A minimal, multi-modal structure for exchanging content
role
that identifies the sender. Valid role formats are:
user
- for messages from usersagent
- for generic agent messagesagent/{name}
- for specific agent messages where name can contain alphanumeric characters, underscores, and hyphens (e.g. agent/image-analyzer
, agent/chat_bot
)Attribute | Required | Description |
---|---|---|
content_type | Yes | MIME type (e.g., text/plain , image/png ) |
content OR content_url | Yes | Content inline or via URL |
content_encoding | No | "plain" (default) or "base64" |
name | No | Makes this part an Artifact |
metadata | No | Additional metadata to provide additional context or semantic information |
name
attribute. They represent important outputs like:
metadata
to provide additional context or semantic information. ACP supports standardized metadata types for citations and trajectory information.
For detailed information about metadata types, usage patterns, and examples, see Message Metadata.
Artifacts
inherit all validation rules from MessagePart
so they must also have either content
or content_url
(never both).content_type
content
or content_url
(not both)name
are Artifactstext/plain
: Plain text contentimage/png
, image/jpeg
: Image contentapplication/json
: JSON dataapplication/pdf
: PDF documentstext/html
: HTML content