mo.ui.file(
    filetypes: Sequence[str] | None = None,
    multiple: bool = False,
    kind: Literal["button", "area"] = "button",
    *,
    max_size: int = 100_000_000,
    label: str = "",
    on_change: Callable[[Sequence[FileUploadResults]], None] | None = None
)

import marimo as mo

# Basic file upload
upload = mo.ui.file(label="**Upload a file:**")
upload

# Specific file types
image_upload = mo.ui.file(
    filetypes=[".jpg", ".png", ".gif"],
    kind="area",
    label="Upload an image"
)

# Multiple files
multi_upload = mo.ui.file(
    multiple=True,
    max_size=10_000_000,  # 10MB
    label="Upload multiple files"
)

# Access uploaded file data
if upload.value:
    file = upload.value[0]
    mo.md(f"""
    **Uploaded:**
    - Name: {file.name}
    - Size: {len(file.contents)} bytes
    - Type: {file.type}
    """)