to None."""
+        self.tool.set_files({"doc": TextFile(source=b"content")})
+        self.tool.set_files(None)
+
+        result = self.tool._run(file_name="doc")
+
+        assert result == "No input files available."
+
+    def test_run_multiple_files(self) -> None:
+        """Test tool can access multiple files."""
+        self.tool.set_files({
+            "file1.txt": TextFile(source=b"content 1"),
+            "file2.txt": TextFile(source=b"content 2"),
+            "file3.txt": TextFile(source=b"content 3"),
+        })
+
+        assert self.tool._run(file_name="file1.txt") == "content 1"
+        assert self.tool._run(file_name="file2.txt") == "content 2"
+        assert self.tool._run(file_name="file3.txt") == "content 3"
+
+    def test_run_with_kwargs(self) -> None:
+        """Test _run ignores extra kwargs."""
+        self.tool.set_files({"doc.txt": TextFile(source=b"content")})
+
+        result = self.tool._run(file_name="doc.txt", extra_arg="ignored")
+
+        assert result == "content"
+
+    def test_args_schema(self) -> None:
+        """Test that args_schema is properly defined."""
+        schema = self.tool.args_schema
+
+        assert "file_name" in schema.model_fields
+        assert schema.model_fields["file_name"].is_required()