# Adding jump to JumpProblem defined from Catalyst model
**URL:** https://discourse.julialang.org/t/adding-jump-to-jumpproblem-defined-from-catalyst-model/127790
**Category:** General Usage
**Tags:** question, catalyst
**Created:** [April 7, 2025, 10:37am UTC](https://discourse.julialang.org/t/adding-jump-to-jumpproblem-defined-from-catalyst-model/127790 "2025-04-07T10:37:13Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@hhindley](https://discourse.julialang.org/u/hhindley)
#### Post date: [April 7, 2025, 10:37am UTC](https://discourse.julialang.org/t/adding-jump-to-jumpproblem-defined-from-catalyst-model/127790/1 "2025-04-07T10:37:13Z")
Hi,
Does anyone know if it’s possible to add a newly defined jump to a JumpProblem which is directly defined from a Catalyst.jl model? This is easily done when building a model straight from Jumps, just add another one to the JumpSet, but I was wondering if it was possible to access the JumpSet from the Catalyst output and add another separately defined jump.
I want to add a conditional event to my model which is defined as a Jump (instead of using callbacks).
Thanks!
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### Author:  [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)
#### Post date: [April 7, 2025, 3:07pm UTC](https://discourse.julialang.org/t/adding-jump-to-jumpproblem-defined-from-catalyst-model/127790/2 "2025-04-07T15:07:35Z")
Open an issue. In general this can be hard because jumps tend to codegen / aggregate together. But you could tag one on after, just right before the jump aggregation. I think this is more for an issue / feature request where you also show an example of what you’re trying to do in order to motivate it a bit more.
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### Author:  [@isaacsas](https://discourse.julialang.org/u/isaacsas)
#### Post date: [April 7, 2025, 4:35pm UTC](https://discourse.julialang.org/t/adding-jump-to-jumpproblem-defined-from-catalyst-model/127790/3 "2025-04-07T16:35:09Z")
Can you explain what you want your event to do / when it should fire? To make sense as a jump it has to have a well-defined `rate` function that determines (stochastically) when it fires.