An S3 snapshot exposure source lets you upload exposure data in batch by delivering gzip-compressed CSV files to an MX8 Labs-managed S3 bucket. This is the right choice when you collect exposure data in your own systems and want to send it server-side — especially if you need to hash IP addresses before they leave your environment.

Before you begin

You'll need the following information ready:

• A source name for this exposure source.
• A retention period (in days) for how long records should be kept.
• Your Hash Salt (if you're salting hashed IPs).
• The column names in your CSV files that correspond to MX8 Labs' required fields.
• Your IAM Role ARN if you want MX8 Labs to grant your AWS role upload permissions (this maps to the External ARN field).

Step 1 — Open the creation dialog

Navigate to your exposure sources and click Create Exposure Source. Select the ** S3 snapshot** card.

Step 2 — Configure basic settings

Fill in the top-level fields:

• Source Name — A descriptive label for this source. This cannot be changed after creation.
• Retention Days — How long MX8 Labs retains exposure records for matching. Defaults to 7 days but can be set longer if your campaign requires it.
• Enabled — On by default. Toggle off to configure without activating.

Step 3 — Add dimensions

Dimensions work the same way as they do for pixel sources — they're additional attributes attached to each exposure record, used as aggregation buckets. Type a dimension name into the Add Dimension ** field and press Enter or click+ Add Dimension**.

Step 4 — Configure field mappings

This is where you tell MX8 Labs how your CSV columns map to the fields it needs. Your column names don't need to match MX8 Labs' — you just need to specify which of your columns corresponds to each field.

Required fields:

• Hash Salt — The salt value used when hashing IP addresses. If you don't use a salt, leave this empty.
• UID Field Mapping — The column name in your CSV that contains the user identifier (e.g., user_id).

Optional fields:

• Exposed IP Field Mapping — The column containing plaintext IP addresses. Provide this or Hashed IP Field Mapping.
• Hashed IP Field Mapping — The column containing hashed IP addresses. Provide this or Exposed IP Field Mapping.
• Brand Field Mapping — The column containing the brand name associated with each exposure.
• External ARN — Your IAM Role ARN. MX8 Labs uses this to grant your AWS role permission to upload files into your dedicated S3 prefix.

Step 5 — Configure dimension mappings

If you added dimensions in Step 3, scroll to the Dimension Mapping ** section and click the+** button to map each dimension to the corresponding column in your CSV.

Step 6 — Create the source

Click Create to save. The source is now ready to receive files.

Note: The hash algorithm is currently fixed to MD5. Other algorithms are available on request — contact your MX8 Labs account team if you need a different algorithm.

What's next

• Server-Side File Delivery & Format Requirements — details on file format, naming, and upload process.
• IP Hashing Rules for Exposure Data — input formatting, salt handling, and output format guidance.