diff --git a/docs/now/2026-09-20-published-test-the-1-untested-function-in-specs-fpga-router-t27.md b/docs/now/2026-09-20-published-test-the-1-untested-function-in-specs-fpga-router-t27.md
new file mode 100644
index 000000000..569501aa4
--- /dev/null
+++ b/docs/now/2026-09-20-published-test-the-1-untested-function-in-specs-fpga-router-t27.md
@@ -0,0 +1,11 @@
+# NOW -- Test the 1 untested function in specs/fpga/router.t27 (published 2026-09-20)
+
+## A bee's work on #4448, published from `queen-4448` (Closes #4448)
+
+- The branch changes 1 file(s): `specs/fpga/router.t27`.
+- `git diff --stat origin/master...queen-4448` reads: 1 file changed, 15 insertions(+)
+- This entry is written by the publisher, not by the bee. A pull request must
+  add exactly one `docs/now/` entry and a bee has no way to know that: its brief
+  names a boundary file and acceptance criteria, and `docs/now/` is neither.
+- What this entry does NOT establish: that the work is correct. The gates on the
+  pull request judge that, and they are the same gates every other change meets.
diff --git a/docs/now/2026-09-22-published-test-the-1-untested-function-in-specs-fpga-router-t27.md b/docs/now/2026-09-22-published-test-the-1-untested-function-in-specs-fpga-router-t27.md
new file mode 100644
index 000000000..78fac1597
--- /dev/null
+++ b/docs/now/2026-09-22-published-test-the-1-untested-function-in-specs-fpga-router-t27.md
@@ -0,0 +1,11 @@
+# NOW -- Test the 1 untested function in specs/fpga/router.t27 (published 2026-09-22)
+
+## A bee's work on #4448, published from `queen-4448` (Closes #4448)
+
+- The branch changes 2 file(s): `docs/now/2026-09-20-published-test-the-1-untested-function-in-specs-fpga-router-t27.md`, `specs/fpga/router.t27`.
+- `git diff --stat origin/master...queen-4448` reads: 2 files changed, 26 insertions(+)
+- This entry is written by the publisher, not by the bee. A pull request must
+  add exactly one `docs/now/` entry and a bee has no way to know that: its brief
+  names a boundary file and acceptance criteria, and `docs/now/` is neither.
+- What this entry does NOT establish: that the work is correct. The gates on the
+  pull request judge that, and they are the same gates every other change meets.
diff --git a/specs/fpga/router.t27 b/specs/fpga/router.t27
index 2423b268c..f9a6fc981 100644
--- a/specs/fpga/router.t27
+++ b/specs/fpga/router.t27
@@ -233,6 +233,21 @@ module Router {
         given e = ConnEdge{.source = "", .sink = "", .kind = 0, .bit_width = 0}
         then validate_edge(e) > 0
 
+    test est_total_wire_basic
+        given edges = [data_edge("a", "b", 32), data_edge("c", "d", 16)]
+        and fanouts = [fanout("net1", 2, 32), fanout("net2", 8, 16), fanout("net3", 32, 8)]
+        then est_total_wire(edges, 2, fanouts, 3) == 88000
+
+    test est_total_wire_zero_fcount
+        given edges = [data_edge("a", "b", 32)]
+        and fanouts = [fanout("net1", 4, 32)]
+        then est_total_wire(edges, 1, fanouts, 0) == 0
+
+    test est_total_wire_zero_fanout
+        given edges = [data_edge("a", "b", 32)]
+        and fanouts = [fanout("net1", 0, 32)]
+        then est_total_wire(edges, 1, fanouts, 1) == 0
+
     // === Invariants ===
 
     invariant wire_length_non_negative