# Example 26: Guarded Toolchain

```mermaid
flowchart LR
  user[user] -->|text (U)| membrane[membrane]
  membrane -->|text (U)| validator[validator]
  validator -->|text (V)| parser[parser]
  parser -->|json (V)| planner[planner]
  planner -->|json (V)| serializer[serializer]
  serializer -->|text (V)| policy[policy]
  policy -->|approval (T)| sink[sink]
  planner -->|json (V)| tool_builder[tool_builder]
  tool_builder -->|toolcall (V)| sink
  validator -->|text (V)| attestor[attestor]
  attestor -->|text (T)| operator_console[operator_console]
```
