Struct Entity 

pub struct Entity {
    pub id: String,
    pub entity_type: EntityType,
    pub name: String,
    pub content: String,
    pub metadata: HashMap<String, String>,
    pub embedding: Option<Vec<f32>>,
    pub created_at: DateTime<Utc>,
    pub updated_at: DateTime<Utc>,
    pub document_time: Option<DateTime<Utc>>,
    pub event_time: Option<DateTime<Utc>>,
    pub source_ref: Option<SourceRef>,
}

An entity in archival memory.

TigerStyle: Explicit fields, no Option where not needed.

Temporal Metadata (ADR-006)

Entities support bi-temporal tracking:

• document_time: When the source document was created (e.g., email sent date)
• event_time: When the event actually occurred (e.g., “I met Alice last Tuesday”)

This enables queries like “What happened last week?” to find events by when they occurred, not just when they were recorded.

Fields

id: String

Unique identifier (UUID v4)

entity_type: EntityType

Type of entity

name: String

Display name

content: String

Main content

metadata: HashMap<String, String>

Additional metadata

embedding: Option<Vec<f32>>

Embedding vector (for semantic search)

created_at: DateTime<Utc>

Creation timestamp (when stored in Umi)

updated_at: DateTime<Utc>

Last update timestamp

document_time: Option<DateTime<Utc>>

When source document was created (e.g., email sent date)

event_time: Option<DateTime<Utc>>

When event actually occurred (e.g., “last Tuesday”)

source_ref: Option<SourceRef>

Reference to source content (for multimedia workflows)

Implementations

impl Entity

pub fn new(entity_type: EntityType, name: String, content: String) -> Self

Create a new entity with required fields.

Panics

Panics if name or content exceed limits.

pub fn builder( entity_type: EntityType, name: String, content: String, ) -> EntityBuilder

Create a builder for more complex entity construction.

pub fn has_embedding(&self) -> bool

Check if entity has an embedding.

pub fn get_metadata(&self, key: &str) -> Option<&str>

Get metadata value.

pub fn update_content(&mut self, content: String)

Update content and timestamp.

pub fn set_embedding(&mut self, embedding: Vec<f32>)

Set embedding.

pub fn set_document_time(&mut self, time: DateTime<Utc>)

Set document time (when source was created).

pub fn set_event_time(&mut self, time: DateTime<Utc>)

Set event time (when event actually occurred).

pub fn document_time(&self) -> Option<DateTime<Utc>>

Get document time.

pub fn event_time(&self) -> Option<DateTime<Utc>>

Get event time.

pub fn has_temporal_metadata(&self) -> bool

Check if entity has temporal metadata.

pub fn set_source_ref(&mut self, source_ref: SourceRef)

Set source reference (for multimedia content).

pub fn source_ref(&self) -> Option<&SourceRef>

Get source reference.

pub fn has_source_ref(&self) -> bool

Check if entity has a source reference.

Trait Implementations

impl Clone for Entity

fn clone(&self) -> Entity

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Entity

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Entity

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Entity

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.