@@ -182,7 +182,7 @@ public function update(EnvironmentVariable $environment_variable, Request $reque
         validator($data, EnvironmentVariable::rules($environment_variable), EnvironmentVariable::messages())->validate();
         $linkedAsset = EnvironmentVariable::validateAssetLinkConsistency($data);
 
-        $fields = ['name', 'description', 'asset_type'];
+        $fields = ['name', 'description', 'asset_type', 'do_not_update'];
         if ($linkedAsset) {
             // Guarantee value is always the selected asset's ID on this instance.
             $data['value'] = (string) $linkedAsset->id;
 
@@ -2,9 +2,13 @@
 
 namespace ProcessMaker\ImportExport\Exporters;
 
+use Illuminate\Database\Eloquent\Model;
 use Illuminate\Support\Facades\Log;
 use ProcessMaker\Enums\ExporterMap;
 use ProcessMaker\ImportExport\DependentType;
+use ProcessMaker\ImportExport\Manifest;
+use ProcessMaker\ImportExport\Options;
+use ProcessMaker\ImportExport\Psudomodels\Psudomodel;
 
 class EnvironmentVariableExporter extends ExporterBase
 {
@@ -16,6 +20,18 @@ class EnvironmentVariableExporter extends ExporterBase
 
     public $incrementStringSeparator = '_';
 
+    public function __construct(
+        Model|Psudomodel|null $model,
+        Manifest $manifest,
+        Options $options,
+        $ignoreExplicitDiscard
+    ) {
+        parent::__construct($model, $manifest, $options, $ignoreExplicitDiscard);
+
+        // PHP does not allow closures as property defaults.
+        $this->discard = fn ($envVar) => (bool) ($envVar->do_not_update ?? false);
+    }
+
     public function export() : void
     {
         $this->addReference(DependentType::ENVIRONMENT_VARIABLE_VALUE, $this->model->value);
 
@@ -47,6 +47,12 @@ abstract class ExporterBase implements ExporterInterface
 
     public $hidden = false;
 
+    /**
+     * When true (or a callable returning true), this asset is explicitly discarded.
+     * Callables receive the model: fn (Model $model): bool
+     *
+     * @var bool|callable
+     */
     public $discard = false;
 
     public static $forceUpdate = false;
@@ -135,7 +141,7 @@ public function uuid() : string
 
     public function include() : bool
     {
-        if ($this->discard) { // Explicit Discard (not from passed-in options)
+        if ($this->isExplicitlyDiscarded()) { // Explicit Discard (not from passed-in options)
             if (!$this->ignoreExplicitDiscard) {
                 return false;
             }
@@ -148,6 +154,32 @@ public function include() : bool
         return true;
     }
 
+    /**
+     * Resolve $discard whether it is a boolean or a callable checked against the model.
+     */
+    public function isExplicitlyDiscarded(): bool
+    {
+        if (is_callable($this->discard)) {
+            return (bool) ($this->discard)($this->model);
+        }
+
+        return (bool) $this->discard;
+    }
+
+    /**
+     * Import-time check: should an existing target model be discarded (not overwritten)?
+     */
+    public static function shouldDiscardExistingModel(?Model $model): bool
+    {
+        if (!$model || !$model->exists) {
+            return false;
+        }
+
+        $exporter = new static($model, new Manifest(), new Options([]), false);
+
+        return $exporter->isExplicitlyDiscarded();
+    }
+
     public function addDependent(string $type, Model|Psudomodel $dependentModel, string $exporterClass, $meta = null)
     {
         $uuid = $dependentModel->uuid;
@@ -304,7 +336,7 @@ public function toArray()
             'hidden' => $this->hidden,
             'mode' => $this->mode,
             'saveAssetsMode' => $this->saveAssetsMode,
-            'explicit_discard' => $this->discard,
+            'explicit_discard' => $this->isExplicitlyDiscarded(),
             'dependents' => array_map(fn ($d) => $d->toArray(), $this->dependents),
             'name' => $this->getName($this->model),
             'description' => $this->getDescription(),
 
@@ -158,6 +158,11 @@ public static function getModel($uuid, $assetInfo, $mode, $exporterClass, $isRoo
             $mode = 'discard';
         }
 
+        // Per-asset explicit discard (e.g. env vars with do_not_update on the target).
+        if ($model && $exporterClass::shouldDiscardExistingModel($model)) {
+            $mode = 'discard';
+        }
+
         if ($exporterClass::$forceUpdate) {
             $mode = 'update';
         }
 
@@ -17,6 +17,7 @@
  *   @OA\Property(property="description", type="string"),
  *   @OA\Property(property="value", type="string"),
  *   @OA\Property(property="asset_type", type="string", nullable=true),
+ *   @OA\Property(property="do_not_update", type="boolean"),
  * ),
  * @OA\Schema(
  *   schema="EnvironmentVariable",
@@ -41,6 +42,11 @@ class EnvironmentVariable extends ProcessMakerModel
         'description',
         'value',
         'asset_type',
+        'do_not_update',
+    ];
+
+    protected $casts = [
+        'do_not_update' => 'boolean',
     ];
 
     protected $hidden = [
@@ -102,6 +108,7 @@ public static function rules($existing = null)
                 'string',
                 Rule::in($allowedAssetTypes),
             ],
+            'do_not_update' => 'boolean',
         ];
     }
 
