Eval-Driven Development Harness
affaan-m/ECC
Sets up eval-driven development for Claude Code workflows: capability and regression evals, three grader types and pass@k reliability metrics.
Evaluate two or more Happier instruction, constitution, or skill variants with blinded organic tasks, controlled context, behavior-based scoring, privacy-safe evidence, and an advisory synthesis.
$ npx skills add happier-dev/happier --skill happier-instruction-eval -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install happier-dev/happier happier-instruction-eval --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/happier-dev/happier.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/happier-instruction-eval .claude/skills/happier-instruction-eval && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "happier-instruction-eval" agent skill from https://github.com/happier-dev/happier/tree/dev/.agents/skills/happier-instruction-eval into .claude/skills/happier-instruction-eval/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "happier-instruction-eval", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/happier-dev/happier/tree/dev/.agents/skills/happier-instruction-evalType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add happier-dev/happier --skill happier-instruction-eval -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install happier-dev/happier happier-instruction-eval --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/happier-dev/happier.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/happier-instruction-eval .agents/skills/happier-instruction-eval && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "happier-instruction-eval" agent skill from https://github.com/happier-dev/happier/tree/dev/.agents/skills/happier-instruction-eval into .agents/skills/happier-instruction-eval/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "happier-instruction-eval", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add happier-dev/happier --skill happier-instruction-eval -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install happier-dev/happier happier-instruction-eval --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/happier-dev/happier.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/happier-instruction-eval .cursor/skills/happier-instruction-eval && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "happier-instruction-eval" agent skill from https://github.com/happier-dev/happier/tree/dev/.agents/skills/happier-instruction-eval into .cursor/skills/happier-instruction-eval/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "happier-instruction-eval", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/happier-dev/happier.git --path .agents/skills/happier-instruction-eval--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add happier-dev/happier --skill happier-instruction-eval -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install happier-dev/happier happier-instruction-eval --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/happier-dev/happier.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/happier-instruction-eval .gemini/skills/happier-instruction-eval && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "happier-instruction-eval" agent skill from https://github.com/happier-dev/happier/tree/dev/.agents/skills/happier-instruction-eval into .gemini/skills/happier-instruction-eval/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "happier-instruction-eval", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install happier-dev/happier happier-instruction-evalInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add happier-dev/happier --skill happier-instruction-eval -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/happier-dev/happier.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/happier-instruction-eval .github/skills/happier-instruction-eval && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "happier-instruction-eval" agent skill from https://github.com/happier-dev/happier/tree/dev/.agents/skills/happier-instruction-eval into .github/skills/happier-instruction-eval/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "happier-instruction-eval", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add happier-dev/happier --skill happier-instruction-eval -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install happier-dev/happier happier-instruction-eval --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/happier-dev/happier.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/happier-instruction-eval .opencode/skills/happier-instruction-eval && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "happier-instruction-eval" agent skill from https://github.com/happier-dev/happier/tree/dev/.agents/skills/happier-instruction-eval into .opencode/skills/happier-instruction-eval/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "happier-instruction-eval", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
happier-instruction-evalEvaluate two or more Happier instruction, constitution, or skill variants with blinded organic tasks, controlled context, behavior-based scoring, privacy-safe evidence, and an advisory synthesis.
Happier Instruction Eval is an agent skill from happier-dev/happier. Evaluate two or more Happier instruction, constitution, or skill variants with blinded organic tasks, controlled context, behavior-based scoring, privacy-safe evidence, and an advisory synthesis. Use only when the user explicitly asks to compare/evaluate instruction variants or an approved instruction program names an evaluation boundary.
Its SKILL.md is about 1.3k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
The repository describes itself as: Web, Desktop & Mobile client and orchestrator for Codex, Claude Code, OpenCode, Pi, Cursor, Grok, Antigravity, Kimi, Augment Code, Qwen, fully end-to-end encrypted. The licence is MIT.
6 steps, taken from the step headings in SKILL.md.
Read from SKILL.md and the folder at commit 493820f. It shows what the files ask for, not the result of running them.
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Happier Instruction Eval loads about 1.3k tokens when it runs. Until then it costs about 91 tokens; SKILL.md has 631 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
The full file from happier-dev/happier at commit 493820f, republished under its MIT licence (© happier-dev). 631 words, ~1,266 tokens.
.claude/skills/happier-instruction-eval/SKILL.md (or your agent's skills folder).Evaluate whether instruction wording changes agent behavior without telling the agents they are being evaluated. This workflow is advisory: it produces evidence for a human decision and never edits the canonical instruction owner by itself.
Name:
Do not evaluate prose elegance in isolation. A useful task forces the instruction to affect routing, investigation, ownership, implementation shape, validation, stopping, or reporting. Skip evaluation when a source inspection or deterministic check can decide the question directly.
Hold constant everything except the instruction variant when practical:
Do not freeze or package a release representation. Temporary instruction variants and isolated outputs are test inputs, not release artifacts.
Each runner receives an organic-looking engineering request, not an evaluation brief. Do not mention the rubric, competing variants, expected lesson, or favored outcome. Do not ask the runner whether it followed the instruction.
Use minimal inherited conversation context. Never expose private transcripts, credentials, customer data, or unrelated work. Prefer synthetic tasks, public evidence, or bounded repository tasks. Historical conversations require explicit sensitive-data authorization and sanitization.
If an assigned tool or model differs between runs, record that as a confound rather than treating model agreement or disagreement as proof. Use repeated trials only when outcome variability is decision-material; never manufacture a fixed sample count.
Inspect what each run actually did:
Score each rubric item from the artifacts and tool evidence. A polished explanation or claimed compliance is not evidence. Mark unavailable observations and confounds explicitly.
