feat: text to image impl (#6437)

fix CLOUD-18
fix CLOUD-28
fix CLOUD-29

.github/actions/deploy/deploy.mjs

@@ -15,6 +15,7 @@ const {
   R2_SECRET_ACCESS_KEY,
   CAPTCHA_TURNSTILE_SECRET,
   COPILOT_OPENAI_API_KEY,
+  COPILOT_FAL_API_KEY,
   MAILER_SENDER,
   MAILER_USER,
   MAILER_PASSWORD,
@@ -101,6 +102,7 @@ const createHelmCommand = ({ isDryRun }) => {
     `--set-string graphql.app.captcha.turnstile.secret="${CAPTCHA_TURNSTILE_SECRET}"`,
     `--set        graphql.app.copilot.enabled=true`,
     `--set-string graphql.app.copilot.openai.key="${COPILOT_OPENAI_API_KEY}"`,
+    `--set-string graphql.app.copilot.fal.key="${COPILOT_FAL_API_KEY}"`,
     `--set        graphql.app.objectStorage.r2.enabled=true`,
     `--set-string graphql.app.objectStorage.r2.accountId="${R2_ACCOUNT_ID}"`,
     `--set-string graphql.app.objectStorage.r2.accessKeyId="${R2_ACCESS_KEY_ID}"`,

.github/helm/affine/charts/graphql/templates/copilot-secret.yaml

@@ -6,4 +6,5 @@ metadata:
 type: Opaque
 data:
   openaiSecret: {{ .Values.app.copilot.openai.key | b64enc }}
+  falSecret: {{ .Values.app.copilot.fal.key | b64enc }}
 {{- end }}

.github/helm/affine/charts/graphql/templates/deployment.yaml

@@ -154,6 +154,11 @@ spec:
               secretKeyRef:
                 name: "{{ .Values.app.copilot.secretName }}"
                 key: openaiSecret
+          - name: COPILOT_FAL_API_KEY
+            valueFrom:
+              secretKeyRef:
+                name: "{{ .Values.app.copilot.secretName }}"
+                key: falSecret
           {{ end }}
           {{ if .Values.app.oauth.google.enabled }}
           - name: OAUTH_GOOGLE_ENABLED

.github/workflows/deploy.yml

@@ -135,6 +135,7 @@ jobs:
           R2_SECRET_ACCESS_KEY: ${{ secrets.R2_SECRET_ACCESS_KEY }}
           CAPTCHA_TURNSTILE_SECRET: ${{ secrets.CAPTCHA_TURNSTILE_SECRET }}
           COPILOT_OPENAI_API_KEY: ${{ secrets.COPILOT_OPENAI_API_KEY }}
+          COPILOT_FAL_API_KEY: ${{ secrets.COPILOT_FAL_API_KEY }}
           MAILER_SENDER: ${{ secrets.OAUTH_EMAIL_SENDER }}
           MAILER_USER: ${{ secrets.OAUTH_EMAIL_LOGIN }}
           MAILER_PASSWORD: ${{ secrets.OAUTH_EMAIL_PASSWORD }}

packages/backend/server/migrations/20240402100608_ai_prompt_session_metadata/migration.sql

@@ -26,6 +26,7 @@ CREATE TABLE "ai_prompts_messages" (
     "idx" INTEGER NOT NULL,
     "role" "AiPromptRole" NOT NULL,
     "content" TEXT NOT NULL,
+    "attachments" JSON,
     "params" JSON,
     "created_at" TIMESTAMPTZ(6) NOT NULL DEFAULT CURRENT_TIMESTAMP
 );
@@ -47,6 +48,8 @@ CREATE TABLE "ai_sessions_messages" (
     "session_id" VARCHAR(36) NOT NULL,
     "role" "AiPromptRole" NOT NULL,
     "content" TEXT NOT NULL,
+    "attachments" JSON,
+    "params" JSON,
     "created_at" TIMESTAMPTZ(6) NOT NULL DEFAULT CURRENT_TIMESTAMP,
     "updated_at" TIMESTAMPTZ(6) NOT NULL,
 

