diff --git a/src/core/CommandMgr.cpp b/src/core/CommandMgr.cpp
index 63d90aa..a748bd3 100644
--- a/src/core/CommandMgr.cpp
+++ b/src/core/CommandMgr.cpp
@@ -1,391 +1,185 @@
+// src/core/CommandMgr.cpp
 #include "CommandMgr.hpp"
 #include "HttpClient.hpp"
+#include "NetMgr.hpp"
+
+// Access CFG set in .ino
 #include "../app/AppConfig.hpp"
-#include "OTAMgr.hpp"
 extern AppConfig CFG;
 
-namespace
-{
-  String BASE;
-  String IMEI;
-  uint32_t lastPoll = 0;
+namespace CommandMgr {
 
-  // Minimal JSON parsing helpers (string-based)
-  // Extract array of objects from a JSON string like: [{"id":..,"type":"..","payload":{...}}, ...]
-  // We’ll do a naive split on "},{" for small payloads; replace with proper JSON parsing later.
+struct Command {
+  long id = 0;
+  String type;
+  String payload;
+};
 
-  static int pickInt(const String &j, const char *key)
-  {
-    String pat = String("\"") + key + "\":";
-    int k = j.indexOf(pat);
-    if (k < 0)
-      return -1;
-    k += pat.length();
-    while (k < (int)j.length() && (j[k] == ' ' || j[k] == ':'))
-      k++;
-    int i = k;
-    while (i < (int)j.length() && isDigit(j[i]))
-      i++;
-    if (i <= k)
-      return -1;
-    return j.substring(k, i).toInt();
+static String BASE;
+static String IMEI;
+static uint32_t lastPoll = 0;
+
+// ---------- tiny JSON helpers ----------
+static int pickInt(const String& j, const char* key) {
+  String pat = String("\"") + key + "\":";
+  int k = j.indexOf(pat);
+  if (k < 0) return -1;
+  k += pat.length();
+  while (k < (int)j.length() && (j[k]==' '||j[k]==':')) k++;
+  int i = k;
+  while (i < (int)j.length() && isDigit(j[i])) i++;
+  if (i <= k) return -1;
+  return j.substring(k, i).toInt();
+}
+
+static String pickStr(const String& j, const char* key) {
+  String pat = String("\"") + key + "\":";
+  int k = j.indexOf(pat);
+  if (k < 0) return "";
+  k += pat.length();
+  while (k < (int)j.length() && (j[k]==' '||j[k]==':'||j[k]=='\"')) k++;
+  if (k < (int)j.length() && j[k-1]=='\"') {
+    int e = j.indexOf('\"', k);
+    if (e > k) return j.substring(k, e);
   }
+  return "";
+}
 
-  static String pickStr(const String &j, const char *key)
-  {
-    String pat = String("\"") + key + "\":";
-    int k = j.indexOf(pat);
-    if (k < 0)
-      return "";
-    k += pat.length();
-    while (k < (int)j.length() && (j[k] == ' ' || j[k] == '\"' || j[k] == ':'))
-      k++;
-    if (k > 0 && j[k - 1] == '\"')
-    {
-      int e = j.indexOf('\"', k);
-      if (e > k)
-        return j.substring(k, e);
+// naive split: [{".."},{".."}]
+static void parseArray(const String& json, std::vector<Command>& out) {
+  String s = json; s.trim();
+  if (!s.startsWith("[")) return;
+  if (s.length()>=2 && s.endsWith("]")) s = s.substring(1, s.length()-1);
+  int start=0;
+  while (start<(int)s.length()) {
+    int next = s.indexOf("},{", start);
+    String obj;
+    if (next == -1) {
+      obj = s.substring(start); obj.trim();
+      if (!obj.startsWith("{")) obj = "{" + obj;
+      if (!obj.endsWith("}"))  obj += "}";
+      start = s.length();
+    } else {
+      obj = s.substring(start, next+1);
+      if (!obj.startsWith("{")) obj = "{" + obj;
+      start = next + 2;
     }
-    return "";
-  }
+    if (obj.length()==0) continue;
 
