Modulr Supply Descriptor Contract
Modulr defines how advertising supply is understood before execution.
The Modulr Supply Descriptor Contract is a machine-readable specification for describing advertising inventory, content context, commercial reasoning capability, suitability, provenance, and confidence in a protocol-neutral format.
Execution layers have standardized faster than intelligence layers.
Advertising systems can transact inventory, but they often lack a consistent way to understand what that inventory contains, what it may be relevant to, and how trustworthy those signals are.
The Supply Descriptor Contract exists to provide a stable, machine-readable representation of supply before any transaction occurs.
Publisher Content
↓
Supply Descriptor ← this specification
↓
Signal Container
↓
Seller Agent
↓
Buyer Agent
↓
Execution
The supply descriptor is upstream of all transaction logic. It describes inventory. It does not price, negotiate, activate, or execute.
Supply Descriptor
│
┌──────────────┼──────────────┐
│ │ │
Identity Semantics Trust
│
Topics · Intent Signals
│
Ownership · Provenance · Confidence
Identity answers: what is being described. Semantics answers: what the supply means and what it enables. Trust answers: who asserts it, where it came from, and how certain it is.
- Identity — how a descriptor instance is addressed and versioned
- Provenance — origin declaration for every signal
- Topics — structured content classification using a defined taxonomy
- Intent Signals — commercial reasoning capabilities the supply structurally affords to autonomous systems
- Suitability — brand safety tier derived from content analysis
- Confidence — degree of certainty in descriptor-level classifications
- Freshness — elapsed time between signal generation and consumption
- Pricing or deal terms
- Negotiation or activation
- Audience identity or behavioral signals
- Ranking, selection, or purchasing decisions
- Execution, bidding, or campaign management
These belong to execution-layer infrastructure.
See docs/public-spec/ownership-model.md for the full layer boundary definition.
Start here:
docs/public-spec/ECOSYSTEM_PLACEMENT.md— supply intelligence chain and ecosystem placementdocs/public-spec/non-goals.mddocs/public-spec/descriptor-principles.mddocs/public-spec/why-descriptors.md— why supply descriptors differ from metadata
Ownership and identity:
Evidence and certainty:
Intent signals:
Protocol alignment:
Interoperability:
interoperability/README.mdinteroperability/adcp.mdinteroperability/prebid.mdinteroperability/seller-agent.mdinteroperability/buyer-agent.md
Examples:
examples/podcast-episode-descriptor.v0.1.jsonexamples/streaming-video-descriptor.v0.1.json(illustrative — not current production coverage)
Modulr emits supply descriptors. Downstream systems decide how to use them.
Modulr does not bid, negotiate, price, transact, or execute media buys.
Publisher-native. Protocol-ready. Neutral by design.
Version: Draft — Public Specification v1 in progress Schema: Draft schema coming in the first public schema release Public review: Early visibility; formal review begins after completion of the foundational specification packet
Complete:
- Descriptor Principles
- Ownership Model
- Identity Model
- Provenance Model
- Confidence Model
- Ecosystem Placement
- Intent Signal Model
- Intent Taxonomy
- Why Descriptors
In progress:
- Suitability Model
- Governance Model
- JSON Schema
Illustrative examples available in /examples.
Governance documentation will be published with the first public schema release.
For contribution guidelines, see docs/public-spec/CONTRIBUTING.md.