diff --git a/check-linuxcnc-tooldata-source-map.sh b/check-linuxcnc-tooldata-source-map.sh
index 656dc85..d782782 100755
--- a/check-linuxcnc-tooldata-source-map.sh
+++ b/check-linuxcnc-tooldata-source-map.sh
@@ -28,6 +28,14 @@ grep -F 'int tool_nml_register(CANON_TOOL_TABLE *tblptr)' \
     "$linuxcnc_root/src/emc/tooldata/tooldata_nml.cc" >/dev/null
 grep -F 'int tooldata_db_init(char progname_plus_args[]' \
     "$linuxcnc_root/src/emc/tooldata/tooldata_db.cc" >/dev/null
+grep -F 'int tooldata_db_getall() {' \
+    "$linuxcnc_root/src/emc/tooldata/tooldata_db.cc" >/dev/null
+grep -F 'if (!db_live) {return -1;}' \
+    "$linuxcnc_root/src/emc/tooldata/tooldata_db.cc" >/dev/null
+grep -F 'int tooldata_db_notify(tool_notify_t ntype,' \
+    "$linuxcnc_root/src/emc/tooldata/tooldata_db.cc" >/dev/null
+grep -F 'if (!db_live) return 0;' \
+    "$linuxcnc_root/src/emc/tooldata/tooldata_db.cc" >/dev/null
 grep -F 'int tooldata_read_entry(const char *input_line)' \
     "$linuxcnc_root/src/emc/tooldata/tooldata_common.cc" >/dev/null
 
@@ -64,10 +72,13 @@ grep -F 'LinuxCNC source basis: src/emc/tooldata/tooldata_mmap.cc provides these
     core/wasm_shims/tooldata/tooldata_mmap_backend.cc >/dev/null
 grep -F 'LinuxCNC source basis: src/emc/tooldata/tooldata_nml.cc and tooldata_db.cc' \
     core/wasm_shims/tooldata/tooldata_runtime_stubs.cc >/dev/null
+grep -F 'returns 0 when' core/wasm_shims/tooldata/tooldata_runtime_stubs.cc >/dev/null
 grep -F 'LinuxCNC source basis: src/emc/tooldata/tooldata_common.cc provides' \
     core/wasm_shims/tooldata/tooldata_common_probe_main.cc >/dev/null
 grep -F 'LinuxCNC source basis: src/emc/tooldata/tooldata_mmap.cc, tooldata_nml.cc,' \
     core/wasm_shims/tooldata/tooldata_probe_main.cc >/dev/null
+grep -F 'tooldata_db_notify() returns 0 without side effects while db_live is' \
+    core/wasm_shims/tooldata/tooldata_probe_main.cc >/dev/null
 grep -F 'core/wasm_shims/tooldata/tooldata_mmap_backend.cc' docs/linuxcnc-wasm-shims-source-map.md >/dev/null
 grep -F 'core/wasm_shims/tooldata/tooldata_runtime_stubs.cc' docs/linuxcnc-wasm-shims-source-map.md >/dev/null
 
@@ -129,6 +140,7 @@ for phrase in [
     "source coverage only",
     "must not become browser API fields",
     "WASM-safe tooldata shims must preserve the LinuxCNC export surface",
+    "inactive-DB return values",
     "./check-linuxcnc-tooldata-source-map.sh",
 ]:
     if phrase not in doc:
diff --git a/check-linuxcnc-wasm-shims-source-map.sh b/check-linuxcnc-wasm-shims-source-map.sh
index 67ad9a1..dfdacc1 100755
--- a/check-linuxcnc-wasm-shims-source-map.sh
+++ b/check-linuxcnc-wasm-shims-source-map.sh
@@ -36,6 +36,8 @@ grep -F 'PythonPlugin::instantiate' "$linuxcnc_root/src/emc/pythonplugin/python_
 grep -F '#define TOOL_MMAP_FILENAME ".tool.mmap"' "$linuxcnc_root/src/emc/tooldata/tooldata_mmap.cc" >/dev/null
 grep -F 'int tool_nml_register(CANON_TOOL_TABLE *tblptr)' "$linuxcnc_root/src/emc/tooldata/tooldata_nml.cc" >/dev/null
 grep -F 'int tooldata_db_init(char progname_plus_args[]' "$linuxcnc_root/src/emc/tooldata/tooldata_db.cc" >/dev/null
+grep -F 'if (!db_live) {return -1;}' "$linuxcnc_root/src/emc/tooldata/tooldata_db.cc" >/dev/null
+grep -F 'if (!db_live) return 0;' "$linuxcnc_root/src/emc/tooldata/tooldata_db.cc" >/dev/null
 
