diff --git a/src/inspector/core.c b/src/inspector/core.c
index 002ecf8..95bbd28 100644
--- a/src/inspector/core.c
+++ b/src/inspector/core.c
@@ -1,5 +1,6 @@
 #include "bind.h"
 #include "http/websocket.h"
+#include "json.h"
 
 #include <stdarg.h>
 #include <stdio.h>
@@ -151,8 +152,18 @@ void inspector_send_ws(inspector_client_t *client, const char *json) {
 
 void inspector_send_response_obj(inspector_client_t *client, int id, const char *result_obj) {
   sbuf_t b = {0};
-  if (sbuf_appendf(&b, "{\"id\":%d,\"result\":%s}", id, result_obj ? result_obj : "{}"))
+  inspector_json_t json;
+  inspector_json_init(&json, &b);
+  if (
+    inspector_json_begin_object(&json) &&
+    inspector_json_key(&json, "id") &&
+    inspector_json_int(&json, id) &&
+    inspector_json_key(&json, "result") &&
+    inspector_json_raw(&json, result_obj ? result_obj : "{}") &&
+    inspector_json_end_object(&json)
+  ) {
     inspector_send_ws(client, b.data);
+  }
   free(b.data);
 }
 
@@ -162,11 +173,23 @@ void inspector_send_empty_result(inspector_client_t *client, int id) {
 
 void inspector_send_error(inspector_client_t *client, int id, int code, const char *message) {
   sbuf_t b = {0};
+  inspector_json_t json;
+  inspector_json_init(&json, &b);
   if (
-    sbuf_appendf(&b, "{\"id\":%d,\"error\":{\"code\":%d,\"message\":", id, code) &&
-    sbuf_json_string(&b, message ? message : "Inspector error") &&
-    sbuf_append(&b, "}}")
-  ) inspector_send_ws(client, b.data);
+    inspector_json_begin_object(&json) &&
+    inspector_json_key(&json, "id") &&
+    inspector_json_int(&json, id) &&
+    inspector_json_key(&json, "error") &&
+    inspector_json_begin_object(&json) &&
+    inspector_json_key(&json, "code") &&
+    inspector_json_int(&json, code) &&
+    inspector_json_key(&json, "message") &&
+    inspector_json_string(&json, message ? message : "Inspector error") &&
+    inspector_json_end_object(&json) &&
+    inspector_json_end_object(&json)
+  ) {
+    inspector_send_ws(client, b.data);
+  }
   free(b.data);
 }
 
