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

# Work with files and artifacts

> Inject files, retain generated artifacts, inspect images, and download bytes after execution.

Upload inputs before a run. After it finishes, read logs from the operation result and download generated files from its saved image.

| Need | Interface | Persistence |
| - | - | - |
| Supply one input | `files={"/guest/path": local_or_bytes}` | Follows that operation and its save choice |
| Prepare reusable files | `apply_files()` or retained run | New image UUID |
| Read one saved file | `image.read()` | Returns bytes without guest compute |
| Download one saved file | `image.download()` or inspect REST API | Local file plus existing image |
| Download a directory | Inspect tar-archive REST endpoint | Local archive plus existing image |

## Generate and retrieve

Complete [Set up access](/sandboxes/start/set-up-access), then place this fragment inside the async `main()` from the [Python quickstart](/sandboxes/start/python-quickstart), replacing its file-saving workflow. It uses the authenticated `client` created there and selects an image containing `mkdir` and `cp`. Use [Generate and download a binary artifact](/sandboxes/cookbook/generate-and-download-binary-artifact) for a complete program, fresh-project setup, and byte-integrity checks.

```python theme={null}
from pathlib import Path

image = await client.images.use("alpine:3.19", strict=True)
run = await image.run(
    shell="mkdir -p /out && cp /input.bin /out/result.bin",
    files={"/input.bin": b"\x00input\xff"},
    disposable=False,
    timeout=30,
)
if run.exit_code != 0 or run.uuid is None:
    raise RuntimeError("File generation failed or returned no saved image")

destination = Path("result.bin")
await run.download("/out/result.bin", destination)
if destination.read_bytes() != b"\x00input\xff":
    raise RuntimeError("Downloaded bytes differ from the input")
print(f"Downloaded and verified {destination}")
```

Expected output: `Downloaded and verified result.bin`.

Use absolute guest paths. The SDK uploads local inputs before spawn and uses content hashes for server-side deduplication. The operation result image is required for post-execution inspection. A disposable result has `uuid is None`.

Captured stdin, stdout, and stderr each default to 1 MiB and can be set up to 10 MiB with `truncate_output_at`; the cap applies to recorded streams, not stdin delivery. `run.result.truncated` is true when either stdout or stderr was truncated. Store large or binary output as a file and validate its size or digest after download.

If an artifact read fails after a successful retained run, retry by the recorded image UUID before executing the producer again. Contact the Sandboxes team before a workload depends on specific upload, download, or image-size limits, or on deletion and retention guarantees for each data surface. Do not put credentials in uploaded inputs, logs, or a retained image.

See [Security and data handling](/sandboxes/operate/security-and-data-handling) and the [file download reference](/api-reference/sandboxes/inspect/download-a-file-from-image).