Harness Engineering vs Spec-Driven Development
What harness engineering means for AI coding agents, how it differs from spec-driven development, and how to run both.
A focused archive of Foundations articles for spec-first teams.
What harness engineering means for AI coding agents, how it differs from spec-driven development, and how to run both.
AGENTS.md is a README for coding agents. The hard part is the boundary: which rules are true for every change, and which belong in a spec for one change.
A Cursor rule that never fires is worse than no rule. Three frontmatter fields decide which of the four types you wrote, and most teams write the dead one.
A five-stage spec-first workflow for teams running AI coding agents: spec packets, bounded tasks, write scopes, evidence gates, and PR review that scales.
OpenSpec vs Superpowers vs Spec Kit, checked Nov 2026: what each one owns, how to combine them, and which to start with.
See how Spec Skills fits spec-first delivery through constrained prompts, spec injection, boundary enforcement, and reviewable AI output.
Same refund feature built two ways: vibe coding ships fast but misses edge cases, while spec coding defines scope, acceptance criteria, tests, and rollout proof.
20 real-world acceptance criteria examples in Given/When/Then format covering authentication, e-commerce, APIs, data processing, payments, and notifications.
How to write a technical specification document for software: the sections to include, five worked examples (config, API, migration, UI), and a copy-ready template.
Define database schemas before writing migrations, including columns, constraints, indexes, API alignment, and rollout order.
AI coding tools drift without constraints, adding fields, renaming functions, expanding scope, and inventing tests. Spec-first prompts keep changes reviewable.
Govern AI-assisted coding with spec-driven prompts: define scope, boundaries, evidence, and audit trails before generated code reaches review.
Design API specs for LLM-powered agentic clients with discoverable fields, idempotency, dry-runs, semantic descriptions, and safe destructive actions.
Quality gates for AI-assisted code: pre-prompt spec checks, diff review, test evidence, and human sign-off before generated code ships.
What is spec-first development? A complete guide to surfacing hidden decisions about scope, contracts, edge cases, and acceptance criteria before coding starts.