---
title: "Effect unknown"
description: "The run called a tool that can change things outside Auto, then stopped before it finished."
url: "https://on.auto/problems/effect_unknown"
last_updated: "2026-11-10T14:41:54+00:00"
---

# Effect unknown

## What it means

The run called a tool that can change things outside Auto, then stopped before it finished. Auto doesn't know whether the tool made its change, so it won't run the work again by itself.

## What to do

Read the problem's `detail` first. It says what happened to this request.

*   Look at the run's history with `get_run_history` to see which tool it called and what it sent.
*   Check the system that tool works on to see whether the change happened.
*   If the change still needs doing, start a new run with a new `run_id`.
*   In a workflow, a `catch` that matches this error decides instead. A retry on status 503 doesn't match it.

## Technical details

*   Type: `https://on.auto/problems/effect_unknown`
*   Status: 409
*   Reason: `conflict`
*   Kind: `effect_unknown`
*   `because`: what stopped the run, when Auto knows

[Responses and errors](https://on.auto/docs/reference/http#responses-and-errors) in the HTTP API reference has the full detail. [Problem types](https://on.auto/problems/) lists every type.

## Sitemap

See the [full documentation and product sitemap](https://on.auto/sitemap.md) for related pages.