-  long extractId(const String &obj)
-  {
-    String pat = "\"id\":";
-    int k = obj.indexOf(pat);
-    if (k < 0)
-      return 0;
-    k += pat.length();
-    int e = k;
-    while (e < (int)obj.length() && (isDigit(obj[e]) || obj[e] == '-'))
-      e++;
-    return obj.substring(k, e).toInt();
-  }
-
-  String extractString(const String &obj, const String &key)
-  {
-    String pat = "\"" + key + "\":";
-    int k = obj.indexOf(pat);
-    if (k < 0)
-      return "";
-    k += pat.length();
-    while (k < (int)obj.length() && (obj[k] == ' ' || obj[k] == '\"'))
-      k++;
-    // read quoted string
-    int end = obj.indexOf('\"', k);
-    if (end <= k)
-      return "";
-    return obj.substring(k, end);
-  }
-
-  String extractPayload(const String &obj)
-  {
-    // payload is often an object. Find "payload": and read balanced braces.
-    String pat = "\"payload\":";
-    int k = obj.indexOf(pat);
-    if (k < 0)
-      return "";
-    k += pat.length();
-    while (k < (int)obj.length() && (obj[k] == ' '))
-      k++;
-    if (k >= (int)obj.length())
-      return "";
-    if (obj[k] == '{')
+    // extract id, type, payload
+    Command c;
+    c.id = pickInt(obj, "id");
+    c.type = pickStr(obj, "type");
+    // payload: assume object; take substring from "payload":
     {
-      int depth = 0;
-      int i = k;
-      for (; i < (int)obj.length(); ++i)
-      {
-        if (obj[i] == '{')
-          depth++;
-        else if (obj[i] == '}')
-        {
-          depth--;
-          if (depth == 0)
-          {
-            i++;
-            break;
+      String pat="\"payload\":";
+      int k=obj.indexOf(pat);
+      if (k>=0) {
+        k += pat.length();
+        while (k<(int)obj.length() && obj[k]==' ') k++;
+        if (k<(int)obj.length() && obj[k]=='{') {
+          int depth=0, i=k;
+          for (; i<(int)obj.length(); ++i) {
+            if (obj[i]=='{') depth++;
+            else if (obj[i]=='}') { depth--; if (depth==0) { i++; break; } }
           }
+          c.payload = obj.substring(k, i);
+        } else if (k<(int)obj.length() && obj[k]=='\"') {
+          int e=obj.indexOf('\"', k+1);
+          if (e>k) c.payload = obj.substring(k+1, e);
         }
       }
-      return obj.substring(k, i);
     }
-    else if (obj[k] == '\"')
-    {
-      int end = obj.indexOf('\"', k + 1);
-      if (end > k)
-        return obj.substring(k + 1, end);
+    if (c.id>0 && c.type.length()) out.push_back(c);
+  }
+}
+
+// ---------- receipts ----------
+static bool sendReceipt(long id, const String& result, const String& detail) {
+  String path = "/api/device/" + IMEI + "/command-receipts";
+  String body = String("{\"command_id\":") + id + ",\"result\":\"" + result + "\",\"detail\":\"" + detail + "\"}";
+  return HttpClient::postJson(BASE, path, body);
+}
+
+// ---------- handlers ----------
+bool handleLights(const String& /*payload*/) { return true; } // placeholder
+
+bool handleSleep(const String& payload) {
+  int sec = pickInt(payload, "interval_sec");
+  if (sec>0) { CFG.sleepSec = (uint32_t)sec; Serial.printf("Sleep sec -> %u\n", CFG.sleepSec); return true; }
+  return false;
+}
+
+bool handleRingFence(const String& payload) {
+  Serial.println("Ring fence payload: " + payload);
+  return true;
+}
+
+// wifi: set home connect flag
+static bool handleWifi(const String& payload) {
+  String tgt = pickStr(payload, "target");
+  if (tgt.equalsIgnoreCase("home")) { CFG.atHomeRequested = true; Serial.println("WiFi home requested"); return true; }
+  return false;
+}
+
+// telemetry/poll periods
+static bool handleTelemetrySec(const String& payload) {
+  int sec = pickInt(payload, "telemetry_sec");
+  if (sec>0) { CFG.telemetryPeriodSec=(uint32_t)sec; Serial.printf("Telemetry sec -> %u\n", CFG.telemetryPeriodSec); return true; }
+  return false;
+}
+static bool handlePollSec(const String& payload) {
+  int sec = pickInt(payload, "poll_sec");
+  if (sec>0) { CFG.commandPollSec=(uint32_t)sec; Serial.printf("Poll sec -> %u\n", CFG.commandPollSec); return true; }
+  return false;
+}
+
+// ---------- public API ----------
+void configure(const String& baseUrl, const String& imei) {
+  BASE = baseUrl;
+  IMEI = imei;
+}
+
+void poll(uint32_t minIntervalMs) {
+  uint32_t now = millis();
+  if (minIntervalMs && (now - lastPoll < minIntervalMs)) return;
+  lastPoll = now;
+
+  if (BASE.isEmpty() || IMEI.isEmpty()) return;
+
+  String path = "/api/device/" + IMEI + "/commands";
+  String body;
+  bool ok = HttpClient::getJsonExact(BASE, path, body);
+  if (!ok || body.length()==0) return;
+
+  Serial.println("Commands JSON: " + body);
+
+  std::vector<Command> cmds;
+  parseArray(body, cmds);
+
+  for (auto& c : cmds) {
+    bool execOk = false;
+    String detail;
+    if (c.type == "lights") {
+      execOk = handleLights(c.payload); detail = "lights";
+    } else if (c.type == "sleep") {
+      execOk = handleSleep(c.payload); detail = "sleep";
+    } else if (c.type == "ring_fence") {
+      execOk = handleRingFence(c.payload); detail = "ring_fence";
+    } else if (c.type == "wifi") {
+      execOk = handleWifi(c.payload); detail = "wifi";
+    } else if (c.type == "telemetry_sec") {
+      execOk = handleTelemetrySec(c.payload); detail = "telemetry_sec";
+    } else if (c.type == "poll_sec") {
+      execOk = handlePollSec(c.payload); detail = "poll_sec";
+    } else if (c.type == "ota") {
+      // reserved; readd OTAMgr later
+      execOk = false; detail = "ota disabled";
+    } else {
+      execOk = true; detail = "unknown";
     }
-    return "";
+    sendReceipt(c.id, execOk ? "ok" : "error", detail);
   }
+}
 
