Struct Message 

pub struct Message {
    pub role: String,
    pub content: String,
    pub id: Option<String>,
    pub source_id: Option<String>,
    pub inserted_by: Option<ContextInsertion>,
}

Fields

role: String

content: String

id: Option<String>

Stable identity for this message, minted by the runtime as msg_ followed by a uuid-v7 simple form. A uuid-v7 carries its own millisecond timestamp, so there is no separate created-at field to keep in step with it.

This is not a content hash. An id must never repeat, even for two messages whose content is byte-identical; a content hash must repeat whenever the content does. The two answer different questions and are never interchangeable.

Stripped before the wire payload is built — see the note on source-id. Minted once, at the message’s creation site, and preserved everywhere after: an id on a message a hook hands back is kept, and so is the id a message reloaded from the conversation record carries. The runtime mints one only for a message that arrives without one.

source_id: Option<String>

Opaque join key back to whatever produced this content — a corpus record, a compaction summary, reloaded history. Recorded verbatim and never parsed, exactly like resource-id in tool metadata: the runtime makes no claim about its shape and reads no meaning out of it.

Both id and source-id are stripped before the driver wire payload is built. A uuid sitting at the head of a cached prefix is volatile content, and would defeat provider prompt-prefix caching on every request. A source-id a hook supplies is carried verbatim; the key is absent when the hook supplied none.

inserted_by: Option<ContextInsertion>

Which hook output put this message into the conversation. Set only by the runtime, at the moment it commits that output, and read from the conversation record wherever the message is served back.

none means no hook output inserted the message: it is a person’s or a delegating caller’s task message, a model turn, a tool result, or a runtime marker, and role tells those apart. The mark is independent of role, so a summary returned as "assistant" or "user" carries it all the same.

A message a hook hands back unchanged keeps the mark it already had: its id names a message in the context the hook was handed, and its role and content equal that message’s. Any other message a hook returns is marked with the output it came in through. A value a hook sets on a message it returns is ignored.

Stripped before the driver wire payload is built, like id and source-id.

Trait Implementations

impl Clone for Message

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl ComponentType for Message

impl Debug for Message

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Lift for Message

impl Lower for Message