Overview

Ads.txt is an IAB initiative created to provide transparency in our programmatic advertising ecosystem.

The functionality is similar to that of robots.txt in that a crawler will request the file and follow instructions within it.

The specification states that publishers may create ads.txt files and place the files to the root of their web server. Third party DSP/Buyer controlled web crawlers may then request this file, parse the information within it, and subsequently use this data to validate who is authorized to sell their inventory.

Listing District M as a DIRECT relationship in your ads.txt file ensures buyers bidding on your inventory through our exchange may validate the relationship and have trust in the inventory.

This article explains how to create an ads.txt file for publishers using District M demand.

Ads.txt Record Information

Ads.txt is a fairly straight forward implementation, containing four plain text records, each comma separated.

Record #1, Record #2, Record #3, Record #4

The record attributes are as follows:

• Record #1
  
  • Domain name of the advertising system
  • Mandatory
  • The canonical domain name of the SSP, Exchange, Header Wrapper, etc system that bidders connect to. This may be the operational domain of the system, if that is different than the parent corporate domain, to facilitate WHOIS and reverse IP lookups to establish clear ownership of the delegate system. Ideally the SSP or Exchange publishes a document detailing what domain name to use. 
    
    
• Record #2
  
  • Publisher’s Account ID
    
  • Mandatory
  • The identifier associated with the seller or reseller account within the advertising system in field #1. This must contain the same value used in transactions (i.e. OpenRTB bid requests) in the field specified by the SSP/exchange. Typically, in OpenRTB, this is publisher.id. For OpenDirect it is typically the publisher’s organization ID.
    Note: Publisher account IDs are provided by your District M account coordinator.
    
    

• Record #3
  
  • Type of Account/ Relationship
  • Mandatory
  • An enumeration of the type of account. A value of ‘DIRECT’ indicates that the Publisher (content owner) directly controls the account indicated in field #2 on the system in field #1. This tends to mean a direct business contract between the Publisher and the advertising system. A value of ‘RESELLER’ indicates that the Publisher has authorized another entity to control the account indicated in field #2 and resell their ad space via the system in field #1. Other types may be added in the future. Note that this field should be treated as case insensitive when interpreting the data. 
    
    
  Record #4
  
  • Certification Authority ID
  • Optional
  • An ID that uniquely identifies the advertising system within a certification authority (this ID maps to the entity listed in field #1). A current certification authority is the Trustworthy Accountability Group (aka TAG), and the TAGID would be included here.
    
    

Sample Ads.txt for District M Publisher Account

Below is a sample ads.txt entry for district m Publisher accounts which also includes additional demand district m is capable of offering to publishers looking for increased bid density.

districtm.io, 123456, DIRECT, 3fd707be9c4527c3
appnexus.com, 1908, RESELLER, f5ab79cb980f11d1
google.com, pub-5555555555555555, RESELLER, f08c47fec0942fa0

Obtaining Ads.txt Records

Ads.txt entries may be generated from the B3 platform by clicking the gear and selecting ads.txt:

From here the district m ads.txt entries for your account will be listed and available to copy and paste into your ads.txt file.

Hosting ads.txt (Access Method)

Publishers implementing District M ads.txt information should adhere to the IAB ads.txt specification section 3.1 ACCESS METHODS.

Your ads.txt file should be hosted on each root domain you are selling inventory, for example, if your site is www.automotivereviews.com, you should host ads.txt at http://www.automotivereviews.com/ads.txt. The file should be accessible via HTTP and HTTPS.

Refer to the IAB ads.txt specification to confirm you are following the specification, if you have any questions or would like District M to validate your implementation please reach out to your account manager.

Ads.txt for Mobile Applications

Ads.txt for Mobile Applications is currently awaiting app store support from the major platforms (Apple iTunes and Google Play Store) before this may be published.

Related Articles and Further Reading

• IAB - ADS.TXT – AUTHORIZED DIGITAL SELLERS
• IAB - HOW TO ADS.TXT
• IAB Tech Lab - Ads.txt Specification Version 1.0
• Digiday - WTF is ads.txt?
• AdExchanger - Domain Spoofing Be Gone: Ads.Txt Will Filter Out Imposter Sites