diff --git a/pm/tasks.org b/pm/tasks.org
index 13cfce7..775561f 100644
--- a/pm/tasks.org
+++ b/pm/tasks.org
@@ -218,6 +218,24 @@
 - commit: `9497565` on branch `cx`
 - tests: `./venv/bin/python -m unittest discover -s tests`; verified shared enriched fields in `giant_output/items_enriched.csv` and `costco_output/items_enriched.csv`
 - date: 2026-03-16
+* [X] t1.8.4: verify and correct costco receipt enumeration (1–2 commits)
+
+** acceptance criteria
+- confirm graphql summary query returns all expected receipts
+- compare `inWarehouse` count vs number of `receipts` returned
+- widen or parameterize date window if necessary; website shows receipts in 3-month windows
+- persist request metadata (`startDate`, `endDate`, `documentType`, `documentSubType`)
+- emit warning when receipt counts mismatch
+
+** notes
+- goal is to confirm we are enumerating all receipts before parsing
+- do not expand schema or parser logic in this task
+- keep changes limited to summary query handling and diagnostics
+
+** evidence
+- commit: `ac82fa6` on branch `cx`
+- tests: `./venv/bin/python -m unittest discover -s tests`; `./venv/bin/python scrape_costco.py --help`; reviewed the sample Costco summary request in `pm/scrape-giant.org` against `costco_output/raw/summary.json` and added 3-month window chunking plus mismatch diagnostics
+- date: 2026-03-16
 * [ ] t1.9: compute normalized comparison metrics (2-4 commits)
 
 ** acceptance criteria