 python3 - "$manifest" <<'PY'
 from pathlib import Path
@@ -115,6 +117,7 @@ for phrase in [
     "CMake `linuxcnc_wasm_safe_probe_shims` set",
     "RS274/WASM manifest",
     "browser-safe LinuxCNC adaptations",
+    "inactive-DB return values",
 ]:
     if phrase not in source_map:
         raise SystemExit(f"docs/linuxcnc-wasm-shims-source-map.md missing boundary phrase: {phrase}")
diff --git a/core/wasm_shims/tooldata/tooldata_probe_main.cc b/core/wasm_shims/tooldata/tooldata_probe_main.cc
index 77497e9..e524516 100644
--- a/core/wasm_shims/tooldata/tooldata_probe_main.cc
+++ b/core/wasm_shims/tooldata/tooldata_probe_main.cc
@@ -113,6 +113,18 @@ int main() {
     if (tooldata_db_getall() != -1) {
         return 28;
     }
+    // LinuxCNC source basis: src/emc/tooldata/tooldata_db.cc
+    // tooldata_db_notify() returns 0 without side effects while db_live is
+    // false, which is the browser-safe shim state for external DB services.
+    if (tooldata_db_notify(SPINDLE_LOAD, 7, 12, uncreated_tool) != 0) {
+        return 57;
+    }
+    if (tooldata_db_notify(SPINDLE_UNLOAD, 7, 12, uncreated_tool) != 0) {
+        return 58;
+    }
+    if (tooldata_db_notify(TOOL_OFFSET, 7, 12, uncreated_tool) != 0) {
+        return 59;
+    }
     std::string missing_db_program_with_arg_string =
         make_temp_path("cnc_tooldata_probe_missing_db_program arg");
     std::vector<char> missing_db_program_with_arg(
diff --git a/core/wasm_shims/tooldata/tooldata_runtime_stubs.cc b/core/wasm_shims/tooldata/tooldata_runtime_stubs.cc
index 04223e7..b66dd4c 100644
--- a/core/wasm_shims/tooldata/tooldata_runtime_stubs.cc
+++ b/core/wasm_shims/tooldata/tooldata_runtime_stubs.cc
@@ -48,6 +48,8 @@ int tooldata_db_init(char progname_plus_args[], int) {
 }
 
 int tooldata_db_notify(tool_notify_t, int, int, CANON_TOOL_TABLE) {
+    // LinuxCNC source basis: src/emc/tooldata/tooldata_db.cc returns 0 when
+    // db_live is false, before formatting or sending any DB notification.
     return 0;
 }
 
diff --git a/docs/linuxcnc-tooldata-source-map.md b/docs/linuxcnc-tooldata-source-map.md
index c5b21c3..20f36d1 100644
--- a/docs/linuxcnc-tooldata-source-map.md
+++ b/docs/linuxcnc-tooldata-source-map.md
@@ -15,6 +15,9 @@ source-link/shim guard only; it must not add CNC behavior and must not expand th
 - `src/emc/tooldata/tooldata_nml.cc` provides the NML tool table registration
   backend selected by `TOOL_NML_FLAG`.
 - `src/emc/tooldata/tooldata_db.cc` provides external database entry points.
+- `src/emc/tooldata/tooldata_db.cc` returns `-1` from
+  `tooldata_db_getall()` when the external DB is not live, and returns `0`
+  from `tooldata_db_notify()` without side effects in that same state.
 - `src/emc/tooldata/tool_mmap_read.cc` and `src/emc/tooldata/tool_watch.cc` are
   utility sources from the same LinuxCNC tooldata build metadata.
 - `src/emc/tooldata/tooldata.hh` declares the tooldata API used by RS274 and
@@ -40,6 +43,8 @@ source-link/shim guard only; it must not add CNC behavior and must not expand th
   they must not become browser API fields or generated switchkins aliases.
 - WASM-safe tooldata shims must preserve the LinuxCNC export surface checked by
   symbol probes.
+- WASM-safe tooldata runtime stubs must keep external database services
+  unavailable while preserving LinuxCNC inactive-DB return values.
 - Native and source-link paths must keep the full LinuxCNC `src/emc/tooldata`
   source directory tracked in the native RS274 manifest.
 - `build-wasm.sh` must run tooldata link and symbol probes before copying
diff --git a/docs/linuxcnc-wasm-shims-source-map.md b/docs/linuxcnc-wasm-shims-source-map.md
index 9378008..d7fbcb4 100644
--- a/docs/linuxcnc-wasm-shims-source-map.md
+++ b/docs/linuxcnc-wasm-shims-source-map.md
@@ -23,7 +23,7 @@ only; it must not add CNC behavior and must not expand the temporary smoke parse
 | `core/wasm_shims/rcs_print_shim.cc` | `src/libnml/rcs/rcs_print.cc` | Provides LinuxCNC RCS print diagnostics used by NML validation. |
 | `core/wasm_shims/rtapi_compat.cc` | `src/rtapi/uspace_common.h`, `src/rtapi/rtapi.h` | Provides userspace RTAPI formatting declarations used by RS274/NML code. |
 | `core/wasm_shims/tooldata/tooldata_mmap_backend.cc` | `src/emc/tooldata/tooldata_mmap.cc` | Replaces native mmap storage with an in-memory WASM-safe backend for probes. |
-| `core/wasm_shims/tooldata/tooldata_runtime_stubs.cc` | `src/emc/tooldata/tooldata_nml.cc`, `src/emc/tooldata/tooldata_db.cc` | Satisfies NML and external tool database entry points without native services. |
+| `core/wasm_shims/tooldata/tooldata_runtime_stubs.cc` | `src/emc/tooldata/tooldata_nml.cc`, `src/emc/tooldata/tooldata_db.cc` | Satisfies NML and external tool database entry points without native services, preserving inactive-DB return values. |
 | `core/wasm_shims/pythonplugin/python_plugin.cc` | `src/emc/pythonplugin/python_plugin.cc`, `src/emc/pythonplugin/python_plugin.hh` | Keeps LinuxCNC PythonPlugin API available while Python execution is disabled for browser-safe probes. |
 
 ## Boundaries