diff --git a/app/Actions/Database/RestartDatabase.php b/app/Actions/Database/RestartDatabase.php
index e1c531182e..66c7c8c961 100644
--- a/app/Actions/Database/RestartDatabase.php
+++ b/app/Actions/Database/RestartDatabase.php
@@ -2,6 +2,7 @@
 
 namespace App\Actions\Database;
 
+use App\Exceptions\RemoteSecretException;
 use App\Models\StandaloneClickhouse;
 use App\Models\StandaloneDragonfly;
 use App\Models\StandaloneKeydb;
@@ -49,6 +50,12 @@ class RestartDatabase
             if ($prerequisiteError !== null) {
                 return $prerequisiteError;
             }
+            // Check remote secrets before stopping: if the secret manager fails, the database keeps running.
+            try {
+                $database->ensureRemoteSecretsResolvable($database->runtime_environment_variables()->get());
+            } catch (RemoteSecretException $e) {
+                return $e->getMessage();
+            }
             StopDatabase::run($database, dockerCleanup: false);
             // The stop can take a while; keep the reservation for the start that follows.
             DatabaseOperationReservation::renew($database->uuid, $reservation);
diff --git a/app/Actions/Database/StartClickhouse.php b/app/Actions/Database/StartClickhouse.php
index 912612ae00..7dde9ac21b 100644
--- a/app/Actions/Database/StartClickhouse.php
+++ b/app/Actions/Database/StartClickhouse.php
@@ -158,11 +158,13 @@ class StartClickhouse
         foreach ($this->database->runtime_environment_variables as $env) {
             $rawValue = (string) $this->database->resolveSecretManagerEnvironmentVariableValue($env);
             $resolvedValue = (string) $this->database->formatEnvironmentVariableValue($env, $rawValue);
+            // Credentials below are placed directly in the compose file (healthcheck, command).
+            $composeFileValue = $this->database->formatComposeFileValue($env, $rawValue);
             $environment_variables->push($env->key.'='.$resolvedValue);
             if ($env->key === 'CLICKHOUSE_USER') {
-                $this->resolvedClickhouseUser = $rawValue;
+                $this->resolvedClickhouseUser = $composeFileValue;
             } elseif ($env->key === 'CLICKHOUSE_PASSWORD') {
-                $this->resolvedClickhousePassword = $rawValue;
+                $this->resolvedClickhousePassword = $composeFileValue;
             }
         }
 
diff --git a/app/Actions/Database/StartMysql.php b/app/Actions/Database/StartMysql.php
index ef0ca2cf3d..a5c9f8515e 100644
--- a/app/Actions/Database/StartMysql.php
+++ b/app/Actions/Database/StartMysql.php
@@ -255,9 +255,11 @@ class StartMysql
         foreach ($this->database->runtime_environment_variables as $env) {
             $rawValue = (string) $this->database->resolveSecretManagerEnvironmentVariableValue($env);
             $resolvedValue = (string) $this->database->formatEnvironmentVariableValue($env, $rawValue);
+            // Credentials below are placed directly in the compose file (healthcheck, command).
+            $composeFileValue = $this->database->formatComposeFileValue($env, $rawValue);
             $environment_variables->push($env->key.'='.$resolvedValue);
             if ($env->key === 'MYSQL_ROOT_PASSWORD') {
-                $this->resolvedMysqlRootPassword = $rawValue;
+                $this->resolvedMysqlRootPassword = $composeFileValue;
             }
         }
 
diff --git a/app/Actions/Database/StartPostgresql.php b/app/Actions/Database/StartPostgresql.php
index abae4630b1..0f1da0e481 100644
--- a/app/Actions/Database/StartPostgresql.php
+++ b/app/Actions/Database/StartPostgresql.php
@@ -264,11 +264,13 @@ class StartPostgresql
         foreach ($this->database->runtime_environment_variables as $env) {
             $rawValue = (string) $this->database->resolveSecretManagerEnvironmentVariableValue($env);
             $resolvedValue = (string) $this->database->formatEnvironmentVariableValue($env, $rawValue);
+            // Credentials below are placed directly in the compose file (healthcheck, command).
+            $composeFileValue = $this->database->formatComposeFileValue($env, $rawValue);
             $environment_variables->push($env->key.'='.$resolvedValue);
             if ($env->key === 'POSTGRES_USER') {
-                $this->resolvedPostgresUser = $rawValue;
+                $this->resolvedPostgresUser = $composeFileValue;
             } elseif ($env->key === 'POSTGRES_DB') {
-                $this->resolvedPostgresDatabase = $rawValue;
+                $this->resolvedPostgresDatabase = $composeFileValue;
             }
         }
 