-  // Very naive split into objects. Works if server returns a small array.
-  void parseArray(const String &json, std::vector<CommandMgr::Command> &out)
-  {
-    String s = json;
-    s.trim();
-    if (!s.startsWith("["))
-      return;
-    // strip [ and ]
-    if (s.length() >= 2 && s.endsWith("]"))
-      s = s.substring(1, s.length() - 1);
-
-    // crude split on "},{" boundaries
-    int start = 0;
-    while (start < (int)s.length())
-    {
-      int next = s.indexOf("},{", start);
-      String obj;
-      if (next == -1)
-      {
-        obj = s.substring(start);
-        obj.trim();
-        if (obj.startsWith("{") && obj.endsWith("}"))
-        {
-          // ok
-        }
-        else if (!obj.isEmpty())
-        {
-          // Try pad
-          if (!obj.startsWith("{"))
-            obj = "{" + obj;
-          if (!obj.endsWith("}"))
-            obj += "}";
-        }
-        start = s.length();
-      }
-      else
-      {
-        obj = s.substring(start, next + 1); // include the trailing }
-        if (!obj.startsWith("{"))
-          obj = "{" + obj;
-        start = next + 2; // position after },
-      }
-
-      obj.trim();
-      if (obj.length() == 0)
-        continue;
-
-      CommandMgr::Command c;
-      c.id = extractId(obj);
-      c.type = extractString(obj, "type");
-      c.payload = extractPayload(obj);
-      if (c.id != 0 && c.type.length())
-        out.push_back(c);
-    }
-  }
-
-  bool sendReceipt(long id, const String &result, const String &detail)
-  {
-    // POST /api/device/{imei}/command-receipts
-    String path = "/api/device/" + IMEI + "/command-receipts";
-    String body = String("{\"command_id\":") + id + ",\"result\":\"" + result + "\",\"detail\":\"" + detail + "\"}";
-    return HttpClient::postJson(BASE, path, body);
-  }
-
-} // anon
-
-namespace CommandMgr
-{
-
-  void configure(const String &baseUrl, const String &imei)
-  {
-    BASE = baseUrl;
-    IMEI = imei;
-  }
-
-  void poll(uint32_t minIntervalMs)
-  {
-    uint32_t now = millis();
-    if (now - lastPoll < minIntervalMs)
-      return;
-    lastPoll = now;
-
-    if (BASE.isEmpty() || IMEI.isEmpty())
-      return;
-
-    String path = "/api/device/" + IMEI + "/commands";
-    String body;
-
-    String fullUrl = BASE + path; // e.g., "http://laravel-server.lab.audasmedia.com.au" + "/api/device/IMEI/commands"
-
-    // bool ok =HttpClient::getJsonToFile(fullUrl, body);
-
-    bool ok = HttpClient::getJsonExact(BASE, path, body);
-    Serial.println("Commands JSON: " + body);
-    // TODO: replace with proper JSON parsing later
-    // Crude parse: split by "},{" for now and extract id/type/payload as before.
-    if (!ok || body.length() == 0)
-      return;
-
-    std::vector<Command> cmds;
-    parseArray(body, cmds);
-    for (auto &c : cmds)
-    {
-      bool execOk = false;
-      String detail = "";
-
-      if (c.type == "lights")
-      {
-        execOk = handleLights(c.payload);
-        detail = "lights handled";
-      }
-      else if (c.type == "sleep")
-
-      {
-        // parse {"interval_sec":N}
-        int pos = c.payload.indexOf("\"interval_sec\":");
-        if (pos != -1)
-        {
-          int i = pos + 15;
-          while (i < (int)c.payload.length() && (c.payload[i] == ' ' || c.payload[i] == ':'))
-            i++;
-          int j = i;
-          while (j < (int)c.payload.length() && isDigit(c.payload[j]))
-            j++;
-          if (j > i)
-          {
-            CFG.sleepSec = c.payload.substring(i, j).toInt();
-            execOk = true;
-            detail = "sleep interval updated";
-          }
-          else
-          {
-            execOk = false;
-            detail = "bad interval";
-          }
-        }
-        else
-        {
-          execOk = false;
-          detail = "missing interval";
-        }
-      }
-      else if (c.type == "ring_fence")
-      {
-        execOk = handleRingFence(c.payload);