 
@@ -18,6 +18,7 @@ public function definition()
             'name' => $this->faker->word(),
             'description' => $this->faker->sentence(),
             'value' => $this->faker->sentence(),
+            'do_not_update' => false,
         ];
     }
 }
@@ -0,0 +1,28 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::table('environment_variables', function (Blueprint $table) {
+            $table->boolean('do_not_update')->default(false)->after('asset_type');
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::table('environment_variables', function (Blueprint $table) {
+            $table->dropColumn('do_not_update');
+        });
+    }
+};
@@ -41,16 +41,18 @@
         :value.sync="value"
         :errors="errors"
       />
+      <do-not-update-switch v-model="doNotUpdate" />
     </modal>
   </div>
 </template>
 
 <script>
   import { FormErrorsMixin, Modal, Required } from "SharedComponents";
   import AssetLinkFields from "./AssetLinkFields.vue";
+  import DoNotUpdateSwitch from "./DoNotUpdateSwitch.vue";
 
   export default {
-    components: { Modal, Required, AssetLinkFields },
+    components: { Modal, Required, AssetLinkFields, DoNotUpdateSwitch },
     mixins: [ FormErrorsMixin ],
     data: function() {
       return {
@@ -59,6 +61,7 @@
         description: '',
         value: '',
         assetType: null,
+        doNotUpdate: false,
         disabled: false,
       }
     },
@@ -68,6 +71,7 @@
         this.description = '';
         this.value = '';
         this.assetType = null;
+        this.doNotUpdate = false;
         this.errors = {};
         this.disabled = false;
       },
@@ -83,6 +87,7 @@
           description: this.description,
           value: this.value,
           asset_type: this.assetType,
+          do_not_update: this.doNotUpdate,
         })
           .then(response => {
             ProcessMaker.alert(this.$t('The environment variable was created.'), 'success');
 
@@ -0,0 +1,32 @@
+<template>
+  <div class="do-not-update-switch pt-3 mt-2 border-top">
+    <div class="d-flex align-items-start">
+      <b-form-checkbox
+        class="mt-1"
+        switch
+        :checked="value"
+        @input="$emit('input', $event)"
+      />
+      <div class="ml-2">
+        <div class="font-weight-bold">
+          <i class="fas fa-lock text-primary mr-1" aria-hidden="true"></i>
+          {{ $t("Do not overwrite this environment variable on import/DevLink") }}
+        </div>
+        <small class="form-text text-muted mb-0">
+          {{ $t("When enabled, the value of this variable will not be overwritten during imports or DevLink synchronization, even if a variable with the same name exists in the source environment.") }}
+        </small>
+      </div>
+    </div>
+  </div>
+</template>
+
+<script>
+export default {
+  props: {
+    value: {
+      type: Boolean,
+      default: false,
+    },
+  },
+};
+</script>
@@ -1,12 +1,14 @@
 import Vue from "vue";
 import AssetLinkFields from "./components/AssetLinkFields.vue";
+import DoNotUpdateSwitch from "./components/DoNotUpdateSwitch.vue";
 
 const initial = window.ProcessMaker.EnvironmentVariableEdit || {};
 
 new Vue({
   el: "#editEnvironmentVariable",
   components: {
     AssetLinkFields,
+    DoNotUpdateSwitch,
   },
   data() {
     return {
@@ -16,6 +18,7 @@ new Vue({
         description: initial.description,
         value: initial.value || null,
         asset_type: initial.asset_type || null,
+        do_not_update: !!initial.do_not_update,
       },
       errors: {
         name: null,
@@ -44,6 +47,7 @@ new Vue({
         description: this.formData.description,
         asset_type: this.formData.asset_type,
         value: this.formData.value,
+        do_not_update: this.formData.do_not_update,
       };
       ProcessMaker.apiClient.put(`environment_variables/${this.formData.id}`, payload)
         .then(() => {
Original file line number	Diff line number	Diff line change
`@@ -158,6 +158,11 @@ public static function getModel($uuid, $assetInfo, $mode, $exporterClass, $isRoo`
`158`	`158`	`$mode = 'discard';`
`159`	`159`	`}`
`160`	`160`
	`161`	`+ // Per-asset explicit discard (e.g. env vars with do_not_update on the target).`
	`162`	`+ if ($model && $exporterClass::shouldDiscardExistingModel($model)) {`
	`163`	`+ $mode = 'discard';`
	`164`	`+ }`
	`165`	`+`
`161`	`166`	`if ($exporterClass::$forceUpdate) {`
`162`	`167`	`$mode = 'update';`
`163`	`168`	`}`
Original file line number	Diff line number	Diff line change
`@@ -18,6 +18,7 @@ public function definition()`
`18`	`18`	`'name' => $this->faker->word(),`
`19`	`19`	`'description' => $this->faker->sentence(),`
`20`	`20`	`'value' => $this->faker->sentence(),`
	`21`	`+ 'do_not_update' => false,`
`21`	`22`	`];`
`22`	`23`	`}`
`23`	`24`	`}`