Agent skill

Pp Shopping

by mvanhorn in mvanhorn/printing-press-library

Every LemmeBuyIt retail endpoint, plus a local store that compares one UPC across 70+ retailers Trigger phrases: compare prices across retailers, find the cheapest retailer for this UPC, find retail…

Apache-2.0Auto-check: notes

Install Pp Shopping

skills CLI
$ npx skills add mvanhorn/printing-press-library --skill pp-shopping -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install mvanhorn/printing-press-library pp-shopping --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/mvanhorn/printing-press-library.git skills-src && mkdir -p .claude/skills && cp -r skills-src/cli-skills/pp-shopping .claude/skills/pp-shopping && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
pp-shopping
GitHub stars
2.1k
Token cost
~3.3k tokens
SKILL.md length
1,371 words
Files
1
Skills in repo
506
Repo updated
First seen
Licence
Apache-2.0

At a glance

Every LemmeBuyIt retail endpoint, plus a local store that compares one UPC across 70+ retailers Trigger phrases: compare prices across retailers, find the cheapest retailer for this UPC, find retail…

  • Works in 3 steps: Install via the Printing Press… → Verify: shopping-pp-cli --version → Ensure the reported install directory is…
  • Phrases: compare prices across retailers
  • SKILL.md covers Prerequisites: Install the CLI, When to Use This CLI, Anti-triggers and Unique Capabilities, plus 11 more sections
  • Calls go, claude and npx; needs SHOPPING_API_KEY

What it does

Pp Shopping is an agent skill from mvanhorn/printing-press-library. Every LemmeBuyIt retail endpoint, plus a local store that compares one UPC across 70+ retailers Trigger phrases: compare prices across retailers, find the cheapest retailer for this UPC, find retail deals over 30% off, is this product profitable to flip on Amazon, show this week's biggest price drops, use shopping, run shopping.

Its SKILL.md is about 3.3k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

The repository describes itself as: Official library of CLIs generated by the CLI Printing Press. Endorsed, tested, and community-contributed. The licence is Apache-2.0.

When your agent uses it

  • Phrases: compare prices across retailers
  • Find the cheapest retailer for this UPC
  • Find retail deals over 30% off
  • Is this product profitable to flip on Amazon

Example prompts

  • “/pp-shopping”

Requirements

  • Node.js
  • A credential in SHOPPING_API_KEY
  • Pre-approved tools (allowed-tools): Read, Bash

Workflow steps

3 steps, taken from the first numbered list in SKILL.md.

  1. Install via the Printing Press installer. It defaults binaries to $HOME/.local/bin on macOS/Linux and…
  2. Verify: shopping-pp-cli --version
  3. Ensure the reported install directory is on $PATH for the agent/runtime that will invoke this skill.

What it can do on your machine

Read from SKILL.md and the folder at commit d9a1696. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves these tools, so the agent can use them without asking each time:

    • Read
    • Bash

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    Shell commands in SKILL.md call:

    • go
    • claude
    • npx

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    Links to these hosts (documentation or services it may open):

    • lemmebuyit.com

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names these keys or tokens, usually read from environment variables:

    • SHOPPING_API_KEY

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Pp Shopping loads about 3.3k tokens when it runs. Until then it costs about 89 tokens; SKILL.md has 1,371 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~89
When it runs · the whole SKILL.md, loaded when a task matches
~3.3k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check: notes

The automated check noted patterns worth knowing about, such as sudo or a known installer.

  • NotePre-approves every shell command (allowed-tools: Bash)SKILL.md
    allowed-tools: Read, Bash

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from mvanhorn/printing-press-library at commit d9a1696, republished under its Apache-2.0 licence (© mvanhorn). 1,371 words, ~3,277 tokens.

