Capture the current authoritative source.
EVIDENCE
How we know.
This source list shows what we checked, when we checked it, how strong the evidence is and what it supports. We also publish limits and open questions.
THE METHOD / SIX VISIBLE STEPS
SOURCEINTERPRETATIONMODEL OR MAPRULE
Record its field, scope and conditions.
Map without erasing semantic differences.
Assign an explicit evidence status.
Add only deterministic tests.
Bind results to the exact versions used.
HOW TO READ EVIDENCE
Five labels separate facts from assumptions.
The current authoritative source explicitly supports the statement.
CCFP translates between documented structures using an explicit interpretation that preserves material differences.
A reasoned CCFP interpretation, clearly distinguished from platform documentation.
Documented, but the capability or contract is new or expected to change.
The available evidence is insufficient; CCFP publishes the uncertainty.
AGENTIC COMMERCE / PROTOCOL WATCH
Where product data ends—and agentic commerce begins.
CCFP tracks these standards because clean product facts may flow through them. The current validator checks feeds and public pages; it does not certify checkout, payment or agent interoperability.
UCP
Universal Commerce Protocol
EMERGING- ROLE
- Commerce capability discovery and flows from product discovery through checkout.
- CCFP BOUNDARY
- Tracked as a downstream commerce layer. UCP endpoint and capability validation are not yet run.
ACP
Agentic Commerce Protocol
EMERGING- ROLE
- Programmatic checkout between buyers, AI agents and sellers.
- CCFP BOUNDARY
- Checkout APIs, credential relay and order lifecycle remain outside the feed validator.
AP2
Agent Payments Protocol
EMERGING- ROLE
- Authorization mandates and evidence for agent-initiated payments.
- CCFP BOUNDARY
- CCFP does not handle payment credentials, authorize spend or validate payment mandates.
A2A
Agent2Agent Protocol
EMERGING- ROLE
- Discovery, task exchange and coordination between independent agents.
- CCFP BOUNDARY
- Agent cards and agent-to-agent operations are tracked, not validated by the current tool.
SOURCE REGISTRY
Current evidence, in public.
Registry retrieved 2026-09-10
Google
DIRECTMerchant Center product data specification
identity · content · classification · variants · media · price · availability · identifiers
Google
DIRECTSupported structured data attributes and values
product-offer-grain · field-mapping · identifiers
Shopify
DIRECTProduct — GraphQL Admin
product · content · classification · media
Shopify
DIRECTProductVariant — GraphQL Admin
variants · sku · barcode · price · inventory · media
Shopify
DIRECTShopify Catalog interfaces
product · variants · media · price · availability · protocol-discovery
UCP
DIRECTUniversal Commerce Protocol catalog capability
product · variants · media · price · availability · protocol-discovery
ACP
DIRECTAgentic Commerce Protocol architecture
checkout · payments · fulfillment · order-lifecycle
OpenAI
EMERGINGPowering product discovery in ChatGPT
product-feed · protocol-discovery · merchant-feed-mechanism
Meta
DIRECTCatalog product data fields
Requirement labels reflect Meta's documented product fields for Ads and Commerce. Category, market and use-case-specific rules remain contextual.
OpenAI
DIRECTProduct Feed specification
This source documents the stable product file-upload contract. Ads and checkout have separate requirements.
OpenAI
DIRECTShopping with ChatGPT Search
merchant-feed-mechanism · ranking-boundary
Shopify
DIRECTProduct CSV documentation
Direct evidence is limited to the source statement. CCFP normalization, bounded coverage and uncertainty are documented in Decision 0002; no universal destination eligibility is implied.
Google
DIRECTCondition vocabulary
Direct evidence is limited to the source statement. CCFP normalization, bounded coverage and uncertainty are documented in Decision 0002; no universal destination eligibility is implied.
Google
DIRECTProduct gender vocabulary
Direct evidence is limited to the source statement. CCFP normalization, bounded coverage and uncertainty are documented in Decision 0002; no universal destination eligibility is implied.
Google
DIRECTAge-group vocabulary
Direct evidence is limited to the source statement. CCFP normalization, bounded coverage and uncertainty are documented in Decision 0002; no universal destination eligibility is implied.
United Nations
DIRECTM49 ISO-alpha2 column snapshot
Direct evidence is limited to the source statement. CCFP normalization, bounded coverage and uncertainty are documented in Decision 0002; no universal destination eligibility is implied.
Stripe
DIRECTBounded currency precision reference
Direct evidence is limited to the source statement. CCFP normalization, bounded coverage and uncertainty are documented in Decision 0002; no universal destination eligibility is implied.