sage

sage is a skill for Claude Code, Codex from gustavobarbosab/sage. It costs 122 tokens per session (1,111 once invoked), scanned A, a copy of sage, MIT.

A spec-first development workflow that turns a feature idea into a written specification, behavior scenarios, code, and supporting documents. SDD means designing from a written specification, while BDD describes expected behavior through scenarios.

In plain words
What is it for?
Use it to draft or update specifications, generate behavior scenarios and implementation files, prepare pull-request or documentation text, and create a project harness with /sage commands.
Why use it?
It reduces ambiguity before implementation by recording what the feature should do and how it should behave. It also keeps code, pull-request notes, and documentation tied to that agreed description.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions CLAUDE.md.

Good fit Use it to draft or update specifications, generate behavior scenarios and implementation files, prepare pull-request or documentation text, and create a project harness with /sage commands.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/gustavobarbosab/sage/claude
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 gustavobarbosab/sage --skill claude
Clone the repo
git clone --depth 1 https://github.com/gustavobarbosab/sage

Made for: Claude Code, Codex.

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 sage

README.md
[![agentmods](https://agentmods.dev/badge/skills/gustavobarbosab/sage/claude.svg)](https://agentmods.dev/skills/gustavobarbosab/sage/claude)
Your own site
<a href="https://agentmods.dev/skills/gustavobarbosab/sage/claude"><img src="https://agentmods.dev/badge/skills/gustavobarbosab/sage/claude.svg" alt="Measured on agentmods" height="20"></a>
Per session 122 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,111 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 100% copy Near-identical to another mod 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 $0.00122 $0.01111
Opus 5 $0.00061 $0.00556
Sonnet 5 $0.00024 $0.00222
Haiku 4.5 $0.00012 $0.00111

Measured 8d ago against content hash c31ab0352a62, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

sage 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 8d ago.

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.

Origin

This is a copy

100% identical to sage — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skill/claude/SKILL.md · 93 lines

How it starts

The opening of the file, as written. The whole thing — 93 lines — stays where its author put it; the contents beside it link to each section on GitHub.

SAGE

Spec · Assert · Generate · Export

A spec-first workflow that combines SDD, BDD, and Harness Engineering to front-load thinking and back-load generation.

spec.md  →  behavior.md  →  code       →  pr.md + doc.md
 (you)      (you + AI)      (you + AI)     (AI + you)

Commands

The user interacts with SAGE using /sage <command> [argument].

Command Argument Reference file Output
/sage spec <description> Feature description, ticket text, or idea references/spec.md Interview → spec.md + behavior.md
/sage behavior (none — reads spec.md) references/behavior.md behavior.md (standalone regeneration)
/sage code (none — reads spec.md + behavior.md) references/code.md Implementation files
/sage update <feedback> Precise feedback tied to spec or behavior references/update.md Updated files
/sage pr (none — reads full context) references/pr.md pr.md
/sage doc (none — reads full context) references/doc.md doc.md
/sage harness init (none — interactive wizard) references/harness-init.md .sage/harness.md
/sage harness generate (none — reads codebase files) references/harness-generate.md .sage/harness.md
/sage harness review (none — reads harness.md) references/harness-review.md Review report

How to handle each command

When the user types a /sage command:

  1. Identify the sub-command from the table above
  2. Read the corresponding reference file — it contains the full prompt and instructions for that step
  3. Extract the inline argument if provided (e.g. /sage spec "Login screen with email and password" → argument is "Login screen with email and password")
  4. Execute the step following the reference file instructions

If the user types /sage with no sub-command, show the command table above and ask which step they want to run.

Special flow for /sage spec

Read the full file on GitHub · 93 lines

Files

What ships with it

11 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. 8d ago First seen · 93 lines · 122 tokens per session scan A c31ab0352a62

Subscribe to this mod's changes

sage is a skill published in the GitHub repository gustavobarbosab/sage (2 stars, last pushed 2mo ago), licensed MIT. It adds 122 tokens to every session and 1,111 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to sage, differing in 0 lines, and is treated as a copy.

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