implement

A specification-led method for implementing coding work from written requirements, while keeping plans, project rules, and evidence in separate files. A specification is a written description of what the work must do.

In plain words
What is it for?
Use it when starting a feature or ticket, deciding how to begin, incorporating review comments, or setting up the method's document structure.
Why use it?
It keeps the intended behavior visible during implementation and carries review feedback back into the work.

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/michaelycjo/specseal/implement
Any agent
npx skills add MichaelYcJo/SpecSeal --skill implement
Clone the repo
git clone --depth 1 https://github.com/MichaelYcJo/SpecSeal

Made for: Claude Code, Codex.

Per session 131 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 6,678 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 $0.00131 $0.06678
Opus 5 $0.00066 $0.03339
Sonnet 5 $0.00026 $0.01336
Haiku 4.5 $0.00013 $0.00668

Measured 2d ago against content hash 509b27ff5408, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

implement 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 2d 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.

skills/implement/SKILL.md · 527 lines

How it starts

The opening of the file, as written. The whole thing — 527 lines — stays where its author put it; the contents beside it link to each section on GitHub.

implement — spec-driven implementation

Methodology for implementing against written specs, leaving durable evidence, and closing the loop with review. Loaded by the smith agent; usable directly.

Document layout — three axes

Every artifact this skill produces goes to exactly one of three roots, split by lifetime, not by who wrote it:

Root Lifetime Test Authority
docs/ Permanent, cumulative Must still be true in 6 months Norms, ratified by humans. Read when the repository has them; never created here — a project's documentation convention is its own
specs/ One work item Its role ends when this work ships (SDD, overview) The contract this work executes against. A human approves plan.md, which is why this is a repository document and not tool state
.specseal/ Mixed — see below Everything this plugin maintains Written and read by machines: the map, the migration config, the follow-up list, task lists

The axis is lifetime and authority, not audience — humans and AI read all three. (Labeling policies "for humans" would push sessions away from reading them, and policy outranks everything else when a repository has it.)

.specseal/ is committed — gitignored files do not follow worktrees or other machines — and its existence is what tells the gates this repository runs the workflow. Inside it, lifetimes differ:

.specseal/
├── map.md            permanent — spec clause ↔ code coordinates (split into map/ if it grows)
├── parity.md         permanent — migration config, only when declared
├── follow-up.md      permanent — schedulable items in a repository with no tracker
└── tasks/            one change

The review round records are not here. They live beside the work item they are about, in specs/<work-item-id>/, together with the routing declaration and the rest of the SDD set:

specs/<work-item-id>/
├── routing.md        the routing answer, written before the first edit
├── spec.md · plan.md · questions.md · overview.md
├── round-N.md        one review round — closed at merge and kept
└── tests-todo.md · evidence-todo.md

Read the full file on GitHub · 527 lines

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. 2d ago First seen · 527 lines · 131 tokens per session scan A 509b27ff5408

Subscribe to this mod's changes

implement is a skill published in the GitHub repository MichaelYcJo/SpecSeal (1 stars, last pushed 2d ago), licensed MIT. It adds 131 tokens to every session and 6,678 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.

Related

Other skills, from other repositories

gsd-audit-milestone

Audit milestone completion against original intent before archiving.

open-gsd/gsd-core · 17 tokens

spec-kitty-charter-doctrine

Run charter interview, generation, context, and sync workflows for project governance in Spec Kitty 3.x. Access doctrine artifacts programmatically via DoctrineService. Resolve agent profiles. Load action-scoped governance context iteratively, not all at once. Triggers: "interview for charter", "generate charter"…

Priivacy-ai/spec-kitty · 135 tokens

conductor-implement

Executes the tasks defined in the specified track's plan. Use this to start or continue working on a feature, bug fix, or chore.

gemini-cli-extensions/conductor · 34 tokens

api-design

Design or review an HTTP/REST/GraphQL API for versioning, pagination, error shapes, idempotency, auth, status codes, cache headers, and breaking-change management. Use when asked to "design an API", "shape the endpoints", "design the schema", "add a new endpoint", "review this API", or when building/modifying a public…

open-gsd/gsd-pi · 91 tokens

create-mcp-server

Build, iterate, and evaluate Model Context Protocol (MCP) servers that expose external services as tools an LLM can call. Covers schema/tool design, error handling, pagination, MCP Inspector testing, and an eval set. Use when asked to "build an MCP server", "create an MCP tool", "wrap this API as MCP", "expose X to…

open-gsd/gsd-pi · 90 tokens

dependency-upgrade

Plan, batch, and verify dependency upgrades safely. Triages outdated packages into risk tiers, upgrades in order (dev/minor/patch first, runtime majors last), verifies each batch, and produces an auditable commit sequence. Use when asked to "upgrade deps", "bump packages", "update nodemodules", "fix vulnerabilities"…

open-gsd/gsd-pi · 90 tokens