Download SKILL.mdSave it as .claude/skills/pp-shopping/SKILL.md (or your agent's skills folder).
name
pp-shopping
description
Every LemmeBuyIt retail endpoint, plus a local store that compares one UPC across 70+ retailers Trigger phrases: `compare prices across retailers`, `find the cheapest retailer for this UPC`, `find retail deals over 30% off`, `is this product profitable to flip on Amazon`, `show this week's biggest price drops`, `use shopping`, `run shopping`.
allowed-tools
Read, Bash
author
NicholasSpisak
license
Apache-2.0
argument-hint
<command> [args] | install cli|mcp
<!-- GENERATED FILE — DO NOT EDIT.
     This file is a verbatim mirror of library/commerce/shopping/SKILL.md,
     regenerated post-merge by tools/generate-skills/. Hand-edits here are
     silently overwritten on the next regen. Edit the library/ source instead.
     See the repository agent guide, section "Generated artifacts: registry.json, cli-skills/". -->

Shopping — Printing Press CLI

Prerequisites: Install the CLI

This skill drives the shopping-pp-cli binary. You must verify the CLI is installed before invoking any command from this skill. If it is missing, install it first:

  1. Install via the Printing Press installer. It defaults binaries to $HOME/.local/bin on macOS/Linux and %LOCALAPPDATA%\Programs\PrintingPress\bin on Windows:
    bash
    npx -y @mvanhorn/printing-press-library install shopping --cli-only
  2. Verify: shopping-pp-cli --version
  3. Ensure the reported install directory is on $PATH for the agent/runtime that will invoke this skill.

If the npx install fails (no Node, offline, etc.), fall back to a direct Go install (requires Go 1.26.6 or newer). This installs into $GOPATH/bin (default $HOME/go/bin), so add that directory to $PATH instead:

bash
go install github.com/mvanhorn/printing-press-library/library/commerce/shopping/cmd/shopping-pp-cli@latest

If --version reports "command not found" after install, the runtime cannot see the binary directory on $PATH. Do not proceed with skill commands until verification succeeds.

Shopping wraps the LemmeBuyIt aggregated-retail API (115M+ products across 70+ retailers) and adds a local SQLite layer no other tool has. index syncs products and price history; compare finds the cheapest retailer for a shared identifier; deals runs a compound discount/price/rating/stock query across stores; arbitrage ranks Amazon FBA resale margin; price-drops surfaces weekly price drops and leaderboard ranks discount buckets. Agent-native --json/--select, offline search, typed exit codes.

When to Use This CLI

Use Shopping for cross-retailer retail-product tasks an agent needs answered fast: find the cheapest retailer for a UPC, surface the best in-stock deals over a discount/price threshold, rank biggest weekly price drops, or evaluate Amazon FBA resale margin. It is strongest when you sync once and run many compound queries against the local store.

Anti-triggers

Do not use this CLI for:

  • Do not use it to place orders, add to cart, or check out — it is a read-only data API.
  • Do not use it for non-retail data or for a single retailer's own order-management API.
  • Do not use it as a real-time price oracle — store-backed queries reflect the last index sync, not the live shelf price.

Unique Capabilities

These capabilities aren't available in any other tool for this API.

Local state that compounds
  • index — Pull products (and optional price history) from one or more retailers into a fast local SQLite store so every other query runs instantly and offline.

    Reach for this first: the compare/deals/arbitrage/analytics commands all read what index populates.

    bash
    shopping-pp-cli index --retailer walmart --retailer target --on-sale --limit 500
  • watch status — Pin items you care about and, after each index refresh, see which ones moved, by how much, and which hit your target price.

    Use it for change-since-last-observation on a curated set instead of re-fetching and eyeballing prices.

    bash
    shopping-pp-cli watch status --json
Cross-retailer intelligence
  • compare — See which synced retailer sells the exact same item (by UPC/EAN/GTIN/ASIN) cheapest right now, ranked, with the savings spread.

