diff --git a/changelog.d/7010-proc-ipc-gate.md b/changelog.d/7010-proc-ipc-gate.md
new file mode 100644
index 0000000000..51de5b09ff
--- /dev/null
+++ b/changelog.d/7010-proc-ipc-gate.md
@@ -0,0 +1 @@
+**Binary size:** `process.send`/`disconnect`/`connected`/`channel` now sit behind a default-on `proc-ipc` feature the compiler enables on any of those property tokens. The IPC send path JSON-serializes every message, so the always-live process-namespace property lookup was statically pinning the whole JSON serializer into binaries that never touch IPC. Detection is deliberately broad (any `send`/`disconnect`/`connected`/`channel` mention enables it) because a miss would leave `process.send` undefined at runtime. Hello world: −16.5 KB (4,245,216 → 4,228,680 bytes).
diff --git a/crates/perry-runtime/Cargo.toml b/crates/perry-runtime/Cargo.toml
index 5bdeecd7e3..513446f015 100644
--- a/crates/perry-runtime/Cargo.toml
+++ b/crates/perry-runtime/Cargo.toml
@@ -22,7 +22,7 @@ crate-type = ["rlib"]
 # actually needs (see optimized_libs.rs), so the heavy subsystems below
 # (regex engine, Temporal, URL/IDNA, normalize, segmenter) are *opt-in per
 # app* and absent from binaries that never use them.
-default = ["full", "regex-engine", "temporal", "url-engine", "string-normalize", "intl-segmenter", "intl-namespace", "global-math", "global-json", "global-reflect", "global-atomics", "global-url", "global-text", "global-websocket", "global-webcrypto", "global-webfetch", "intl-locale", "intl-datetime", "diagnostics", "mod-dgram", "mod-http2-constants", "dyn-eval", "keepalive-anchors", "alloc-mimalloc"]
+default = ["full", "regex-engine", "temporal", "url-engine", "string-normalize", "intl-segmenter", "intl-namespace", "global-math", "global-json", "global-reflect", "global-atomics", "global-url", "global-text", "global-websocket", "global-webcrypto", "global-webfetch", "proc-ipc", "intl-locale", "intl-datetime", "diagnostics", "mod-dgram", "mod-http2-constants", "dyn-eval", "keepalive-anchors", "alloc-mimalloc"]
 # Compile the ~490 `#[used]` keep-alive anchor statics (`KEEP_*`, `keep!`,
 # `K*`/`G*` fn-pointer statics) that pin codegen-facing `#[no_mangle]` entry
 # points as dead-strip roots. They exist for the whole-program bitcode-LTO
@@ -155,6 +155,13 @@ global-text = []
 global-websocket = []
 global-webcrypto = []
 global-webfetch = []
+# `process.send` / `disconnect` / `connected` / `channel` — the child-process
+# IPC channel. The send path JSON-serializes every message, so the always-live
+# process-namespace property lookup statically pinned the whole `crate::json`
+# serializer (~84 KB) into binaries that never touch IPC. The compiler enables
+# this on any of the four property tokens (over-approximate: a missed
+# detection would make `process.send` undefined, so err toward enabling).
+proc-ipc = []
 # `Intl.getCanonicalLocales` / `*.supportedLocalesOf` BCP-47 (UTS #35) language-tag
 # canonicalization via `icu_locale_core` (the data-free structural parser — case
 # normalization, variant ordering, extension well-formedness, UTS35 rejection of
diff --git a/crates/perry-runtime/src/process/ipc.rs b/crates/perry-runtime/src/process/ipc.rs
index 2a938cfbad..f133e83118 100644
--- a/crates/perry-runtime/src/process/ipc.rs
+++ b/crates/perry-runtime/src/process/ipc.rs
@@ -202,6 +202,17 @@ fn ipc_is_connected() -> bool {
     state.available && state.connected
 }
 
+/// IPC-backed `process` properties. Behind `proc-ipc` (default-on, compiler
+/// detected): with the feature off the channel can never be used by this
+/// program, so returning `None` keeps the always-live process-namespace
+/// lookup from statically pinning the IPC send path and, through it, the JSON
+/// serializer.
