update-code

An application-layer code updater that applies approved changes to a Python application's commands, queries, and operational code.

In plain words
What is it for?
Use it after application update reports have been refreshed to gather changes, implement them in the application package, and review the result.
Why use it?
It removes the need to manually trace specification changes through application-service source files. It also provides an optional review step.

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/voro6yov/spec-driven-development/update-code
Any agent
npx skills add voro6yov/spec-driven-development --skill update-code
Clone the repo
git clone --depth 1 https://github.com/voro6yov/spec-driven-development

Made for: Claude Code, Codex.

Per session 48 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,324 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 $0.00048 $0.01324
Opus 5 $0.00024 $0.00662
Sonnet 5 $0.00010 $0.00265
Haiku 4.5 $0.00005 $0.00132

Measured yesterday against content hash 60836fdaed44, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

update-code 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.

plugins/application-spec/skills/update-code/SKILL.md · 94 lines

How it starts

The opening of the file, as written. The whole thing — 94 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are the application-layer code updater. After /update-specs has refreshed <stem>.application/updates.md and <stem>.application/ops-updates.md, this skill propagates those deltas into the application package source via gather → implement → review.

This skill is independently invocable (/application-spec:update-code <diagram> [--review]) and is run as part of Wave 2 of /spec-core:update-code (in parallel with persistence). It reads settled domain source; it edits only the application package; it never invokes another plugin.

The two-axis rule — the application layer is a no-op only when both the commands/queries axis (updates.md) and the ops axis (ops-updates.md) are empty — lives entirely inside @application-spec:code-brief-writer, which reads both reports. This skill does not parse either body; it only checks whether the brief-writer produced a brief.

Inputs & outputs

  • Reads <dir>/<stem>.application/updates.md (preflight). Resolves locations via @spec-core:target-locations-finder application. The agents own every other read, including the optional ops-updates.md.
  • The agents write the durable artifacts: code-brief.md (Phase 1), code-changes.md + source edits (Phase 2), code-review.md (Phase 3).

Workflow

Step 0 — Parse arguments

$ARGUMENTS carries <domain_diagram> [--review]. Set RUN_REVIEW=true iff --review is present anywhere; strip it and bind $DIAGRAM to the remaining positional. If none remains:

ERROR: /application-spec:update-code requires <domain_diagram>. Usage: /application-spec:update-code <domain_diagram> [--review]

Step 1 — Preflight

Derive <stem>/<dir> per spec-core:naming-conventions. Read <dir>/<stem>.application/updates.md. If missing, hard-fail:

ERROR: <stem>.application/updates.md not found. Run `/update-specs <domain_diagram>` before `/update-code`.

(The ops-axis report <stem>.application/ops-updates.md is optional — its presence/absence is the brief-writer's concern, not a preflight gate here.)

Read the full file on GitHub · 94 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. yesterday First seen · 94 lines · 48 tokens per session scan A 60836fdaed44

Subscribe to this mod's changes

update-code is a skill published in the GitHub repository voro6yov/spec-driven-development (4 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 48 tokens to every session and 1,324 once invoked, about $0.0002 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.

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