    Use it to answer 'who has this cheapest' in one call instead of N per-retailer lookups.

    bash
    shopping-pp-cli compare 012345678905 --lookup-type upc --in-stock --json
  • deals — Surface deals that clear several bars at once — deep discount, under a price ceiling, well-reviewed, in stock — across all tracked retailers in one ranked list.

    Pick this when an agent needs the best deals worth a human's time, not a raw product dump.

    bash
    shopping-pp-cli deals --min-discount 30 --max-price 100 --min-rating 4 --in-stock --sort discount --json
Profitability
  • arbitrage — Rank synced products by what you would net reselling them on Amazon after referral and FBA fees, filtered by ROI and buy price.

    Use it to filter clearance products down to the ones that actually clear a resale ROI bar.

    bash
    shopping-pp-cli arbitrage --retailer walmart --min-roi 30 --max-buy-price 50 --in-stock --json
Time-series analytics
  • price-drops — Rank the products that fell the most over the last week (or N weeks) across everything synced, by both dollar and percent drop.

    Reach for it to catch fresh markdowns first instead of re-pulling each product's history by hand.

    bash
    shopping-pp-cli price-drops --weeks 1 --min-drop-pct 15 --limit 25 --json
  • leaderboard — Show which retailers and categories are consistently the deepest-discount buckets in your synced data, by average discount, on-sale count, or average price.

    Use it to decide which retailer/category to scan first when hunting deals.

    bash
    shopping-pp-cli leaderboard --by avg-discount --limit 15 --json

Command Reference

amazon — Manage amazon

  • shopping-pp-cli amazon <asin> — Returns chart-ready weekly Amazon-side time-series data for a specific ASIN — direct access to amazon_price_history

retailers — Operations related to retailers and their products.

  • shopping-pp-cli retailers — Retrieves a list of retailers that the authenticated API key has access to.

status — API health and status checks.

  • shopping-pp-cli status — Provides the current operational status of the API service, including database connectivity.
Finding the right command

When you know what you want to do but not which command does it, ask the CLI directly:

bash
shopping-pp-cli which "<capability in your own words>"

which resolves a natural-language capability query to the best matching command from this CLI's curated feature index. Exit code 0 means at least one match; exit code 2 means no confident match — fall back to --help or use a narrower query.

Recipes

Cheapest retailer for a UPC
bash
shopping-pp-cli compare 012345678905 --lookup-type upc --in-stock --json --select results.retailer_id,results.current_price

Cross-retailer compare narrowed to the two fields an agent needs to act on.

Best in-stock deals
bash
shopping-pp-cli deals --min-discount 40 --max-price 75 --in-stock --sort discount --limit 20 --json

Compound discount/price/stock query ranked by discount over the synced store.

FBA arbitrage shortlist
bash
shopping-pp-cli arbitrage --retailer walmart --min-roi 30 --max-buy-price 50 --json --select results.product_name,results.roi,results.net_margin

Rank resale candidates by ROI, selecting only the decision fields.

Show full SKILL.md (603 more words)Show less
This week's biggest drops
bash
shopping-pp-cli price-drops --weeks 1 --min-drop-pct 20 --limit 25 --json

Weekly time-series delta ranking across every synced product.

Auth Setup

Authenticate with a single LemmeBuyIt API key sent as the X-API-Key header on every request (set SHOPPING_API_KEY, or run shopping-pp-cli auth set-token <key>). Free keys reach the /shopping/ product surface; paid keys additionally unlock full product search, weekly price history, Amazon ASIN history, and the Amazon profitability data that powers arbitrage. Get a key at https://www.lemmebuyit.com/developer.

Run shopping-pp-cli doctor to verify setup.

Agent Mode

Add --agent to any command. Expands to: --json --compact --no-input --no-color --yes.