diff --git a/app/Actions/Database/StartRedis.php b/app/Actions/Database/StartRedis.php
index 14f31f64ac..c5d2d66f8e 100644
--- a/app/Actions/Database/StartRedis.php
+++ b/app/Actions/Database/StartRedis.php
@@ -4,6 +4,7 @@ namespace App\Actions\Database;
 
 use App\Exceptions\DatabaseStartException;
 use App\Helpers\SslHelper;
+use App\Models\EnvironmentVariable;
 use App\Models\SslCertificate;
 use App\Models\StandaloneRedis;
 use App\Traits\ExecutesDatabaseStartCommands;
@@ -252,7 +253,7 @@ class StartRedis
                 $environment_variables->push($env->key.'='.$this->database->resolveSecretManagerEnvironmentVariable($env));
 
                 if ($env->key === 'REDIS_PASSWORD') {
-                    $this->resolvedRedisPassword = $this->database->resolveSecretManagerEnvironmentVariableValue($env);
+                    $this->resolvedRedisPassword = $this->redisPasswordForComposeFile($env);
 
                     if (! $usesSecretManager) {
                         $this->database->update(['redis_password' => $this->resolvedRedisPassword]);
@@ -274,7 +275,7 @@ class StartRedis
                 }
 
                 if ($env->key === 'REDIS_PASSWORD') {
-                    $this->resolvedRedisPassword = $this->database->resolveSecretManagerEnvironmentVariableValue($env);
+                    $this->resolvedRedisPassword = $this->redisPasswordForComposeFile($env);
                 } elseif ($env->key === 'REDIS_USERNAME') {
                     $this->resolvedRedisUsername = $this->database->resolveSecretManagerEnvironmentVariableValue($env);
                 }
@@ -288,6 +289,17 @@ class StartRedis
         return $environment_variables->all();
     }
 
+    /**
+     * The password is placed directly in the compose command, so a remote secret value is escaped
+     * the same way as its environment entry. Other values stay unchanged.
+     */
+    private function redisPasswordForComposeFile(EnvironmentVariable $env): ?string
+    {
+        $value = $this->database->resolveSecretManagerEnvironmentVariableValue($env);
+
+        return $value === null ? null : $this->database->formatComposeFileValue($env, $value);
+    }
+
     private function buildStartCommand(): string
     {
         $redisPassword = $this->resolvedRedisPassword ?? $this->database->redis_password;
diff --git a/app/Actions/Service/StartService.php b/app/Actions/Service/StartService.php
index 35a154b882..d928866f1d 100644
--- a/app/Actions/Service/StartService.php
+++ b/app/Actions/Service/StartService.php
@@ -24,6 +24,9 @@ class StartService
     public function handle(Service $service, bool $pullLatestImages = false, bool $stopBeforeStart = false)
     {
         $service->parse();
+        // Fetch remote secrets before stopping: if the secret manager fails, the service keeps running.
+        // saveComposeConfigs() below reuses the fetched secrets.
+        $service->ensureRemoteSecretsResolvable($service->environment_variables()->get());
         if ($this->shouldStopBeforeStarting($pullLatestImages, $stopBeforeStart)) {
             StopService::run(service: $service, dockerCleanup: false);
         }
diff --git a/app/Exceptions/RemoteSecretException.php b/app/Exceptions/RemoteSecretException.php
new file mode 100644
index 0000000000..1763a5687e
--- /dev/null
+++ b/app/Exceptions/RemoteSecretException.php
@@ -0,0 +1,12 @@
+<?php
+
+namespace App\Exceptions;
+
+use RuntimeException;
+
+/**
+ * Remote secrets of a resource could not be resolved, for example because the secret manager is
+ * unreachable or a referenced key does not exist. The message names no secret values, so it can be
+ * shown to the user.
+ */
+class RemoteSecretException extends RuntimeException {}
diff --git a/app/Jobs/ApplicationDeploymentJob.php b/app/Jobs/ApplicationDeploymentJob.php
index af4cd2c264..57c5503092 100644
--- a/app/Jobs/ApplicationDeploymentJob.php
+++ b/app/Jobs/ApplicationDeploymentJob.php
@@ -22,6 +22,7 @@ use App\Models\SwarmDocker;
 use App\Notifications\Application\DeploymentFailed;
 use App\Notifications\Application\DeploymentSuccess;
 use App\Support\RemoteSecretReferences;
+use App\Support\RemoteSecretValueFormatter;
 use App\Support\ValidationPatterns;
 use App\Traits\EnvironmentVariableAnalyzer;
 use App\Traits\ExecuteRemoteCommand;
@@ -1632,12 +1633,7 @@ class ApplicationDeploymentJob implements ShouldBeEncrypted, ShouldQueue
      */
     private function format_remote_secret_value(string $value): string
     {
-        if (! str_contains($value, "'")) {
-            return "'".$value."'";
-        }
-
-        // Fall back to double quotes; $$ escapes compose interpolation.
-        return '"'.str_replace(['\\', '"', '$'], ['\\\\', '\\"', '$$'], $value).'"';
+        return RemoteSecretValueFormatter::dotenv($value);
     }
 
