diff --git a/codegen/src/generator.rs b/codegen/src/generator.rs
index a465fb5..baf7cc8 100644
--- a/codegen/src/generator.rs
+++ b/codegen/src/generator.rs
@@ -20,7 +20,7 @@ use comline_codegen::{GenRequest, GeneratedFile, Mode, PackageMeta};
 /// `comline-runtime` — the crate the generated RPC code links against. Pinned
 /// by git rev (no crates.io yet); see design/runtime-repo-structure.md.
 const RUNTIME_GIT: &str = "https://github.com/ComlineProject/runtime";
-const RUNTIME_REV: &str = "435b7e833f970fadf4edbedcade20037143713d5";
+const RUNTIME_REV: &str = "0501812f57817d7b11165bc6a24f54afa45acb16";
 
 pub fn generate_rust(req: &GenRequest) -> Result<Vec<GeneratedFile>> {
     match req.mode {
@@ -240,6 +240,9 @@ struct FnInfo {
     /// explicit `-> ()` (`KindValue::Unit`) is *not* this — it's a normal
     /// request/response with an empty ack (§4.4).
     one_way: bool,
+    /// `@timeout_ms = N` on the function — the client method calls
+    /// `Client::call_with_timeout` with `Duration::from_millis(N)`.
+    timeout_ms: Option<u64>,
 }
 
 fn protocol(proto: &str, functions: &[FrozenUnit], errors: &HashMap<u16, String>) -> String {
@@ -248,11 +251,14 @@ fn protocol(proto: &str, functions: &[FrozenUnit], errors: &HashMap<u16, String>
         .filter_map(|f| match f {
             FrozenUnit::Function {
                 name,
+                parameters,
                 arguments,
                 _return,
                 throws,
                 ..
-            } => Some(fn_info(proto, name, arguments, _return, throws, errors)),
+            } => Some(fn_info(
+                proto, name, parameters, arguments, _return, throws, errors,
+            )),
             _ => None,
         })
         .collect();
@@ -455,9 +461,13 @@ fn protocol(proto: &str, functions: &[FrozenUnit], errors: &HashMap<u16, String>
             "    pub fn {}(&mut self{args}) -> Result<{}, CallError<{}>> {{",
             f.name, f.ret, f.err_ty
         ));
-        l.push(format!(
-            "        let (reply, fmt) = self.0.call({i}u16, {param_expr})?;"
-        ));
+        let call = match f.timeout_ms {
+            Some(ms) => format!(
+                "self.0.call_with_timeout({i}u16, {param_expr}, core::time::Duration::from_millis({ms}))"
+            ),
+            None => format!("self.0.call({i}u16, {param_expr})"),
+        };
+        l.push(format!("        let (reply, fmt) = {call}?;"));
         l.push("        match reply {".into());
         l.push(
             "            Envelope::Ok(payload) => fmt.decode(payload).map_err(CallError::Runtime),"
@@ -490,12 +500,14 @@ fn protocol(proto: &str, functions: &[FrozenUnit], errors: &HashMap<u16, String>
 fn fn_info(
     proto: &str,
     name: &str,
+    parameters: &[FrozenUnit],
     arguments: &[FrozenArgument],
     ret: &Option<KindValue>,
     throws: &[u16],
     errors: &HashMap<u16, String>,
 ) -> FnInfo {
     let pascal_fn = pascal(name);
+    let timeout_ms = annotation(parameters, "timeout_ms").and_then(|v| v.parse::<u64>().ok());
     let args: Vec<Arg> = arguments
         .iter()
         .map(|a| {
@@ -541,9 +553,19 @@ fn fn_info(
         err_ty: format!("{proto}{pascal_fn}Error"),
         throws,
         one_way,
+        timeout_ms,
     }
 }
 
+/// The value of a scalar `@key = value` annotation (frozen as
+/// `FrozenUnit::Property`), by key.
+fn annotation<'a>(parameters: &'a [FrozenUnit], key: &str) -> Option<&'a str> {
+    parameters.iter().find_map(|p| match p {
+        FrozenUnit::Property { name, expression } if name == key => expression.as_deref(),
+        _ => None,
+    })
+}
+
 /// `(signature type, params-struct field type)` for a function argument.
 /// A `str` / `string` arg is passed by reference and decoded borrowed from
 /// the receive buffer; everything else is owned (borrowed arrays / nested
diff --git a/codegen/tests/compiles.rs b/codegen/tests/compiles.rs
index c4466e5..5e3800b 100644
--- a/codegen/tests/compiles.rs
+++ b/codegen/tests/compiles.rs
@@ -101,6 +101,19 @@ fn chat_schema() -> Vec<FrozenUnit> {
                 ),
                 function("wipe", vec![], Some(KindValue::Unit), vec![]),
                 function("poke", vec![], None, vec![]),
+                // @timeout_ms = 3000 → the client emits `call_with_timeout`
+                FrozenUnit::Function {
+                    docstring: String::new(),
+                    parameters: vec![FrozenUnit::Property {
+                        name: "timeout_ms".into(),
+                        expression: Some("3000".into()),
+                    }],
+                    name: "await_ack".into(),
+                    arguments: vec![arg("token", KindValue::Namespaced("string".into(), None))],
+                    _return: Some(KindValue::Unit),
+                    throws: vec![],
+                    span: (0, 0),
+                },
             ],
             span: (0, 0),
         },
diff --git a/codegen/tests/generate.rs b/codegen/tests/generate.rs
index 90afed7..8157547 100644
--- a/codegen/tests/generate.rs
+++ b/codegen/tests/generate.rs
@@ -219,6 +219,48 @@ fn protocol_errors_map_to_ordinals_and_a_union() {
     assert!(src.contains("self.0.notify(2u16, &ChatPokeParams { note })"));
 }
 
+#[test]
+fn timeout_ms_annotation_emits_call_with_timeout() {
+    let proto = FrozenUnit::Protocol {
+        docstring: "Api".to_string(),
+        parameters: vec![],
+        name: "Api".to_string(),
+        functions: vec![
+            // @timeout_ms = 2500
+            FrozenUnit::Function {
+                docstring: String::new(),
+                name: "slow".to_string(),
+                parameters: vec![FrozenUnit::Property {
+                    name: "timeout_ms".to_string(),
+                    expression: Some("2500".to_string()),
+                }],
+                arguments: vec![],
+                _return: Some(KindValue::Primitive(Primitive::U32(None))),
+                throws: vec![],
+                span: (0, 0),
+            },
+            // no annotation
+            FrozenUnit::Function {
+                docstring: String::new(),
+                name: "fast".to_string(),
+                parameters: vec![],
+                arguments: vec![],
+                _return: Some(KindValue::Primitive(Primitive::U32(None))),
+                throws: vec![],
+                span: (0, 0),
+            },
+        ],
+        span: (0, 0),
+    };
+    let schemas = vec![("api".to_string(), vec![proto])];
+    let src = generate_rust(&code_req(&schemas)).unwrap().remove(0).contents;
+
+    assert!(src.contains(
+        "self.0.call_with_timeout(0u16, &(), core::time::Duration::from_millis(2500))?;"
+    ));
+    assert!(src.contains("self.0.call(1u16, &())?;"));
+}
+
 #[test]
 fn an_all_one_way_protocol_leaves_the_dispatch_out_param_unbound() {
     let proto = FrozenUnit::Protocol {