  • Pipeable — JSON on stdout, errors on stderr

  • Filterable — --select keeps a subset of fields. Dotted paths descend into nested structures; arrays traverse element-wise. Critical for keeping context small on verbose APIs:

    bash
    shopping-pp-cli retailers --agent --select id,name,status
  • Previewable — --dry-run shows the request without sending

  • Offline-friendly — sync/search commands can use the local SQLite store when available

  • Non-interactive — never prompts, every input is a flag

  • Read-only — do not use this CLI for create, update, delete, publish, comment, upvote, invite, order, send, or other mutating requests

Response envelope

Commands that read from the local store or the API wrap output in a provenance envelope:

json
{
  "meta": {"source": "live" | "local", "synced_at": "...", "reason": "..."},
  "results": <data>
}

Parse .results for data and .meta.source to know whether it's live or local. A human-readable N results (live) summary is printed to stderr only when stdout is a terminal AND no machine-format flag (--json, --csv, --compact, --quiet, --plain, --select) is set — piped/agent consumers and explicit-format runs get pure JSON on stdout.

Agent Feedback

When you (or the agent) notice something off about this CLI, record it:

shopping-pp-cli feedback "the --since flag is inclusive but docs say exclusive"
shopping-pp-cli feedback --stdin < notes.txt
shopping-pp-cli feedback list --json --limit 10

Entries are stored locally at ~/.local/share/shopping-pp-cli/feedback.jsonl. They are never POSTed unless SHOPPING_FEEDBACK_ENDPOINT is set AND either --send is passed or SHOPPING_FEEDBACK_AUTO_SEND=true. Default behavior is local-only.

Write what surprised you, not a bug report. Short, specific, one line: that is the part that compounds.

Output Delivery

Every command accepts --deliver <sink>. The output goes to the named sink in addition to (or instead of) stdout, so agents can route command results without hand-piping. Three sinks are supported:

SinkEffect
stdoutDefault; write to stdout only
file:<path>Atomically write output to <path> (tmp + rename)
webhook:<url>POST the output body to the URL (application/json or application/x-ndjson when --compact)

Unknown schemes are refused with a structured error naming the supported set. Webhook failures return non-zero and log the URL + HTTP status on stderr.

Named Profiles

A profile is a saved set of flag values, reused across invocations. Use it when a scheduled agent calls the same command every run with the same configuration - HeyGen's "Beacon" pattern.

shopping-pp-cli profile save briefing --json
shopping-pp-cli --profile briefing retailers
shopping-pp-cli profile list --json
shopping-pp-cli profile show briefing
shopping-pp-cli profile delete briefing --yes

Explicit flags always win over profile values; profile values win over defaults. agent-context lists all available profiles under available_profiles so introspecting agents discover them at runtime.

Exit Codes

CodeMeaning
0Success
2Usage error (wrong arguments)
3Resource not found
4Authentication required
5API error (upstream issue)
7Rate limited (wait and retry)
10Config error

Argument Parsing

Parse $ARGUMENTS:

  1. Empty, help, or --help → show shopping-pp-cli --help output
  2. Starts with install → ends with mcp → MCP installation; otherwise → see Prerequisites above
  3. Anything else → Direct Use (execute as CLI command with --agent)

MCP Server Installation

  1. Install the MCP server:
    bash
    go install github.com/mvanhorn/printing-press-library/library/commerce/shopping/cmd/shopping-pp-mcp@latest
  2. Register with Claude Code:
    bash
    claude mcp add shopping-pp-mcp -- shopping-pp-mcp
  3. Verify: claude mcp list

Direct Use

  1. Check if installed: which shopping-pp-cli If not found, offer to install (see Prerequisites at the top of this skill).
  2. Match the user query to the best command from the Unique Capabilities and Command Reference above.
  3. Execute with the --agent flag:
    bash
    shopping-pp-cli <command> [subcommand] [args] --agent
  4. If ambiguous, drill into subcommand help: shopping-pp-cli <command> --help.

© mvanhorn, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in cli-skills/pp-shopping of mvanhorn/printing-press-library.

