feat(ts): add system prompt for chat engine (#92)

.changeset/silly-keys-wonder.md

+---
+"create-llama": patch
+---
+
+Add system prompt env variable for TS

helpers/env-variables.ts

@@ -249,13 +249,6 @@ const getFrameworkEnvs = (
       description: "The port to start the backend app.",
       value: port?.toString() || "8000",
     },
-    // TODO: Once LlamaIndexTS supports string templates, move this to `getEngineEnvs`
-    {
-      name: "SYSTEM_PROMPT",
-      description: `Custom system prompt.
-Example:
-SYSTEM_PROMPT="You are a helpful assistant who helps users with their questions."`,
-    },
   ];
 };
 
@@ -267,6 +260,12 @@ const getEngineEnvs = (): EnvVar[] => {
         "The number of similar embeddings to return when retrieving documents.",
       value: "3",
     },
+    {
+      name: "SYSTEM_PROMPT",
+      description: `Custom system prompt.
+Example:
+SYSTEM_PROMPT="You are a helpful assistant who helps users with their questions."`,
+    },
   ];
 };
 

templates/components/engines/typescript/agent/chat.ts

@@ -41,5 +41,6 @@ export async function createChatEngine() {
 
   return new OpenAIAgent({
     tools,
+    systemPrompt: process.env.SYSTEM_PROMPT,
   });
 }

templates/components/engines/typescript/chat/chat.ts

@@ -16,5 +16,6 @@ export async function createChatEngine() {
   return new ContextChatEngine({
     chatModel: Settings.llm,
     retriever,
+    systemPrompt: process.env.SYSTEM_PROMPT,
   });
 }