+#[cfg(not(feature = "proc-ipc"))]
+pub(crate) fn process_ipc_property(_name: &str) -> Option<f64> {
+    None
+}
+
+#[cfg(feature = "proc-ipc")]
 pub(crate) fn process_ipc_property(name: &str) -> Option<f64> {
     match name {
         "send" | "disconnect" | "connected" | "channel" => {}
diff --git a/crates/perry/src/commands/compile/collect_modules/feature_detect.rs b/crates/perry/src/commands/compile/collect_modules/feature_detect.rs
index 9f939f6b81..2c9fd1ce0b 100644
--- a/crates/perry/src/commands/compile/collect_modules/feature_detect.rs
+++ b/crates/perry/src/commands/compile/collect_modules/feature_detect.rs
@@ -363,6 +363,18 @@ pub(super) fn detect_optional_feature_usage(
         {
             ctx.uses_global_webfetch = true;
         }
+        // `process` IPC channel properties. Bare-token matching on purpose:
+        // the property name reaches the runtime as a string, so any `send` /
+        // `disconnect` / `connected` / `channel` mention enables the path. A
+        // miss would make `process.send` undefined at runtime, so this errs
+        // heavily toward enabling.
+        if hir_debug.contains("\"send\"")
+            || hir_debug.contains("\"disconnect\"")
+            || hir_debug.contains("\"connected\"")
+            || hir_debug.contains("\"channel\"")
+        {
+            ctx.uses_proc_ipc = true;
+        }
         // `Intl.getCanonicalLocales(...)` / `Intl.*.supportedLocalesOf(...)` gate
         // `perry-runtime/intl-locale` (`icu_locale_core` BCP-47 canonicalization).
         // Both lower with the method name as a `property` token.
diff --git a/crates/perry/src/commands/compile/optimized_libs/freshness.rs b/crates/perry/src/commands/compile/optimized_libs/freshness.rs
index cf2470591b..c4e3e7e2be 100644
--- a/crates/perry/src/commands/compile/optimized_libs/freshness.rs
+++ b/crates/perry/src/commands/compile/optimized_libs/freshness.rs
@@ -88,7 +88,7 @@ pub(crate) fn auto_optimized_cache_key(
 ) -> String {
     let target_str = target.unwrap_or("host");
     format!(
-        "{}|{}|{}|wasm={}|regex={}|temporal={}|ee={}|url={}|norm={}|seg={}|loc={}|intlns={}|gns={}{}{}{}{}{}{}{}{}|diag={}|dgram={}|http2={}|dyneval={}|sizeopt={}|anchors={}|v={}",
+        "{}|{}|{}|wasm={}|regex={}|temporal={}|ee={}|url={}|norm={}|seg={}|loc={}|intlns={}|gns={}{}{}{}{}{}{}{}{}{}|diag={}|dgram={}|http2={}|dyneval={}|sizeopt={}|anchors={}|v={}",
         feature_arg,
         panic_abort_safe,
         target_str,
@@ -110,6 +110,7 @@ pub(crate) fn auto_optimized_cache_key(
         ctx.uses_global_websocket,
         ctx.uses_global_webcrypto,
         ctx.uses_global_webfetch,
+        ctx.uses_proc_ipc,
         ctx.uses_diagnostics,
         ctx.uses_dgram,
         // HTTP/2 imports and dynamic builtin resolution pull in
@@ -196,6 +197,7 @@ pub(crate) fn auto_optimized_cross_features(
         (ctx.uses_global_websocket, "global-websocket"),
         (ctx.uses_global_webcrypto, "global-webcrypto"),
         (ctx.uses_global_webfetch, "global-webfetch"),
+        (ctx.uses_proc_ipc, "proc-ipc"),
     ] {
         if used || dynamic_code {
             cross_features.push(format!("perry-runtime/{feat}"));
diff --git a/crates/perry/src/commands/compile/types.rs b/crates/perry/src/commands/compile/types.rs
index 5ce05b181a..0723c87a1f 100644
--- a/crates/perry/src/commands/compile/types.rs
+++ b/crates/perry/src/commands/compile/types.rs
@@ -700,6 +700,8 @@ pub struct CompilationContext {
     pub uses_global_websocket: bool,
     pub uses_global_webcrypto: bool,
     pub uses_global_webfetch: bool,
+    /// `process.send`/`disconnect`/`connected`/`channel` — gates `proc-ipc`.
+    pub uses_proc_ipc: bool,
     pub uses_intl_locale: bool,
     /// Whether any TS module localizes a date/time — `Intl.DateTimeFormat`, or
     /// `Date.prototype.toLocale{,Date,Time}String`. Gates
@@ -1058,6 +1060,7 @@ impl CompilationContext {
             uses_global_websocket: false,
             uses_global_webcrypto: false,
             uses_global_webfetch: false,
+            uses_proc_ipc: false,
             uses_intl_locale: false,
             uses_intl_datetime: false,
             uses_diagnostics: false,