packages/backend/server/schema.prisma

@@ -430,15 +430,16 @@ enum AiPromptRole {
 }
 
 model AiPromptMessage {
-  promptId  Int          @map("prompt_id") @db.Integer
+  promptId    Int          @map("prompt_id") @db.Integer
   // if a group of prompts contains multiple sentences, idx specifies the order of each sentence
-  idx       Int          @db.Integer
+  idx         Int          @db.Integer
   // system/assistant/user
-  role      AiPromptRole
+  role        AiPromptRole
   // prompt content
-  content   String       @db.Text
-  params    Json?        @db.Json
-  createdAt DateTime     @default(now()) @map("created_at") @db.Timestamptz(6)
+  content     String       @db.Text
+  attachments Json?        @db.Json
+  params      Json?        @db.Json
+  createdAt   DateTime     @default(now()) @map("created_at") @db.Timestamptz(6)
 
   prompt AiPrompt @relation(fields: [promptId], references: [id], onDelete: Cascade)
 
@@ -462,12 +463,14 @@ model AiPrompt {
 }
 
 model AiSessionMessage {
-  id        String       @id @default(uuid()) @db.VarChar(36)
-  sessionId String       @map("session_id") @db.VarChar(36)
-  role      AiPromptRole
-  content   String       @db.Text
-  createdAt DateTime     @default(now()) @map("created_at") @db.Timestamptz(6)
-  updatedAt DateTime     @updatedAt @map("updated_at") @db.Timestamptz(6)
+  id          String       @id @default(uuid()) @db.VarChar(36)
+  sessionId   String       @map("session_id") @db.VarChar(36)
+  role        AiPromptRole
+  content     String       @db.Text
+  attachments Json?        @db.Json
+  params      Json?        @db.Json
+  createdAt   DateTime     @default(now()) @map("created_at") @db.Timestamptz(6)
+  updatedAt   DateTime     @updatedAt @map("updated_at") @db.Timestamptz(6)
 
   session AiSession @relation(fields: [sessionId], references: [id], onDelete: Cascade)
 

packages/backend/server/src/config/affine.env.ts

@@ -20,6 +20,7 @@ AFFiNE.ENV_MAP = {
   THROTTLE_TTL: ['rateLimiter.ttl', 'int'],
   THROTTLE_LIMIT: ['rateLimiter.limit', 'int'],
   COPILOT_OPENAI_API_KEY: 'plugins.copilot.openai.apiKey',
+  COPILOT_FAL_API_KEY: 'plugins.copilot.fal.apiKey',
   REDIS_SERVER_HOST: 'plugins.redis.host',
   REDIS_SERVER_PORT: ['plugins.redis.port', 'int'],
   REDIS_SERVER_USER: 'plugins.redis.username',