diff --git a/src/inspector/json.c b/src/inspector/json.c
new file mode 100644
index 0000000..dac428a
--- /dev/null
+++ b/src/inspector/json.c
@@ -0,0 +1,130 @@
+#include "json.h"
+
+#include <inttypes.h>
+#include <string.h>
+
+void inspector_json_init(inspector_json_t *json, sbuf_t *out) {
+  json->out = out;
+  json->depth = 0;
+  json->wrote_root = false;
+}
+
+static bool inspector_json_before_value(inspector_json_t *json) {
+  if (!json || !json->out) return false;
+
+  if (json->depth == 0) {
+    if (json->wrote_root) return false;
+    json->wrote_root = true;
+    return true;
+  }
+
+  inspector_json_frame_t *frame = &json->stack[json->depth - 1];
+  if (frame->type == INSPECTOR_JSON_ARRAY) {
+    if (frame->needs_comma && !sbuf_append(json->out, ",")) return false;
+    frame->needs_comma = true;
+    return true;
+  }
+
+  if (!frame->expecting_value) return false;
+  frame->expecting_value = false;
+  return true;
+}
+
+static bool inspector_json_push(inspector_json_t *json, inspector_json_container_t type) {
+  if (json->depth >= sizeof(json->stack) / sizeof(json->stack[0])) return false;
+  json->stack[json->depth++] = (inspector_json_frame_t){
+    .type = type,
+    .needs_comma = false,
+    .expecting_value = false,
+  };
+  return true;
+}
+
+static bool inspector_json_pop(inspector_json_t *json, inspector_json_container_t type) {
+  if (!json || json->depth == 0) return false;
+  inspector_json_frame_t *frame = &json->stack[json->depth - 1];
+  if (frame->type != type || frame->expecting_value) return false;
+  json->depth--;
+  return true;
+}
+
+bool inspector_json_begin_object(inspector_json_t *json) {
+  return
+    inspector_json_before_value(json) &&
+    sbuf_append(json->out, "{") &&
+    inspector_json_push(json, INSPECTOR_JSON_OBJECT);
+}
+
+bool inspector_json_end_object(inspector_json_t *json) {
+  return
+    inspector_json_pop(json, INSPECTOR_JSON_OBJECT) &&
+    sbuf_append(json->out, "}");
+}
+
+bool inspector_json_begin_array(inspector_json_t *json) {
+  return 
+    inspector_json_before_value(json) &&
+    sbuf_append(json->out, "[") &&
+    inspector_json_push(json, INSPECTOR_JSON_ARRAY);
+}
+
+bool inspector_json_end_array(inspector_json_t *json) {
+  return 
+    inspector_json_pop(json, INSPECTOR_JSON_ARRAY) &&
+    sbuf_append(json->out, "]");
+}
+
+bool inspector_json_key(inspector_json_t *json, const char *key) {
+  if (!json || json->depth == 0) return false;
+  inspector_json_frame_t *frame = &json->stack[json->depth - 1];
+  if (frame->type != INSPECTOR_JSON_OBJECT || frame->expecting_value) return false;
+
+  if (frame->needs_comma && !sbuf_append(json->out, ",")) return false;
+  if (!sbuf_json_string(json->out, key ? key : "")) return false;
+  if (!sbuf_append(json->out, ":")) return false;
+
+  frame->needs_comma = true;
+  frame->expecting_value = true;
+  return true;
+}
+
+bool inspector_json_raw(inspector_json_t *json, const char *raw) {
+  return inspector_json_before_value(json) && sbuf_append(json->out, raw ? raw : "null");
+}
+
+bool inspector_json_string(inspector_json_t *json, const char *value) {
+  return inspector_json_string_len(json, value ? value : "", value ? strlen(value) : 0);
+}
+
+bool inspector_json_string_len(inspector_json_t *json, const char *value, size_t len) {
+  return inspector_json_before_value(json) &&
+         sbuf_json_string_len(json->out, value ? value : "", value ? len : 0);
+}
+
+bool inspector_json_bool(inspector_json_t *json, bool value) {
+  return inspector_json_raw(json, value ? "true" : "false");
+}
+
+bool inspector_json_int(inspector_json_t *json, int value) {
+  if (!inspector_json_before_value(json)) return false;
+  return sbuf_appendf(json->out, "%d", value);
+}
+
+bool inspector_json_uint64(inspector_json_t *json, uint64_t value) {
+  if (!inspector_json_before_value(json)) return false;
+  return sbuf_appendf(json->out, "%" PRIu64, value);
+}
+
+bool inspector_json_size(inspector_json_t *json, size_t value) {
+  if (!inspector_json_before_value(json)) return false;
+  return sbuf_appendf(json->out, "%zu", value);
+}
+
+bool inspector_json_double(inspector_json_t *json, double value) {
+  if (!inspector_json_before_value(json)) return false;
+  return sbuf_appendf(json->out, "%.6f", value);
+}
+
+bool inspector_json_null(inspector_json_t *json) {
+  return inspector_json_raw(json, "null");
+}
diff --git a/src/inspector/json.h b/src/inspector/json.h
new file mode 100644
index 0000000..6095299
--- /dev/null
+++ b/src/inspector/json.h
@@ -0,0 +1,41 @@
+#ifndef ANT_INSPECTOR_JSON_H
+#define ANT_INSPECTOR_JSON_H
+
+#include "bind.h"
+
+typedef enum {
+  INSPECTOR_JSON_OBJECT,
+  INSPECTOR_JSON_ARRAY
+} inspector_json_container_t;
+
+typedef struct {
+  inspector_json_container_t type;
+  bool needs_comma;
+  bool expecting_value;
+} inspector_json_frame_t;
+
+typedef struct {
+  sbuf_t *out;
+  inspector_json_frame_t stack[32];
+  size_t depth;
+  bool wrote_root;
+} inspector_json_t;
+
+void inspector_json_init(inspector_json_t *json, sbuf_t *out);
+bool inspector_json_begin_object(inspector_json_t *json);
+bool inspector_json_end_object(inspector_json_t *json);
+bool inspector_json_begin_array(inspector_json_t *json);
+bool inspector_json_end_array(inspector_json_t *json);
+
+bool inspector_json_key(inspector_json_t *json, const char *key);
+bool inspector_json_raw(inspector_json_t *json, const char *raw);
+bool inspector_json_string(inspector_json_t *json, const char *value);
+bool inspector_json_string_len(inspector_json_t *json, const char *value, size_t len);
+bool inspector_json_bool(inspector_json_t *json, bool value);
+bool inspector_json_int(inspector_json_t *json, int value);
+bool inspector_json_uint64(inspector_json_t *json, uint64_t value);
+bool inspector_json_size(inspector_json_t *json, size_t value);
+bool inspector_json_double(inspector_json_t *json, double value);
+bool inspector_json_null(inspector_json_t *json);
+
+#endif
diff --git a/src/inspector/network.c b/src/inspector/network.c
index 0ff7bf8..a1792a5 100644
--- a/src/inspector/network.c
+++ b/src/inspector/network.c
@@ -1,6 +1,7 @@
 #include "bind.h"
 #include "base64.h"
 #include "inspector.h"
+#include "json.h"
 