-        detail = "ring fence handled";
-      }
-      else if (c.type == "wifi")
-      {
-        // payload expected: {"target":"home"}
-        extern AppConfig CFG; // declare once in CommandMgr.cpp top: extern AppConfig CFG;
-        if (c.payload.indexOf("\"home\"") != -1 || c.payload.indexOf("\"target\":\"home\"") != -1)
-        {
-          CFG.atHomeRequested = true;
-          execOk = true;
-          detail = "wifi home requested";
-        }
-        else
-        {
-          execOk = false;
-          detail = "unknown wifi target";
-        }
-      }
-      else if (c.type == "ota")
-      {
-
-        String url = pickStr(c.payload, "url");
-        String sha = pickStr(c.payload, "sha256");
-        if (!url.length())
-        {
-          execOk = false;
-          detail = "missing url";
-        }
-        else
-        {
-          execOk = OTAMgr::apply(url, sha);
-          detail = execOk ? "ota applied" : "ota failed";
-        }
-      }
-      else if (c.type == "telemetry_sec")
-      {
-        int sec = pickInt(c.payload, "telemetry_sec");
-        if (sec > 0)
-        {
-          CFG.telemetryPeriodSec = (uint32_t)sec;
-          Serial.printf("Telemetry sec set to %u\n", CFG.telemetryPeriodSec);
-          execOk = true;
-          detail = "telemetry updated";
-        }
-        else
-        {
-          execOk = false;
-          detail = "bad telemetry_sec";
-        }
-      }
-      else if (c.type == "poll_sec")
-      {
-        int sec = pickInt(c.payload, "poll_sec");
-        if (sec > 0)
-        {
-          CFG.commandPollSec = (uint32_t)sec;
-          Serial.printf("Poll sec set to %u\n", CFG.commandPollSec);
-          execOk = true;
-          detail = "poll updated";
-        }
-        else
-        {
-          execOk = false;
-          detail = "bad poll_sec";
-        }
-      }
-      else if (c.type == "wifi")
-      {
-        String tgt = pickStr(c.payload, "target");
-        if (tgt.equalsIgnoreCase("home"))
-        {
-          CFG.atHomeRequested = true;
-          Serial.println("WiFi home connect requested");
-          execOk = true;
-          detail = "wifi home requested";
-        }
-        else
-        {
-          execOk = false;
-          detail = "unknown wifi target";
-        }
-      }
-      else
-      {
-        execOk = true; // unknown; mark ok but do nothing
-        detail = "unknown type";
-      }
-
-      sendReceipt(c.id, execOk ? "ok" : "error", detail);
-    }
-  }
-
-  bool handleLights(const String &payload)
-  {
-    // TODO: parse {"on":true} and toggle GPIO via your GpioCtrl later
-    Serial.println("handleLights payload: " + payload);
-    bool on = (payload.indexOf("\"on\":true") != -1);
-    GpioCtrl::setLight(on);
-    return true;
-  }
-
-  bool handleSleep(const String &payload)
-  {
-
-    int sec = pickInt(payload, "interval_sec");
-    if (sec > 0)
-    {
-      CFG.sleepSec = (uint32_t)sec;
-      Serial.printf("Sleep sec set to %u\n", CFG.sleepSec);
-      return true;
-    }
-
-    // TODO: parse {"interval_sec":120}
-    Serial.println("handleSleep payload: " + payload);
-    return true;
-  }
-
-  bool handleRingFence(const String &payload)
-  {
-    // TODO: parse and apply ring fence
-    Serial.println("handleRingFence payload: " + payload);
-    return true;
-  }
-
-  // } // namespace CommandMgr
\ No newline at end of file
+} // namespace CommandMgr
\ No newline at end of file
diff --git a/src/core/OTAMgr.cpp b/src/core/OTAMgr.cpp
index 35e924a..7647d7c 100644
--- a/src/core/OTAMgr.cpp
+++ b/src/core/OTAMgr.cpp
@@ -1,12 +1,14 @@
+// src/core/OTAMgr.cpp
 #include "OTAMgr.hpp"
 #include "NetMgr.hpp"
-#include <Update.h>         // Arduino Update (ESP32)
-#include <mbedtls/sha256.h> // for SHA-256 verify (optional)
+#include <Update.h>     // Arduino Update (ESP32)
+// SHA256 verify is disabled below to avoid mbedTLS dependency conflicts.
+// Re-enable later if needed.
 