packages/backend/server/src/data/migrations/utils/prompts.ts

@@ -31,10 +31,22 @@ export const prompts: Prompt[] = [
     model: 'gpt-4-vision-preview',
     messages: [],
   },
+  {
+    name: 'debug:action:dalle3',
+    action: 'image',
+    model: 'dall-e-3',
+    messages: [],
+  },
+  {
+    name: 'debug:action:fal-sd15',
+    action: 'image',
+    model: '110602490-lcm-sd15-i2i',
+    messages: [],
+  },
   {
     name: 'Summary',
     action: 'text',
-    model: 'gpt-3.5-turbo',
+    model: 'gpt-4-turbo-preview',
     messages: [
       {
         role: 'assistant',
@@ -46,7 +58,7 @@ export const prompts: Prompt[] = [
   {
     name: 'Summary the webpage',
     action: 'text',
-    model: 'gpt-3.5-turbo',
+    model: 'gpt-4-turbo-preview',
     messages: [
       {
         role: 'assistant',
@@ -58,7 +70,7 @@ export const prompts: Prompt[] = [
   {
     name: 'Explain this image',
     action: 'text',
-    model: 'gpt-3.5-turbo',
+    model: 'gpt-4-vision-preview',
     messages: [
       {
         role: 'assistant',
@@ -70,7 +82,7 @@ export const prompts: Prompt[] = [
   {
     name: 'Explain this code',
     action: 'text',
-    model: 'gpt-3.5-turbo',
+    model: 'gpt-4-turbo-preview',
     messages: [
       {
         role: 'assistant',
@@ -82,7 +94,7 @@ export const prompts: Prompt[] = [
   {
     name: 'Translate to',
     action: 'text',
-    model: 'gpt-3.5-turbo',
+    model: 'gpt-4-turbo-preview',
     messages: [
       {
         role: 'assistant',
@@ -108,7 +120,7 @@ export const prompts: Prompt[] = [
   {
     name: 'Write an article about this',
     action: 'text',
-    model: 'gpt-3.5-turbo',
+    model: 'gpt-4-turbo-preview',
     messages: [
       {
         role: 'assistant',
@@ -119,7 +131,7 @@ export const prompts: Prompt[] = [
   {
     name: 'Write a twitter about this',
     action: 'text',
-    model: 'gpt-3.5-turbo',
+    model: 'gpt-4-turbo-preview',
     messages: [
       {
         role: 'assistant',
@@ -130,7 +142,7 @@ export const prompts: Prompt[] = [
   {
     name: 'Write a poem about this',
     action: 'text',
-    model: 'gpt-3.5-turbo',
+    model: 'gpt-4-turbo-preview',
     messages: [
       {
         role: 'assistant',
@@ -141,7 +153,7 @@ export const prompts: Prompt[] = [
   {
     name: 'Write a blog post about this',
     action: 'text',
-    model: 'gpt-3.5-turbo',
+    model: 'gpt-4-turbo-preview',
     messages: [
       {
         role: 'assistant',
@@ -152,7 +164,7 @@ export const prompts: Prompt[] = [
   {
     name: 'Change tone to',
     action: 'text',
-    model: 'gpt-3.5-turbo',
+    model: 'gpt-4-turbo-preview',
     messages: [
       {
         role: 'assistant',
@@ -165,7 +177,7 @@ export const prompts: Prompt[] = [
   {
     name: 'Brainstorm ideas about this',
     action: 'text',
-    model: 'gpt-3.5-turbo',
+    model: 'gpt-4-turbo-preview',
     messages: [
       {
         role: 'assistant',
@@ -177,7 +189,7 @@ export const prompts: Prompt[] = [
   {
     name: 'Improve writing for it',
     action: 'text',
-    model: 'gpt-3.5-turbo',
+    model: 'gpt-4-turbo-preview',
     messages: [
       {
         role: 'assistant',
@@ -189,7 +201,7 @@ export const prompts: Prompt[] = [
   {
     name: 'Improve grammar for it',
     action: 'text',
-    model: 'gpt-3.5-turbo',
+    model: 'gpt-4-turbo-preview',
     messages: [
       {
         role: 'assistant',
@@ -201,7 +213,7 @@ export const prompts: Prompt[] = [
   {
     name: 'Fix spelling for it',
     action: 'text',
-    model: 'gpt-3.5-turbo',
+    model: 'gpt-4-turbo-preview',
     messages: [
       {
         role: 'assistant',
@@ -227,7 +239,7 @@ export const prompts: Prompt[] = [
   {
     name: 'Find action items from it',
     action: 'todo-list',
-    model: 'gpt-3.5-turbo',
+    model: 'gpt-4-turbo-preview',
     messages: [
       {
         role: 'assistant',
@@ -239,7 +251,7 @@ export const prompts: Prompt[] = [
   {
     name: 'Check code error',
     action: 'text',
-    model: 'gpt-3.5-turbo',
+    model: 'gpt-4-turbo-preview',
     messages: [
       {
         role: 'assistant',
@@ -251,7 +263,7 @@ export const prompts: Prompt[] = [
   {
     name: 'Create a presentation',
     action: 'text',
-    model: 'gpt-3.5-turbo',
+    model: 'gpt-4-turbo-preview',
     messages: [
       {
         role: 'assistant',
@@ -263,7 +275,7 @@ export const prompts: Prompt[] = [
   {
     name: 'Create headings',
     action: 'text',
-    model: 'gpt-3.5-turbo',
+    model: 'gpt-4-turbo-preview',
     messages: [
       {
         role: 'assistant',

packages/backend/server/src/plugins/copilot/controller.ts

@@ -23,12 +23,13 @@ import {
 import { Public } from '../../core/auth';
 import { CurrentUser } from '../../core/auth/current-user';
 import { CopilotProviderService } from './providers';
-import { ChatSessionService } from './session';
+import { ChatSession, ChatSessionService } from './session';
 import { CopilotCapability } from './types';
 
 export interface ChatEvent {
-  data: string;
+  type: 'attachment' | 'message';
   id?: string;
+  data: string;
 }
 
