diff --git a/wasm-port/docs/porting-steps-standalone.md b/wasm-port/docs/porting-steps-standalone.md
index 39e20c9..6216104 100644
--- a/wasm-port/docs/porting-steps-standalone.md
+++ b/wasm-port/docs/porting-steps-standalone.md
@@ -396,6 +396,13 @@ Current verified progress:
   `tests/fixtures/gcode/probe_semantics.ngc` and
   `tests/fixtures/canon/probe_semantics.events` pin `G38.2`, `G38.3`,
   `G38.4`, and `G38.5` probe type handling.
+- `runtime/core/linuxcnc_wrap/linuxcnc_interp_minimal_runtime.cpp` now records
+  speed/feed synchronization and rigid-tap canonical boundary calls emitted by
+  vendored `interp_convert.cc::convert_straight()`: `START_SPEED_FEED_SYNCH`,
+  `STOP_SPEED_FEED_SYNCH`, and `RIGID_TAP`.
+  `tests/fixtures/gcode/threading_sync.ngc` and
+  `tests/fixtures/canon/threading_sync.events` pin `G33` spindle-synchronized
+  straight feed and `G33.1` rigid tap behavior.
 - `tests/fixtures/gcode_errors/g1_zero_feed.ngc` and
   `tests/fixtures/canon_errors/g1_zero_feed.expected` pin the negative
   `G1` zero-feed case. The source basis is LinuxCNC
diff --git a/wasm-port/runtime/core/linuxcnc_wrap/linuxcnc_interp_minimal_runtime.cpp b/wasm-port/runtime/core/linuxcnc_wrap/linuxcnc_interp_minimal_runtime.cpp
index fb079e4..3605056 100644
--- a/wasm-port/runtime/core/linuxcnc_wrap/linuxcnc_interp_minimal_runtime.cpp
+++ b/wasm-port/runtime/core/linuxcnc_wrap/linuxcnc_interp_minimal_runtime.cpp
@@ -154,9 +154,25 @@ void SET_NAIVECAM_TOLERANCE(double tolerance)
 void SET_CUTTER_RADIUS_COMPENSATION(double) {}
 void START_CUTTER_RADIUS_COMPENSATION(int) {}
 void STOP_CUTTER_RADIUS_COMPENSATION() {}
-void START_SPEED_FEED_SYNCH(int, double, bool) {}
-void STOP_SPEED_FEED_SYNCH() {}
-void RIGID_TAP(int, double, double, double, double) {}
+void START_SPEED_FEED_SYNCH(int spindle, double feed_per_revolution, bool velocity_mode)
+{
+    std::ostringstream oss;
+    oss << "START_SPEED_FEED_SYNCH spindle=" << spindle
+        << " feed_per_revolution=" << feed_per_revolution
+        << " velocity_mode=" << velocity_mode;
+    standalone::push_canon_event(oss.str());
+}
+void STOP_SPEED_FEED_SYNCH() { standalone::push_canon_event("STOP_SPEED_FEED_SYNCH"); }
+void RIGID_TAP(int lineno, double x, double y, double z, double scale)
+{
+    std::ostringstream oss;
+    oss << "RIGID_TAP line=" << lineno
+        << " x=" << x
+        << " y=" << y
+        << " z=" << z
+        << " scale=" << scale;
+    standalone::push_canon_event(oss.str());
+}
 void STRAIGHT_PROBE(int lineno,
                     double x, double y, double z,
                     double a, double b, double c,
diff --git a/wasm-port/tests/fixtures/canon/threading_sync.events b/wasm-port/tests/fixtures/canon/threading_sync.events
new file mode 100644
index 0000000..8757a8f
--- /dev/null
+++ b/wasm-port/tests/fixtures/canon/threading_sync.events
@@ -0,0 +1,11 @@
+canon_event=SELECT_PLANE plane=1
+canon_event=STRAIGHT_TRAVERSE line=1 x=0 y=0 z=0 a=0 b=0 c=0 u=0 v=0 w=0
+canon_event=SET_SPINDLE_SPEED spindle=0 speed=600
+canon_event=START_SPINDLE_CLOCKWISE spindle=0 wait_for_at_speed=1
+canon_event=START_SPEED_FEED_SYNCH spindle=0 feed_per_revolution=0.05 velocity_mode=0
+canon_event=STRAIGHT_FEED line=3 x=0 y=0 z=-1 a=0 b=0 c=0 u=0 v=0 w=0
+canon_event=STOP_SPEED_FEED_SYNCH
+canon_event=START_SPEED_FEED_SYNCH spindle=0 feed_per_revolution=0.05 velocity_mode=0
+canon_event=RIGID_TAP line=4 x=0 y=0 z=0 scale=2
+canon_event=STOP_SPEED_FEED_SYNCH
+canon_event=STOP_SPINDLE_TURNING spindle=0
diff --git a/wasm-port/tests/fixtures/gcode/threading_sync.ngc b/wasm-port/tests/fixtures/gcode/threading_sync.ngc
new file mode 100644
index 0000000..839e776
--- /dev/null
+++ b/wasm-port/tests/fixtures/gcode/threading_sync.ngc
@@ -0,0 +1,5 @@
+G90 G17 G0 X0 Y0 Z0
+S600 M3
+G33 Z-1 K0.05
+G33.1 Z0 K0.05 I2
+M5