diff --git a/src/cleveragents/cli/commands/plan.py b/src/cleveragents/cli/commands/plan.py
index f3a249d6b..d76bb564e 100644
--- a/src/cleveragents/cli/commands/plan.py
+++ b/src/cleveragents/cli/commands/plan.py
@@ -4374,6 +4374,144 @@ def _get_decision_label(decision_type: str, per_type_ordinal: int = 0) -> str:
     return base_label
 
 
+def _build_tree_envelope(
+    plan_id: str,
+    tree_data: list[dict[str, object]],
+    decisions: list[Decision],
+    show_superseded: bool = False,
+) -> dict[str, object]:
+    """Build the spec-required envelope for ``agents plan tree --format json/yaml``."""
+    from datetime import timezone
+
+    filtered = (
+        decisions if show_superseded else [d for d in decisions if not d.is_superseded]
+    )
+
+    def count_nodes(nodes: list[dict[str, object]]) -> int:
+        count = 0
+        for node in nodes:
+            count += 1
+            children = node.get("children", [])
+            if isinstance(children, list):
+                count += count_nodes(children)
+        return count
+
+    def compute_depth(nodes: list[dict[str, object]]) -> int:
+        if not nodes:
+            return 0
+        max_depth = 0
+        for node in nodes:
+            children = node.get("children", [])
+            if isinstance(children, list) and children:
+                max_depth = max(max_depth, 1 + compute_depth(children))
+        return max_depth
+
+    nodes_count = count_nodes(tree_data)
+    tree_depth = compute_depth(tree_data)
+
+    child_plan_ids: set[str] = set()
+    for d in filtered:
+        if d.decision_type in ("subplan_spawn", "subplan_parallel_spawn"):
+            if hasattr(d, "plan_id") and d.plan_id:
+                child_plan_ids.add(d.plan_id)
+
+    child_plans_count = len(child_plan_ids)
+    child_plans_str = f"{child_plans_count}+" if child_plans_count > 0 else "0"
+
+    invariants_count = sum(
+        1 for d in filtered if d.decision_type == "invariant_enforced"
+    )
+
+    superseded_count = sum(1 for d in decisions if d.is_superseded)
+
+    summary = {
+        "nodes": nodes_count,
+        "depth": tree_depth,
+        "child_plans": child_plans_str,
+        "invariants": invariants_count,
+        "superseded": superseded_count,
+    }
+
+    type_counts: dict[str, int] = {}
+    decision_ids: dict[str, str] = {}
+
+    for d in filtered:
+        type_counts[d.decision_type] = type_counts.get(d.decision_type, 0) + 1
+        ordinal = type_counts[d.decision_type]
+
+        if d.decision_type == "prompt_definition":
+            key = "root"
+        elif d.decision_type == "invariant_enforced":
+            key = f"invariant_{ordinal}"
+        elif d.decision_type == "strategy_choice":
+            key = "strategy"
+        elif d.decision_type == "implementation_choice":
+            key = f"implementation_{ordinal}"
+        elif d.decision_type == "subplan_spawn":
+            key = f"spawn_{ordinal}"
+        elif d.decision_type == "subplan_parallel_spawn":
+            key = f"parallel_{ordinal}"
+        else:
+            key = f"{d.decision_type}_{ordinal}"
+
+        decision_ids[key] = d.decision_id
+
+    child_plans_list: list[dict[str, object]] = []
+    for d in filtered:
+        if d.decision_type in ("subplan_spawn", "subplan_parallel_spawn"):
+            if hasattr(d, "plan_id") and d.plan_id:
+                child_plans_list.append(
+                    {
+                        "id": d.plan_id,
+                        "phase": "execute",
+                        "state": "queued",
+                    }
+                )
+
+    timing: dict[str, object] = {
+        "started": datetime.now(timezone.utc).isoformat(),
+        "duration_ms": 0,
+    }
+
+    def convert_tree_node(node: dict[str, object]) -> dict[str, object]:
+        """Convert internal tree node format to spec format."""
+        spec_node: dict[str, object] = {
+            "type": node.get("type"),
+            "description": node.get("question"),
+        }
+
+        if node.get("confidence") is not None:
+            spec_node["confidence"] = node.get("confidence")
+
+        if node.get("type") in ("subplan_spawn", "subplan_parallel_spawn"):
+            spec_node["plan_id"] = node.get("plan_id", "")
+
+        children = node.get("children", [])
+        if isinstance(children, list) and children:
+            spec_node["children"] = [convert_tree_node(child) for child in children]
+
+        return spec_node
+
+    spec_tree = convert_tree_node(tree_data[0]) if tree_data else {}
+
+    data: dict[str, object] = {
+        "plan_id": plan_id,
+        "tree": spec_tree,
+        "summary": summary,
+        "child_plans": child_plans_list,
+        "decision_ids": decision_ids,
+    }
+
+    return {
+        "command": "plan tree",
+        "status": "ok",
+        "exit_code": 0,
+        "data": data,
+        "timing": timing,
+        "messages": ["Decision tree rendered"],
+    }
+
+
 @app.command("tree")
 def tree_decisions_cmd(
     plan_id: Annotated[
@@ -4410,7 +4548,8 @@ def tree_decisions_cmd(
     )
 
     if fmt in (OutputFormat.JSON, OutputFormat.YAML):
-        console.print(format_output(tree_data, fmt))
+        envelope = _build_tree_envelope(plan_id, tree_data, decisions, show_superseded)
+        console.print(format_output(envelope, fmt))
     elif fmt == OutputFormat.TABLE:
         # Flatten for table view
         filtered = (