Craigslist's JSON-LD has no ID field — we join 290 of 325 listings by title alone

Quick answer Craigslist search pages ship two copies of every listing: a static HTML list, and a JSON-LD <script> block with images, currency, and geo-coordinates. The obvious move is to join them by ID. Don't — Craigslist's JSON-LD carries no shared identifier at all , not a bare post ID, not a URL, not a SKU. The only field both copies reliably share is the listing's title, and titles repeat. We joined by title through a per-title FIFO queue and measured it recovering 290 of 325 listings (89%) end-to-end on a captured 298-item page. That number is the ceiling of what a title-only join can do on this page shape — plan your field completeness around it, don't assume 100%. Why can't you just match the JSON-LD by ID? 🧩 When we built the Craigslist Multi-City Listings Scraper , the first design assumed what almost every JSON-LD block on almost every e-commerce-shaped site provides: a productID , a sku , a url , an @id — something that lines up a JSON entry with its DOM counterpart deterministically. Live inspection of a captured Craigslist search page found none of those. Each itemListElement entry has exactly name , image , offers , @type , and a position field that looks like it should solve the problem — until you check it against the static list past the first ~18 entries, where some static-list rows have no JSON-LD counterpart at all and the position numbering drifts out of alignment. So the join key that's actually usable, live, is title — and titles aren't unique. The fix is a FIFO queue per title: walk the static <li> list in document order, and for each title pop the next unconsumed JSON-LD entry with a matching name. # actors/craigslist-listings-scraper/src/search_parser.py def _parse_ld_json ( tree : HTMLParser ) -> dict [ str , deque [ _LdEntry ]]: by_title : dict [ str , deque [ _LdEntry ]] = defaultdict ( deque ) for list_item in data . get ( " itemListElement " , []): entry = _ld_entry_from_item ( list_item ) title = list_item . get ( " item " , {}). get