Struct LoopCheckpoint 

pub struct LoopCheckpoint {
    pub schema_version: u32,
    pub run_id: String,
    pub session_id: String,
    pub turn: usize,
    pub messages: Vec<Message>,
    pub total_usage: TokenUsage,
    pub tool_calls_count: usize,
    pub verification_reports: Vec<VerificationReport>,
    pub checkpoint_ms: u64,
}

Snapshot of the agent loop at the boundary between tool rounds.

Stored under run_id so resume tooling can address the correct run without scanning all checkpoints of a session.

Fields

schema_version: u32

Schema version — see LOOP_CHECKPOINT_SCHEMA_VERSION.

run_id: String

Logical run identifier. Matches the run_id carried by crate::run::RunSnapshot and AgentEvents.

session_id: String

Parent session id — redundant with run_id lookup but useful for store layouts that key by (session_id, run_id).

turn: usize

1-based tool round counter at checkpoint time. 0 is reserved for “no rounds completed yet”.

messages: Vec<Message>

Conversation history including the just-returned tool results. On resume, the new agent loop starts from this exact message list.

total_usage: TokenUsage

Running token usage at checkpoint time. Lets resume re-emit progress metrics without re-querying the LLM provider.

tool_calls_count: usize

How many tool calls have been executed total in this run.

verification_reports: Vec<VerificationReport>

Verification reports collected so far in this run.

checkpoint_ms: u64

Wall-clock timestamp when the checkpoint was written (Unix epoch ms — sourced from the session’s HostEnv).

Trait Implementations

impl Clone for LoopCheckpoint

fn clone(&self) -> LoopCheckpoint

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LoopCheckpoint

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for LoopCheckpoint

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for LoopCheckpoint

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

where __S: Serializer,

Serialize this value into the given Serde serializer.