 @Controller('/api/copilot')
@@ -38,13 +39,54 @@ export class CopilotController {
     private readonly provider: CopilotProviderService
   ) {}
 
+  private async hasAttachment(sessionId: string, messageId?: string) {
+    const session = await this.chatSession.get(sessionId);
+    if (!session) {
+      throw new BadRequestException('Session not found');
+    }
+
+    if (messageId) {
+      const message = await session.getMessageById(messageId);
+      if (Array.isArray(message.attachments) && message.attachments.length) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  private async appendSessionMessage(
+    sessionId: string,
+    message?: string,
+    messageId?: string
+  ): Promise<ChatSession> {
+    const session = await this.chatSession.get(sessionId);
+    if (!session) {
+      throw new BadRequestException('Session not found');
+    }
+
+    if (messageId) {
+      await session.pushByMessageId(messageId);
+    } else {
+      if (!message || !message.trim()) {
+        throw new BadRequestException('Message is empty');
+      }
+      session.push({
+        role: 'user',
+        content: decodeURIComponent(message),
+        createdAt: new Date(),
+      });
+    }
+    return session;
+  }
+
   @Public()
   @Get('/chat/:sessionId')
   async chat(
     @CurrentUser() user: CurrentUser,
     @Req() req: Request,
     @Param('sessionId') sessionId: string,
-    @Query('message') content: string,
+    @Query('message') message: string | undefined,
+    @Query('messageId') messageId: string | undefined,
     @Query() params: Record<string, string | string[]>
   ): Promise<string> {
     const provider = this.provider.getProviderByCapability(
@@ -53,21 +95,16 @@ export class CopilotController {
     if (!provider) {
       throw new InternalServerErrorException('No provider available');
     }
-    const session = await this.chatSession.get(sessionId);
-    if (!session) {
-      throw new BadRequestException('Session not found');
-    }
-    if (!content || !content.trim()) {
-      throw new BadRequestException('Message is empty');
-    }
-    session.push({
-      role: 'user',
-      content: decodeURIComponent(content),
-      createdAt: new Date(),
-    });
+
+    const session = await this.appendSessionMessage(
+      sessionId,
+      message,
+      messageId
+    );
 
     try {
       delete params.message;
+      delete params.messageId;
       const content = await provider.generateText(
         session.finish(params),
         session.model,
@@ -98,7 +135,8 @@ export class CopilotController {
     @CurrentUser() user: CurrentUser,
     @Req() req: Request,
     @Param('sessionId') sessionId: string,
-    @Query('message') content: string,
+    @Query('message') message: string | undefined,
+    @Query('messageId') messageId: string | undefined,
     @Query() params: Record<string, string>
   ): Promise<Observable<ChatEvent>> {
     const provider = this.provider.getProviderByCapability(
@@ -107,20 +145,15 @@ export class CopilotController {
     if (!provider) {
       throw new InternalServerErrorException('No provider available');
     }
-    const session = await this.chatSession.get(sessionId);
-    if (!session) {
-      throw new BadRequestException('Session not found');
-    }
-    if (!content || !content.trim()) {
-      throw new BadRequestException('Message is empty');
-    }
-    session.push({
-      role: 'user',
-      content: decodeURIComponent(content),
-      createdAt: new Date(),
-    });
+
+    const session = await this.appendSessionMessage(
+      sessionId,
+      message,
+      messageId
+    );
 
