diff --git a/config/platform-infra/langbot.yaml b/config/platform-infra/langbot.yaml
index 1de3ed23..568c0e68 100644
--- a/config/platform-infra/langbot.yaml
+++ b/config/platform-infra/langbot.yaml
@@ -7,6 +7,9 @@ metadata:
   relatedIssues:
     - 297
 
+defaults:
+  targetId: G14
+
 image:
   repository: rockchin/langbot
   tag: v4.10.1
diff --git a/config/platform-infra/n8n.yaml b/config/platform-infra/n8n.yaml
index f29356f7..feb334ea 100644
--- a/config/platform-infra/n8n.yaml
+++ b/config/platform-infra/n8n.yaml
@@ -7,6 +7,9 @@ metadata:
   relatedIssues:
     - 300
 
+defaults:
+  targetId: G14
+
 image:
   repository: n8nio/n8n
   tag: "1.123.55"
diff --git a/scripts/src/platform-infra-langbot.ts b/scripts/src/platform-infra-langbot.ts
index d8e27f71..55824a77 100644
--- a/scripts/src/platform-infra-langbot.ts
+++ b/scripts/src/platform-infra-langbot.ts
@@ -53,6 +53,7 @@ interface LangBotConfig {
   version: number;
   kind: "platform-infra-langbot";
   metadata: { id: string; owner: string; relatedIssues: number[] };
+  defaults: { targetId: string };
   image: { repository: string; tag: string; pullPolicy: "Always" | "IfNotPresent" | "Never" };
   dependencyImages: { postgresClient: string };
   targets: LangBotTarget[];
@@ -127,7 +128,7 @@ interface PublicExposure {
 }
 
 interface CommonOptions {
-  targetId: string;
+  targetId: string | null;
   full: boolean;
   raw: boolean;
 }
@@ -197,7 +198,7 @@ export async function runLangBotCommand(config: UniDeskConfig, args: string[]):
 }
 
 function parseCommonOptions(args: string[]): CommonOptions {
-  let targetId = "G14";
+  let targetId: string | null = null;
   let full = false;
   let raw = false;
   for (let index = 0; index < args.length; index += 1) {
@@ -216,7 +217,7 @@ function parseCommonOptions(args: string[]): CommonOptions {
       throw new Error(`unsupported langbot option: ${arg}`);
     }
   }
-  if (!/^[A-Za-z0-9._-]+$/u.test(targetId)) throw new Error("--target must be a simple target id");
+  if (targetId !== null && !/^[A-Za-z0-9._-]+$/u.test(targetId)) throw new Error("--target must be a simple target id");
   return { targetId, full, raw };
 }
 
@@ -226,7 +227,8 @@ function parseApplyOptions(args: string[]): ApplyOptions {
     return arg !== "--confirm" && arg !== "--dry-run" && arg !== "--wait" && previous !== "--component" && previous !== "--lines" && previous !== "--path";
   });
   const common = parseCommonOptions(commonArgs);
-  if (args.some((arg) => !["--target", "--confirm", "--dry-run", "--wait", common.targetId].includes(arg) && !arg.startsWith("--target="))) {
+  const allowedArgs = ["--target", "--confirm", "--dry-run", "--wait", ...(common.targetId === null ? [] : [common.targetId])];
+  if (args.some((arg) => !allowedArgs.includes(arg) && !arg.startsWith("--target="))) {
     for (let index = 0; index < args.length; index += 1) {
       const arg = args[index];
       if (arg === "--target") {
@@ -298,6 +300,7 @@ function readLangBotConfig(): LangBotConfig {
   const kind = stringField(root, "kind", "");
   if (kind !== "platform-infra-langbot") throw new Error("config/platform-infra/langbot.yaml.kind must be platform-infra-langbot");
   const metadata = objectField(root, "metadata", "");
+  const defaults = objectField(root, "defaults", "");
   const image = objectField(root, "image", "");
   const dependencyImages = objectField(root, "dependencyImages", "");
   const runtime = objectField(root, "runtime", "");
@@ -316,6 +319,9 @@ function readLangBotConfig(): LangBotConfig {
       owner: stringField(metadata, "owner", "metadata"),
       relatedIssues: numberArrayField(metadata, "relatedIssues", "metadata"),
     },
+    defaults: {
+      targetId: stringField(defaults, "targetId", "defaults"),
+    },
     image: {
       repository: stringField(image, "repository", "image"),
       tag: stringField(image, "tag", "image"),
@@ -372,6 +378,7 @@ function readLangBotConfig(): LangBotConfig {
   if (!isImageReference(`${config.image.repository}:${config.image.tag}`)) throw new Error("config/platform-infra/langbot.yaml.image must render a valid image reference");
   if (!isImageReference(config.dependencyImages.postgresClient)) throw new Error("config/platform-infra/langbot.yaml.dependencyImages.postgresClient must be an image reference");
   if (config.targets.length === 0) throw new Error("config/platform-infra/langbot.yaml.targets must not be empty");
+  assertKnownEnabledTarget(config.targets, config.defaults.targetId, "defaults.targetId");
   return config;
 }
 
