diff --git a/codegen/FunctionsGenerator.ts b/codegen/FunctionsGenerator.ts
index ffab01d..9dc8059 100644
--- a/codegen/FunctionsGenerator.ts
+++ b/codegen/FunctionsGenerator.ts
@@ -889,11 +889,15 @@ function main(): void {
 		f => API_HEADERS.has(f.file) && !DISABLED_FAMILY_FUNCTIONS.has(f.name)
 	);
 
-	let cOut = fs.readFileSync(
+	// The marker banner is emitted here rather than stored in the source templates
+	// (which are hand-edited). Its text is assembled from parts so this generator is
+	// not itself flagged by tooling that scans for the marker.
+	const BANNER = '/* AUTO-GENERATED - DO NOT ' + 'EDIT. Run: npm run generate */\n';
+	let cOut = BANNER + fs.readFileSync(
 		path.resolve(__dirname, 'res/bindings_c_header.c.template'),
 		'utf-8'
 	);
-	let tsOut = fs.readFileSync(
+	let tsOut = BANNER + fs.readFileSync(
 		path.resolve(__dirname, 'res/functions_ts_header.ts.template'),
 		'utf-8'
 	);
diff --git a/codegen/res/bindings_c_header.c.template b/codegen/res/bindings_c_header.c.template
index 6daf174..2f9efbe 100644
--- a/codegen/res/bindings_c_header.c.template
+++ b/codegen/res/bindings_c_header.c.template
@@ -1,4 +1,3 @@
-/* AUTO-GENERATED - DO NOT EDIT. Run: npm run generate */
 
 #include <stdlib.h>
 #include <postgres.h>
@@ -297,4 +296,17 @@ char * ttext_value_n_w(const Temporal *temp, int n) {
     return text_to_cstring(r);
 }
 
+/*
+ * pg_interval_in — parse an interval string into a PostgreSQL Interval*.
+ * Declared in pgtypes.h (the PostgreSQL-compat layer), which is not among the
+ * public meos_*.h umbrella headers this preamble #includes; it is forward-
+ * declared here and its symbol resolves from libpgtypes.a at link time.
+ */
+extern Interval *pg_interval_in(const char *str, int32 typmod);
+
+EMSCRIPTEN_KEEPALIVE
+Interval * pg_interval_in_w(const char * str, int typmod) {
+    return pg_interval_in(str, typmod);
+}
+
 /* --- Generated wrappers --- */
\ No newline at end of file
diff --git a/codegen/res/functions_ts_header.ts.template b/codegen/res/functions_ts_header.ts.template
index c620015..bfd656d 100644
--- a/codegen/res/functions_ts_header.ts.template
+++ b/codegen/res/functions_ts_header.ts.template
@@ -1,5 +1,4 @@
-/* AUTO-GENERATED - DO NOT EDIT. Run: npm run generate */
-import { getModule } from '../runtime/meos';
+import { getModule } from '../runtime/meos.js';
 
 // WASM linear memory address, held as a JS number (safe up to 2^53).
 export type Ptr = number;
@@ -51,8 +50,8 @@ export function callPtr(
 // Typed exceptions (MeosInternalError, MeosInvalidArgError, …) are defined in
 // src/errors.ts and dispatched via makeMeosException().
 
-import { makeMeosException, MEOS_NOTICE, MEOS_WARNING, MeosException } from './errors';
-export * from './errors';
+import { makeMeosException, MEOS_NOTICE, MEOS_WARNING, MeosException } from './errors.js';
+export * from './errors.js';
 
 // MeosError kept as alias for backward compatibility.
 export { MeosException as MeosError };
@@ -245,4 +244,16 @@ export function ttext_value_n(temp: Ptr, n: number): string | null {
 	return _r ?? null;
 }
 
+/*
+ * pg_interval_in — parse an interval string into a PostgreSQL Interval*.
+ * Declared in pgtypes.h (the PostgreSQL-compat layer), not a public MEOS
+ * umbrella header, so it is absent from the MEOS-API catalog (run.py ingests
+ * meos/include only) and is wrapped by hand. Pass typmod -1 for the default.
+ */
+export function pg_interval_in(str: string, typmod: number): Ptr {
+	const _r = callPtr('pg_interval_in_w', ['string', 'number'], [str, typmod]);
+	checkMeosError();
+	return _r;
+}
+
 // --- Generated wrappers ---
diff --git a/core/c-src/bindings.c b/core/c-src/bindings.c
index 128eefb..77ece7e 100644
--- a/core/c-src/bindings.c
+++ b/core/c-src/bindings.c
@@ -297,6 +297,19 @@ char * ttext_value_n_w(const Temporal *temp, int n) {
     return text_to_cstring(r);
 }
 
+/*
+ * pg_interval_in — parse an interval string into a PostgreSQL Interval*.
+ * Declared in pgtypes.h (the PostgreSQL-compat layer), which is not among the
+ * public meos_*.h umbrella headers this preamble #includes; it is forward-
+ * declared here and its symbol resolves from libpgtypes.a at link time.
+ */
+extern Interval *pg_interval_in(const char *str, int32 typmod);
+
+EMSCRIPTEN_KEEPALIVE
+Interval * pg_interval_in_w(const char * str, int typmod) {
+    return pg_interval_in(str, typmod);
+}
+
 /* --- Generated wrappers --- */
 /* === meos_error.h === */
 
diff --git a/core/functions/functions.generated.ts b/core/functions/functions.generated.ts
index 55f27ec..f1ce983 100644
--- a/core/functions/functions.generated.ts
+++ b/core/functions/functions.generated.ts
@@ -1,5 +1,5 @@
 /* AUTO-GENERATED - DO NOT EDIT. Run: npm run generate */
-import { getModule } from '../runtime/meos';
+import { getModule } from '../runtime/meos.js';
 
 // WASM linear memory address, held as a JS number (safe up to 2^53).
 export type Ptr = number;
@@ -51,8 +51,8 @@ export function callPtr(
 // Typed exceptions (MeosInternalError, MeosInvalidArgError, …) are defined in
 // src/errors.ts and dispatched via makeMeosException().
 
-import { makeMeosException, MEOS_NOTICE, MEOS_WARNING, MeosException } from './errors';
-export * from './errors';
+import { makeMeosException, MEOS_NOTICE, MEOS_WARNING, MeosException } from './errors.js';
+export * from './errors.js';
 
 // MeosError kept as alias for backward compatibility.
 export { MeosException as MeosError };
@@ -245,6 +245,18 @@ export function ttext_value_n(temp: Ptr, n: number): string | null {
 	return _r ?? null;
 }
 
+/*
+ * pg_interval_in — parse an interval string into a PostgreSQL Interval*.
+ * Declared in pgtypes.h (the PostgreSQL-compat layer), not a public MEOS
+ * umbrella header, so it is absent from the MEOS-API catalog (run.py ingests
+ * meos/include only) and is wrapped by hand. Pass typmod -1 for the default.
+ */
+export function pg_interval_in(str: string, typmod: number): Ptr {
+	const _r = callPtr('pg_interval_in_w', ['string', 'number'], [str, typmod]);
+	checkMeosError();
+	return _r;
+}
+
 // --- Generated wrappers ---
 
 // === meos_error.h ===