     private function generate_runtime_environment_variables()
diff --git a/app/Jobs/DatabaseStartJob.php b/app/Jobs/DatabaseStartJob.php
index 4ec5630935..39f940c802 100644
--- a/app/Jobs/DatabaseStartJob.php
+++ b/app/Jobs/DatabaseStartJob.php
@@ -14,6 +14,7 @@ use App\Actions\Database\StartSqlite;
 use App\Enums\ProcessStatus;
 use App\Events\DatabaseStatusChanged;
 use App\Exceptions\DatabaseStartException;
+use App\Exceptions\RemoteSecretException;
 use App\Models\StandaloneClickhouse;
 use App\Models\StandaloneDragonfly;
 use App\Models\StandaloneKeydb;
@@ -142,7 +143,9 @@ class DatabaseStartJob implements ShouldBeEncrypted, ShouldQueue
 
             ResourceStartActivity::markFailed(
                 $activity,
-                $exception instanceof DatabaseStartException ? $exception->getMessage() : 'Database start failed.',
+                $exception instanceof DatabaseStartException || $exception instanceof RemoteSecretException
+                    ? $exception->getMessage()
+                    : 'Database start failed.',
             );
         } finally {
             event(new DatabaseStatusChanged($this->userId));
diff --git a/app/Models/Service.php b/app/Models/Service.php
index 545250013b..3d795efac0 100644
--- a/app/Models/Service.php
+++ b/app/Models/Service.php
@@ -1605,7 +1605,7 @@ class Service extends BaseModel
             return 3;
         });
         foreach ($sorted as $env) {
-            $envs->push("{$env->key}={$this->resolveSecretManagerEnvironmentVariable($env)}");
+            $envs->push("{$env->key}={$this->resolveSecretManagerDotenvValue($env)}");
         }
         if ($envs->count() === 0) {
             $commands[] = "touch {$environmentFile}";
diff --git a/app/Support/RemoteSecretValueFormatter.php b/app/Support/RemoteSecretValueFormatter.php
new file mode 100644
index 0000000000..fa2d4d5218
--- /dev/null
+++ b/app/Support/RemoteSecretValueFormatter.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace App\Support;
+
+/**
+ * Formats values fetched from a secret manager so that Docker Compose uses them exactly as they are:
+ * no interpolation, no comments, and no extra lines.
+ */
+class RemoteSecretValueFormatter
+{
+    /**
+     * A value for a dotenv file that Docker Compose reads (a project .env or an env_file). Single
+     * quotes keep the value literal, also newlines and "#". A value with a single quote, or one that
+     * ends with a backslash (which would escape the closing quote), uses double quotes instead,
+     * where \, " and $ must be escaped ($$ stops interpolation).
+     */
+    public static function dotenv(string $value): string
+    {
+        if (! str_contains($value, "'") && ! str_ends_with($value, '\\')) {
+            return "'".$value."'";
+        }
+
+        return '"'.str_replace(['\\', '"', '$'], ['\\\\', '\\"', '$$'], $value).'"';
+    }
+
+    /**
+     * A value written directly into a generated compose file, such as an `environment:` entry,
+     * a command, or a healthcheck. Compose does not parse quotes there and only interpolates "$".
+     */
+    public static function composeFile(string $value): string
+    {
+        return str_replace('$', '$$', $value);
+    }
+}
diff --git a/app/Traits/HasSecretManager.php b/app/Traits/HasSecretManager.php
index 230232c503..4e5d066261 100644
--- a/app/Traits/HasSecretManager.php
+++ b/app/Traits/HasSecretManager.php
@@ -2,12 +2,14 @@
 
 namespace App\Traits;
 
+use App\Exceptions\RemoteSecretException;
 use App\Models\EnvironmentVariable;
 use App\Models\SecretManagerLink;
 use App\Support\RemoteSecretReferences;
+use App\Support\RemoteSecretValueFormatter;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\MorphOne;
-use RuntimeException;
+use Throwable;
 
 trait HasSecretManager
 {
@@ -46,6 +48,9 @@ trait HasSecretManager
         ]);
     }
 
+    /**
+     * The value for an `environment:` entry of a generated compose file (standalone databases).
+     */
     public function resolveSecretManagerEnvironmentVariable(EnvironmentVariable $environmentVariable): ?string
     {
         $value = $this->resolveSecretManagerEnvironmentVariableValue($environmentVariable);
@@ -53,7 +58,62 @@ trait HasSecretManager
         return $this->formatEnvironmentVariableValue($environmentVariable, $value);
     }
 