     delete params.message;
+    delete params.messageId;
     return from(
       provider.generateTextStream(session.finish(params), session.model, {
         signal: req.signal,
@@ -130,7 +163,9 @@ export class CopilotController {
       connect(shared$ =>
         merge(
           // actual chat event stream
-          shared$.pipe(map(data => ({ id: sessionId, data }))),
+          shared$.pipe(
+            map(data => ({ type: 'message' as const, id: sessionId, data }))
+          ),
           // save the generated text to the session
           shared$.pipe(
             toArray(),
@@ -148,4 +183,66 @@ export class CopilotController {
       )
     );
   }
+
+  @Public()
+  @Sse('/chat/:sessionId/images')
+  async chatImagesStream(
+    @CurrentUser() user: CurrentUser | undefined,
+    @Req() req: Request,
+    @Param('sessionId') sessionId: string,
+    @Query('message') message: string | undefined,
+    @Query('messageId') messageId: string | undefined,
+    @Query() params: Record<string, string>
+  ): Promise<Observable<ChatEvent>> {
+    const provider = this.provider.getProviderByCapability(
+      (await this.hasAttachment(sessionId, messageId))
+        ? CopilotCapability.ImageToImage
+        : CopilotCapability.TextToImage
+    );
+    if (!provider) {
+      throw new InternalServerErrorException('No provider available');
+    }
+
+    const session = await this.appendSessionMessage(
+      sessionId,
+      message,
+      messageId
+    );
+
+    delete params.message;
+    delete params.messageId;
+    return from(
+      provider.generateImagesStream(session.finish(params), session.model, {
+        signal: req.signal,
+        user: user?.id,
+      })
+    ).pipe(
+      connect(shared$ =>
+        merge(
+          // actual chat event stream
+          shared$.pipe(
+            map(attachment => ({
+              type: 'attachment' as const,
+              id: sessionId,
+              data: attachment,
+            }))
+          ),
+          // save the generated text to the session
+          shared$.pipe(
+            toArray(),
+            concatMap(attachments => {
+              session.push({
+                role: 'assistant',
+                content: '',
+                attachments: attachments,
+                createdAt: new Date(),
+              });
+              return from(session.save());
+            }),
+            switchMap(() => EMPTY)
+          )
+        )
+      )
+    );
+  }
 }

packages/backend/server/src/plugins/copilot/index.ts

@@ -3,16 +3,19 @@ import { QuotaService } from '../../core/quota';
 import { PermissionService } from '../../core/workspaces/permission';
 import { Plugin } from '../registry';
 import { CopilotController } from './controller';
+import { ChatMessageCache } from './message';
 import { PromptService } from './prompt';
 import {
   assertProvidersConfigs,
   CopilotProviderService,
+  FalProvider,
   OpenAIProvider,
   registerCopilotProvider,
 } from './providers';
 import { CopilotResolver, UserCopilotResolver } from './resolver';
 import { ChatSessionService } from './session';
 
+registerCopilotProvider(FalProvider);
 registerCopilotProvider(OpenAIProvider);
 
 @Plugin({
@@ -22,6 +25,7 @@ registerCopilotProvider(OpenAIProvider);
     QuotaService,
     ChatSessionService,
     CopilotResolver,
+    ChatMessageCache,
     UserCopilotResolver,
     PromptService,
     CopilotProviderService,

packages/backend/server/src/plugins/copilot/message.ts

@@ -0,0 +1,35 @@
+import { randomUUID } from 'node:crypto';
+
+import { Injectable, Logger } from '@nestjs/common';
+
+import { SessionCache } from '../../fundamentals';
+import { SubmittedMessage, SubmittedMessageSchema } from './types';
+
+const CHAT_MESSAGE_KEY = 'chat-message';
+const CHAT_MESSAGE_TTL = 3600 * 1 * 1000; // 1 hours
+
+@Injectable()
+export class ChatMessageCache {
+  private readonly logger = new Logger(ChatMessageCache.name);
+  constructor(private readonly cache: SessionCache) {}
+
+  async get(id: string): Promise<SubmittedMessage | undefined> {
+    return await this.cache.get(`${CHAT_MESSAGE_KEY}:${id}`);
+  }
+
+  async set(message: SubmittedMessage): Promise<string | undefined> {
+    try {
+      const parsed = SubmittedMessageSchema.safeParse(message);
+      if (parsed.success) {
+        const id = randomUUID();
+        await this.cache.set(`${CHAT_MESSAGE_KEY}:${id}`, parsed.data, {
+          ttl: CHAT_MESSAGE_TTL,
+        });
+        return id;
+      }
+    } catch (e: any) {
+      this.logger.error(`Failed to get chat message from cache: ${e.message}`);
+    }
+    return undefined;
+  }
+}

