Feat: user defined prompt. (#9972)

### What problem does this PR solve?


### Type of change

- [x] New Feature (non-breaking change which adds functionality)

api/apps/canvas_app.py

@@ -470,3 +470,16 @@ def sessions(canvas_id):
     except Exception as e:
         return server_error_response(e)
 
+
+@manager.route('/prompts', methods=['GET'])  # noqa: F821
+@login_required
+def prompts():
+    from rag.prompts.prompts import ANALYZE_TASK_SYSTEM, ANALYZE_TASK_USER, NEXT_STEP, REFLECT, SUMMARY4MEMORY, RANK_MEMORY, CITATION_PROMPT_TEMPLATE
+    return get_json_result(data={
+        "task_analysis": ANALYZE_TASK_SYSTEM + ANALYZE_TASK_USER,
+        "plan_generation": NEXT_STEP,
+        "reflection": REFLECT,
+        "context_summary": SUMMARY4MEMORY,
+        "context_ranking": RANK_MEMORY,
+        "citation_guidelines": CITATION_PROMPT_TEMPLATE
+    })