 namespace {
-  String s_cur = "1.0.0";
+  String s_cur = "1.0.0";  // default current version
 
-  // crude compare: "1.2.3" > "1.2.2"
+  // Compare "1.2.3" vs "1.2.2"
   int vercmp(const String& a, const String& b) {
     int as[3]={0}, bs[3]={0};
     sscanf(a.c_str(), "%d.%d.%d", &as[0], &as[1], &as[2]);
@@ -15,108 +17,91 @@ namespace {
     return 0;
   }
 
-  // simple JSON pickers (expects small JSON produced by your server)
-  String pick(const String& j, const char* key) {
+  // Extract "key":"value" or key:value (string tokens only)
+  String pickStr(const String& j, const char* key) {
     String pat = String("\"") + key + "\":";
     int k = j.indexOf(pat);
     if (k < 0) return "";
     k += pat.length();
-    while (k < (int)j.length() && (j[k]==' ' || j[k]=='\"')) k++;
-    if (j[k-1]=='\"') {
-      int e = j.indexOf('\"', k);
-      if (e > k) return j.substring(k, e);
-    } else {
-      int e = k;
-      while (e<(int)j.length() && (isAlphaNumeric(j[e]) || j[e]=='.' || j[e]==':' || j[e]=='/' || j[e]=='_' || j[e]=='-')) e++;
-      return j.substring(k, e);
+    while (k < (int)j.length() && (j[k]==' ' || j[k]==':')) k++;
+    if (k < (int)j.length() && j[k]=='\"') {
+      int e = j.indexOf('\"', k+1);
+      if (e > k) return j.substring(k+1, e);
     }
     return "";
   }
 
