# Is there a template to implement simple solvers in MathOptInterface?

**URL:** https://discourse.julialang.org/t/is-there-a-template-to-implement-simple-solvers-in-mathoptinterface/41190
**Category:** General Usage
**Created:** [June 11, 2020, 9:35am UTC](https://discourse.julialang.org/t/is-there-a-template-to-implement-simple-solvers-in-mathoptinterface/41190 "2020-06-11T09:35:04Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![SteffenPL](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/steffenpl/32/206270_2.png) [@SteffenPL](https://discourse.julialang.org/u/SteffenPL)
#### Post date: [June 11, 2020, 9:35am UTC](https://discourse.julialang.org/t/is-there-a-template-to-implement-simple-solvers-in-mathoptinterface/41190/1 "2020-06-11T09:35:04Z")

</div>

I am trying to implement an Uzawa algorithm and would like to use the MathOptInterface.

However, I struggle to find a good template to extend for my purpose. The available nonlinear solver IPOPT has a complicated wrapper…

How difficult is it to implement for example a simple Newton method with MOI?  
I expected it should be a few lines, but I can’t figure out where to start.

With JuMP.AbstractNLPEvaluator I could implement it, but I would like to have it as a solver  
[https://jump.dev/JuMP.jl/v0.21.1/nlp/#Querying-derivatives-from-a-JuMP-model-1](https://jump.dev/JuMP.jl/v0.21.1/nlp/#Querying-derivatives-from-a-JuMP-model-1)