 #include <inttypes.h>
 #include <stdlib.h>
@@ -145,31 +146,29 @@ void inspector_get_response_body(inspector_client_t *client, int id, yyjson_val
   uint64_t request_id = inspector_request_id_param(params);
   inspector_network_entry_t *entry = inspector_network_entry_for_id(request_id, false);
   sbuf_t b = {0};
+  inspector_json_t json;
   size_t out_len = 0;
   char *encoded = NULL;
+  bool ok = false;
 
-  if (!entry || !entry->response_body || entry->response_body_len == 0) {
-    inspector_send_response_obj(client, id, "{\"body\":\"\",\"base64Encoded\":false}");
-    return;
+  if (!entry || !entry->response_body || entry->response_body_len == 0) out_len = 0; else {
+    encoded = ant_base64_encode(entry->response_body, entry->response_body_len, &out_len);
+    if (!encoded) { inspector_send_error(client, id, -32000, "Out of memory"); return; }
   }
 
-  encoded = ant_base64_encode(entry->response_body, entry->response_body_len, &out_len);
-  if (!encoded) {
-    inspector_send_error(client, id, -32000, "Out of memory");
-    return;
-  }
-
-  if (!sbuf_append(&b, "{\"body\":") ||
-      !sbuf_json_string_len(&b, encoded, out_len) ||
-      !sbuf_append(&b, ",\"base64Encoded\":true}")) {
-    free(encoded);
-    free(b.data);
-    inspector_send_error(client, id, -32000, "Out of memory");
-    return;
-  }
+  inspector_json_init(&json, &b);
+  if (!inspector_json_begin_object(&json)) goto done;
+  if (!inspector_json_key(&json, "body")) goto done;
+  if (!inspector_json_string_len(&json, encoded ? encoded : "", out_len)) goto done;
+  if (!inspector_json_key(&json, "base64Encoded")) goto done;
+  if (!inspector_json_bool(&json, encoded != NULL)) goto done;
+  if (!inspector_json_end_object(&json)) goto done;
+  ok = true;
 
+done:
+  if (ok) inspector_send_response_obj(client, id, b.data);
+  else inspector_send_error(client, id, -32000, "Out of memory");
   free(encoded);
-  inspector_send_response_obj(client, id, b.data);
   free(b.data);
 }
 
@@ -177,21 +176,18 @@ void inspector_get_request_post_data(inspector_client_t *client, int id, yyjson_
   uint64_t request_id = inspector_request_id_param(params);
   inspector_network_entry_t *entry = inspector_network_entry_for_id(request_id, false);
   sbuf_t b = {0};
-
-  if (!entry || !entry->request_body || entry->request_body_len == 0) {
-    inspector_send_response_obj(client, id, "{\"postData\":\"\"}");
-    return;
-  }
-
-  if (!sbuf_append(&b, "{\"postData\":") ||
-      !sbuf_json_string_len(&b, (const char *)entry->request_body, entry->request_body_len) ||
-      !sbuf_append(&b, "}")) {
-    free(b.data);
-    inspector_send_error(client, id, -32000, "Out of memory");
-    return;
-  }
-
-  inspector_send_response_obj(client, id, b.data);
+  inspector_json_t json;
+  inspector_json_init(&json, &b);
+  const char *body = entry && entry->request_body ? (const char *)entry->request_body : "";
+  size_t body_len = entry && entry->request_body ? entry->request_body_len : 0;
+  bool ok =
+    inspector_json_begin_object(&json) &&
+    inspector_json_key(&json, "postData") &&
+    inspector_json_string_len(&json, body, body_len) &&
+    inspector_json_end_object(&json);
+
+  if (ok) inspector_send_response_obj(client, id, b.data);
+  else inspector_send_error(client, id, -32000, "Out of memory");
   free(b.data);
 }
 uint64_t ant_inspector_network_request(
diff --git a/src/inspector/router.c b/src/inspector/router.c
index 833a835..988b764 100644
--- a/src/inspector/router.c
+++ b/src/inspector/router.c
@@ -1,6 +1,8 @@
 #include "bind.h"
 #include "gc.h"
+#include "json.h"
 
