marketplace-purchase-vetting

Marketplace Purchase Vetting

Use this when the user asks whether a local listing is a scam, "too good to be true," worth looking at, or a good deal. Also use this when he asks you to find options — search/discover candidates, then vet the best ones. The goal is not a generic buying guide; it is a practical risk read with clear next steps.

Two modes: Discovery (find me options) and Vetting (check this listing). Run them in sequence when the user hasn't identified a specific listing.

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Mode 1: Discovery — Search for candidates in the area

Run this first when the user says "find me a car/suv/truck for $X in our area" without a specific link. The output is a ranked shortlist of the best live options.

Facebook Marketplace search procedure

Read before a broad or tightly constrained vehicle hunt; it documents radius conversion, ignored filters, regional partitioning, feed virtualization, and dealer/down-payment traps.

1. Set up the search URL. Facebook Marketplace uses structured URL parameters:

https://www.facebook.com/marketplace/{city}/vehicles?minPrice={min}&maxPrice={max}&sortBy=creation_time_descend&exact=false

• Default to the user's nearest metro area as the city slug; ask when unclear.
• Set price range with ~$500 buffer below max budget (e.g. $3,000--$4,000 for a $3.5k budget) so the floor filters out junk but the ceiling doesn't miss negotiable listings.
• sortBy=creation_time_descend shows newest first — gives the freshest picks.

1. Navigate in a logged-in browser session. Facebook Marketplace requires authentication to show results. Use the browser tool (Chrome CDP). Navigate to the constructed URL.

2. Scrape the results page via CDP Runtime.evaluate — much faster than clicking each listing:

JSON.stringify(Array.from(document.querySelectorAll(
'a[href*="/marketplace/item/"]'
)).map(a => ({
text: a.innerText.trim(),
url: (a.href.match(/marketplace\/item\/(\d+)/) || [])[1]
})).filter(x => x.text))

This returns all visible listings' title, price, location, item ID as one JSON blob.