> ## Documentation Index > Fetch the complete documentation index at: https://docs.hotglue.com/llms.txt > Use this file to discover all available pages before exploring further. # Snapshots > What snapshotting is, and how to use it # What is Snapshotting? hotglue's transformation layer allows you to save and persist data across sync jobs for every tenant. This feature is called **snapshotting**. Some use cases include: * storing some metadata about the tenant necessary for the transformation script to run (mapping, an API key/identifier, etc.) * persisting a **state** of the data that this tenant has already synced. For example, you could keep a full copy of all the data the tenant has synced to detect which records are new vs updated. * allowing different integrations to access information about the tenant. For example, you could correlate data across Salesforce and Quickbooks to generate some unified output. # How to use Snapshots? ## Transformation Script [](https://docs.hotglue.com/docs/snapshots#transformation-script) **Note:** this guide assumes you've read the [writing a basic script](https://docs.hotglue.com/docs/writing-a-basic-script) of the docs. As described in the [writing a basic script](https://docs.hotglue.com/docs/writing-a-basic-script#standard-directories) section, one of the standard directories for hotglue transformation scripts is the `snapshots` directory. Any data saved to that directory will be persisted across job runs. Let's walk through a quick sample using pandas: ```python util.py theme={null} import os import pandas as pd def get_snapshot(snapshot_dir, stream): snap_path = f"{snapshot_dir}/{stream}.snapshot.csv" # Ensure file exists if os.path.isfile(snap_path) is False: return None # Read the old snapshot, if present snap_df = pd.read_csv(snap_path) return snap_df def update_snapshot(snapshot_dir, stream, key, data_df, persist=True, override=False, drop_column=None, sort_columns=None, drop_duplicates=True): snap_df = data_df if drop_duplicates: snap_df = snap_df.drop_duplicates(key, keep="last") if not override: # Get the old snapshot dataframe psnap_df = get_snapshot(snapshot_dir, stream) if psnap_df is not None: # Combine with prior snapshot snap_df = snap_df.set_index( key).combine_first(psnap_df.set_index(key)) snap_df = snap_df.reset_index() if drop_column is not None: snap_df = snap_df.drop(columns=drop_column, errors='ignore') if persist: # Save this snapshot in correct spot snap_path = f"{snapshot_dir}/{stream}.snapshot.csv" snap_df.to_csv(snap_path, index=False) if sort_columns is not None: snap_df.sort_values(by=sort_columns) return snap_df ``` The file above defines two functions: * `update_snapshot` is designed to take data new data from a job sync, and append it to any existing snapshot. This will ensure every job run has access to the full history of data that has been synced by this tenant * `get_snapshot` reads the snapshot directory to get the snapshot for the `stream` id passed (you can think of a `stream` as the name of a table) Using the above, we could do the following in our `etl.ipynb` to generate a snapshot of all the `Account` data from an integration (like Quickbooks): ```python etl.ipynb theme={null} import gluestick as gs import pandas as pd import os from lib import util # standard directory for hotglue ROOT_DIR = os.environ.get("ROOT_DIR", ".") INPUT_DIR = f"{ROOT_DIR}/sync-output" OUTPUT_DIR = f"{ROOT_DIR}/etl-output" SNAPSHOT_DIR = f"{ROOT_DIR}/snapshots" # Read input data input_data = gs.read_csv_folder(INPUT_DIR) # Create a snapshot of the Account stream if it is available if input_data.get("Account") is not None: util.update_snapshot( SNAPSHOT_DIR, "Account", ['Id'], input_data["Account"] ) # Get Account snapshot data accounts = util.get_snapshot(SNAPSHOT_DIR, "Account") ``` That's all there is to it! ## API Additionally, you can modify the snapshots on a tenant level [via the API](https://docs.hotglue.com/reference/tenants-delete-snapshot). For example, you could save a tenant `config.json` in the snapshot to store some metadata such as an API key programmatically. ## Managing Snapshots in the UI Snapshots can now be managed directly in the hotglue UI. In addition to the API, you can edit them through the dashboard. Follow the steps below to manage snapshots for a specific tenant: 1. Navigate to the Tenants section from the left-hand navigation menu. Go to Tenants 2. Click on the desired tenant. Click on the desired tenant 3. A slide-in panel will open for the selected tenant. Click on the **Snapshots** tab. Click on the Snapshots header 4. Within the Snapshots tab, you can **Upload** new files, **Create folders** to organize them, **Download** existing files, and **Delete** items that are no longer needed — all directly from the UI. Snapshots Tab Snapshots are created at the tenant level and can only be viewed and managed within that specific tenant.