> ## Documentation Index
> Fetch the complete documentation index at: https://docs.beam.cloud/llms.txt
> Use this file to discover all available pages before exploring further.

# Ephemeral Files and Images

> Storing ephemeral files for images, audio files, and more.

You may want to save data produced by your tasks. Beam provides an abstraction called `Output`, which allows you to save files or directories and generate public URLs to access them.

## Saving Files

To save an `Output`, you can write any filetype to Beam's `/tmp` directory.

Here's what your code might look like:

```python theme={null}
from beam import function, Output


@function()
def save_output():
    # File is saved to /tmp directory
    file_name = "/tmp/my_output.txt"

    # Write to new text file
    with open(file_name, "w") as f:
        f.write("This is an output, a glorious text file.")

    # Save output
    output_file = Output(path=file_name)
    output_file.save()

    # Generate and return a public URL
    public_url = output_file.public_url(expires=400)
    return {"output_url": public_url}
```

### Directories

You can also create public URLs for directories, by passing in a directory path:

```python theme={null}
# Generate a public URL for a directory
file_path = "./tmp/waveforms"
output = Output(path=file_path)
output.save()

# Returns https://app.beam.cloud/output/id/abe0c95a-2cd1-40b3-bace-9225f2c79c6d
output_url = output.public_url()
```

### PIL Images

If your app uses PIL, `Output` includes a wrapper around PIL to simplify the process of generating a public URL for the PIL image file:

```python theme={null}
# Save a PIL image
image = pipe(...)

# Persist the PIL image to an Output
output = Output.from_pil_image(image).save()
```

Here's a full example:

```python theme={null}
from beam import Image as BeamImage, Output, function


@function(
    image=BeamImage(
        python_packages=[
            "pillow",
        ],
    ),
)
def save_image():
    from PIL import Image as PILImage

    # Generate PIL image
    pil_image = PILImage.new(
        "RGB", (100, 100), color="white"
    )  # Creating a 100x100 white image

    # Save image file
    output = Output.from_pil_image(pil_image)
    output.save()

    # Retrieve pre-signed URL for output file
    url = output.public_url(expires=400)
    print(url)

    # Print other details about the output
    print(f"Output ID: {output.id}")
    print(f"Output Path: {output.path}")
    print(f"Output Stats: {output.stat()}")
    print(f"Output Exists: {output.exists()}")

    return {"image": url}


if __name__ == "__main__":
    save_image()
```

When you run this function, it will return a pre-signed URL to the image:

```bash theme={null}
https://app.beam.cloud/output/id/abe0c95a-2cd1-40b3-bace-9225f2c79c6d
```

## Generating Public URLs

Your app might return files from the API, such as images or MP3s. You can use `Output` to generate a public URL to access the content.

<Frame>
  <img src="https://mintcdn.com/slai-beam/vg5aTEbpFmupCYom/img/v2/output-graphic.png?fit=max&auto=format&n=vg5aTEbpFmupCYom&q=85&s=93bf6bd0d3dd58537935d18e43ee81ab" width="1092" height="706" data-path="img/v2/output-graphic.png" />
</Frame>

### Expiring Public URLs

You can pass an optional `expires` parameter to `output.public_url` to control how long to persist the file before it is deleted.

<Info>By default, public URLs are automatically deleted after 1 hour.</Info>

```python theme={null}
# Delete public URL after 5 minutes
output.public_url(expires=300)
```