+    /**
+     * The value for a line of a dotenv file that Docker Compose reads (the service .env file).
+     */
+    public function resolveSecretManagerDotenvValue(EnvironmentVariable $environmentVariable): ?string
+    {
+        $value = $this->resolveSecretManagerEnvironmentVariableValue($environmentVariable);
+
+        if ($value !== null && $this->environmentVariableUsesSecretManager($environmentVariable)) {
+            return RemoteSecretValueFormatter::dotenv($value);
+        }
+
+        return $this->formatLocalEnvironmentVariableValue($environmentVariable, $value);
+    }
+
+    /**
+     * Formats a resolved value for an `environment:` entry of a generated compose file. Remote secret
+     * values are used exactly as they are; other values keep their existing format.
+     */
     public function formatEnvironmentVariableValue(EnvironmentVariable $environmentVariable, ?string $value): ?string
+    {
+        if ($value !== null && $this->environmentVariableUsesSecretManager($environmentVariable)) {
+            return RemoteSecretValueFormatter::composeFile($value);
+        }
+
+        return $this->formatLocalEnvironmentVariableValue($environmentVariable, $value);
+    }
+
+    /**
+     * Formats a resolved value that is placed directly in a generated compose file, such as a
+     * password in a command or healthcheck. Remote secret values are escaped for compose
+     * interpolation; other values stay unchanged, as before.
+     */
+    public function formatComposeFileValue(EnvironmentVariable $environmentVariable, string $value): string
+    {
+        return $this->environmentVariableUsesSecretManager($environmentVariable)
+            ? RemoteSecretValueFormatter::composeFile($value)
+            : $value;
+    }
+
+    /**
+     * Resolves every remote secret reference of the given variables now, so that an unreachable
+     * secret manager or a missing key stops an operation before it stops the running resource.
+     * The fetched secrets stay cached on this model for the start that follows.
+     *
+     * @param  iterable<EnvironmentVariable>  $environmentVariables
+     *
+     * @throws RemoteSecretException
+     */
+    public function ensureRemoteSecretsResolvable(iterable $environmentVariables): void
+    {
+        foreach ($environmentVariables as $environmentVariable) {
+            $this->resolveSecretManagerEnvironmentVariableValue($environmentVariable);
+        }
+    }
+
+    private function formatLocalEnvironmentVariableValue(EnvironmentVariable $environmentVariable, ?string $value): ?string
     {
         if ($value === null) {
             return null;
@@ -81,7 +141,7 @@ trait HasSecretManager
             $missing = RemoteSecretReferences::missingKeys($value, $secrets);
 
             if ($missing !== []) {
-                throw new RuntimeException('Missing secret keys: '.implode(', ', $missing)." (referenced by {$environmentVariable->key}).");
+                throw new RemoteSecretException('Missing secret keys: '.implode(', ', $missing)." (referenced by {$environmentVariable->key}).");
             }
 
             $value = RemoteSecretReferences::substitute($value, $secrets);
@@ -116,10 +176,16 @@ trait HasSecretManager
         $link = $this->secretManagerLink()->with('integrationToken')->first();
 
         if (! $link) {
-            throw new RuntimeException('Environment variables reference remote secrets, but no secret manager source is configured.');
+            throw new RemoteSecretException('Environment variables reference remote secrets, but no secret manager source is configured.');
         }
 
-        return $this->resolvedSecretManagerValues = $link->fetchSecrets();
+        try {
+            return $this->resolvedSecretManagerValues = $link->fetchSecrets();
+        } catch (RemoteSecretException $e) {
+            throw $e;
+        } catch (Throwable $e) {
+            throw new RemoteSecretException('Could not fetch remote secrets: '.$e->getMessage(), previous: $e);
+        }
     }
 
     /** @return array<string, string> */
diff --git a/app/Traits/HasSecretManagerAutocomplete.php b/app/Traits/HasSecretManagerAutocomplete.php
index 1b46ca2dd5..b210b0be29 100644
--- a/app/Traits/HasSecretManagerAutocomplete.php
+++ b/app/Traits/HasSecretManagerAutocomplete.php
@@ -3,6 +3,8 @@
 namespace App\Traits;
 
 use App\Models\SecretManagerLink;
+use Illuminate\Support\Facades\Cache;
+use Illuminate\Support\Facades\RateLimiter;
 
 /**
  * Exposes the resource's secret manager source to the env-var-input
@@ -17,6 +19,12 @@ trait HasSecretManagerAutocomplete
         return $this->secretManagerLinkForAutocomplete() !== null;
     }
 