packages/backend/server/src/plugins/copilot/providers/fal.ts

@@ -0,0 +1,92 @@
+import assert from 'node:assert';
+
+import {
+  CopilotCapability,
+  CopilotImageToImageProvider,
+  CopilotProviderType,
+  PromptMessage,
+} from '../types';
+
+export type FalConfig = {
+  apiKey: string;
+};
+
+export type FalResponse = {
+  images: Array<{ url: string }>;
+};
+
+export class FalProvider implements CopilotImageToImageProvider {
+  static readonly type = CopilotProviderType.FAL;
+  static readonly capabilities = [CopilotCapability.ImageToImage];
+
+  readonly availableModels = [
+    // image to image
+    // https://blog.fal.ai/building-applications-with-real-time-stable-diffusion-apis/
+    '110602490-lcm-sd15-i2i',
+  ];
+
+  constructor(private readonly config: FalConfig) {
+    assert(FalProvider.assetsConfig(config));
+  }
+
+  static assetsConfig(config: FalConfig) {
+    return !!config.apiKey;
+  }
+
+  getCapabilities(): CopilotCapability[] {
+    return FalProvider.capabilities;
+  }
+
+  // ====== image to image ======
+  async generateImages(
+    messages: PromptMessage[],
+    model: string = this.availableModels[0],
+    options: {
+      signal?: AbortSignal;
+      user?: string;
+    } = {}
+  ): Promise<Array<string>> {
+    const { content, attachments } = messages.pop() || {};
+    if (!this.availableModels.includes(model)) {
+      throw new Error(`Invalid model: ${model}`);
+    }
+    if (!content) {
+      throw new Error('Prompt is required');
+    }
+    if (!Array.isArray(attachments) || !attachments.length) {
+      throw new Error('Attachments is required');
+    }
+
+    const data = (await fetch(`https://${model}.gateway.alpha.fal.ai/`, {
+      method: 'POST',
+      headers: {
+        Authorization: `key ${this.config.apiKey}`,
+        'Content-Type': 'application/json',
+      },
+      body: JSON.stringify({
+        image_url: attachments[0],
+        prompt: content,
+        sync_mode: true,
+        seed: 42,
+        enable_safety_checks: false,
+      }),
+      signal: options.signal,
+    }).then(res => res.json())) as FalResponse;
+
+    return data.images.map(image => image.url);
+  }
+
+  async *generateImagesStream(
+    messages: PromptMessage[],
+    model: string = this.availableModels[0],
+    options: {
+      signal?: AbortSignal;
+      user?: string;
+    } = {}
+  ): AsyncIterable<string> {
+    const ret = await this.generateImages(messages, model, options);
+    for (const url of ret) {
+      yield url;
+    }
+  }
+}

packages/backend/server/src/plugins/copilot/providers/index.ts

@@ -134,4 +134,5 @@ export class CopilotProviderService {
   }
 }
 
+export { FalProvider } from './fal';
 export { OpenAIProvider } from './openai';

packages/backend/server/src/plugins/copilot/providers/openai.ts

@@ -5,22 +5,31 @@ import { ClientOptions, OpenAI } from 'openai';
 import {
   ChatMessageRole,
   CopilotCapability,
+  CopilotImageToTextProvider,
   CopilotProviderType,
   CopilotTextToEmbeddingProvider,
+  CopilotTextToImageProvider,
   CopilotTextToTextProvider,
   PromptMessage,
 } from '../types';
 
 const DEFAULT_DIMENSIONS = 256;
 
+const SIMPLE_IMAGE_URL_REGEX = /^(https?:\/\/|data:image\/)/;
+
 export class OpenAIProvider
-  implements CopilotTextToTextProvider, CopilotTextToEmbeddingProvider
+  implements
+    CopilotTextToTextProvider,
+    CopilotTextToEmbeddingProvider,
+    CopilotTextToImageProvider,
+    CopilotImageToTextProvider
 {
   static readonly type = CopilotProviderType.OpenAI;
   static readonly capabilities = [
     CopilotCapability.TextToText,
     CopilotCapability.TextToEmbedding,
     CopilotCapability.TextToImage,
+    CopilotCapability.ImageToText,
   ];
 
   readonly availableModels = [
@@ -35,6 +44,8 @@ export class OpenAIProvider
     // moderation
     'text-moderation-latest',
     'text-moderation-stable',
+    // text to image
+    'dall-e-3',
   ];
 
   private readonly instance: OpenAI;
@@ -52,12 +63,29 @@ export class OpenAIProvider
     return OpenAIProvider.capabilities;
   }
 
