Create the segment data files to upload

Integration Partners
Last Updated: August 11, 2026•

Before you begin: Register your segments using a taxonomy file.

Create the segment data files that contain segment information using the required CSV format. Segment data files contain the data-to-segment associations to be ingested by Index. For a list of supported ad request signals that can be included in the data file, see List of supported ad request signals that can be included in the data file.

The following instructions explain how to add new segment data or delete existing segment data. To be able to successfully upload a file, the following requirements must be met:

  • All segments that you want to include in the segment data file must have been registered with Index.

  • Files must be:

    • UTF-8 encoded

    • GZIP compressed (.gz)

  • File size must not exceed 5 GB after being compressed. Split large files into multiple smaller files and compress each one.

  • File uploads are limited to 6 GB per UTC day. Files beyond this limit are processed the next day in upload timestamp order.

  1. Create a CSV file that contains the data-to-segment associations using the following format, where:

    • Each line must include at least one segment ID

    • There is a maximum of 1000 segment IDs per line

    • No duplicate segment IDs can exist in a single line

    <ID>,<externalSegmentID_1>,<externalSegmentID_2>,...

    Example

    id123,segA,segB,segC  
id456,segA  
id789,segB,segC

  2. Name the file using this naming structure: <randomSuffix>.<operationType>.csv.gz, where:

    • randomSuffix: Short alphanumeric string to ensure uniqueness. File names must be unique within each folder. A recommended way to keep file names unique is to use a timestamp in the file name.

    • operationType: Can either be append to add new segments or delete to remove segments.

    3. Example

    f3a9c2.append.csv.gz 
92b7fd.delete.csv.gz

  3. Upload the segment file to your designated bucket and the correct folder. The folder name must tell Index what type of identifier is used in the first column of your file. All files in a folder must use the same identifier type. Uploading a file to the wrong folder may result in validation or processing errors.

    Example: Amazon S3

    s3://your-bucket/deviceip/f3a9c2.append.csv.gzs3://your-bucket/url/f3a9c2.append.csv.gzs3://your-bucket/id5/f3a9c2.append.csv.gz

    Example: Google Cloud Storage

    gs://your-bucket/deviceip/f3a9c2.append.csv.gzgs://your-bucket/url/f3a9c2.append.csv.gzgs://your-bucket/id5/f3a9c2.append.csv.gz