Originally published on LinkedIn on November 9, 2025.


Hari Krishnan’s article examines OpenSpec as a Spec-Driven Development (SDD) tool, highlighting its distinctive approach of maintaining a single “source of truth” specification.

Key Concepts

OpenSpec’s Workflow Structure

The tool manages three types of specifications:

  • Change Specifications (Delta Specs) marking sections as “ADDED,” “MODIFIED,” or “REMOVED”
  • A living “Source of Truth” spec representing current system state
  • Archived Specifications preserving historical delta specs

Problems Solved

I identify critical limitations with competing tools like Spec-Kit and Kiro:

  1. Fragmented Understanding - “Feature-level specs are often fragmented across subfolders” making systemic comprehension difficult
  2. Spec Evolution Confusion - Unclear mechanisms for how specifications evolve over time
  3. Unintended Interactions - “Every new feature added risks unintentionally affecting existing behaviour, since there is no unified view”

Alignment Levels

The article references Birgitta Boeckeler’s framework of three alignment categories:

  • Spec-First - Specs guide initial exploration but diverge from implementation
  • Spec-Anchored - Continuous validation against unified specifications remains possible
  • Spec-As-Source - Not discussed in detail

OpenSpec enables Spec-Anchored validation through its single source-of-truth model.

Observed Advantages

  • Faster iteration cycles maintaining developer focus
  • Natural brownfield project support
  • Reduced context switching during development