Pp Shopping

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:

   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:

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.

  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.

  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.

  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.

  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.

  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.

  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.

  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:

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

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

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

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.

This week's biggest drops

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:

  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:

{
  "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:

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

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:

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

2. Register with Claude Code:

   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:

   shopping-pp-cli <command> [subcommand] [args] --agent
   

4. If ambiguous, drill into subcommand help: shopping-pp-cli <command> --help.