sdd-apply

An execution role for implementing software tasks from written specifications and design documents. SDD means specification-driven development.

In plain words
What is it for?
Use it when an orchestrator assigns one or more implementation tasks that must follow an existing specification and design.
Why use it?
It defines what the implementation agent receives, how it should carry out the work, and how it should save the results.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/gentleman-programming/gentle-ai/sdd-apply
Any agent
npx skills add Gentleman-Programming/gentle-ai --skill sdd-apply
Clone the repo
git clone --depth 1 https://github.com/Gentleman-Programming/gentle-ai

Made for: Claude Code, Codex.

Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,122 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00000 $0.04122
Opus 5 $0.00000 $0.02061
Sonnet 5 $0.00000 $0.00824
Haiku 4.5 $0.00000 $0.00412

Measured yesterday against content hash 313584863f1a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

sdd-apply 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 yesterday.

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.

internal/assets/skills/sdd-apply/SKILL.md · 339 lines

How it starts

The opening of the file, as written. The whole thing — 339 lines — stays where its author put it; the contents beside it link to each section on GitHub.


name: sdd-apply description: "Implement SDD tasks from specs and design. Trigger: orchestrator launches apply for one or more change tasks." disable-model-invocation: true user-invocable: false license: MIT metadata: author: gentleman-programming version: "3.0" delegate_only: true

Execution Role

Confirm your role before acting. You are the dedicated sdd-apply sub-agent unless you loaded this skill directly through the skill() tool.

  • If you are the sdd-apply sub-agent, continue with the phase work below. Do not delegate. Do not call the Skill tool.
  • If you loaded this skill through the skill() tool, you are the orchestrator. Stop here and delegate to the dedicated sdd-apply sub-agent using your platform's delegation primitive (for example, task(...) or a sub-agent invocation).

Language Domain Contract

Generated technical artifacts default to English. Do not inherit the user's conversational language or the active persona's regional voice for SDD artifacts unless the user explicitly requests that artifact language or the project convention requires it.

If technical artifacts are explicitly requested in another language, use a neutral/professional register unless the user explicitly requests a different tone or regional variant.

Public/contextual comments follow the target context language by default. Explicit user language or tone overrides win; otherwise use a neutral/professional register unless the target context clearly calls for another tone or regional variant.

Purpose

You are a sub-agent responsible for IMPLEMENTATION. You receive specific tasks from tasks.md and implement them by writing actual code. You follow the specs and design strictly.

What You Receive

From the orchestrator:

  • Change name
  • The specific task(s) to implement (e.g., "Phase 1, tasks 1.1-1.3")
  • Artifact store mode as REPORTED by native status (engram | openspec | hybrid | none) — consume it, never re-derive it
  • Structured status from skills/_shared/sdd-status-contract.md: schemaName, planningHome, changeRoot, artifactPaths, contextFiles, applyState, task progress, dependency states, and actionContext
  • Delivery strategy and resolved workload decision (ask-on-risk | auto-chain | single-pr | exception-ok, plus PR slice or size:exception when applicable)

Read the full file on GitHub · 339 lines

Files

What ships with it

1 file 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. yesterday First seen · 339 lines · 0 tokens per session scan A 313584863f1a

Subscribe to this mod's changes

sdd-apply is a skill published in the GitHub repository Gentleman-Programming/gentle-ai (6,080 stars, last pushed yesterday), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 4,122 tokens. 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 2026-08-30.

Related

Other skills, from other repositories

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

next-cache-components-adoption

Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…

vercel/next.js · 95 tokens

babysit-pr

Babysit a GitHub pull request after creation by continuously polling review comments, CI checks/workflow runs, and mergeability state until the PR is merged/closed or user help is required. Diagnose failures, retry likely flaky failures up to 3 times, auto-fix/push branch-related issues when appropriate, and keep…

openai/codex · 114 tokens

imagegen

Generate or edit raster images when the task benefits from AI-created bitmap visuals such as photos, illustrations, textures, sprites, mockups, or transparent-background cutouts. Use when Codex should create a brand-new image, transform an existing image, or derive visual variants from references, and the output…

openai/codex · 113 tokens

cpu-profile-analysis

Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…

microsoft/vscode · 71 tokens

next-cache-components-optimizer

Drive a Next.js route to instant navigation by setting up an agentic loop, under Cache Components / PPR, on initial load (hard navigation) and client-side navigation (soft navigation). Encode the goal as a failing @next/playwright instant() e2e and work it to green, one verified route at a time; the shipped test then…

vercel/next.js · 170 tokens