Open the folder on GitHubat commit d9a1696

Compare with similar skills

Pp Shopping next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Pp Shopping compared with similar skills
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Pp Shopping this skillmvanhorn/printing-press-library2.1k—~3.3kAutomated safety check: NotesApache-2.0
Agent App Storeruvnet/ruflo74k2 repos~1kAutomated safety check: PassMIT
Shoppingasgeirtj/system_prompts_leaks69k—~3.7kAutomated safety check: PassCC0-1.0
Shoppingcodewhale-hq/Codewhale41k—~265Automated safety check: PassMIT
App Store Optimizationalirezarezvani/claude-skills28k1 repos~4.2kAutomated safety check: PassMIT
Eas App Storessickn33/agentic-awesome-skills47k1 repos~1.9kAutomated safety check: PassMIT

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Questions about Pp Shopping

What does Pp Shopping do?

Every LemmeBuyIt retail endpoint, plus a local store that compares one UPC across 70+ retailers Trigger phrases: compare prices across retailers, find the cheapest retailer for this UPC, find retail…. Pp Shopping is an agent skill from mvanhorn/printing-press-library. Every LemmeBuyIt retail endpoint, plus a local store that compares one UPC across 70+ retailers Trigger phrases: compare prices across retailers, find the cheapest retailer for this UPC, find retail deals over 30% off, is this product profitable to flip on Amazon, show this week's biggest price drops, use shopping, run shopping.

When should I use Pp Shopping?

Pp Shopping fits situations like: phrases: compare prices across retailers; find the cheapest retailer for this UPC; find retail deals over 30% off; is this product profitable to flip on Amazon.

How do I install Pp Shopping in Claude Code?

Run `npx skills add mvanhorn/printing-press-library --skill pp-shopping -a claude-code`. Or copy the skill folder (cli-skills/pp-shopping in mvanhorn/printing-press-library) into .claude/skills/pp-shopping in your project. Claude Code loads it when a task matches its description.

How do I install Pp Shopping in Codex?

Run `npx skills add mvanhorn/printing-press-library --skill pp-shopping -a codex`. Or copy the skill folder (cli-skills/pp-shopping in mvanhorn/printing-press-library) into .agents/skills/pp-shopping in your project. Codex loads it when a task matches its description.

Can I use Pp Shopping in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add mvanhorn/printing-press-library --skill pp-shopping -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/pp-shopping, .gemini/skills/pp-shopping, .github/skills/pp-shopping and .opencode/skills/pp-shopping in your project.

What does Pp Shopping need to run?

Going by SKILL.md and its folder, Pp Shopping needs the command-line tools its instructions call (go, claude and npx) and credentials named SHOPPING_API_KEY. Our summary lists: Node.js; A credential in SHOPPING_API_KEY. Its frontmatter pre-approves these tools: Read, Bash.

Does Pp Shopping access the network?

SKILL.md names 1 domain. As links in the text: lemmebuyit.com. This is read from the text; nothing was executed.

Is Pp Shopping safe to install?

Our automated static check of SKILL.md found notes only (pre-approves every shell command (allowed-tools: bash)), nothing it rates as a warning. It is not a guarantee. Review the folder before installing.

What licence does Pp Shopping use?

Pp Shopping is published under the Apache-2.0 licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Pp Shopping use?

About 3.3k tokens (SKILL.md is roughly 13k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Pp Shopping?

Skills that share tags, products or a category with Pp Shopping: Agent App Store (ruvnet/ruflo, 74k stars), Shopping (asgeirtj/system_prompts_leaks, 69k stars), Shopping (codewhale-hq/Codewhale, 41k stars) and App Store Optimization (alirezarezvani/claude-skills, 28k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Pp Shopping?

mvanhorn (a GitHub user) maintains it in mvanhorn/printing-press-library, which has 2,056 GitHub stars. The repository holds 506 skills in this directory. The repository was last updated on October 9, 2026.

Source: mvanhorn/printing-press-library on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.