diff --git a/.gitignore b/.gitignore
index 6ee4ea0f5a5..e0bc892d767 100644
--- a/.gitignore
+++ b/.gitignore
@@ -19,4 +19,5 @@ tilt_config.json
 hubspot.config.yml
 AGENTS.md
 CLAUDE.md
+lefthook.yml
 .claude
diff --git a/packages/cli/package.json b/packages/cli/package.json
index 87c6d0dc37d..18f4ece41f9 100644
--- a/packages/cli/package.json
+++ b/packages/cli/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@botpress/cli",
-  "version": "6.2.5",
+  "version": "6.2.6",
   "description": "Botpress CLI",
   "scripts": {
     "build": "pnpm run build:types && pnpm run bundle && pnpm run template:gen",
@@ -28,7 +28,7 @@
     "@apidevtools/json-schema-ref-parser": "^11.7.0",
     "@botpress/chat": "0.5.5",
     "@botpress/client": "1.38.2",
-    "@botpress/sdk": "6.4.1",
+    "@botpress/sdk": "6.4.2",
     "@bpinternal/const": "^0.1.0",
     "@bpinternal/tunnel": "^0.1.1",
     "@bpinternal/verel": "^0.2.0",
diff --git a/packages/cli/src/utils/require-utils.ts b/packages/cli/src/utils/require-utils.ts
index dba7acdd1b3..f2ff1251b88 100644
--- a/packages/cli/src/utils/require-utils.ts
+++ b/packages/cli/src/utils/require-utils.ts
@@ -1,3 +1,4 @@
+import * as sdk from '@botpress/sdk'
 import Module from 'module'
 import pathlib from 'path'
 