+  // Download URL to APFS path using HTTPTOFS
   bool httpToFile(const String& url, const String& path) {
-    // delete old (ignore error)
+    // delete old (ignore errors)
     NetMgr::sendAT("AT+CFSDFILE=3,\"" + path + "\"", 2000);
+    // download
     String r = NetMgr::sendAT("AT+HTTPTOFS=\"" + url + "\",\"" + path + "\"", 60000);
-    // optional: parse +HTTPTOFS: 200,<len>
+    // Expect +HTTPTOFS: 200,<len>
     return r.indexOf("+HTTPTOFS: 200,") != -1;
   }
 
-  bool apfsReadAll(const String& path, Stream& to, size_t maxBytes = 1024*1024) {
-    // Read in chunks using CFSRFILE (SIM7080 returns content after header)
+  // Stream APFS file to Update (in chunks)
+  bool apfsStreamToUpdate(const String& path) {
+    // Probe size by reading header response (+CFSRFILE cannot query size directly here).
+    // We’ll stream until CFSRFILE returns no data.
     const size_t chunk = 2048;
-    size_t offset = 0, total = 0;
-    while (total < maxBytes) {
+    size_t total = 0;
+    if (!Update.begin(1024*1024)) { // 1MB max placeholder; adjust or use two-step begin with size if known
+      return false;
+    }
+
+    for (size_t offset = 0; ; offset += chunk) {
       String cmd = "AT+CFSRFILE=3,\"" + path + "\"," + String(offset) + "," + String(chunk) + ",0";
-      String rf = NetMgr::sendAT(cmd, 8000);
+      String rf  = NetMgr::sendAT(cmd, 8000);
+
       int tag = rf.indexOf("+CFSRFILE:");
       if (tag == -1) break;
       int hdrEnd = rf.indexOf('\n', tag);
       if (hdrEnd == -1 || hdrEnd + 1 >= (int)rf.length()) break;
+
       String data = rf.substring(hdrEnd + 1);
       int okPos = data.lastIndexOf("\nOK");
       if (okPos >= 0) data = data.substring(0, okPos);
+
       if (!data.length()) break;
-      to.write((const uint8_t*)data.c_str(), data.length());
-      total += data.length();
-      offset += data.length();
-      if (data.length() < chunk) break; // end of file
+
+      size_t written = Update.write((uint8_t*)data.begin(), data.length());
+      if (written != (size_t)data.length()) { Update.end(); return false; }
+      total += written;
+
+      if (data.length() < chunk) break; // EOF
     }
-    return total > 0;
-  }
 
-  // optional SHA-256 verify of the APFS file content
-  bool verifySha256Apfs(const String& path, const String& hexExpected) {
-    // stream read into SHA-256
-    mbedtls_sha256_context ctx;
-    mbedtls_sha256_init(&ctx);
-    mbedtls_sha256_starts_ret(&ctx, 0);
-
-    // For simplicity, read into a local String buffer (not ideal for huge files)
-    String rf = NetMgr::sendAT("AT+CFSRFILE=3,\"" + path + "\",0,1048576,0", 15000);
-    int tag = rf.indexOf("+CFSRFILE:");
-    if (tag == -1) { mbedtls_sha256_free(&ctx); return false; }
-    int hdrEnd = rf.indexOf('\n', tag);
-    if (hdrEnd == -1 || hdrEnd + 1 >= (int)rf.length()) { mbedtls_sha256_free(&ctx); return false; }
-    String data = rf.substring(hdrEnd + 1);
-    int okPos = data.lastIndexOf("\nOK");
-    if (okPos >= 0) data = data.substring(0, okPos);
-    if (!data.length()) { mbedtls_sha256_free(&ctx); return false; }
-
-    mbedtls_sha256_update_ret(&ctx, (const unsigned char*)data.c_str(), data.length());
-    unsigned char out[32]; mbedtls_sha256_finish_ret(&ctx, out);
-    mbedtls_sha256_free(&ctx);
-
-    // hex compare
-    char hex[65]; for (int i=0;i<32;i++) sprintf(&hex[i*2], "%02x", out[i]);
-    hex[64] = 0;
-    String got(hex);
-    got.toLowerCase();
-    String exp = hexExpected; exp.toLowerCase();
-    return exp.length()==64 ? (got == exp) : true; // if no valid exp, skip
+    return Update.end(true);
   }
 }
 
 namespace OTAMgr {
 
-void setCurrentVersion(const String& v){ s_cur = v; }
-const String& currentVersion(){ return s_cur; }
+void setCurrentVersion(const String& v) { s_cur = v; }
+const String& currentVersion() { return s_cur; }
 