Give one judge all outputs under neutral labels and the same precommitted rubric. The judge must:
The orchestrator re-derives decision-material claims from the underlying artifacts. Agreement between runners, judge, and orchestrator raises a question's priority; it does not replace evidence.
Report:
Use the final response unless the user requested durable evaluation tracking. Do not create a new report file, update AGENTS.md, or propagate a variant to another repository without explicit change authority. If an accepted change affects the 0.2 source line, use .agents/skills/happier-port-0-2-to-0-3 for its destination disposition.
© happier-dev, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Just SKILL.md in .agents/skills/happier-instruction-eval of happier-dev/happier.
Open the folder on GitHubat commit 493820f
Happier Instruction Eval next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Happier Instruction Eval this skillhappier-dev/happier | 1.9k | — | ~1.3k | Automated safety check: Pass | MIT | |
| Eval-Driven Development Harnessaffaan-m/ECC | 274k | — | ~1.5k | Automated safety check: Pass | MIT | |
| Evalalirezarezvani/claude-skills | 28k | 1 repos | ~618 | Automated safety check: Pass | MIT | |
| Eval Harnessaffaan-m/ECC | 274k | — | ~2.2k | Automated safety check: Pass | MIT | |
| Harness Evaltech-leads-club/agent-skills | 7k | — | ~3.9k | Automated safety check: Pass | CC-BY-4.0 | |
| Eval Harnessaffaan-m/ECC | 274k | 1 repos | ~1.7k | Automated safety check: Pass | MIT |
affaan-m/ECC
Sets up eval-driven development for Claude Code workflows: capability and regression evals, three grader types and pass@k reliability metrics.
alirezarezvani/claude-skills
Evaluate and rank agent results by metric or LLM judge for an AgentHub session.
affaan-m/ECC
Eval-driven development (EDD) framework for AI coding sessions — define capability and regression evals before coding, grade with code-based, model-based, rule, or human graders, and track pass@k…
tech-leads-club/agent-skills
Evaluates a repository's agent harness (AGENTS.md, rules, skills) for broken paths, redundant instructions and usefulness, and stops at reports.
affaan-m/ECC
Eval-driven development (EDD) ilkelerini uygulayan Claude Code oturumları için formal değerlendirme çerçevesi
diegosouzapw/OmniRoute
Creates and runs LLM evaluation suites from the omniroute CLI, follows live runs, shows scorecards, compares models and ties eval runs into CI.
happier-dev/happier
Conduct evidence-backed Happier code, plan-completeness, session, worktree, feature, commit, branch, PR, codebase, and release-readiness reviews with affected-corridor analysis, high-confidence…
happier-dev/happier
Stabilize failing, flaky, slow, or repeatedly rerun Happier CI and nightlies by collecting all reachable failures from one exact attempt, correcting canonical causes in one batch, simplifying…
happier-dev/happier
Reconnoiter, classify, validate, group, and commit a large or continuously changing Happier worktree as coherent, human-understandable commits while preserving concurrent work and excluding…
happier-dev/happier
Resolve Happier's private release authority and run an exact-SHA release or nightly through cheap admission, verified CI evidence, resumable immutable candidates, and terminal publication proof.
happier-dev/happier
Diagnose and explain a Happier runtime, session, daemon, provider (Claude/Codex/OpenCode), authentication, or connectivity incident from logs, structured diagnostics, runtime state, and source…
happier-dev/happier
Implement, change, build, fix, refactor, migrate, or apply accepted review findings in the Happier repositories with canonical-owner discovery, scope-preserving solution economy, TDD, efficient…
Evaluate two or more Happier instruction, constitution, or skill variants with blinded organic tasks, controlled context, behavior-based scoring, privacy-safe evidence, and an advisory synthesis. Happier Instruction Eval is an agent skill from happier-dev/happier. Evaluate two or more Happier instruction, constitution, or skill variants with blinded organic tasks, controlled context, behavior-based scoring, privacy-safe evidence, and an advisory synthesis.
Happier Instruction Eval fits situations like: explicitly asks to compare/evaluate instruction variants; an approved instruction program names an evaluation boundary.
Run `npx skills add happier-dev/happier --skill happier-instruction-eval -a claude-code`. Or copy the skill folder (.agents/skills/happier-instruction-eval in happier-dev/happier) into .claude/skills/happier-instruction-eval in your project. Claude Code loads it when a task matches its description.
Run `npx skills add happier-dev/happier --skill happier-instruction-eval -a codex`. Or copy the skill folder (.agents/skills/happier-instruction-eval in happier-dev/happier) into .agents/skills/happier-instruction-eval in your project. Codex loads it when a task matches its description.
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add happier-dev/happier --skill happier-instruction-eval -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/happier-instruction-eval, .gemini/skills/happier-instruction-eval, .github/skills/happier-instruction-eval and .opencode/skills/happier-instruction-eval in your project.
SKILL.md names no scripts, command-line tools or credentials: Happier Instruction Eval is instructions for the agent only.
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
Happier Instruction Eval is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
About 1.3k tokens (SKILL.md is roughly 5.1k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
Skills that share tags, products or a category with Happier Instruction Eval: Eval-Driven Development Harness (affaan-m/ECC, 274k stars), Eval (alirezarezvani/claude-skills, 28k stars), Eval Harness (affaan-m/ECC, 274k stars) and Harness Eval (tech-leads-club/agent-skills, 7k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
happier-dev (a GitHub organization) maintains it in happier-dev/happier, which has 1,876 GitHub stars. The repository holds 28 skills in this directory. The repository was last updated on October 7, 2026.
Source: happier-dev/happier on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.