Supply chain transparency in CTV means the ability to verify that an ad impression was delivered to a real CTV device, within a declared publisher app, and that each intermediary in the path from buyer to publisher is disclosed. In web advertising, tools like ads.txt and sellers.json established a framework for supply chain disclosure. CTV has its own versions of these mechanisms, plus additional layers of complexity introduced by TV OS platforms, SSAI delivery, and India's mixed programmatic infrastructure.
The CTV supply chain problem
A buyer using DV360 to purchase CTV inventory may receive impressions that pass through: DSP → SSP → publisher ad server → app → device. Each handoff introduces a potential transparency gap. Without supply chain disclosure, a buyer cannot verify whether the impression was on the declared publisher's app, on a real CTV device, or whether the SSP in the middle was authorised by the publisher to sell that inventory. CTV supply chain fraud — where impressions are sold misrepresenting the publisher or device type — is real, though less prevalent in India than in the US open exchange.
App-ads.txt for CTV
App-ads.txt is the IAB Tech Lab standard for CTV publisher supply chain disclosure. Publishers hosting a streaming app on Android TV, Amazon Fire TV, or other CTV platforms publish an app-ads.txt file listing every SSP and reseller authorised to sell their inventory. Buyers and DSPs check the app-ads.txt file against the SSP listed in the bid request — if the SSP is not declared in the file, the impression may be unauthorised.
India CTV app-ads.txt adoption: major publishers (JioHotstar, Zee5, SonyLIV) maintain app-ads.txt files. Mid-tier and regional publishers have inconsistent implementation. Where app-ads.txt is absent, buyers have no machine-readable disclosure of authorised sellers.
Sellers.json for CTV
Sellers.json is the complementary standard published by SSPs and ad networks, listing every publisher they are authorised to represent. A buyer can cross-reference the SSP's sellers.json against the publisher's app-ads.txt to verify the supply path is fully disclosed from both sides. PubMatic and Magnite maintain sellers.json files covering their India CTV publishers.
SupplyChain (schain) object in OpenRTB
The OpenRTB schain object travels with each bid request and lists every entity in the supply chain — publisher, SSP, any resellers — in sequence. A complete schain with verified node identifiers lets the buyer trace the full path of an impression. DSPs like DV360 and TTD check schain completeness and may reject bid requests with incomplete or unverifiable chains. In India CTV, schain completeness is high for direct publisher-to-SSP paths; it is lower where inventory passes through multiple resellers.
India-specific supply chain considerations
JioHotstar's proprietary path: JioHotstar's primary inventory does not flow through independent SSPs, so app-ads.txt and sellers.json cross-referencing applies only to its programmatic SSP-accessed inventory, not its direct programmatic infrastructure. Buyers purchasing JioHotstar direct programmatic must trust JioHotstar's own supply chain disclosure.
SSAI obfuscation: When publishers use server-side ad insertion (SSAI), the ad request originates from the SSAI platform's server, not the viewer's device. The schain and app information in the bid request reflects the SSAI platform as an intermediary, not the end viewer device. This is technically correct but makes device-level verification harder.
Recommended India CTV supply chain hygiene: Use only SSPs with complete sellers.json; bid only on app bundle IDs verified in app-ads.txt; use DSP schain filtering to exclude incomplete paths; deploy DoubleVerify or IAS for independent app verification on programmatic buys.