How do I use openspec with opencode in plan mode

[Aditeya]

In OpenCode in Plan mode if i develop a spec, the agent won't be able to write it to file because there aren't any write permissions, I have to switch to build mode, but sometimes in build mode it just decides to implement it.

This just sucks so ideally I'd like some solution where plan mode only modifies spec, is there some solution to do this?

[TabishB]

@Aditeya I've found that this largely depends on the quality of model you use and how good it is with following instructions.

With Sonnet 4.5 it would always do this, but I've found that Opus 4.5 handles instructions a lot better.

You can also try using the new experimental workflow which might improve your experience too.

[Aditeya]

I did use opus 4.5 . The problem is plan mode in open code prevents writing files. I need a plan mode that allows writing but only to openspec? how would i go about doing that?

[Aditeya]

I found an opencode plugin that does exactly what I want. plan mode with openspec file writing support

https://github.com/Octane0411/opencode-plugin-openspec