+    /** Seconds that fetched key names are reused for the same secret manager source. */
+    private const SECRET_MANAGER_KEYS_CACHE_SECONDS = 60;
+
+    /** Secret manager requests that one user can start from the autocomplete per minute. */
+    private const SECRET_MANAGER_KEYS_REQUESTS_PER_MINUTE = 10;
+
     /**
      * @return list<string>
      */
@@ -30,15 +38,34 @@ trait HasSecretManagerAutocomplete
             return [];
         }
 
-        try {
-            $this->authorize('view', $link->resourceable);
-            $keys = array_keys($link->fetchSecrets());
-            sort($keys);
+        $this->authorize('view', $link->resourceable);
 
-            return $keys;
+        // Only key names are cached. Another token or other settings use another cache entry.
+        $cacheKey = 'secret-manager-keys:'.$link->id.':'.hash('sha256', json_encode([
+            $link->integration_token_id,
+            $link->settings,
+            $link->integrationToken?->updated_at?->getTimestamp(),
+        ]));
+        $cachedKeys = Cache::get($cacheKey);
+        if (is_array($cachedKeys)) {
+            return $cachedKeys;
+        }
+
+        $rateLimitKey = 'secret-manager-keys:user:'.auth()->id();
+        if (RateLimiter::tooManyAttempts($rateLimitKey, self::SECRET_MANAGER_KEYS_REQUESTS_PER_MINUTE)) {
+            throw new \RuntimeException('Too many secret manager key requests. Try again in '.RateLimiter::availableIn($rateLimitKey).' seconds.');
+        }
+        RateLimiter::hit($rateLimitKey, 60);
+
+        try {
+            $keys = array_keys($link->fetchSecrets());
         } catch (\Throwable) {
             throw new \RuntimeException('Unable to fetch secret manager keys.');
         }
+        sort($keys);
+        Cache::put($cacheKey, $keys, self::SECRET_MANAGER_KEYS_CACHE_SECONDS);
+
+        return $keys;
     }
 
