What is mock-data-maintainer?

A skill for creating realistic, reusable sample data such as test records, demo content, screenshots, CSV files, JSON, SQL, or TypeScript fixtures.

Use it to prepare data for local development, bug reproduction, automated tests, product demos, screenshots, and workflow examples.

It avoids random or inconsistent placeholder data that can make tests, demos, and explanations hard to trust.

How Undertone0809/rudder configures Claude Code and Codex

Reuse

Borrowing it

Nothing to install: this file belongs to Undertone0809/rudder. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/Undertone0809/rudder/main/.agents/skills/maintainer/mock-data-maintainer/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/Undertone0809/rudder

Made for: Claude Code, 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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/undertone0809/rudder/mock-data-maintainer/github.svg)](https://agentmods.dev/skills/undertone0809/rudder/mock-data-maintainer)

Your own site

<a href="https://agentmods.dev/skills/undertone0809/rudder/mock-data-maintainer"><img src="https://agentmods.dev/badge/skills/undertone0809/rudder/mock-data-maintainer/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/undertone0809/rudder/mock-data-maintainer"><img src="https://agentmods.dev/badge/skills/undertone0809/rudder/mock-data-maintainer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 50 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,834 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits

NVIDIA SkillSpector warn 7 Sept 2026

SkillSpector: 1 finding, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

high System Prompt Leakage · line 30
Skill contains instructions that could directly expose system prompts, internal rules, or hidden instructions to users or external parties.

Fix: Remove any instructions that reveal, print, or output system prompts or internal rules. System instructions should never be exposed to end users.

How audits are shown

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.

Model	Per session	Once invoked
Fable 5.1	$0.00050	$0.02834
Opus 5.5	$0.00020	$0.01134
Sonnet 5.5	$0.00010	$0.00567
Haiku 4.5	$0.00005	$0.00283

Measured 2mo ago against content hash 7bc158276b12, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

mock-data-maintainer 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 2mo ago.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/capture-landing-proof-shots.ts, scripts/seed-rudder-studio.ts), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

.agents/skills/maintainer/mock-data-maintainer/SKILL.md · 316 lines

How it starts

The opening of the file, as written. The whole thing — 316 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Mock Data Maintainer

Use this skill to create mock data that is useful, coherent, and easy to reuse. The goal is not random fake records. The goal is scenario data that supports testing, screenshots, demos, and clear user understanding.

First Decision

Classify the request into one primary intent before generating data:

testing data: local dev, E2E, bug reproduction, contract checks, edge states
screenshot/demo data: local screenshots, landing proof shots, README, decks
user-scenario data: explain a workflow, persona, problem, or product value
static artifact data: CSV, JSON, SQL, Markdown table, or TypeScript fixture

If the prompt implies multiple intents, produce one shared scenario spine and then adapt outputs for each intent. For example, one Rudder launch-week org can serve local screenshots, workflow explanation, and E2E fixture design.

Reference Selection

Read only the references needed for the request:

references/scenario-index.md: scenario catalog and selection rules
references/quality-bar.md: realism, determinism, privacy, and output rules
references/rudder-studio-scenario.md: canonical month-long "Rudder uses Rudder to build and grow Rudder" org, with reusable JSON fixtures and seed script
references/rudder-landing-demo-org.md: canonical screenshot-ready Rudder org
references/rudder-test-fixtures.md: Rudder testing and edge-state fixtures
references/rudder-user-scenarios.md: Rudder user stories and scenario spines
references/generic-saas-dashboard.md: SaaS metrics, billing, and ops data
references/generic-crm-sales.md: CRM, pipeline, account, and support data
references/edge-states.md: empty, error, boundary, permission, and conflict states

Bundled Scripts

Use bundled scripts when the user needs live Rudder data instead of static records:

scripts/capture-landing-proof-shots.ts: boots an isolated Rudder instance, seeds the canonical landing demo org, and optionally captures proof-shot screenshots. Use LANDING_SHOTS_SKIP_CAPTURE=1 LANDING_SHOTS_HOLD_OPEN=1 for seed-only local screenshot prep.
scripts/seed-rudder-studio.ts: seeds the reusable Rudder Studio org into a running local dev instance. Use it when the user wants a realistic month-long Rudder org, "using Rudder to build Rudder", natural Calendar work history, or durable user-scenario data.

Read the full file on GitHub · 316 lines

Files

What ships with it

18 files 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.

2mo ago First seen · 316 lines · 50 tokens per session scan A 7bc158276b12

Subscribe to this mod's changes

mock-data-maintainer is a skill published in the GitHub repository Undertone0809/rudder (294 stars, last pushed yesterday), licensed Apache-2.0. It adds 50 tokens to every session and 2,834 once invoked, about $0.0002 per session on Opus 5.5. 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.

Testing

research-engineer

An uncompromising Academic Research Engineer. Operates with absolute scientific rigor, objective criticism, and zero flair. Focuses on theoretical correctness, formal verification, and optimal implementation across any required technology.

davila7/claude-code-templates · 43 tokens

tika-eval-compare

Compare extracts from two Tika builds over a corpus to detect regressions in content, encoding, exceptions, and embedded-document handling. Use for "compare before/after extracts", "eval this change against the corpus".

apache/tika · 50 tokens

cua-driver

Use Cua Driver for desktop or browser tasks that are awkward or unavailable through Bash/APIs, or when the user explicitly wants GUI interaction: app testing, visual bug reproduction, form filling, calendar entry, screenshots, and demo recording. Also covers Cua setup; not OpenAI Codex Computer Use or web research.

davidondrej/skills · 68 tokens

rudder: Skill for Claude Code