@@ -20,6 +21,12 @@ export const requireJsCode = <T>(code: string): T => {
     return m.exports
   } catch (thrown: unknown) {
     const error = thrown instanceof Error ? thrown : new Error(`${thrown}`)
+    // sdk.errors.isDefinitionError() handles cross-bundle detection: esbuild inlines a separate
+    // copy of @botpress/sdk into the compiled definition artifact, so instanceof alone is
+    // unreliable. See the isDefinitionError() docstring in the SDK for the full explanation.
+    if (sdk.errors.isDefinitionError(thrown)) {
+      throw error
+    }
     throw _injectStackTrace(error, code, filename)
   }
 }
diff --git a/packages/cli/templates/empty-bot/package.json b/packages/cli/templates/empty-bot/package.json
index 1093408fdba..4e43060fbae 100644
--- a/packages/cli/templates/empty-bot/package.json
+++ b/packages/cli/templates/empty-bot/package.json
@@ -6,7 +6,7 @@
   "private": true,
   "dependencies": {
     "@botpress/client": "1.38.2",
-    "@botpress/sdk": "6.4.1"
+    "@botpress/sdk": "6.4.2"
   },
   "devDependencies": {
     "@types/node": "^22.16.4",
diff --git a/packages/cli/templates/empty-integration/package.json b/packages/cli/templates/empty-integration/package.json
index 17c974337b2..e44b3e1d11d 100644
--- a/packages/cli/templates/empty-integration/package.json
+++ b/packages/cli/templates/empty-integration/package.json
@@ -7,7 +7,7 @@
   "private": true,
   "dependencies": {
     "@botpress/client": "1.38.2",
-    "@botpress/sdk": "6.4.1"
+    "@botpress/sdk": "6.4.2"
   },
   "devDependencies": {
     "@types/node": "^22.16.4",
diff --git a/packages/cli/templates/empty-plugin/package.json b/packages/cli/templates/empty-plugin/package.json
index 0d19f6fa2bf..940124243c1 100644
--- a/packages/cli/templates/empty-plugin/package.json
+++ b/packages/cli/templates/empty-plugin/package.json
@@ -6,7 +6,7 @@
   },
   "private": true,
   "dependencies": {
-    "@botpress/sdk": "6.4.1"
+    "@botpress/sdk": "6.4.2"
   },
   "devDependencies": {
     "@types/node": "^22.16.4",
diff --git a/packages/cli/templates/hello-world/package.json b/packages/cli/templates/hello-world/package.json
index ff1fd2b5b87..2731e770fe7 100644
--- a/packages/cli/templates/hello-world/package.json
+++ b/packages/cli/templates/hello-world/package.json
@@ -7,7 +7,7 @@
   "private": true,
   "dependencies": {
     "@botpress/client": "1.38.2",
-    "@botpress/sdk": "6.4.1"
+    "@botpress/sdk": "6.4.2"
   },
   "devDependencies": {
     "@types/node": "^22.16.4",
diff --git a/packages/cli/templates/webhook-message/package.json b/packages/cli/templates/webhook-message/package.json
index 629883658a1..641374dc417 100644
--- a/packages/cli/templates/webhook-message/package.json
+++ b/packages/cli/templates/webhook-message/package.json
@@ -7,7 +7,7 @@
   "private": true,
   "dependencies": {
     "@botpress/client": "1.38.2",
-    "@botpress/sdk": "6.4.1",
+    "@botpress/sdk": "6.4.2",
     "axios": "^1.6.8"
   },
   "devDependencies": {
diff --git a/packages/cognitive/package.json b/packages/cognitive/package.json
index de5d22393c5..da09ef75793 100644
--- a/packages/cognitive/package.json
+++ b/packages/cognitive/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@botpress/cognitive",
-  "version": "0.4.5",
+  "version": "0.4.6",
   "description": "Wrapper around the Botpress Client to call LLMs",
   "main": "./dist/index.cjs",
   "module": "./dist/index.mjs",
diff --git a/packages/llmz/package.json b/packages/llmz/package.json
index ce21d88fd8e..ff60f3922e8 100644
--- a/packages/llmz/package.json
+++ b/packages/llmz/package.json
@@ -2,7 +2,7 @@
   "name": "llmz",
   "type": "module",
   "description": "LLMz - An LLM-native Typescript VM built on top of Zui",
-  "version": "0.0.63",
+  "version": "0.0.64",
   "types": "./dist/index.d.ts",
   "main": "./dist/index.cjs",
   "module": "./dist/index.js",
@@ -72,7 +72,7 @@
   },
   "peerDependencies": {
     "@botpress/client": "1.38.2",
-    "@botpress/cognitive": "0.4.5",
+    "@botpress/cognitive": "0.4.6",
     "@bpinternal/thicktoken": "^2.0.0",
     "@bpinternal/zui": "^2.1.1"
   },
diff --git a/packages/sdk/package.json b/packages/sdk/package.json
index 478671a01bb..d77120600e5 100644
--- a/packages/sdk/package.json
+++ b/packages/sdk/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@botpress/sdk",
-  "version": "6.4.1",
+  "version": "6.4.2",
   "description": "Botpress SDK",
   "main": "./dist/index.cjs",
   "module": "./dist/index.mjs",
diff --git a/packages/sdk/src/bot/definition.ts b/packages/sdk/src/bot/definition.ts
index e53c52ab89d..b38665176c6 100644
--- a/packages/sdk/src/bot/definition.ts
+++ b/packages/sdk/src/bot/definition.ts
@@ -1,6 +1,7 @@
 import { Table } from '@botpress/client'
 import { SchemaTransformOptions } from '../common/types'
 import * as consts from '../consts'
+import { DefinitionError } from '../errors'
 import { IntegrationPackage, PluginPackage } from '../package'
 import { PluginInterfaceExtension, PluginIntegrationExtension } from '../plugin'
 import { SchemaDefinition } from '../schema'
@@ -272,7 +273,7 @@ export class BotDefinition<
     const integrationAlias = config?.alias ?? integrationPkg.name
 
     if (self.integrations[integrationAlias]) {
-      throw new Error(`Another integration with alias "${integrationAlias}" is already installed in the bot`)
+      throw new DefinitionError(`Another integration with alias "${integrationAlias}" is already installed in the bot`)
     }
 
     self.integrations[integrationAlias] = {
@@ -295,7 +296,7 @@ export class BotDefinition<
     const pluginAlias = config.alias ?? pluginPkg.name
 
     if (self.plugins[pluginAlias]) {
-      throw new Error(`Another plugin with alias "${pluginAlias}" is already installed in the bot`)
+      throw new DefinitionError(`Another plugin with alias "${pluginAlias}" is already installed in the bot`)
     }
     // Resolve backing integrations for plugin interfaces:
     const interfaces: Record<string, PluginInterfaceExtension> = Object.fromEntries(
@@ -307,7 +308,7 @@ export class BotDefinition<
           if (!integrationInstance) {
             const availableIntegrations = Object.keys(this.integrations ?? {}).join(', ') || '(none)'
 
-            throw new Error(
+            throw new DefinitionError(
               `Interface with alias "${pluginIfaceAlias}" of plugin with alias "${pluginAlias}" ` +
                 `references integration with alias "${pluginIfaceConfig.integrationAlias}" which is not installed. ` +
                 'Please make sure to add the integration via addIntegration() before calling addPlugin().\n' +
@@ -322,7 +323,7 @@ export class BotDefinition<
             const availableInterfaces =
               Object.keys(integrationInstance.definition.interfaces ?? {}).join(', ') || '(none)'
 
