(registered 2026-06-03, last updated 2026-06-03)

Type name: application

Subtype name: vnd.agtp.identity+yaml

Required parameters: N/A

Optional parameters:

charset: must be UTF-8 if present.

version: identifies the Agent Identity Document schema version.
The current version is "1.0". If absent, the receiver SHOULD
assume the latest version it understands and verify against the
agtp_version field in the document body.

Encoding considerations:

The content is YAML 1.2 encoded as UTF-8 per the YAML 1.2
specification (yaml.org/spec/1.2.2). The "+yaml" structured
syntax suffix per RFC 9512 indicates that the content can be
processed by generic YAML tooling without AGTP-specific support.

Security considerations:

Agent Identity Documents are public identity records; they are
intended to be served and consumed without confidentiality
requirements.

YAML deserializers MUST be configured to disable language-native
type instantiation (e.g., Python's yaml.safe_load rather than
yaml.load). The Agent Identity Document schema is purely scalar
and collection types — strings, numbers, booleans, lists, and
maps; no custom tags or language-native objects are used or
permitted.

All other security considerations from
"application/vnd.agtp.identity+json" apply: claim integrity,
agent_id matching, issuer validation, no executable content.

Interoperability considerations:

This media type is a presentation alternative to
"application/vnd.agtp.identity+json". The two carry the same
information modeled in the same eleven-field schema. AGTP servers
MAY support both formats and select via content negotiation;
clients SHOULD accept "application/vnd.agtp.identity+json" as the
baseline interoperable format.

The YAML form exists for human readability — agent authors who
hand-edit Agent Identity Documents typically prefer YAML;
automated consumers typically prefer JSON.

Published specification:

Hood, C., "Agent Transfer Protocol (AGTP)",
Work in Progress, Internet-Draft,
draft-hood-independent-agtp-07, May 2026.
<https://datatracker.ietf.org/doc/draft-hood-independent-agtp/>

Applications that use this media type:

The Agent Transfer Protocol (AGTP). The reference AGTP server
serves Agent Identity Documents in this format on request via
Accept header content negotiation. The "elemen" desktop browser
displays Agent Identity Documents in this format in its YAML
view.

Fragment identifier considerations:

AGTP does not define fragment identifier semantics for this type
beyond those defined in the YAML 1.2 specification.

Restrictions on usage: none

Additional information:

Deprecated alias names for this type: none
Magic number(s): none
File extension(s): .agent.yaml, .agent.yml
Macintosh file type code(s): none
Object Identifier(s) or OID(s): none

Person & email address to contact for further information:

Chris Hood (chris&nomotic.ai)

Intended usage: COMMON

Author:

Chris Hood (chris&nomotic.ai)

Change controller:

Chris Hood / Nomotic, Inc. (chris&nomotic.ai)