diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5ff0a88..1d0ff7f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,17 @@
 All notable changes to `overlay-social` (Python). Mirrors
 `@overlay-social/sdk` (TypeScript) one-to-one.
 
+## Unreleased
+
+### Fixed
+- `get_feed(bbox=...)` sent the box longitude first, but `/v1/feed` reads it
+  latitude first, so the box selected the wrong area (usually none). The
+  argument is still `(west, south, east, north)`; it is now sent as
+  `south,west,north,east`, the same fix as `@overlay-social/sdk`. Callers that
+  worked around this by passing latitude first should switch to the
+  documented order. A `bbox` that is not four values raises `ValueError`
+  instead of being forwarded as is.
+
 ## 0.3.0 — 2026-07-29
 
 ### Added
@@ -13,8 +24,9 @@ All notable changes to `overlay-social` (Python). Mirrors
   `numbers` when a key owns more than one). Additive: comes alongside
   `author`, never replaces it, and is absent (not `None`) when the author
   has no number. `membership_proof: "none"` is explicit that the value is
-  read from Zanaadu's registry, not verified against their Merkle tree.
-  See `peck-overlay-schema/ZANAADU_POSTANCHOR_FORMAT.md` §13.
+  read from Zanaadu's registry, not verified against their Merkle tree. The
+  number is derived from Zanaadu's registry transactions (a registration
+  advances a counter; entries can change owner through their marketplace).
 