@@ -422,9 +429,16 @@ function parseTarget(record: Record<string, unknown>, index: number): LangBotTar
   };
 }
 
-function resolveTarget(langbot: LangBotConfig, targetId: string): LangBotTarget {
-  const target = langbot.targets.find((item) => item.id.toLowerCase() === targetId.toLowerCase());
-  if (target === undefined) throw new Error(`unknown LangBot target ${targetId}; known targets: ${langbot.targets.map((item) => item.id).join(", ")}`);
+function assertKnownEnabledTarget(targets: LangBotTarget[], targetId: string, path: string): void {
+  const target = targets.find((item) => item.id.toLowerCase() === targetId.toLowerCase());
+  if (target === undefined) throw new Error(`config/platform-infra/langbot.yaml.${path} references unknown target ${targetId}; known targets: ${targets.map((item) => item.id).join(", ")}`);
+  if (!target.enabled) throw new Error(`config/platform-infra/langbot.yaml.${path} references disabled target ${target.id}`);
+}
+
+function resolveTarget(langbot: LangBotConfig, targetId: string | null): LangBotTarget {
+  const resolvedTargetId = targetId ?? langbot.defaults.targetId;
+  const target = langbot.targets.find((item) => item.id.toLowerCase() === resolvedTargetId.toLowerCase());
+  if (target === undefined) throw new Error(`unknown LangBot target ${resolvedTargetId}; known targets: ${langbot.targets.map((item) => item.id).join(", ")}`);
   if (!target.enabled) throw new Error(`LangBot target ${target.id} is disabled in config/platform-infra/langbot.yaml`);
   return target;
 }
@@ -1000,7 +1014,7 @@ function prepareSecretMaterial(langbot: LangBotConfig): SecretMaterial {
 
 export function readLangBotRuntimeConfig(): Record<string, unknown> {
   const langbot = readLangBotConfig();
-  const target = resolveTarget(langbot, "G14");
+  const target = resolveTarget(langbot, null);
   return {
     publicBaseUrl: target.publicExposure.publicBaseUrl,
     expectedNamespace: target.namespace,
diff --git a/scripts/src/platform-infra-n8n.ts b/scripts/src/platform-infra-n8n.ts
index 68a1d792..9d054969 100644
--- a/scripts/src/platform-infra-n8n.ts
+++ b/scripts/src/platform-infra-n8n.ts
@@ -53,6 +53,7 @@ interface N8nConfig {
   version: number;
   kind: "platform-infra-n8n";
   metadata: { id: string; owner: string; relatedIssues: number[] };
+  defaults: { targetId: string };
   image: { repository: string; tag: string; pullPolicy: "Always" | "IfNotPresent" | "Never" };
   dependencyImages: { postgresClient: string };
   targets: N8nTarget[];
@@ -96,7 +97,7 @@ interface N8nTarget extends PublicServiceTarget {
 }
 
