Discovery Extension

The discovery object carries the OASF skills and domains of an artifact on their own, without a record around them, so that other formats can embed them as an extension. A consumer can then search those artifacts by skill and domain with the same vocabulary as OASF records.

Payload

Attribute	Requirement	Description
schema_version	required	The OASF version the payload conforms to.
skills	required	Skill references (name and/or id), as in a record.
domains	recommended	Domain references (name and/or id), as in a record.

{
  "schema_version": "1.1.0",
  "skills": [{"name": "software_engineering/code_debugging/error_handling", "id": 60602}],
  "domains": [{"name": "technology/networking/network_security", "id": 10305}]
}

A payload validates on its own like any other schema object, for example through POST /api/validate/object/discovery on the OASF server. An unknown skill or domain fails with the same error as inside a record.

Extension Identifier

Each host format names the extension in the form it expects:

• A2A Agent Card: the URI <schema_url>/<version>/objects/discovery on the OASF schema server the payload validates against, for example https://schema.oasf.outshift.com/1.1.0/objects/discovery. A server running locally works the same way. A2A identifies an extension by a URI and recommends hosting the extension's specification at it; this URI is the object's page on the schema server. Consumers recognize the extension by the /objects/discovery path on a schema server they are configured to accept.
• AI Catalog: the reverse-DNS key org.agntcy.oasf.discovery.v1. AI Catalog entries are long-lived, so the key does not depend on where the schema is hosted.

In both formats the payload is the same, and its schema_version is the version that counts; a version in the A2A URI is informational.

The reverse-DNS key is permanent: once artifacts carry it, it is not renamed. A change to the payload that is not backward compatible gets a new key, such as org.agntcy.oasf.discovery.v2.

Embedding

The payload is the same in every host format. Only its placement differs, because each host format fixes how an extension is wrapped: the payload goes, unchanged, into the slot that the host format reserves for extension data.

Host format	Identifier	Where the payload goes
A2A Agent Card	uri of an AgentExtension, set to the URI	params of that extension
AI Catalog	key of the entry's extensions map, set to the reverse-DNS	value of that key

A2A Agent Card

In an A2A Agent Card, the payload is the params of an AgentExtension in capabilities.extensions:

{
  "capabilities": {
    "extensions": [
      {
        "uri": "https://schema.oasf.outshift.com/1.1.0/objects/discovery",
        "description": "OASF skills and domains",
        "params": {
          "schema_version": "1.1.0",
          "skills": [{"name": "software_engineering/code_debugging/error_handling", "id": 60602}],
          "domains": [{"name": "technology/networking/network_security", "id": 10305}]
        }
      }
    ]
  }
}

AI Catalog Entry

In an AI Catalog entry, the payload is the value of the key in the entry's extensions map:

{
  "specVersion": "1.0",
  "entries": [
    {
      "identifier": "urn:example:agents:network-debugger",
      "type": "application/a2a-agent-card+json",
      "version": "1.0.0",
      "url": "https://agents.example.com/network-debugger/.well-known/agent-card.json",
      "extensions": {
        "org.agntcy.oasf.discovery.v1": {
          "schema_version": "1.1.0",
          "skills": [{"name": "software_engineering/code_debugging/error_handling", "id": 60602}],
          "domains": [{"name": "technology/networking/network_security", "id": 10305}]
        }
      }
    }
  ]
}