hive-c0re/src/job_queue/mod.rs

@@ -217,7 +217,15 @@ impl JobQueue {
     ) -> anyhow::Result<u64> {
         let mut inner = self.lock();
         let container = inner
-            .append(NodeKind::Dag { source, reason }, Vec::new(), None)
+            .append(
+                NodeKind::Dag {
+                    source,
+                    reason,
+                    created_at: Utc::now(),
+                },
+                Vec::new(),
+                None,
+            )
             .map_err(|e| anyhow::anyhow!("job_queue: container insert failed: {e}"))?;
         insert_group(&mut inner, declare, Some(container))?;
         drop(inner);
@@ -399,15 +407,15 @@ fn container(sched: &Sched, dag_id: u64) -> Option<NodeId> {
 /// DAG drops out of the snapshot entirely (a `Failed` one lingers until
 /// aged out).
 fn dag_view(sched: &Sched, container: NodeId) -> Option<DagView> {
-    // Read straight off the container's payload: the domain fields have a
+    // Read straight off the container's payload: the three fields have a
     // single home there, so an intermediate owned copy of them was a second
     // type describing the same data rather than a grouping side-table.
-    //
-    // `created_at` is NOT among them — it comes off the container node itself
-    // below, where the graph stamps it for every node. Keeping a payload copy
-    // would record one instant in two places.
-    let node = sched.graph().node(container)?;
-    let NodeKind::Dag { source, reason } = &node.payload else {
+    let NodeKind::Dag {
+        source,
+        reason,
+        created_at,
+    } = &sched.graph().node(container)?.payload
+    else {
         return None;
     };
     let all: Vec<_> = sched.graph().descendants(container).collect();
@@ -486,7 +494,7 @@ fn dag_view(sched: &Sched, container: NodeId) -> Option<DagView> {
         id: container.get(),
         source: *source,
         reason: reason.clone(),
-        created_at: node.created_at,
+        created_at: *created_at,
         started_at: started.into_iter().min(),
         finished_at: is_terminal.then(|| finished.into_iter().max()).flatten(),
         nodes,

hive-c0re/src/job_queue/model.rs

@@ -12,6 +12,7 @@
 //! DAG can span agents). See `docs/coordinator.md::Job queue` for the
 //! full design.
 
+use chrono::{DateTime, Utc};
 pub use hive_host_sock::jobs::{DagView, PermPayload, Source, State};
 use serde::Serialize;
 
@@ -275,12 +276,11 @@ pub enum NodeKind {
     /// the DAG state. Pure grouping — lease- and
     /// build-slot-exempt; the executor instant-completes it (`Done`) so it
     /// reaches `Finishing` and its children start.
-    ///
-    /// No `created_at` here: the graph stamps [`hive_jobq::Node::created_at`] on
-    /// every node at insert, so the container already has one. A second copy in
-    /// the payload would be the same instant recorded twice, with only this
-    /// variant's version reachable to a generic viewer.
-    Dag { source: Source, reason: String },
+    Dag {
+        source: Source,
+        reason: String,
+        created_at: DateTime<Utc>,
+    },
 }
 
 /// How a hive-c0re node describes itself to a generic graph viewer.

hive-jobq-wire/src/lib.rs

@@ -152,9 +152,6 @@ pub struct GraphNode {
     /// What must hold before this node runs. Omitted when empty.
     #[serde(default, skip_serializing_if = "Vec::is_empty")]
     pub deps: Vec<GraphDep>,
-    /// When the node was inserted into the graph. Always present — a node that
-    /// exists was created, so unlike the two below this is not an `Option`.
-    pub created_at: DateTime<Utc>,
     /// When the node entered `Running`. `None` until it starts; a node that
     /// never ran keeps `None`.
     #[serde(default, skip_serializing_if = "Option::is_none")]
@@ -257,7 +254,6 @@ fn wire_node<N: WireNode, R: WireResource>(node: &hive_jobq::Node<N, R>) -> Grap
         parent: node.parent.map(NodeId::get),
         state: node.state,
         deps: node.deps.iter().map(wire_dep).collect(),
-        created_at: node.created_at,
         started_at: node.started_at,
         finished_at: node.finished_at,
         error: node.error.clone(),
@@ -447,7 +443,6 @@ mod tests {
             parent,
             state,
             deps,
-            created_at: chrono::DateTime::<chrono::Utc>::default(),
             started_at: None,
             finished_at: None,
             error: None,

hive-jobq/src/lib.rs

@@ -255,9 +255,9 @@ impl State {
 }
 
 /// Wall-clock UTC now — the source for node lifecycle timestamps
-/// ([`Node::created_at`] / [`Node::started_at`] / [`Node::finished_at`]). The
-/// graph stamps its own timestamps rather than threading a clock through every
-/// call, so a node's timing is self-contained. Derived from `SystemTime` (the workspace `chrono`
+/// ([`Node::started_at`] / [`Node::finished_at`]). The graph stamps its own
+/// timestamps rather than threading a clock through every call, so a node's
+/// timing is self-contained. Derived from `SystemTime` (the workspace `chrono`
 /// carries no `clock` feature, matching `hive_sh4re::wire_time`), truncated to
 /// whole seconds; a pre-epoch or out-of-range clock clamps to the epoch.
 fn now_utc() -> DateTime<Utc> {
@@ -291,14 +291,6 @@ pub struct Node<N, R> {
     pub deps: Vec<Dep<R>>,
     /// Lifecycle state.
     pub state: State,
-    /// UTC instant the node was inserted into the graph. Stamped by the graph.
-    ///
-    /// Not an `Option`, unlike its two siblings below: starting and finishing
-    /// are events that may never happen, but a node that exists was created.
-    /// Together the three are the node's whole lifecycle — a caller asking
-    /// "how long did this sit before it ran" needs this end of the interval,
-    /// and previously had to get it from a wrapper the graph knows nothing about.
-    pub created_at: DateTime<Utc>,
     /// UTC instant the node entered [`State::Running`] (`None` until it starts;
     /// a cancelled node never ran, so it stays `None`). Stamped by the graph.
     pub started_at: Option<DateTime<Utc>>,
@@ -489,7 +481,6 @@ impl<N, R> Graph<N, R> {
             payload,
             deps,
             state: State::Pending,
-            created_at: now_utc(),
             started_at: None,
             finished_at: None,
             error: None,
@@ -943,7 +934,6 @@ mod tests {
                     when: DepWhen::AFTER_OK,
                 }],
                 state: State::Pending,
-                created_at: now_utc(),
                 started_at: None,
                 finished_at: None,
                 error: None,
@@ -964,7 +954,6 @@ mod tests {
                 payload: "x",
                 deps: vec![],
                 state: State::Pending,
-                created_at: now_utc(),
                 started_at: None,
                 finished_at: None,
                 error: None,