Pros and Cons of OpenSpec compared to Spec Kit- Greenfield/Browfield development

[morpheus9393]

Hi everyone,

I'm new to this ecosystem and want to start with one of the available tools. I'm currently trying to understand the differences between Spec Kit and OpenSpec.

From what I've gathered:

• OpenSpec seems to be more geared toward "brownfield" scenarios
• Spec Kit appears to be the more general-purpose option

My questions:

1. What are the key pros and cons of each approach?
2. When you mention OpenSpec is "more for brownfield" – does that mean it doesn't make sense or is significantly harder to implement when starting a new greenfield project from scratch?
3. For someone developing a completely new piece of software (starting from 0), which would you recommend and why?

I'd really appreciate any insights from your experiences. Thanks for sharing your opinions!

[TabishB]

I've responded to you in the other discussion on spec-kit:

github/spec-kit#1536 (comment)

[clay-good]

Answered above — @TabishB replied in the spec-kit thread.

One correction worth leaving here for future readers: OpenSpec is not brownfield-only. It's brownfield-first, which means it doesn't require an upfront baseline of your codebase — but the loop is identical on a greenfield project, and your specs/ folder simply starts empty and fills in from change one.

• Using OpenSpec in an Existing Project
• Getting Started

Closing as answered — reopen if you want to compare specific behaviours.