gbg

gbg is a skill for Claude Code, Codex from cielebak/goal-by-goal. It costs 150 tokens per session (2,574 once invoked), scanned A, original, MIT.

A planning workflow that turns a product requirements document, feature idea, or brief into ordered development goals. Each goal includes tasks, success conditions, and a review before the next goal or commit.

In plain words
What is it for?
Use it to plan features, minimum viable products, migrations, refactors, or security work that can be divided into reviewable milestones.
Why use it?
It removes uncertainty from large changes by making the work smaller and checking each part before continuing. A PRD is a document describing what a product or feature should do.

Skill for Claude CodeCodex

Written for Claude Code and Codex: shipped in a Claude Code plugin, but also runs codex exec. Also seen: mentions CLAUDE.md; mentions Codex.

Part of the goal-by-goal plugin — 1 skill shipped together

Good fit Use it to plan features, minimum viable products, migrations, refactors, or security work that can be divided into reviewable milestones.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/cielebak/goal-by-goal/gbg
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add cielebak/goal-by-goal --skill gbg
Clone the repo
git clone --depth 1 https://github.com/cielebak/goal-by-goal

Made for: Claude Code, Codex.

Or install goal-by-goal, the plugin that ships this one along with the rest of its 1 skill.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for gbg

README.md
[![agentmods](https://agentmods.dev/badge/skills/cielebak/goal-by-goal/gbg/github.svg)](https://agentmods.dev/skills/cielebak/goal-by-goal/gbg)
Your own site
<a href="https://agentmods.dev/skills/cielebak/goal-by-goal/gbg"><img src="https://agentmods.dev/badge/skills/cielebak/goal-by-goal/gbg/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for gbg

Your own site · 80×15
<a href="https://agentmods.dev/skills/cielebak/goal-by-goal/gbg"><img src="https://agentmods.dev/badge/skills/cielebak/goal-by-goal/gbg.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 150 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,574 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00150 $0.02574
Opus 5 $0.00075 $0.01287
Sonnet 5 $0.00030 $0.00515
Haiku 4.5 $0.00015 $0.00257

Measured 11d ago against content hash 0f7deb4efa59, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

gbg scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (templates/gbg-review.sh), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/gbg/SKILL.md · 214 lines

How it starts

The opening of the file, as written. The whole thing — 214 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Goal-by-Goal Plan

Convert an unstructured plan, PRD, or conversation context into a goal-by-goal execution document with a strict reviewer gate between goals. Implementation agent (Claude) executes one goal at a time. Reviewer agent (Codex / human senior) reviews read-only after each goal. Commit only on PASS.

When to use

  • Building a feature that splits into a few independently shippable steps
  • Greenfield MVPs that decompose into 5–12 reviewable milestones
  • Multi-week migrations (platform parity, framework upgrades, stack swaps)
  • Large refactors with clear surface area
  • Security hardening / compliance work
  • Any development where "did we actually do it correctly?" needs a second pair of eyes between commits

When NOT to use

  • One-shot bugfixes
  • Exploratory spikes without success criteria
  • Pure design exploration
  • Trivial single-file changes

Process

1. Locate the source plan

Ask user where the plan lives. Accept any of:

  • A PRD file path
  • A GitHub issue URL (gh issue view <n> --comments)
  • A conversation summary in chat
  • A bullet list

If unclear, ask: "Where does the plan live, or should I draft it from this conversation?"

2. Gather project parameters

Ask user (one block, not one-by-one):

  1. Project scope name (kebab-case, used in paths and commit scope). E.g. android-parity, react-to-solid, auth-hardening.
  2. Reviewer — ask the user, present Codex as the default and recommended choice. Offer Claude as a second option, and let them type anything else (GPT / human senior / multi-reviewer) by hand. The choice drives how the review gate runs:
    • Codex (or any CLI reviewer) → the generated scripts/gbg-review.sh wrapper (codex exec --sandbox read-only).
    • Claude → spawn a read-only review Agent/Task with the reviewer prompt; save its verdict to the same docs/<scope>/reviews/goal-XX-<reviewer>.md.
    • Anything else → run the reviewer manually with the prompt; save the verdict to the same path.
  3. Required checks — exact bash commands per platform (build, test, lint). E.g. ./gradlew :app:assembleDebug, xcodebuild test ..., npm test.
  4. Locked decisions — things the user does NOT want re-litigated mid-execution (stack choices, scope boundaries, out-of-scope items).
  5. Current state summary — known issues, gaps, anything pre-existing.
  6. Language — copy in PL or EN? (Default EN for code/docs, PL for user-facing strings if iOS/Android app.)
  7. Target goal count — 5–12 typical. Default 8.

Read the full file on GitHub · 214 lines

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 11d ago First seen · 214 lines · 150 tokens per session scan A 0f7deb4efa59

Subscribe to this mod's changes

gbg is a skill published in the GitHub repository cielebak/goal-by-goal (1 stars, last pushed 2mo ago), licensed MIT. It adds 150 tokens to every session and 2,574 once invoked, about $0.0007 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.