Struct AgentState 

pub struct AgentState {
    pub messages: Vec<Message>,
    pub iteration: usize,
    pub stop_reason: Option<StopReason>,
    pub tool_results: Vec<ToolResult>,
    pub total_tokens: usize,
    pub input_tokens: usize,
    pub output_tokens: usize,
}

Agent execution state

Tracks the full lifecycle of an agent conversation including messages, token usage, tool results, and iteration progress.

Derives Serialize/Deserialize for session persistence and cross-process state transfer (e.g. oxios supervisor serialization).

Fields

messages: Vec<Message>

Conversation message history (user, assistant, and tool-result messages).

iteration: usize

Current agent loop iteration (incremented after each assistant turn).

stop_reason: Option<StopReason>

The reason the last turn stopped, if any.

tool_results: Vec<ToolResult>

Accumulated results from tool executions in the current conversation.

total_tokens: usize

Cumulative token count (input + output) across all turns.

input_tokens: usize

Cumulative prompt / input tokens across all turns.

output_tokens: usize

Cumulative completion / output tokens across all turns.

Implementations

impl AgentState

pub fn new() -> Self

Create a new, default-initialized agent state.

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

Add a user message

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

Add an assistant message

pub fn add_tool_result(&mut self, tool_call_id: String, content: String)

Add a tool result message to both the message history and the tool results list.

pub fn increment_iteration(&mut self)

Increment the iteration counter after an assistant turn completes.

pub fn set_stop_reason(&mut self, reason: StopReason)

Record the reason the last turn stopped.

pub fn record_usage(&mut self, input: usize, output: usize)

Accumulate token usage from a completed LLM call.

pub fn clear(&mut self)

Clear all state, resetting for a new conversation.

pub fn replace_messages(&mut self, messages: Vec<Message>)

Replace the entire message history (used after context compaction).

pub fn estimate_tokens(&self) -> usize

Rough token-count estimate based on the serialized message JSON length.

pub fn is_complete(&self) -> bool

Returns true if the agent has signaled a stop reason.

Trait Implementations

impl Clone for AgentState

fn clone(&self) -> AgentState

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for AgentState

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

Formats the value using the given formatter.

impl Default for AgentState

fn default() -> AgentState

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for AgentState

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for AgentState

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

where __S: Serializer,

Serialize this value into the given Serde serializer.