---
url: >-
  https://adk.nht.io/api/@nhtio/adk/exceptions/variables/E_OUTPUT_PIPELINE_ERROR.md
description: >-
  Emitted (via the `error` event) when a non-abort error propagates out of the
  output middleware pipeline during {@link @nhtio/adk!TurnRunner.run}.
---

# Variable: E\_OUTPUT\_PIPELINE\_ERROR

```ts
const E_OUTPUT_PIPELINE_ERROR: CreatedException<[]>;
```

Defined in: [lib/exceptions/runtime.ts:73](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/lib/exceptions/runtime.ts#L73)

Emitted (via the `error` event) when a non-abort error propagates out of the output
middleware pipeline during [@nhtio/adk!TurnRunner.run](../../turn_runner/classes/TurnRunner.md#run).

## Remarks

Not fatal — the turn runner emits this on the `error` event rather than throwing, so
registered listeners can handle or log the failure without crashing the pipeline. `turnEnd`
still fires.