-            throw new Error(
+            throw new DefinitionError(
               `Interface with alias "${pluginIfaceConfig.integrationInterfaceAlias}" does not exist in integration ` +
                 `"${integrationInstance.name}" referenced by interface with alias "${pluginIfaceAlias}" of plugin ` +
                 `with alias "${pluginAlias}".\nAvailable interface aliases: ${availableInterfaces}`
@@ -562,7 +563,7 @@ export class BotDefinition<
         const backingIntegration = this.integrations?.[pluginInterfaceExtension.integrationAlias]
 
         if (!backingIntegration) {
-          throw new Error(
+          throw new DefinitionError(
             `Interface with alias "${interfaceAlias}" of plugin with alias "${pluginAlias}" references integration "${pluginInterfaceExtension.name}" which is not installed`
           )
         }
diff --git a/packages/sdk/src/errors.ts b/packages/sdk/src/errors.ts
new file mode 100644
index 00000000000..b6655263359
--- /dev/null
+++ b/packages/sdk/src/errors.ts
@@ -0,0 +1,27 @@
+/**
+ * Thrown by SDK definition classes (BotDefinition, IntegrationDefinition, PluginDefinition, etc.)
+ * for intentional validation errors whose message is already clear.
+ *
+ * The CLI detects this class to suppress the "Offending code:" section that it normally
+ * appends to errors thrown during definition file evaluation.
+ */
+export class DefinitionError extends Error {
+  /** @internal Marker used by {@link isDefinitionError} to survive esbuild bundle boundaries. */
+  public readonly __IS_SDK_ERROR__ = true as const
+  public readonly type = 'definition_error' as const
+}
+
+/**
+ * Type guard to detect {@link DefinitionError} across esbuild bundle boundaries.
+ *
+ * Tries `instanceof` first (same bundle), then falls back to the `__IS_SDK_ERROR__` marker
+ * and `type` field for cross-bundle cases where esbuild inlines a separate copy of the SDK class.
+ */
+export const isDefinitionError = (error: unknown): error is DefinitionError =>
+  error instanceof DefinitionError ||
+  (typeof error === 'object' &&
+    error !== null &&
+    '__IS_SDK_ERROR__' in error &&
+    error.__IS_SDK_ERROR__ === true &&
+    'type' in error &&
+    error.type === 'definition_error')
diff --git a/packages/sdk/src/index.ts b/packages/sdk/src/index.ts
index 0ca8f0af4a9..4c7325473c2 100644
--- a/packages/sdk/src/index.ts
+++ b/packages/sdk/src/index.ts
@@ -83,6 +83,8 @@ export {
 
 export * as version from './version-utils'
 
+export * as errors from './errors'
+
 export {
   //
   IntegrationPackage,
diff --git a/packages/sdk/src/integration/definition/index.ts b/packages/sdk/src/integration/definition/index.ts
index 42aa01ba2f2..b7f4f9c4c69 100644
--- a/packages/sdk/src/integration/definition/index.ts
+++ b/packages/sdk/src/integration/definition/index.ts
@@ -1,5 +1,6 @@
 import type * as esbuild from 'esbuild'
 import { SchemaTransformOptions } from '../../common/types'
+import { DefinitionError } from '../../errors'
 import { resolveInterface } from '../../interface/resolve'
 import { InterfacePackage } from '../../package'
 import * as utils from '../../utils'
@@ -316,7 +317,7 @@ export class IntegrationDefinition<
     const unbrandedEntity = utils.records.pairs(extensionBuilderOutput.entities).find(([_k, e]) => !isBranded(e))
     if (unbrandedEntity) {
       // this means the user tried providing a plain schema without referencing an entity from the integration
-      throw new Error(
+      throw new DefinitionError(
         `Cannot extend interface "${interfacePkg.name}" with entity "${unbrandedEntity[0]}"; the provided schema is not part of the integration's entities.`
       )
     }
diff --git a/packages/sdk/src/plugin/definition.ts b/packages/sdk/src/plugin/definition.ts
index 9975784d923..7c5be58d924 100644
--- a/packages/sdk/src/plugin/definition.ts
+++ b/packages/sdk/src/plugin/definition.ts
@@ -10,6 +10,7 @@ import {
   WorkflowDefinition,
 } from '../bot/definition'
 import { SchemaTransformOptions } from '../common/types'
+import { DefinitionError } from '../errors'
 import { IntegrationPackage, InterfacePackage } from '../package'
 import * as typeUtils from '../utils/type-utils'
 import { SDK_VERSION } from '../version'
@@ -254,7 +255,7 @@ export class PluginDefinition<
 
