Video summary

Up & Running with GitHub Spec Kit #2 - The /constitution Command

Main summary

Key takeaways

Technology

Overview

This video walks through setting up Spec Kit’s “specd driven development” cycle using the /constitution command to define “non-negotiable” project principles that a coding agent must follow going forward.

Key technological concepts / features

Constitution file as durable “memory”

  • Inside the project’s specify folder there is a constitution.mmd (Markdown) template.
  • The constitution records governing principles, such as:
    • Accessibility always first
    • Required frameworks must always be used
    • UX cleanliness
    • Mandatory unit testing
  • These principles are intended to override other guidance for future specs/plans/code generated by the agent.

Using constitution via Copilot / Spec Kit

You can either:

  • Manually edit constitution.mmd, or
  • Run:
    • /constitution + arguments

Any text typed after the command becomes “arguments” that the prompt uses to fill placeholder tokens.

Template placeholders + automatic filling

The /constitution command triggers a “constitution prompt” that:

  • Locates the memory folder constitution file
  • Replaces placeholder tokens in square brackets with values derived from the user’s arguments
  • May also update other Spec Kit template files to keep them aligned with the new constitution

Tutorial-specific content: what the example constitution did

The example entered principles including:

  • Clean code
  • Simple UX
  • Responsive design
  • Minimal dependencies
  • Explicit testing policy: “absolutely no testing” (no unit/integration/end-to-end tests)

Because testing was declared “non-negotiable,” the command also:

  • Updated three other template files by removing or modifying testing-related guidance, making the “no testing” policy consistent across templates.

Analysis / guidance mentioned

  • The presenter intentionally reduced testing for a throwaway tutorial app, noting that:
    • Spec Kit prompts are geared toward test-driven development, which can be time-consuming.
    • For a production app, they’d likely specify a clearer testing stance instead of reducing it.
  • They recommend trying the workflow with different AI models, because Spec Kit output quality varies:
    • They personally liked “Sonic” for step-by-step real-time visibility.
    • They sometimes switch to “GPT5” for task creation.

Output / verification behavior

After running the command, it:

  • Reports that it successfully created the constitution and lists the principles it applied
  • Updates the constitution file by replacing placeholders with actual principle content
  • Derives the updated technology stack section from package.json, including framework versions (e.g., Next.js/React/Tailwind as referenced in the example prompt)

Wrap-up

  • The constitution run establishes “walls/boundaries” so later commands and generated code remain compliant.
  • Next lesson: making a spec for a new feature.

Main speakers / sources

  • Speaker: The video presenter (single narrator guiding setup and commands)
  • Source technology/tooling: GitHub Spec Kit via Copilot, specifically the /constitution command and its underlying “constitution prompt”

Original video