+#include <stdlib.h>
 #include <string.h>
 
 typedef void (*inspector_route_fn)(
@@ -66,10 +68,41 @@ static void route_get_isolate_id(inspector_client_t *client, int id, yyjson_val
 }
 
 static void route_schema_domains(inspector_client_t *client, int id, yyjson_val *params) {
-  inspector_send_response_obj(
-    client, id,
-    "{\"domains\":[{\"name\":\"Runtime\",\"version\":\"1.3\"},{\"name\":\"Console\",\"version\":\"1.3\"},{\"name\":\"Debugger\",\"version\":\"1.3\"},{\"name\":\"Network\",\"version\":\"1.3\"},{\"name\":\"HeapProfiler\",\"version\":\"1.3\"},{\"name\":\"Profiler\",\"version\":\"1.3\"}]}"
-  );
+  static const char *domains[] = {
+    "Runtime",
+    "Console",
+    "Debugger",
+    "Network",
+    "HeapProfiler",
+    "Profiler",
+  };
+  
+  sbuf_t b = {0};
+  inspector_json_t json;
+  inspector_json_init(&json, &b);
+  bool ok = false;
+
+  if (!inspector_json_begin_object(&json)) goto done;
+  if (!inspector_json_key(&json, "domains")) goto done;
+  if (!inspector_json_begin_array(&json)) goto done;
+  
+  for (size_t i = 0; i < sizeof(domains) / sizeof(domains[0]); i++) {
+    if (!inspector_json_begin_object(&json)) goto done;
+    if (!inspector_json_key(&json, "name")) goto done;
+    if (!inspector_json_string(&json, domains[i])) goto done;
+    if (!inspector_json_key(&json, "version")) goto done;
+    if (!inspector_json_string(&json, "1.3")) goto done;
+    if (!inspector_json_end_object(&json)) goto done;
+  }
+  
+  if (!inspector_json_end_array(&json)) goto done;
+  if (!inspector_json_end_object(&json)) goto done;
+  ok = true;
+
+done:
+  if (ok) inspector_send_response_obj(client, id, b.data);
+  else inspector_send_error(client, id, -32000, "Out of memory");
+  free(b.data);
 }
 
 static void route_network_get_response_body(inspector_client_t *client, int id, yyjson_val *params) {
diff --git a/src/inspector/server.c b/src/inspector/server.c
index 4588653..28f409d 100644
--- a/src/inspector/server.c
+++ b/src/inspector/server.c
@@ -2,6 +2,7 @@
 #include "internal.h"
 #include "inspector.h"
 #include "http/websocket.h"
+#include "json.h"
 #include "modules/crypto.h"
 
 #include <stdio.h>
@@ -104,16 +105,12 @@ static bool request_path_matches_uuid(const char *req) {
 
 static bool inspector_append_target_url(sbuf_t *b, const char *file) {
   if (!file || !*file || strcmp(file, "[repl]") == 0 || strcmp(file, "ant") == 0)
-    return sbuf_json_string(b, "file:///");
-  if (inspector_is_url_like(file)) return sbuf_json_string(b, file);
+    return sbuf_append(b, "file:///");
+  if (inspector_is_url_like(file)) return sbuf_append(b, file);
   if (file[0] == '/') {
-    if (!sbuf_append(b, "\"file://")) return false;
-    if (!sbuf_append(b, file)) return false;
-    return sbuf_append(b, "\"");
+    return sbuf_append(b, "file://") && sbuf_append(b, file);
   }
-  if (!sbuf_append(b, "\"file:///")) return false;
-  if (!sbuf_append(b, file)) return false;
-  return sbuf_append(b, "\"");
+  return sbuf_append(b, "file:///") && sbuf_append(b, file);
 }
 
