Struct ModelContext 

pub struct ModelContext<'a> {

    pub model: &'a ModelRouter,
    pub provider: &'a str,
    pub session_id: &'a str,
    pub session_context: &'a SessionContext,
    pub metadata: &'a BTreeMap<String, Value>,
    pub turn_id: &'a str,
    pub model_step: usize,
    pub context_window: i64,
    pub instructions: &'a str,
    pub last_usage: Option<&'a TokenUsage>,
    pub tools: &'a Catalog,
    pub events: &'a mut Vec<EventMsg>,
    pub usage: &'a mut Vec<TokenUsage>,
    /* private fields */
}

Mutable state exposed immediately before a model request.

Fields

model: &'a ModelRouter

provider: &'a str

session_id: &'a str

session_context: &'a SessionContext

metadata: &'a BTreeMap<String, Value>

turn_id: &'a str

model_step: usize

context_window: i64

instructions: &'a str

last_usage: Option<&'a TokenUsage>

tools: &'a Catalog

events: &'a mut Vec<EventMsg>

usage: &'a mut Vec<TokenUsage>

Implementations

impl ModelContext<'_>

pub fn input(&self) -> &[Value]

Returns durable provider-neutral model context.

pub fn request_input(&self) -> &[Value]

Returns the request input including earlier request-only middleware additions.

pub fn rewrite_input( &mut self, reason: ContextRewriteReason, input: Vec<Value>, ) -> Result<()>

Replaces active model context and advances its rewrite epoch once per boundary.

pub fn append_model_input(&mut self, item: Value)

Appends durable provider context without adding synthetic replay history.

pub fn push_input(&mut self, item: Value) -> Result<MessageTarget>

Appends durable input to model context and its transcript journal.

pub fn estimated_input_tokens(&self) -> i64

Estimates serialized model input at four bytes per token.