new-feature

new-feature is a skill for Claude Code, Codex from undeadlist/claude-code-agents. It costs 14 tokens per session (269 once invoked), scanned A, original, MIT.

A workflow for building a new feature with test-driven development, meaning tests are written before the feature code.

In plain words
What is it for?
Use it for new API, library, database, background-job, or interface features: define the requirements, write tests, implement the feature, run all tests, and perform browser checks when there is a user interface.
Why use it?
It turns a feature request into checked, repeatable behavior and helps reveal regressions before the work is considered complete.

Skill for Claude CodeCodex

Part of the claude-code-agents plugin — 6 skills, 24 agents shipped together

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/undeadlist/claude-code-agents/new-feature
Any agent
npx skills add undeadlist/claude-code-agents --skill new-feature
Clone the repo
git clone --depth 1 https://github.com/undeadlist/claude-code-agents

Made for: Claude Code, Codex.

Or install claude-code-agents, the plugin that ships this one along with the rest of its 6 skills, 24 agents.

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 new-feature

README.md
[![agentmods](https://agentmods.dev/badge/skills/undeadlist/claude-code-agents/new-feature.svg)](https://agentmods.dev/skills/undeadlist/claude-code-agents/new-feature)
Your own site
<a href="https://agentmods.dev/skills/undeadlist/claude-code-agents/new-feature"><img src="https://agentmods.dev/badge/skills/undeadlist/claude-code-agents/new-feature.svg" alt="Measured on agentmods" height="20"></a>
Per session 14 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 269 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 $0.00014 $0.00269
Opus 5 $0.00007 $0.00134
Sonnet 5 $0.00003 $0.00054
Haiku 4.5 $0.00001 $0.00027

Measured 4d ago against content hash c514e7abdd97, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

new-feature 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 4d 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/new-feature/SKILL.md · 53 lines

What it actually says

New Feature Workflow

Build features using test-driven development. Provide the feature specification when invoking.

Execution (Sequential)

Step 1: Write Tests

Spawn test-writer with the feature requirements:

  • Analyze feature specification
  • Write failing tests first
  • Cover happy path + edge cases

Step 2: Implement Feature

Spawn code-fixer with the feature requirements and test files:

  • Implement feature following existing patterns
  • Make all new tests pass

Step 3: Verify

Spawn test-runner:

  • Run all tests (new + existing)
  • Verify no regressions

Step 4: Browser QA (if UI feature)

Spawn browser-qa-agent:

  • Navigate to the new feature
  • Test interactions
  • Check for console errors

Usage

Provide feature requirements when invoking:

/new-feature

Feature: User profile update endpoint
- PUT /api/users/:id
- Allow updating: name, email, avatar
- Require authentication
- Validate email format
- Return updated user

Skip browser-qa for

  • Pure API features (no UI)
  • Library/utility code
  • Database migrations
  • Background jobs
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. 4d ago First seen · 53 lines · 14 tokens per session scan A c514e7abdd97

Subscribe to this mod's changes

new-feature is a skill published in the GitHub repository undeadlist/claude-code-agents (147 stars, last pushed 2mo ago), licensed MIT. It adds 14 tokens to every session and 269 once invoked, about $0.0001 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 2026-08-30.

Related

Other skills, from other repositories