     private function secretManagerLinkForAutocomplete(): ?SecretManagerLink
diff --git a/tests/Feature/SecretManagers/RemoteSecretResourceLifecycleTest.php b/tests/Feature/SecretManagers/RemoteSecretResourceLifecycleTest.php
new file mode 100644
index 0000000000..c93d3a1849
--- /dev/null
+++ b/tests/Feature/SecretManagers/RemoteSecretResourceLifecycleTest.php
@@ -0,0 +1,292 @@
+<?php
+
+use App\Actions\Database\RestartDatabase;
+use App\Actions\Database\StartPostgresql;
+use App\Actions\Database\StartRedis;
+use App\Actions\Database\StopDatabase;
+use App\Actions\Service\StartService;
+use App\Actions\Service\StopService;
+use App\Enums\ActivityTypes;
+use App\Enums\ProcessStatus;
+use App\Events\DatabaseStatusChanged;
+use App\Jobs\ApplicationDeploymentJob;
+use App\Jobs\DatabaseStartJob;
+use App\Livewire\Project\Shared\EnvironmentVariable\Show;
+use App\Models\Application;
+use App\Models\Environment;
+use App\Models\InstanceSettings;
+use App\Models\IntegrationToken;
+use App\Models\PrivateKey;
+use App\Models\Project;
+use App\Models\Server;
+use App\Models\Service;
+use App\Models\StandalonePostgresql;
+use App\Models\StandaloneRedis;
+use App\Models\Team;
+use App\Models\User;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Support\Facades\Event;
+use Illuminate\Support\Facades\Http;
+use Illuminate\Support\Facades\Process;
+use Illuminate\Support\Facades\Storage;
+use Illuminate\Support\Str;
+use Livewire\Livewire;
+
+uses(RefreshDatabase::class);
+
+const REMOTE_SECRET_LIFECYCLE_DOPPLER_URL = 'https://api.doppler.com/*';
+
+beforeEach(function () {
+    Server::flushIdentityMap();
+    InstanceSettings::unguarded(fn () => InstanceSettings::firstOrCreate(['id' => 0]));
+    Storage::fake('ssh-keys');
+    Storage::fake('ssh-mux');
+
+    $this->team = Team::factory()->create();
+    $this->user = User::factory()->create();
+    $this->team->members()->attach($this->user->id, ['role' => 'owner']);
+    session(['currentTeam' => $this->team]);
+    $this->actingAs($this->user);
+
+    $this->server = Server::factory()->create(['team_id' => $this->team->id]);
+    $privateKey = PrivateKey::factory()->create(['team_id' => $this->team->id]);
+    $this->server->update(['private_key_id' => $privateKey->id]);
+    $this->server->settings()->update(['is_reachable' => true, 'is_usable' => true, 'force_disabled' => false]);
+    $this->destination = $this->server->standaloneDockers()->firstOrFail();
+    $project = Project::factory()->create(['team_id' => $this->team->id]);
+    $this->environment = Environment::factory()->create(['project_id' => $project->id]);
+
+    $this->token = IntegrationToken::query()->create([
+        'team_id' => $this->team->id,
+        'provider' => 'doppler',
+        'name' => 'Doppler',
+        'token' => 'the-secret-token',
+        'capabilities' => ['secrets'],
+    ]);
+});
+
+function remoteSecretLifecycleService(): Service
+{
+    $service = Service::factory()->create([
+        'environment_id' => test()->environment->id,
+        'server_id' => test()->server->id,
+        'destination_id' => test()->destination->id,
+        'destination_type' => test()->destination->getMorphClass(),
+        'docker_compose' => "services:\n  app:\n    image: alpine\n",
+    ]);
+    $service->secretManagerLink()->create(['integration_token_id' => test()->token->id]);
+
+    return $service;
+}
+
+function remoteSecretLifecyclePostgres(): StandalonePostgresql
+{
+    $database = StandalonePostgresql::create([
+        'uuid' => (string) Str::uuid(),
+        'name' => 'db',
+        'postgres_user' => 'postgres',
+        'postgres_password' => 'password',
+        'postgres_db' => 'db',
+        'image' => 'postgres:17-alpine',
+        'status' => 'running:healthy',
+        'environment_id' => test()->environment->id,
+        'destination_id' => test()->destination->id,
+        'destination_type' => test()->destination->getMorphClass(),
+    ]);
+    $database->secretManagerLink()->create(['integration_token_id' => test()->token->id]);
+
+    return $database;
+}
+
+/**
+ * Returns the .env file content that saveComposeConfigs() writes to the server.
+ */
+function remoteSecretLifecycleWrittenEnvFile(Service $service): string
+{
+    $commands = collect();
+    Process::fake(function ($process) use ($commands) {
+        $commands->push($process->command);
+
+        return Process::result(output: '');
+    });
+
+    $service->saveComposeConfigs();
+
+    preg_match("/echo '([A-Za-z0-9+\/=]+)' \| base64 -d \| tee [^ ]+\.env\.tmp/", $commands->implode("\n"), $matches);
+
+    return base64_decode($matches[1] ?? '');
+}
+
+/*
+ * Expected values were checked with `docker compose config` (Compose v2 dotenv parser): single quotes
+ * keep everything literal, including newlines and "#"; a backslash before the closing single quote
+ * escapes it; double quotes need \\, \" and $$.
+ */
+dataset('remote secret dotenv values', [
+    'newline that would add a variable' => ["line1\nSERVICE_PASSWORD_APP=injected", "'line1\nSERVICE_PASSWORD_APP=injected'"],
+    'single quote and dollar' => ["it's \$HOME", '"it\'s $$HOME"'],
