add history endpoint

api/routes/tasks.py

@@ -3,9 +3,11 @@ from fastapi.responses import JSONResponse
 
 from api.contracts.task_schemas import (
     BrowserTaskAcceptedResponse,
+    BrowserTaskHistoryResponse,
     BrowserTaskRequest,
     BrowserTaskResultResponse,
     BrowserTaskStatusResponse,
+    TaskHistoryEvent,
 )
 from api.domain.task_status import TaskStatus
 from api.repositories.task_store import TaskRecord
@@ -69,6 +71,32 @@ async def get_task_result(
     )
 
 
+@router.get("/tasks/{task_id}/history", response_model=BrowserTaskHistoryResponse)
+async def get_task_history(
+        task_id: str,
+        service: TaskService = Depends(get_task_service),
+) -> JSONResponse | BrowserTaskHistoryResponse:
+    rec = await service.get_task(task_id)
+    if rec is None:
+        raise HTTPException(status_code=404, detail="Task not found")
+
+    if rec.status in (TaskStatus.queued, TaskStatus.running):
+        return JSONResponse(
+            status_code=202,
+            content={
+                "task_id": rec.task_id,
+                "status": rec.status.value,
+                "history": rec.history,
+            },
+        )
+
+    return BrowserTaskHistoryResponse(
+        task_id=rec.task_id,
+        status=rec.status,
+        history=_to_history_events(rec),
+    )
+
+
 def _to_status_response(rec: TaskRecord) -> BrowserTaskStatusResponse:
     return BrowserTaskStatusResponse(
         task_id=rec.task_id,
@@ -78,3 +106,24 @@ def _to_status_response(rec: TaskRecord) -> BrowserTaskStatusResponse:
         finished_at=rec.finished_at,
         error=rec.error,
     )
+
+
+def _to_history_events(rec: TaskRecord) -> list[TaskHistoryEvent]:
+    events: list[TaskHistoryEvent] = []
+    for index, item in enumerate(rec.history, start=1):
+        kind = str(item.get("kind") or item.get("type") or "system")
+        content = item.get("content")
+        if content is not None:
+            content = str(content)
+        data = item.get("data")
+        if not isinstance(data, dict):
+            data = {}
+
+        step = item.get("step")
+        if not isinstance(step, int):
+            step = index
+
+        events.append(TaskHistoryEvent(step=step, kind=kind, content=content, data=data))
+
+    return events
+