# OpenTap runner overwrite leaf.config

**URL:** <https://forum.opentap.io/t/opentap-runner-overwrite-leaf-config/2712>\
**Category:** Technical\
**Tags:** plugin\
**Created:** [October 9, 2026, 5:24pm UTC](https://forum.opentap.io/t/opentap-runner-overwrite-leaf-config/2712 "2026-10-09T17:24:03Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![fauser](https://avatars.discourse-cdn.com/v4/letter/f/85f322/32.png) [@fauser](https://forum.opentap.io/u/fauser)\
**Post date:** [October 9, 2026, 5:24pm UTC](https://forum.opentap.io/t/opentap-runner-overwrite-leaf-config/2712/1 "2026-10-09T17:24:03Z")

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How can I prevent the OpenTap Runner from overwriting `leaf.config`?

For example, to change the IP address or increase the maximum payload?

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<div class="post-metadata">

**Author:** ![heine.otte](https://avatars.discourse-cdn.com/v4/letter/h/8c91f0/32.png) [@heine.otte](https://forum.opentap.io/u/heine.otte)\
**Post date:** [October 16, 2026, 7:36am UTC](https://forum.opentap.io/t/opentap-runner-overwrite-leaf-config/2712/2 "2026-10-16T07:36:20Z")

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Hi @fauser,

Unfortunately, you can’t. The Runner rewrites leaf.config every time it starts, so manual changes get overwritten.

Also, on newer versions of the Runner, raising the maximum payload wouldn’t help for messages the Runner publishes, because it always sends them in ~90KB chunks. This is because, in our case, the NATS.Client NuGet package performs poorly when publishing larger messages. You can read more on our chunking protocol here: [OpenTAP Runner](https://doc.opentap.io/runner/#chunked-transfer-protocol)

Regarding changing the IP address: I’m not sure I understand what you need. Could you describe what you’re trying to achieve?