+    'double quote and backslash' => ['say "hi" \\o/', "'say \"hi\" \\o/'"],
+    'trailing backslash' => ['ends with \\', '"ends with \\\\"'],
+    'comment marker' => ['value #not-a-comment', "'value #not-a-comment'"],
+    'dollar' => ['p4$$word', "'p4$\$word'"],
+]);
+
+test('remote secret values are written to the service .env file as exact dotenv literals', function (string $secret, string $expected) {
+    Http::fake([REMOTE_SECRET_LIFECYCLE_DOPPLER_URL => Http::response(['API_KEY' => $secret])]);
+    $service = remoteSecretLifecycleService();
+    $service->environment_variables()->create(['key' => 'API_KEY', 'value' => '{{vault.API_KEY}}']);
+
+    expect(remoteSecretLifecycleWrittenEnvFile($service))->toContain("API_KEY={$expected}");
+})->with('remote secret dotenv values');
+
+test('literal service variables with remote secrets are written as valid dotenv literals', function () {
+    Http::fake([REMOTE_SECRET_LIFECYCLE_DOPPLER_URL => Http::response(['API_KEY' => "it's"])]);
+    $service = remoteSecretLifecycleService();
+    $service->environment_variables()->create(['key' => 'API_KEY', 'value' => '{{vault.API_KEY}}', 'is_literal' => true]);
+
+    expect(remoteSecretLifecycleWrittenEnvFile($service))->toContain('API_KEY="it\'s"');
+});
+
+test('service variables without remote secrets keep their .env format', function () {
+    $service = remoteSecretLifecycleService();
+    $service->environment_variables()->create(['key' => 'PLAIN', 'value' => 'say "hi"']);
+
+    expect(remoteSecretLifecycleWrittenEnvFile($service))->toContain('PLAIN=say \"hi\"');
+    Http::assertNothingSent();
+});
+
+test('the application deployment formats remote secrets with the same dotenv rules', function (string $secret, string $expected) {
+    $job = (new ReflectionClass(ApplicationDeploymentJob::class))->newInstanceWithoutConstructor();
+
+    expect((new ReflectionMethod($job, 'format_remote_secret_value'))->invoke($job, $secret))->toBe($expected);
+})->with('remote secret dotenv values');
+
+test('remote secret values reach the database container environment unchanged', function () {
+    $secret = "pa\$word \"q\" 'q' \\ #x\nNEXT=1";
+    Http::fake([REMOTE_SECRET_LIFECYCLE_DOPPLER_URL => Http::response(['PG_PASSWORD' => $secret])]);
+    $database = remoteSecretLifecyclePostgres();
+    $database->runtime_environment_variables()->create(['key' => 'POSTGRES_PASSWORD', 'value' => '{{vault.PG_PASSWORD}}']);
+    $database->runtime_environment_variables()->create(['key' => 'LITERAL_PASSWORD', 'value' => '{{vault.PG_PASSWORD}}', 'is_literal' => true]);
+
+    $action = new StartPostgresql;
+    $action->database = $database;
+    $environmentVariables = (new ReflectionMethod($action, 'generate_environment_variables'))->invoke($action);
+
+    // Compose environment entries are not dotenv: quotes stay part of the value and only "$" is interpolated.
+    $composeValue = str_replace('$', '$$', $secret);
+    expect($environmentVariables)->toContain("POSTGRES_PASSWORD={$composeValue}")
+        ->and($environmentVariables)->toContain("LITERAL_PASSWORD={$composeValue}");
+});
+
+test('redis remote passwords are escaped the same way in the environment and the start command', function () {
+    Http::fake([REMOTE_SECRET_LIFECYCLE_DOPPLER_URL => Http::response(['REDIS_PASSWORD' => 'p4$word'])]);
+    $redis = StandaloneRedis::forceCreate([
+        'uuid' => (string) Str::uuid(),
+        'name' => 'redis',
+        'image' => 'redis:7-alpine',
+        'environment_id' => $this->environment->id,
+        'destination_id' => $this->destination->id,
+        'destination_type' => $this->destination->getMorphClass(),
+    ]);
+    $redis->secretManagerLink()->create(['integration_token_id' => $this->token->id]);
+    $redis->runtime_environment_variables()->create(['key' => 'REDIS_PASSWORD', 'value' => '{{vault.REDIS_PASSWORD}}']);
+
+    $action = new StartRedis;
+    $action->database = $redis;
+    $environmentVariables = (new ReflectionMethod($action, 'generate_environment_variables'))->invoke($action);
+    $startCommand = (new ReflectionMethod($action, 'buildStartCommand'))->invoke($action);
+
+    expect($environmentVariables)->toContain('REDIS_PASSWORD=p4$$word')
+        ->and($startCommand)->toContain('--requirepass p4$$word');
+});
+
+test('a service restart keeps the service running when remote secrets cannot be fetched', function () {
+    Http::fake([REMOTE_SECRET_LIFECYCLE_DOPPLER_URL => Http::response(['messages' => ['Doppler is down']], 503)]);
+    StopService::shouldRun()->never();
+    $service = remoteSecretLifecycleService();
+    $service->environment_variables()->create(['key' => 'API_KEY', 'value' => '{{vault.API_KEY}}']);
+
+    expect(fn () => StartService::run($service, stopBeforeStart: true))
+        ->toThrow(RuntimeException::class, 'Doppler is down');
+});
+
+test('a service restart fetches remote secrets only once', function () {
+    Http::fake([REMOTE_SECRET_LIFECYCLE_DOPPLER_URL => Http::response(['API_KEY' => 'value'])]);
+    Process::fake(['*' => Process::result(output: '')]);
+    StopService::shouldRun();
