sparkvibeai/blog · field notes on the spec layer
the spec layer journal
Spec-driven development, the end of vibe coding, and how to write — and score — the specs you hand to AI coding agents. Written by the team building the calibrated spec layer between intent and code.
The Agentic Loop Is a Dumb Search. Score the Spec Instead.
An agentic loop is a powerful search with no built-in objective — so it thrashes, doom-loops, and burns tokens (one team reported a $47K runaway loop). A good starting spec, scored before the loop runs, aims it and tells it when to stop.
tools comparisonSpec Kit vs. Kiro vs. Tessl vs. OpenSpec — and the Layer They All Miss
Four serious spec-driven development tools, one common blind spot: none of them tell you whether the spec is any good before you build. A field guide to the category — and the missing scoring layer.
practitioner guideHow to Write a Spec for an AI Coding Agent (Claude Code, Cursor, Codex)
The agent isn't guessing because it's dumb — it's guessing because your spec left the gap. A copy-paste template and the seven sections that stop AI coding agents from inventing requirements.
spec-driven developmentVibe Coding vs. Spec-Driven Development: Surviving the 6-Month Wall
Vibe coding is unbeatable for the first weekend and brutal by month six. Here's exactly where the wall is, why it's there, and how a spec-first workflow gets you past it without killing the velocity.
fundamentalsWhat Is Spec-Driven Development? (And the Question Every Guide Skips)
A plain-English definition, the Spec → Plan → Tasks → Build loop, the honest answer to "isn't this just waterfall?", and the one thing almost every guide leaves out: how you know the spec is good.