     for (const alias of [...Object.keys(props.integrations ?? {}), ...Object.keys(props.interfaces ?? {})]) {
       if (aliases.has(alias)) {
-        throw new Error(
+        throw new DefinitionError(
           `Duplicate interface or integration alias detected in plugin definition: '${alias}'. ` +
             'Please use unique aliases for each interface and integration.'
         )
diff --git a/packages/vai/package.json b/packages/vai/package.json
index be11cef47f5..edf3b0ee560 100644
--- a/packages/vai/package.json
+++ b/packages/vai/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@botpress/vai",
-  "version": "0.0.23",
+  "version": "0.0.24",
   "description": "Vitest AI (vai) – a vitest extension for testing with LLMs",
   "types": "./dist/index.d.ts",
   "exports": {
diff --git a/packages/zai/package.json b/packages/zai/package.json
index ebc305f7271..4fb14d2f911 100644
--- a/packages/zai/package.json
+++ b/packages/zai/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@botpress/zai",
   "description": "Zui AI (zai) – An LLM utility library written on top of Zui and the Botpress API",
-  "version": "2.6.10",
+  "version": "2.6.11",
   "main": "./dist/index.js",
   "types": "./dist/index.d.ts",
   "exports": {
@@ -32,7 +32,7 @@
   "author": "",
   "license": "ISC",
   "dependencies": {
-    "@botpress/cognitive": "0.4.5",
+    "@botpress/cognitive": "0.4.6",
     "json5": "^2.2.3",
     "jsonrepair": "^3.10.0",
     "lodash-es": "^4.17.21",
diff --git a/plugins/conversation-insights/package.json b/plugins/conversation-insights/package.json
index 8c9fd190aa8..3eb2118686d 100644
--- a/plugins/conversation-insights/package.json
+++ b/plugins/conversation-insights/package.json
@@ -7,7 +7,7 @@
   },
   "private": true,
   "dependencies": {
-    "@botpress/cognitive": "0.4.5",
+    "@botpress/cognitive": "0.4.6",
     "@botpress/sdk": "workspace:*",
     "browser-or-node": "^2.1.1",
     "jsonrepair": "^3.10.0"
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 8e3e52b4d94..308b60c0474 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -2533,7 +2533,7 @@ importers:
         specifier: 1.38.2
         version: link:../client
       '@botpress/sdk':
-        specifier: 6.4.1
+        specifier: 6.4.2
         version: link:../sdk
       '@bpinternal/const':
         specifier: ^0.1.0
@@ -2657,7 +2657,7 @@ importers:
         specifier: 1.38.2
         version: link:../../../client
       '@botpress/sdk':
-        specifier: 6.4.1
+        specifier: 6.4.2
         version: link:../../../sdk
     devDependencies:
       '@types/node':
@@ -2673,7 +2673,7 @@ importers:
         specifier: 1.38.2
         version: link:../../../client
       '@botpress/sdk':
-        specifier: 6.4.1
+        specifier: 6.4.2
         version: link:../../../sdk
     devDependencies:
       '@types/node':
@@ -2686,7 +2686,7 @@ importers:
   packages/cli/templates/empty-plugin:
     dependencies:
       '@botpress/sdk':
-        specifier: 6.4.1
+        specifier: 6.4.2
         version: link:../../../sdk
     devDependencies:
       '@types/node':
@@ -2702,7 +2702,7 @@ importers:
         specifier: 1.38.2
         version: link:../../../client
       '@botpress/sdk':
-        specifier: 6.4.1
+        specifier: 6.4.2
         version: link:../../../sdk
     devDependencies:
       '@types/node':
@@ -2718,7 +2718,7 @@ importers:
         specifier: 1.38.2
         version: link:../../../client
       '@botpress/sdk':
-        specifier: 6.4.1
+        specifier: 6.4.2
         version: link:../../../sdk
       axios:
         specifier: ^1.6.8
@@ -2872,7 +2872,7 @@ importers:
         specifier: 1.38.2
         version: link:../client
       '@botpress/cognitive':
-        specifier: 0.4.5
+        specifier: 0.4.6
         version: link:../cognitive
       '@bpinternal/thicktoken':
         specifier: ^2.0.0
@@ -3058,7 +3058,7 @@ importers:
   packages/zai:
     dependencies:
       '@botpress/cognitive':
-        specifier: 0.4.5
+        specifier: 0.4.6
         version: link:../cognitive
       '@bpinternal/thicktoken':
         specifier: ^1.0.0
@@ -3171,7 +3171,7 @@ importers:
   plugins/conversation-insights:
     dependencies:
       '@botpress/cognitive':
-        specifier: 0.4.5
+        specifier: 0.4.6
         version: link:../../packages/cognitive
       '@botpress/sdk':
         specifier: workspace:*