Class: Message

Defined in: src/lib/classes/message.ts:157

An immutable, validated conversation message from a human participant or the model.

Remarks

Covers only user and assistant roles — system instructions, developer directives, and tool results are not represented here. Constructed from a RawMessage via rawMessageSchema. Temporal fields are normalised to Luxon DateTime instances at construction time. Both content and identity.representation are @nhtio/adk!Tokenizable so token cost can be estimated inline.

A message may carry content (text), attachments (media), or both. The cross-field rule on rawMessageSchema enforces that at least one is present. Downstream code that reaches for message.content must handle the attachments-only case where content is undefined.

Constructors

Constructor

new Message(raw: RawMessage): Message;

Defined in: src/lib/classes/message.ts:226

Parameters

Parameter	Type	Description
raw	RawMessage	The raw message input validated against rawMessageSchema.

Returns

Message

Throws

@nhtio/adk!E_INVALID_INITIAL_MESSAGE_VALUE when raw does not satisfy the schema — including the cross-field rule that at least one of content or attachments must be present and non-empty.

Properties

Property	Modifier	Type	Default value	Description	Defined in
attachments	readonly	readonly Media[]	undefined	Media attachments carried by this message. Remarks Always defined as a frozen array — empty when the message has no attachments. Both user and assistant messages may carry attachments. Each entry carries its own trustTier and modalityHazard; the renderer wraps each in its own trust envelope independent of the message envelope.	src/lib/classes/message.ts:204
content	readonly	Tokenizable | undefined	undefined	The message content as a @nhtio/adk!Tokenizable for inline token estimation, or undefined for attachments-only messages. Remarks undefined when the message was constructed with only attachments. Render code that needs the text portion must guard for the missing case rather than blindly calling message.content.toString().	src/lib/classes/message.ts:194
createdAt	readonly	DateTime	undefined	When this message was created.	src/lib/classes/message.ts:208
id	readonly	string	undefined	Stable unique identifier for this message.	src/lib/classes/message.ts:182
identity	readonly	Identity	undefined	The identity of the participant who authored this message.	src/lib/classes/message.ts:206
role	readonly	MessageRole	undefined	Whether this message is from the human participant or the model.	src/lib/classes/message.ts:184
updatedAt	readonly	DateTime	undefined	When this message was last modified.	src/lib/classes/message.ts:210
schema	static	ObjectSchema<RawMessage>	rawMessageSchema	Validator schema that accepts a RawMessage object. Remarks Reusable fragment for any schema that needs to validate or nest a message entry — for example, a collection schema that holds an array of messages.	src/lib/classes/message.ts:165

Methods

[ENCODE_METHOD]()

ENCODE_METHOD: unknown;

Defined in: src/lib/classes/message.ts:304

Serialise this Message into an @nhtio/encoder snapshot.

Returns

unknown

A RawMessage-shaped snapshot.

Remarks

Emits a RawMessage-shaped object holding the live nested primitives — content (@nhtio/adk!Tokenizable), attachments (@nhtio/adk!Media[]), identity (@nhtio/adk!Identity), and Luxon temporal fields — which the encoder recurses into. A text-only message round-trips trivially; a message carrying @nhtio/adk!Media round-trips only if each attachment's reader is describable (a fromWebFile-backed attachment throws @nhtio/adk!E_READER_NOT_DESCRIBABLE at encode). The frozen attachments array is copied to a plain array for the snapshot. Round-trips via Message.[DECODE_METHOD].

---

[DECODE_METHOD]()

static DECODE_METHOD: Message;

Defined in: src/lib/classes/message.ts:324

Reconstruct a Message from a Message.[ENCODE_METHOD] snapshot.

Parameters

Parameter	Type	Description
data	unknown	The snapshot produced by Message.[ENCODE_METHOD].

Returns

Message

A fully-validated Message.

---

isMessage()

static isMessage(value: unknown): value is Message;

Defined in: src/lib/classes/message.ts:177

Returns true if value is a Message instance.

Parameters

Parameter	Type	Description
value	unknown	The value to test.

Returns

value is Message

true when value is a Message instance.

Remarks

Uses @nhtio/adk!isInstanceOf for cross-realm safety — instanceof would fail for instances created in a different module copy or VM context.