eg-new-feature

eg-new-feature is a skill for Codex from vshvedov/elephant-goldfish. It costs 27 tokens per session (2,403 once invoked), scanned A, original, MIT.

A workflow for building a new software feature from a description or GitHub issue. It creates a design document, checks that design against the codebase, implements the feature, reviews it, and validates the result.

In plain words
What is it for?
It helps turn feature ideas into designs and code across areas such as user interfaces, APIs, databases, background jobs, integrations, and generated code.
Why use it?
It reduces the risk of designing a feature that conflicts with existing screens, APIs, data, permissions, conventions, or project priorities.

Skill for Codex

Written for Codex: agents/openai.yaml present. Also seen: mentions CLAUDE.md; mentions subagents; mentions AGENTS.md.

Good fit It helps turn feature ideas into designs and code across areas such as user interfaces, APIs, databases, background jobs, integrations, and generated code.

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Install with agentmods
npx agentmods add skills/vshvedov/elephant-goldfish/eg-new-feature
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 vshvedov/elephant-goldfish --skill eg-new-feature
Clone the repo
git clone --depth 1 https://github.com/vshvedov/elephant-goldfish

Made for: 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 eg-new-feature

README.md
[![agentmods](https://agentmods.dev/badge/skills/vshvedov/elephant-goldfish/eg-new-feature/github.svg)](https://agentmods.dev/skills/vshvedov/elephant-goldfish/eg-new-feature)
Your own site
<a href="https://agentmods.dev/skills/vshvedov/elephant-goldfish/eg-new-feature"><img src="https://agentmods.dev/badge/skills/vshvedov/elephant-goldfish/eg-new-feature/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for eg-new-feature

Your own site · 80×15
<a href="https://agentmods.dev/skills/vshvedov/elephant-goldfish/eg-new-feature"><img src="https://agentmods.dev/badge/skills/vshvedov/elephant-goldfish/eg-new-feature.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 27 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,403 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00027 $0.02403
Opus 5 $0.00014 $0.01202
Sonnet 5 $0.00005 $0.00481
Haiku 4.5 $0.00003 $0.00240

Measured 12d ago against content hash 8171cb2adc23, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

eg-new-feature scanned grade A with 1 finding 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 12d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

For UI changes, drive the feature in the browser or simulator before reporting it done. For backend-only changes, use focused tests, curl/API checks, logs, or equivalent runtime verification.
codex/skills/eg-new-feature/SKILL.md · 184 lines

How it starts

The opening of the file, as written. The whole thing — 184 lines — stays where its author put it; the contents beside it link to each section on GitHub.

EG New Feature Skill

Build a new feature using the elephant/goldfish workflow. Use the user's text around the $eg-new-feature skill mention as the feature description. If no description is provided, ask for one.

If the feature description is a GitHub issue URL or #<number>, fetch it with gh issue view <number> --json title,body,labels,comments and seed the design doc from it.

Before designing, check AGENTS.md/CLAUDE.md for project-specific eg-* skills or workflow routing notes. If the request clearly belongs to a more specific local workflow, tell the user and switch only if they agree.

Scope

Restate the request in one or two sentences and ask the user to confirm if the request is ambiguous or high-impact. For a sharp request, proceed after the restatement.

Do a surface-area sanity check based on the current repo: UI, API, database/schema, background job, external integration, generated code, mobile/platform-specific work, or backend-only logic. Stop for confirmation when the request appears high-impact, destructive, cross-tenant/auth-sensitive, or out of phase with documented project priorities.

Design Doc

Print a design doc before coding. For substantial features, infer a project-appropriate docs path from AGENTS.md/CLAUDE.md or docs/, then ask before saving it.

DESIGN DOC
- Why: <user problem this solves>
- Scope: <in scope and explicitly out>
- Surfaces touched: <files, routes, models, components, jobs, external services>
- Interfaces: <props, signatures, API shapes, DB columns, event payloads>
- UX flow: <click-by-click for UI or request-by-request for backend>
- Project-specific constraints: <auth/scoping, lifecycle, generated code, platform, performance, or other constraints discovered from the repo>
- Failure modes: <what breaks and what the user/API sees>
- Verification criteria: <unit tests, integration/E2E, manual Browser Use/simulator steps>
- Out-of-scope follow-ups: <noted, not built>

For UI work, sketch the structure in plain text or pseudo-JSX. If a visual reference is needed, ask for the existing component or screen to mirror.

Read the full file on GitHub · 184 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. 12d ago First seen · 184 lines · 27 tokens per session scan A 8171cb2adc23

Subscribe to this mod's changes

eg-new-feature is a skill published in the GitHub repository vshvedov/elephant-goldfish (44 stars, last pushed 4mo ago), licensed MIT. It adds 27 tokens to every session and 2,403 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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