View schema JSON
The formal JSON schema defining the structure and fields for the MSP-1 canonical term.
MSP-1 schema
canonical
Defines the preferred authoritative URL representation of a resource when multiple URLs, copies, mirrors, variants, or representations may exist.
canonical schema definition
Machine-readable structure for declaring a canonical URL and optional canonicalization context.
canonical schema JSON
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"$id": "https://msp-1.org/schema/canonical/canonical.json",
"title": "MSP-1 Canonical Schema",
"description": "Schema for declaring the preferred authoritative URL representation of an MSP-1 resource.",
"$comment": "MSP-1 v1.0.2 treats canonical as an object with a required url field. Canonical identifies the preferred authoritative URL representation; it does not declare trust level, verification status, or compliance.",
"type": "object",
"properties": {
"url": {
"type": "string",
"format": "uri",
"description": "The canonical, authoritative URL for the resource."
},
"reason": {
"type": "string",
"description": "Optional explanation for why this URL is considered canonical."
},
"lastReviewed": {
"type": "string",
"format": "date",
"description": "Optional date when the canonical URL designation was last reviewed or confirmed."
},
"authority": {
"type": "string",
"format": "uri",
"description": "Optional identifier for the authority declaring the canonical URL."
}
},
"required": ["url"],
"additionalProperties": false,
"examples": [
{
"url": "https://msp-1.org/spec/canonical/"
},
{
"url": "https://photographyselect.com/lighting-guide/",
"reason": "This is the officially maintained and updated version."
},
{
"url": "https://msp-1.org/spec/canonical/",
"reason": "Primary publisher-maintained version.",
"lastReviewed": "2026-06-24"
}
]
}
Namespace reference
See the conceptual definition of canonical URL representation, including distinction from url, id, authority, and trust.
Schema notes
The canonical MSP-1 v1.0.2 form for canonical is an object with url as the required field.
canonical is related to url, id, authority, and trust, but it is not interchangeable with them. canonical identifies the preferred URL representation; it does not establish authority, trust, or correctness by itself.