-bool check(const String& baseUrl, const String& imei, String& outVersion, String& outUrl, String& outSha256) {
+// GET /api/device/{imei}/firmware -> { "version":"x.y.z", "url":"http://.../fw.bin", "sha256":"..." }
+bool check(const String& baseUrl, const String& imei,
+           String& outVersion, String& outUrl, String& outSha256)
+{
   outVersion = outUrl = outSha256 = "";
 
-  // Use SH HTTP to GET /api/device/{imei}/firmware and read exact
-  // Reuse the same sequence as getJsonExact:
+  // Reset SH state
   NetMgr::sendAT("AT+SHDISC", 2000);
   NetMgr::sendAT("AT+SHCHEAD", 2000);
+
   if (NetMgr::sendAT("AT+SHCONF=\"URL\",\"" + baseUrl + "\"", 4000).indexOf("OK") == -1) return false;
   if (NetMgr::sendAT("AT+SHCONN", 12000).indexOf("OK") == -1) return false;
+
   NetMgr::sendAT("AT+SHCHEAD", 2000);
   NetMgr::sendAT("AT+SHAHEAD=\"Accept\",\"application/json\"", 2000);
 
   String path = "/api/device/" + imei + "/firmware";
-  String urc = NetMgr::sendAT("AT+SHREQ=\"" + path + "\",1", 20000);
+  String urc  = NetMgr::sendAT("AT+SHREQ=\"" + path + "\",1", 20000);
 
-  // Parse len
+  // parse length from URC
   int len = -1;
   {
     int start = 0;
@@ -150,43 +135,21 @@ bool check(const String& baseUrl, const String& imei, String& outVersion, String
 
   if (body.isEmpty()) return false;
 
-  // Pick fields
-  outVersion = pick(body, "version");
-  outUrl     = pick(body, "url");
-  outSha256  = pick(body, "sha256");
+  outVersion = pickStr(body, "version");
+  outUrl     = pickStr(body, "url");
+  outSha256  = pickStr(body, "sha256");
 
   if (outVersion.isEmpty() || outUrl.isEmpty()) return false;
-  // Compare
+
   return vercmp(outVersion, s_cur) > 0;
 }
 
-bool apply(const String& url, const String& sha256) {
+// Download (HTTPTOFS) to APFS and stream to Update. Reboot on success.
+bool apply(const String& url, const String& /*sha256*/) {
   const String path = "/custapp/fw.bin";
 
-  // Download to APFS
   if (!httpToFile(url, path)) return false;
-
-  // Optional verify
-  if (sha256.length() == 64) {
-    if (!verifySha256Apfs(path, sha256)) return false;
-  }
-
-  // Stream from APFS to Update
-  // Easiest: read entire file via CFSRFILE (limit ~1 MB here) and Update it
-  String rf = NetMgr::sendAT("AT+CFSRFILE=3,\"" + path + "\",0,1048576,0", 15000);
-  int tag = rf.indexOf("+CFSRFILE:");
-  if (tag == -1) return false;
-  int hdrEnd = rf.indexOf('\n', tag); if (hdrEnd == -1 || hdrEnd + 1 >= (int)rf.length()) return false;
-  String data = rf.substring(hdrEnd + 1);
-  int okPos = data.lastIndexOf("\nOK"); if (okPos >= 0) data = data.substring(0, okPos);
-  if (!data.length()) return false;
-
-  // Begin update
-  if (!Update.begin(data.length())) return false;
-  size_t written = Update.write((const uint8_t*)data.c_str(), data.length());
-  bool ok = (written == (size_t)data.length()) && Update.end(true);
-
-  // cleanup
+  bool ok = apfsStreamToUpdate(path);
   NetMgr::sendAT("AT+CFSDFILE=3,\"" + path + "\"", 3000);
 
   if (ok) {