 static bool inspector_append_devtools_url(sbuf_t *b) {
@@ -132,28 +129,54 @@ static bool inspector_append_browser_devtools_url(sbuf_t *b) {
 
 static char *json_list_response(void) {
   sbuf_t b = {0};
+  sbuf_t devtools = {0};
+  sbuf_t target = {0};
+  sbuf_t websocket = {0};
+  
   inspector_script_t *entry = inspector_entry_script();
   const char *file = entry && entry->url
     ? entry->url
     : (g_inspector.js && g_inspector.js->filename ? g_inspector.js->filename : "ant");
   uv_pid_t pid = uv_os_getpid();
-  if (!sbuf_append(&b, "[")) goto fail;
-  if (!sbuf_append(&b, "{\"description\":\"ant[")) goto fail;
-  if (!sbuf_appendf(&b, "%d", (int)pid)) goto fail;
-  if (!sbuf_append(&b, "]\",\"devtoolsFrontendUrl\":\"")) goto fail;
-  if (!inspector_append_devtools_url(&b)) goto fail;
-  if (!sbuf_append(&b, "\",\"id\":\"")) goto fail;
-  if (!sbuf_append(&b, g_inspector.uuid)) goto fail;
-  if (!sbuf_append(&b, "\",\"title\":\"ant[")) goto fail;
-  if (!sbuf_appendf(&b, "%d", (int)pid)) goto fail;
-  if (!sbuf_append(&b, "]\"")) goto fail;
-  if (!sbuf_append(&b, ",\"type\":\"node\",\"url\":")) goto fail;
-  if (!inspector_append_target_url(&b, file)) goto fail;
-  if (!sbuf_append(&b, ",\"webSocketDebuggerUrl\":\"ws://")) goto fail;
-  if (!sbuf_append(&b, g_inspector.host)) goto fail;
-  if (!sbuf_appendf(&b, ":%d/%s\"}]", g_inspector.port, g_inspector.uuid)) goto fail;
+
+  if (!inspector_append_devtools_url(&devtools)) goto fail;
+  if (!inspector_append_target_url(&target, file)) goto fail;
+  if (!sbuf_append(&websocket, "ws://")) goto fail;
+  if (!sbuf_append(&websocket, g_inspector.host)) goto fail;
+  if (!sbuf_appendf(&websocket, ":%d/%s", g_inspector.port, g_inspector.uuid)) goto fail;
+
+  char title[64];
+  snprintf(title, sizeof(title), "ant[%d]", (int)pid);
+
+  inspector_json_t json;
+  inspector_json_init(&json, &b);
+  if (!inspector_json_begin_array(&json)) goto fail;
+  if (!inspector_json_begin_object(&json)) goto fail;
+  if (!inspector_json_key(&json, "description")) goto fail;
+  if (!inspector_json_string(&json, title)) goto fail;
+  if (!inspector_json_key(&json, "devtoolsFrontendUrl")) goto fail;
+  if (!inspector_json_string(&json, devtools.data)) goto fail;
+  if (!inspector_json_key(&json, "id")) goto fail;
+  if (!inspector_json_string(&json, g_inspector.uuid)) goto fail;
+  if (!inspector_json_key(&json, "title")) goto fail;
+  if (!inspector_json_string(&json, title)) goto fail;
+  if (!inspector_json_key(&json, "type")) goto fail;
+  if (!inspector_json_string(&json, "node")) goto fail;
+  if (!inspector_json_key(&json, "url")) goto fail;
+  if (!inspector_json_string(&json, target.data)) goto fail;
+  if (!inspector_json_key(&json, "webSocketDebuggerUrl")) goto fail;
+  if (!inspector_json_string(&json, websocket.data)) goto fail;
+  if (!inspector_json_end_object(&json)) goto fail;
+  if (!inspector_json_end_array(&json)) goto fail;
+
+  free(devtools.data);
+  free(target.data);
+  free(websocket.data);
   return b.data;
 fail:
+  free(devtools.data);
+  free(target.data);
+  free(websocket.data);
   free(b.data);
   return NULL;
 }