Agent skill · operations · github
github-codespaces-efficiency
Audit and improve GitHub Codespaces efficiency. Use this skill when a user wants faster Codespaces startup, lower Codespaces spend, slim devcontainers, right-size machines, tune idle timeout, or scope prebuilds to branches with sustained usage.
Why this skill is useful
Provides specific guidance on optimizing GitHub Codespaces configurations, including machine sizing and prebuild strategies that the AI wouldn't reliably generate on its own.
What it needs
Requires gh installed locally. About 3k tokens when loaded. Last updated 2026-08-07. 37,534 stars on the source repository.
What this skill does
GitHub Codespaces Efficiency Use this skill as a lean entrypoint for GitHub Codespaces efficiency work. Inspect the repo, identify waste, and load only needed references. If no .devcontainer/ exists yet, load references/codespaces.md and define a baseline before proceeding with the steps below. Use This Skill When The user wants faster Codespaces startup or lower Codespaces spend. The repo has a .devcontainer/ or explicit Codespaces configuration questions. The user asks for devcontainer optimization, machine sizing, prebuild strategy, or idle-timeout guidance. The user is setting up Codespaces for the first time or needs help creating a new .devcontainer/ from scratch. Load Only What You Need references/codespaces.md — devcontainer, machine-sizing, prebuild, idle-timeout guidance, and reporting. references/review-rubric.md — load only for review passes. Core Workflow 1. Measure first If gh auth fails or the user lacks repo admin scope, proceed with static analysis of .devcontainer/ files; mark machine-type and prebuild recommendations as unverified. Look for: devcontainer image >2 GB or more than 10 features, machine type larger than usage data supports, missing devcontainer-lock.json (recommend adding — many repos predate lock-file support), prebuilds scoped too broadly, and idle timeout mismatched to usage patterns. 2. Apply guardrails Check each proposed fix against these rules before recommending it: 1. Does not remove tools the team uses every day — drop any fix that strips required development tools or extensions. 2. Does not assume smaller is always better — balance machine cost against developer experience and throughput. 3. Does not turn the devcontainer into a production image — drop any fix that adds production-only dependencies unless the team explicitly requires it. 4. Incremental changes preferred — a greenfield baseline is appropriate only when no .devcontainer/ exists; flag (do not drop) changes that restructure an existing config. 5. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills github/github-codespaces-efficiency