+    $service = remoteSecretLifecycleService();
+    $service->environment_variables()->create(['key' => 'API_KEY', 'value' => '{{vault.API_KEY}}']);
+
+    StartService::run($service, stopBeforeStart: true);
+
+    Http::assertSentCount(1);
+});
+
+test('a database restart keeps the database running and reports the secret manager error', function () {
+    Http::fake([REMOTE_SECRET_LIFECYCLE_DOPPLER_URL => Http::response(['messages' => ['Doppler is down']], 503)]);
+    StopDatabase::shouldRun()->never();
+    $database = remoteSecretLifecyclePostgres();
+    $database->runtime_environment_variables()->create(['key' => 'POSTGRES_PASSWORD', 'value' => '{{vault.PG_PASSWORD}}']);
+
+    expect(RestartDatabase::run($database))->toBeString()->toContain('Doppler is down');
+});
+
+test('a database start job shows the secret manager error instead of a generic failure', function () {
+    Event::fake([DatabaseStatusChanged::class]);
+    Http::fake([REMOTE_SECRET_LIFECYCLE_DOPPLER_URL => Http::response(['messages' => ['Doppler is down']], 503)]);
+    $database = remoteSecretLifecyclePostgres();
+    $database->runtime_environment_variables()->create(['key' => 'POSTGRES_PASSWORD', 'value' => '{{vault.PG_PASSWORD}}']);
+    $activity = activity()
+        ->withProperties([
+            'type' => ActivityTypes::INLINE->value,
+            'type_uuid' => $database->uuid,
+            'status' => ProcessStatus::QUEUED->value,
+            'team_id' => $this->team->id,
+            'operation' => 'database-start',
+        ])
+        ->event(ActivityTypes::INLINE->value)
+        ->log('[]');
+
+    expect(fn () => DatabaseStartJob::dispatchSync(StandalonePostgresql::class, $database->id, $this->team->id, $activity->id, null))
+        ->toThrow(RuntimeException::class);
+
+    expect(data_get($activity->refresh(), 'properties.error'))->toContain('Doppler is down');
+});
+
+test('the secret key autocomplete reuses recently fetched key names', function () {
+    Http::fake([REMOTE_SECRET_LIFECYCLE_DOPPLER_URL => Http::response(['B_KEY' => 'b', 'A_KEY' => 'a'])]);
+    $application = Application::factory()->create([
+        'environment_id' => $this->environment->id,
+        'destination_id' => $this->destination->id,
+        'destination_type' => $this->destination->getMorphClass(),
+    ]);
+    $application->secretManagerLink()->create(['integration_token_id' => $this->token->id]);
+    $env = $application->environment_variables()->create(['key' => 'MY_VAR', 'value' => 'plain']);
+    $component = Livewire::test(Show::class, ['env' => $env, 'type' => 'application'])->instance();
+
+    expect($component->fetchSecretManagerKeys())->toBe(['A_KEY', 'B_KEY'])
+        ->and($component->fetchSecretManagerKeys())->toBe(['A_KEY', 'B_KEY']);
+    Http::assertSentCount(1);
+});
+
+test('the secret key autocomplete limits how often a user can contact the secret manager', function () {
+    Http::fake([REMOTE_SECRET_LIFECYCLE_DOPPLER_URL => Http::response(['A_KEY' => 'a'])]);
+    $application = Application::factory()->create([
+        'environment_id' => $this->environment->id,
+        'destination_id' => $this->destination->id,
+        'destination_type' => $this->destination->getMorphClass(),
+    ]);
+    $link = $application->secretManagerLink()->create(['integration_token_id' => $this->token->id]);
+    $env = $application->environment_variables()->create(['key' => 'MY_VAR', 'value' => 'plain']);
+    $component = Livewire::test(Show::class, ['env' => $env, 'type' => 'application']);
+
+    // A changed source is fetched again, so each request reaches the secret manager.
+    foreach (range(1, 10) as $attempt) {
+        $link->update(['settings' => ['project' => "project-{$attempt}", 'config' => 'prd']]);
+        $component->call('fetchSecretManagerKeys');
+    }
+    $link->update(['settings' => ['project' => 'project-11', 'config' => 'prd']]);
+
+    expect(fn () => $component->call('fetchSecretManagerKeys'))->toThrow(RuntimeException::class, 'Too many');
+    Http::assertSentCount(10);
+});
diff --git a/tests/Feature/SecretManagers/SecretManagerLinkTest.php b/tests/Feature/SecretManagers/SecretManagerLinkTest.php
index d26f00c7c1..3cad814ea6 100644
--- a/tests/Feature/SecretManagers/SecretManagerLinkTest.php
+++ b/tests/Feature/SecretManagers/SecretManagerLinkTest.php
@@ -262,9 +262,9 @@ test('redis remote credentials stay deployment-local and use raw values in the s
     expect($password->fresh()->value)->toBe('{{team.REDIS_PASSWORD}}')
         ->and($sharedPassword->fresh()->value)->toBe('{{vault.REDIS_PASSWORD}}')
         ->and($username->fresh()->value)->toBe('{{vault.REDIS_USERNAME}}')
-        ->and($environmentVariables)->toContain('REDIS_PASSWORD=p4$$word')
+        ->and($environmentVariables)->toContain('REDIS_PASSWORD=p4$$$$word')
         ->and($environmentVariables)->toContain('REDIS_USERNAME=remote-user')
-        ->and($startCommand)->toContain('--requirepass p4$$word');
+        ->and($startCommand)->toContain('--requirepass p4$$$$word');
 });
 
 test('all deployable environment-variable resources support secret managers', function (string $resourceClass) {