diff --git a/esphome/components/api/proto.cpp b/esphome/components/api/proto.cpp
index cb3813ef87..7a638680be 100644
--- a/esphome/components/api/proto.cpp
+++ b/esphome/components/api/proto.cpp
@@ -20,7 +20,7 @@ void ProtoWriteBuffer::encode_varint_raw_slow_(uint32_t value) {
   *this->pos_++ = static_cast<uint8_t>(value);
 }
 
-uint32_t ProtoVarInt::parse_slow(const uint8_t *buffer, uint32_t len, proto_varint_value_t &value) {
+ProtoVarIntResult ProtoVarInt::parse_slow(const uint8_t *buffer, uint32_t len) {
   // Multi-byte varint: first byte already checked to have high bit set
   uint32_t result32 = buffer[0] & 0x7F;
 #ifdef USE_API_VARINT64
@@ -32,30 +32,28 @@ uint32_t ProtoVarInt::parse_slow(const uint8_t *buffer, uint32_t len, proto_vari
     uint8_t val = buffer[i];
     result32 |= uint32_t(val & 0x7F) << (i * 7);
     if ((val & 0x80) == 0) {
-      value = result32;
-      return i + 1;
+      return {result32, i + 1};
     }
   }
 #ifdef USE_API_VARINT64
-  return parse_wide(buffer, len, result32, value);
+  return parse_wide(buffer, len, result32);
 #else
-  return PROTO_VARINT_PARSE_FAILED;
+  return {0, PROTO_VARINT_PARSE_FAILED};
 #endif
 }
 
 #ifdef USE_API_VARINT64
-uint32_t ProtoVarInt::parse_wide(const uint8_t *buffer, uint32_t len, uint32_t result32, uint64_t &value) {
+ProtoVarIntResult ProtoVarInt::parse_wide(const uint8_t *buffer, uint32_t len, uint32_t result32) {
   uint64_t result64 = result32;
   uint32_t limit = std::min(len, uint32_t(10));
   for (uint32_t i = 4; i < limit; i++) {
     uint8_t val = buffer[i];
     result64 |= uint64_t(val & 0x7F) << (i * 7);
     if ((val & 0x80) == 0) {
-      value = result64;
-      return i + 1;
+      return {result64, i + 1};
     }
   }
-  return PROTO_VARINT_PARSE_FAILED;
+  return {0, PROTO_VARINT_PARSE_FAILED};
 }
 #endif
 
@@ -224,13 +222,11 @@ void ProtoDecodableMessage::decode(const uint8_t *buffer, size_t length) {
       value = *ptr++;
       return true;
     }
-    // Separate out variable so the fast path above keeps `value` in a register
-    proto_varint_value_t wide;
-    uint32_t consumed = ProtoVarInt::parse_slow(ptr, end - ptr, wide);
-    if (consumed == PROTO_VARINT_PARSE_FAILED)
+    auto res = ProtoVarInt::parse_non_empty(ptr, end - ptr);
+    if (!res.has_value())
       return false;
-    value = wide;
-    ptr += consumed;
+    value = res.value;
+    ptr += res.consumed;
     return true;
   };
 
diff --git a/esphome/components/api/proto.h b/esphome/components/api/proto.h
index 1d88088536..e9f855785e 100644
--- a/esphome/components/api/proto.h
+++ b/esphome/components/api/proto.h
@@ -145,9 +145,7 @@ class ProtoVarInt {
     // (booleans, small enums, field tags, small message sizes/types).
     if ((buffer[0] & 0x80) == 0) [[likely]]
       return {buffer[0], 1};
-    ProtoVarIntResult res;
-    res.consumed = parse_slow(buffer, len, res.value);
-    return res;
+    return parse_slow(buffer, len);
   }
 
   /// Parse a varint from buffer (safe for empty buffers).
@@ -158,16 +156,13 @@ class ProtoVarInt {
     return parse_non_empty(buffer, len);
   }
 
-  /// Multi-byte varint (first byte has the high bit set), outlined to keep the fast path small.
-  /// Writes the value and returns the bytes consumed, PROTO_VARINT_PARSE_FAILED when truncated.
-  static uint32_t parse_slow(const uint8_t *buffer, uint32_t len, proto_varint_value_t &value)
-      __attribute__((noinline));
-
  protected:
+  // Slow path for multi-byte varints (>= 128), outlined to keep fast path small
+  static ProtoVarIntResult parse_slow(const uint8_t *buffer, uint32_t len) __attribute__((noinline));
+
 #ifdef USE_API_VARINT64
   /// Continue parsing varint bytes 4-9 with 64-bit arithmetic.
-  static uint32_t parse_wide(const uint8_t *buffer, uint32_t len, uint32_t result32, uint64_t &value)
-      __attribute__((noinline));
+  static ProtoVarIntResult parse_wide(const uint8_t *buffer, uint32_t len, uint32_t result32) __attribute__((noinline));
 #endif
 };