CometMarketplaceRecordPDPDwellTimeMutation

Seen 15 time(s) in 7 run(s).

What it sent and what came back (the newest 1 from our runs)

Read from each run's own recording (rule 73), secrets and signed link tokens taken out. Kept in ~/.logCli/rea/clientFacts.json, so it stays after the run is pruned.

runs/host/20261026T180628_61594285317994, openAny: read /marketplace/item/<id>/: 200, 385 ms

Sent:

{
  "fb_api_caller_class": "RelayModern",
  "fb_api_req_friendly_name": "CometMarketplaceRecordPDPDwellTimeMutation",
  "server_timestamps": "true",
  "variables": {
    "input": {
      "listing_id": "1818774979262678",
      "start_time": 1793038230032,
      "actor_id": "61594285317994",
      "client_mutation_id": "3"
    }
  },
  "doc_id": "24177643518491637"
}

Answered:

{
  "data": {
    "marketplace_record_pdp_dwell_time": true
  },
  "extensions": {
    "server_metadata": {
      "request_start_time_ms": 1793038235386,
      "time_at_flush_ms": 1793038235585
    },
    "is_final": true
  }
}

What it does

Records how long the viewer stayed on a Marketplace listing's page (PDP, product details page): it sends input and reads back marketplace_record_pdp_dwell_time. In our runs it fired 73-112 ms into each openAny step that read a /marketplace/item/<id>/ listing, three times in two runs, so it reports the dwell on the listing just opened.

What our machine does with it

The feed warm-up's openListings step (src/facebook/warmup/activities/helpers/feed.ts, openAny /marketplace/item/ 1-3) opens the listing that makes Facebook's client send it; the dwell between opening and coming back is ours (openAny's reading pause). The machine never waits for it or reads it: the step passes on the listing's URL. It matters because it is Facebook's own measure of how long each listing was looked at, so the reading pauses in openAny are what it reports.

What can go wrong

None seen: all three answered 200 in 588-893 ms. A failure here would not stop the step (nothing waits on it). A login wall or checkpoint after it is a page state (rule 54): the agent hooks report it and the step's snapshot shows it.