Hi there! I wrote down an article that compares OpenSpec and SpecKit.
TLDR: SpecKit has significantly more abilities for extending its workflow, but it is also harder to adopt. OpenSpec default workflow looks like more complete and easier, but there are less abilities to extend it.
Thariq Shihipar from Anthropic wrote an article about finding the unknowns with Fable (I'll provide a link in a first comment). I found it intersting in the context of Spec Driven Development with AI agents. First of all, let me place some terms the author defines in original article, they are:
So, we start with a spec draft (or a prompt), it contains only Known Knowns. But after that we have three different groups of Unknowns. Some of them could be disclosured after initial agent analyse. For example, aligning spec with current product behavior, finding out some restrictions that are in our code, and so on.
Could we say that after that the specification is ready? I think not and that's why. Thariq says very clever thought: The map is not the territory. We do not know the reality until we try to experience it. I'll building my own plugin for Spec Driven Development (also, I'll provide a link in a first comment), and for me I found following workflow very effective: write spec together with agent -> review it -> write plan together with agent -> review it -> implement step by step also reviewing results on every stage.
Before we have a acceptable-for-us plan we are guessing about the path. When we start to execute steps we are mapping a territory. And on every step, no matter how accurately we have made an initial analysis, some cuvets will be discovered. Each of them probably will mutate the specification.
At the end we have code done, and only at that exact moment we have a spec done. Until that, we simply did not disclosured Unknowns we have to bake into spec. That's the workflow I'm trying to support in my plugin. Do you do so? Or maybe you think about specs in different way?
Disclosure: I built this. It's called SpecBuddy, link at the bottom.
It adds a control layer over whichever coding agent you already run in your JetBrains IDE (Claude Code or Codex).
Instead of the agent generating a big diff you review afterwards, it drafts a spec, then a plan — both of which you approve or rewrite — and then executes one step at a time, each step reviewable.
It also handles the no-spec case: chat with the agent normally, and the plugin still intercepts changes as diffs you can comment on inline and send back.
It installs on the whole family from 2026.1 — IDEA, PyCharm, GoLand, WebStorm, Rider, CLion and the rest — but I've only properly tested it in IDEA. If you run it somewhere else, I'd really like to know whether it holds up.
https://plugins.jetbrains.com/plugin/32645-specbuddy
Would love bug reports — it's early.
Disclosure: I built this. It's called SpecBuddy, link at the bottom.
I've been working spec-first with Claude Code for a while, and the friction that kept getting me is that the pieces live in three different places: the spec is a file, the agent is in a terminal, the review happens in git. The methodology holds up fine — but the loop is stitched together, and I lose more time moving between those places than I save.
So I tried making the spec and the plan first-class objects inside the IDE instead:
- You describe the task. The agent drafts a spec from it plus your codebase. You edit and approve it.
- From the approved spec it drafts a step-by-step plan. You approve or rewrite it.
- Only then does it generate — one step at a time. Every step comes back as a diff you accept, reject, or roll back before the next one runs.
Where it differs from the neighbours is mostly the cost of entry: Spec Kit asks you to learn a command surface, Kiro asks you to switch IDEs. This is a plugin in the IDE you already have, running on top of the agent you already run (Claude Code or Codex).
I'm posting it here because this is where people already work this way, and I'd rather hear from you than from a general audience.
Honest scope: IntelliJ only for now, and it is a beta — there are rough edges.
https://plugins.jetbrains.com/plugin/32645-specbuddy
Feedback very welcome, especially if you try it and it gets in your way.
