Add custom system prompt (#61)

* Add custom system prompt

* Update settings.test.ts

* Paraphrase prompt

src/settings/SettingTab.tsx

@@ -155,6 +155,24 @@ export class SmartCopilotSettingTab extends PluginSettingTab {
           }),
       )
 
+    new Setting(containerEl)
+      .setHeading()
+      .setName('System Prompt')
+      .setDesc('This prompt will be added to the beginning of every chat.')
+
+    new Setting(containerEl)
+      .setClass('smtcmp-setting-textarea')
+      .addTextArea((text) =>
+        text
+          .setValue(this.plugin.settings.systemPrompt)
+          .onChange(async (value) => {
+            await this.plugin.setSettings({
+              ...this.plugin.settings,
+              systemPrompt: value,
+            })
+          }),
+      )
+
     new Setting(containerEl).setHeading().setName('RAG Options')
 
     new Setting(containerEl)

src/types/settings.test.ts

@@ -11,6 +11,7 @@ describe('parseSmartCopilotSettings', () => {
       chatModel: 'claude-3-5-sonnet-latest',
       applyModel: 'gpt-4o-mini',
       embeddingModel: 'text-embedding-3-small',
+      systemPrompt: '',
       ragOptions: {
         chunkSize: 1000,
         thresholdTokens: 8192,

src/types/settings.ts

@@ -25,6 +25,7 @@ const smartCopilotSettingsSchema = z.object({
   chatModel: chatModelSchema.catch('claude-3-5-sonnet-latest'),
   applyModel: applyModelSchema.catch('gpt-4o-mini'),
   embeddingModel: embeddingModelSchema.catch('text-embedding-3-small'),
+  systemPrompt: z.string().catch(''),
   ragOptions: z
     .object({
       chunkSize: z.number().catch(1000),

src/utils/promptGenerator.ts

@@ -86,6 +86,8 @@ export class PromptGenerator {
 
     const systemMessage = this.getSystemMessage(shouldUseRAG)
 
+    const customInstructionMessage = this.getCustomInstructionMessage()
+
     const currentFile = lastUserMessage.mentionables.find(
       (m) => m.type === 'current-file',
     )?.file
@@ -95,6 +97,7 @@ export class PromptGenerator {
 
     const requestMessages: RequestMessage[] = [
       systemMessage,
+      ...(customInstructionMessage ? [customInstructionMessage] : []),
       ...(currentFileMessage ? [currentFileMessage] : []),
       ...compiledMessages.slice(-20).map((message): RequestMessage => {
         if (message.role === 'user') {
@@ -311,6 +314,20 @@ The user has full access to the file, so they prefer seeing only the changes in
     }
   }
 
+  private getCustomInstructionMessage(): RequestMessage | null {
+    const customInstruction = this.settings.systemPrompt.trim()
+    if (!customInstruction) {
+      return null
+    }
+    return {
+      role: 'user',
+      content: `Here are additional instructions to follow in your responses when relevant. There's no need to explicitly acknowledge them:
+<custom_instructions>
+${customInstruction}
+</custom_instructions>`,
+    }
+  }
+
   private async getCurrentFileMessage(
     currentFile: TFile,
   ): Promise<RequestMessage> {

styles.css

@@ -741,3 +741,19 @@ button.smtcmp-chat-input-model-select {
     opacity: 1;
   }
 }
+
+.smtcmp-setting-textarea {
+  display: block;
+  border-top: none;
+  padding: 0;
+
+  .smtcmp-item-control {
+    width: 100%;
+  }
+
+  textarea {
+    width: 100%;
+    min-height: 100px;
+    resize: none;
+  }
+}