 interface CommonOptions {
-  targetId: string;
+  targetId: string | null;
   full: boolean;
   raw: boolean;
 }
@@ -158,7 +159,7 @@ export async function runN8nCommand(config: UniDeskConfig, args: string[]): Prom
 }
 
 function parseCommonOptions(args: string[]): CommonOptions {
-  let targetId = "G14";
+  let targetId: string | null = null;
   let full = false;
   let raw = false;
   for (let index = 0; index < args.length; index += 1) {
@@ -177,7 +178,7 @@ function parseCommonOptions(args: string[]): CommonOptions {
       throw new Error(`unsupported n8n option: ${arg}`);
     }
   }
-  if (!/^[A-Za-z0-9._-]+$/u.test(targetId)) throw new Error("--target must be a simple target id");
+  if (targetId !== null && !/^[A-Za-z0-9._-]+$/u.test(targetId)) throw new Error("--target must be a simple target id");
   return { targetId, full, raw };
 }
 
@@ -876,6 +877,7 @@ function readN8nConfig(): N8nConfig {
   const kind = stringField(root, "kind", "");
   if (kind !== "platform-infra-n8n") throw new Error(`${configLabel}.kind must be platform-infra-n8n`);
   const metadata = objectField(root, "metadata", "");
+  const defaults = objectField(root, "defaults", "");
   const image = objectField(root, "image", "");
   const dependencyImages = objectField(root, "dependencyImages", "");
   const runtime = objectField(root, "runtime", "");
@@ -893,6 +895,9 @@ function readN8nConfig(): N8nConfig {
       owner: stringField(metadata, "owner", "metadata"),
       relatedIssues: numberArrayField(metadata, "relatedIssues", "metadata"),
     },
+    defaults: {
+      targetId: stringField(defaults, "targetId", "defaults"),
+    },
     image: {
       repository: stringField(image, "repository", "image"),
       tag: stringField(image, "tag", "image"),
@@ -944,6 +949,7 @@ function readN8nConfig(): N8nConfig {
   if (!isImageReference(`${config.image.repository}:${config.image.tag}`)) throw new Error(`${configLabel}.image must render a valid image reference`);
   if (!isImageReference(config.dependencyImages.postgresClient)) throw new Error(`${configLabel}.dependencyImages.postgresClient must be an image reference`);
   if (config.targets.length === 0) throw new Error(`${configLabel}.targets must not be empty`);
+  assertKnownEnabledTarget(config.targets, config.defaults.targetId, "defaults.targetId");
   return config;
 }
 
@@ -994,9 +1000,16 @@ function parseTarget(record: Record<string, unknown>, index: number): N8nTarget
   };
 }
 
-function resolveTarget(n8n: N8nConfig, targetId: string): N8nTarget {
-  const target = n8n.targets.find((item) => item.id.toLowerCase() === targetId.toLowerCase());
-  if (target === undefined) throw new Error(`unknown n8n target ${targetId}; known targets: ${n8n.targets.map((item) => item.id).join(", ")}`);
+function assertKnownEnabledTarget(targets: N8nTarget[], targetId: string, path: string): void {
+  const target = targets.find((item) => item.id.toLowerCase() === targetId.toLowerCase());
+  if (target === undefined) throw new Error(`${configLabel}.${path} references unknown target ${targetId}; known targets: ${targets.map((item) => item.id).join(", ")}`);
+  if (!target.enabled) throw new Error(`${configLabel}.${path} references disabled target ${target.id}`);
+}
+
+function resolveTarget(n8n: N8nConfig, targetId: string | null): N8nTarget {
+  const resolvedTargetId = targetId ?? n8n.defaults.targetId;
+  const target = n8n.targets.find((item) => item.id.toLowerCase() === resolvedTargetId.toLowerCase());
+  if (target === undefined) throw new Error(`unknown n8n target ${resolvedTargetId}; known targets: ${n8n.targets.map((item) => item.id).join(", ")}`);
   if (!target.enabled) throw new Error(`n8n target ${target.id} is disabled in ${configLabel}`);
   return target;
 }