 ## 0.2.0 — 2026-06-12
 
diff --git a/README.md b/README.md
index 80df88c..04934e8 100644
--- a/README.md
+++ b/README.md
@@ -83,7 +83,7 @@ notifs = overlay.get_notifications("<posting-address>", limit=50)
 overlay.get_follows("<address>")          # follower/following counts + rows
 overlay.get_blocks("<address>")           # OUTGOING block/mute list only
 overlay.get_feed(near={"lat": 59.94, "lng": 10.76}, radius_km=2)   # geo
-overlay.get_feed(bbox=(10.5, 59.8, 11.0, 60.1))                    # bounding box
+overlay.get_feed(bbox=(10.5, 59.8, 11.0, 60.1))                    # bounding box (west, south, east, north)
 overlay.verify_root("tm_social-content")  # on-chain anchor vs live state-root
 ```
 
diff --git a/overlay_social/client.py b/overlay_social/client.py
index 456e74a..62df513 100644
--- a/overlay_social/client.py
+++ b/overlay_social/client.py
@@ -6,7 +6,7 @@
 REST facade that actually runs today (verified against overlay.peck.to), NOT
 the BRC-24 ``peck-schema`` lookup (that lookup is a no-op).
 
-Semantics mirror @overlay-social/sdk and peck-web/overlay_client.py:
+Semantics mirror @overlay-social/sdk:
   * ``resolve_identities`` returns ``{}`` on ANY error and omits keys without a
     canonical ProfileToken, so a feed UI can enrich defensively and NEVER break.
   * single-item lookups return ``None`` for missing/invalid (404/400/empty).
@@ -66,7 +66,10 @@ def put(k: str, v: Any) -> None:
     put("author", params.get("author"))
     put("order", params.get("order", "desc"))
     put("before", params.get("before"))
-    # Geo: near={"lat":..,"lng":..} (+ radius_km) → haversine; bbox=(w,s,e,n).
+    # Geo: near={"lat":..,"lng":..} (+ radius_km) → haversine, or
+    # bbox=(west, south, east, north) (longitude first, the GeoJSON order).
+    # On the wire the overlay reads latitude first: bbox=south,west,north,east.
+    # `near` wins when both are given.
     near = params.get("near")
     if near:
         lat = near.get("lat") if isinstance(near, dict) else near[0]
@@ -74,7 +77,11 @@ def put(k: str, v: Any) -> None:
         put("near", f"{lat},{lng}")
         put("radius_km", params.get("radius_km"))
     elif params.get("bbox"):
-        put("bbox", ",".join(str(x) for x in params["bbox"]))
+        try:
+            west, south, east, north = params["bbox"]
+        except (TypeError, ValueError):
+            raise ValueError("bbox must be (west, south, east, north)") from None
+        put("bbox", f"{south},{west},{north},{east}")
     return out
 
 
diff --git a/overlay_social/models.py b/overlay_social/models.py
index 716134e..b820fae 100644
--- a/overlay_social/models.py
+++ b/overlay_social/models.py
@@ -35,8 +35,10 @@ class SourceHandle(_SourceHandleRequired, total=False):
     May appear at ``PeckRow["source_handle"]``. Today the only source is
     Zanaadu: it sells on-chain "user numbers" (an on-chain collectibles
     registry), and rows with ``app == "zanaadu"`` carry the holder's number
-    here. See ``peck-overlay-schema/ZANAADU_POSTANCHOR_FORMAT.md`` §13 for
-    the full derivation and its proof gap.
+    here. The number is derived from Zanaadu's own registry transactions: a
+    registration advances a counter and the new entry takes the counter's
+    previous value, and an entry can later change owner through Zanaadu's
+    marketplace, so it is not always readable from a single transaction.
 
     ``namespace`` is mandatory and comes first so the value can never be
     shown bare and mistaken for a peck handle — render it qualified, e.g.
@@ -57,7 +59,7 @@ class SourceHandle(_SourceHandleRequired, total=False):
     - ``numbers`` (all numbers this key owns at the source, ascending) is
       only present when there is more than one; ``value``/``number`` are
       then the lowest. Tie-break for "which number is primary" when a key
-      owns several is NOT proven on-chain (§13.7) — lowest was chosen for
+      owns several is NOT proven on-chain — lowest was chosen for
       stability over time, not because it is confirmed canonical.
     """
 
diff --git a/tests/test_feed_query.py b/tests/test_feed_query.py
new file mode 100644
index 0000000..208993e
--- /dev/null
+++ b/tests/test_feed_query.py
@@ -0,0 +1,89 @@
+"""Offline tests for the /v1/feed query the clients send.
+
+No network: the clients are given an ``httpx`` mock transport that records the
+request, so these run everywhere (unlike the live tests in ``test_client.py``).
+"""
+
+from __future__ import annotations
+
+import httpx
+import pytest
+
+from overlay_social import AsyncOverlayClient, OverlayClient
+
+_EMPTY_FEED = {"status": "ok", "data": [], "limit": 50, "offset": 0}
+
+
+def _recording_handler(calls: list[httpx.Request]):
+    def handler(request: httpx.Request) -> httpx.Response:
+        calls.append(request)
+        return httpx.Response(200, json=_EMPTY_FEED)
+
+    return handler
+
+
+def _sync_client(calls: list[httpx.Request]) -> OverlayClient:
+    transport = httpx.MockTransport(_recording_handler(calls))
+    return OverlayClient(base_url="https://overlay.test", client=httpx.Client(transport=transport))
+
+
+def _async_client(calls: list[httpx.Request]) -> AsyncOverlayClient:
+    transport = httpx.MockTransport(_recording_handler(calls))
+    return AsyncOverlayClient(
+        base_url="https://overlay.test", client=httpx.AsyncClient(transport=transport)
+    )
+
+
+# Oslo: longitude about 10.7, latitude about 59.9.
+# The argument is (west, south, east, north), longitude first (GeoJSON order).
+OSLO_BBOX = (10.6, 59.8, 10.9, 60.0)
+# The overlay reads minLat,minLng,maxLat,maxLng.
+OSLO_WIRE = "59.8,10.6,60.0,10.9"
+
+
+def test_bbox_is_sent_latitude_first_sync() -> None:
+    calls: list[httpx.Request] = []
+    with _sync_client(calls) as o:
+        o.get_feed(bbox=OSLO_BBOX)
+    assert calls[0].url.params["bbox"] == OSLO_WIRE
+
+
+@pytest.mark.asyncio
+async def test_bbox_is_sent_latitude_first_async() -> None:
+    calls: list[httpx.Request] = []
+    async with _async_client(calls) as o:
+        await o.get_feed(bbox=OSLO_BBOX)
+    assert calls[0].url.params["bbox"] == OSLO_WIRE
+
+
+def test_bbox_accepts_a_list_and_integers() -> None:
+    calls: list[httpx.Request] = []
+    with _sync_client(calls) as o:
+        o.get_feed(bbox=[10, 59, 11, 60])
+    assert calls[0].url.params["bbox"] == "59,10,60,11"
+
+
+def test_near_wins_over_bbox_and_keeps_its_wire_format() -> None:
+    calls: list[httpx.Request] = []
+    with _sync_client(calls) as o:
+        o.get_feed(near={"lat": 59.9, "lng": 10.7}, radius_km=3, bbox=(1, 2, 3, 4))
+    params = calls[0].url.params
+    assert params["near"] == "59.9,10.7"
+    assert params["radius_km"] == "3"
+    assert "bbox" not in params
+
+
+def test_no_bbox_param_without_a_geo_filter() -> None:
+    calls: list[httpx.Request] = []
+    with _sync_client(calls) as o:
+        o.get_feed(limit=5)
+    assert "bbox" not in calls[0].url.params
+
+
+@pytest.mark.parametrize("bad", [(1, 2, 3), (1, 2, 3, 4, 5), 7])
+def test_bbox_with_the_wrong_shape_is_rejected_before_any_request(bad: object) -> None:
+    calls: list[httpx.Request] = []
+    with _sync_client(calls) as o:
+        with pytest.raises(ValueError, match="west, south, east, north"):
+            o.get_feed(bbox=bad)
+    assert calls == []