What is list-expander?

A process for expanding a small list of known good companies into a larger list of similar potential customers. It studies how the seed companies appear in company databases, finds lookalikes, and tests broader search filters.

Use it to grow a hard-to-find business-to-business prospect list from a handful of confirmed companies, then produce qualified companies and measured search filters.

Niche searches often miss suitable companies because databases label them differently from the keywords you expect. This process starts with real matches and checks the accuracy of each expansion method.

list-expander — Skill by growthenginenowoslawski/coldoutboundskills

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 growthenginenowoslawski/coldoutboundskills --skill list-expander

Clone the repo

git clone --depth 1 https://github.com/growthenginenowoslawski/coldoutboundskills

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/growthenginenowoslawski/coldoutboundskills/list-expander/github.svg)](https://agentmods.dev/skills/growthenginenowoslawski/coldoutboundskills/list-expander)

Your own site

<a href="https://agentmods.dev/skills/growthenginenowoslawski/coldoutboundskills/list-expander"><img src="https://agentmods.dev/badge/skills/growthenginenowoslawski/coldoutboundskills/list-expander/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/growthenginenowoslawski/coldoutboundskills/list-expander"><img src="https://agentmods.dev/badge/skills/growthenginenowoslawski/coldoutboundskills/list-expander.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 158 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,763 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: 14 findings, up to medium

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 →

medium MCP Rug Pull · line 19
npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.

Fix: Pin the version: npx @scope/[email protected]
medium MCP Rug Pull · line 45
npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.

Fix: Pin the version: npx @scope/[email protected]
medium MCP Rug Pull · line 52
npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.

Fix: Pin the version: npx @scope/[email protected]
medium MCP Rug Pull · line 78
npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.

Fix: Pin the version: npx @scope/[email protected]
medium MCP Rug Pull · line 81
npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.

Fix: Pin the version: npx @scope/[email protected]
medium MCP Rug Pull · line 84
npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.

Fix: Pin the version: npx @scope/[email protected]
medium MCP Rug Pull · line 86
npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.

Fix: Pin the version: npx @scope/[email protected]
medium MCP Rug Pull · line 101
npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.

Fix: Pin the version: npx @scope/[email protected]
medium MCP Rug Pull · line 102
npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.

Fix: Pin the version: npx @scope/[email protected]
medium MCP Rug Pull · line 103
npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.

Fix: Pin the version: npx @scope/[email protected]
medium MCP Rug Pull · line 104
npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.

Fix: Pin the version: npx @scope/[email protected]
medium MCP Rug Pull · line 112
npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.

Fix: Pin the version: npx @scope/[email protected]
medium MCP Rug Pull · line 114
npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.

Fix: Pin the version: npx @scope/[email protected]
medium Rogue Agent · line 66
Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.

Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.

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	$0.00158	$0.02763
Opus 5.5	$0.00063	$0.01105
Sonnet 5.5	$0.00032	$0.00553
Haiku 4.5	$0.00016	$0.00276

Measured 2mo ago against content hash adb225aa477a, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

list-expander 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 9 executable files (scripts/contact-count.ts, scripts/fingerprint.ts, scripts/lib.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.

skills/list-expander/SKILL.md · 169 lines

How it starts

The opening of the file, as written. The whole thing — 169 lines — stays where its author put it; the contents beside it link to each section on GitHub.

List Expander — seed companies → lookalikes → mined filters → qualified TAM

The problem this solves

Niche lists come out tiny because we search databases with narrow explicit keywords, but real good-fit companies (e.g. Atlantic Medical Group, Hackensack Meridian) often don't carry that keyword in their database record. Instead of guessing keywords top-down, this skill works bottom-up: take companies you KNOW fit, discover how the database actually tags them, expand via lookalike engines, and only then derive the wide-net filters — with measured precision per filter — before pulling and AI-qualifying at scale.

Pipeline (5 phases)

All scripts live in scripts/, run with npx tsx, and are dependency-free (node ≥ 18 native fetch). Every script takes --help. Keys load from the repo-root .env (see .env.example), falling back to ~/.env. Artifacts land in ~/output/list-expander/{run}/.

Phase 1  fingerprint.ts    seeds → how each shows up in Prospeo + its live homepage
Phase 2  lookalikes.ts     seeds → candidates via Prospeo lookalike + Exa + Parallel
                           (qualify candidates → lookalikes-confirmed.csv)
Phase 3  mine-filters.ts   confirmed fits → candidate filters → scorecard (volume × precision)
Phase 4  pull.ts           winning filters → wide pull, auto-shard, dedup, exclusions
         score-batch.ts    scale AI qualification (gpt-5-nano by default)
         verify-website.ts second pass on QUALIFIED rows: live homepage fetch →
                           dead / suspended-parked / live; live sites re-judged on
                           their CURRENT content (catches stale-DB ghosts). Always run —
                           DB descriptions happily qualify dead companies otherwise.
Phase 5  contact-count.ts  verified-email TAM ceiling (free Prospeo count trick)
         report.ts         single-file HTML transparency report for the client

Phase 0 — inputs

~10 seed companies known for sure to fit (domains).
1–2 sentence ICP description ("multi-site medical/specialty groups in the US, ≥$3M revenue").
Optional: exclusion CSV (companies already in campaigns).

Read the full file on GitHub · 169 lines

Files

What ships with it

9 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 · 169 lines · 158 tokens per session scan A adb225aa477a

Subscribe to this mod's changes

list-expander is a skill published in the GitHub repository growthenginenowoslawski/coldoutboundskills (802 stars, last pushed 1mo ago), licensed MIT. It adds 158 tokens to every session and 2,763 once invoked, about $0.0006 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.

Marketing and SEO Research

list-expander next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
list-expandergrowthenginenowoslawski/coldoutboundskills	Skill	802	1mo ago	MIT	A	158	Claude Code, Codex
imagegenopenai/codex	Skill	133k	today	Apache-2.0	A	113	Codex
playwright-climicrosoft/playwright	Skill	99k	yesterday	Apache-2.0	A	19	Claude Code
local-ai-agentsmicrosoft/ai-agents-for-beginners	Skill	79k	4d ago	MIT	A	200	Claude Code, Codex
systematic-debuggingobra/superpowers	Skill	313k	3d ago	MIT	A	21	Claude Code
next-cache-components-adoptionvercel/next.js	Skill	143k	today	MIT	A	95	Claude Code
chat-pet-sprite-creationmicrosoft/vscode	Skill	195k	today	MIT	A	53	Claude Code, Codex