-  private chatToGPTMessage(messages: PromptMessage[]) {
+  private chatToGPTMessage(
+    messages: PromptMessage[]
+  ): OpenAI.Chat.Completions.ChatCompletionMessageParam[] {
     // filter redundant fields
-    return messages.map(message => ({
-      role: message.role,
-      content: message.content,
-    }));
+    return messages.map(({ role, content, attachments }) => {
+      if (Array.isArray(attachments)) {
+        const contents = [
+          { type: 'text', text: content },
+          ...attachments
+            .filter(url => SIMPLE_IMAGE_URL_REGEX.test(url))
+            .map(url => ({
+              type: 'image_url',
+              image_url: { url, detail: 'low' },
+            })),
+        ];
+        return {
+          role,
+          content: contents,
+        } as OpenAI.Chat.Completions.ChatCompletionMessageParam;
+      } else {
+        return { role, content };
+      }
+    });
   }
 
   private checkParams({
@@ -194,4 +222,44 @@ export class OpenAIProvider
     });
     return result.data.map(e => e.embedding);
   }
+
+  // ====== text to image ======
+  async generateImages(
+    messages: PromptMessage[],
+    model: string = 'dall-e-3',
+    options: {
+      signal?: AbortSignal;
+      user?: string;
+    } = {}
+  ): Promise<Array<string>> {
+    const { content: prompt } = messages.pop() || {};
+    if (!prompt) {
+      throw new Error('Prompt is required');
+    }
+    const result = await this.instance.images.generate(
+      {
+        prompt,
+        model,
+        response_format: 'url',
+        user: options.user,
+      },
+      { signal: options.signal }
+    );
+
+    return result.data.map(image => image.url).filter((v): v is string => !!v);
+  }
+
+  async *generateImagesStream(
+    messages: PromptMessage[],
+    model: string = 'dall-e-3',
+    options: {
+      signal?: AbortSignal;
+      user?: string;
+    } = {}
+  ): AsyncIterable<string> {
+    const ret = await this.generateImages(messages, model, options);
+    for (const url of ret) {
+      yield url;
+    }
+  }
 }

packages/backend/server/src/plugins/copilot/resolver.ts

@@ -1,3 +1,4 @@
+import { Logger } from '@nestjs/common';
 import {
   Args,
   Field,
@@ -12,7 +13,7 @@ import {
 } from '@nestjs/graphql';
 import { SafeIntResolver } from 'graphql-scalars';
 
-import { CurrentUser, Public } from '../../core/auth';
+import { CurrentUser } from '../../core/auth';
 import { QuotaService } from '../../core/quota';
 import { UserType } from '../../core/user';
 import { PermissionService } from '../../core/workspaces/permission';
@@ -21,11 +22,19 @@ import {
   PaymentRequiredException,
   TooManyRequestsException,
 } from '../../fundamentals';
-import { ChatSessionService, ListHistoriesOptions } from './session';
-import { AvailableModels, type ChatHistory, type ChatMessage } from './types';
+import { ChatSessionService } from './session';
+import {
+  AvailableModels,
+  type ChatHistory,
+  type ChatMessage,
+  type ListHistoriesOptions,
+  SubmittedMessage,
+} from './types';
 
 registerEnumType(AvailableModels, { name: 'CopilotModel' });
 
+const COPILOT_LOCKER = 'copilot';
+
 // ================== Input Types ==================
 
 @InputType()
@@ -48,6 +57,21 @@ class CreateChatSessionInput {
   promptName!: string;
 }
 
+@InputType()
+class CreateChatMessageInput implements Omit<SubmittedMessage, 'params'> {
+  @Field(() => String)
+  sessionId!: string;
+
+  @Field(() => String)
+  content!: string;
+
+  @Field(() => [String], { nullable: true })
+  attachments!: string[] | undefined;
+
+  @Field(() => String, { nullable: true })
+  params!: string | undefined;
+}
+
 @InputType()
 class QueryChatHistoriesInput implements Partial<ListHistoriesOptions> {
   @Field(() => Boolean, { nullable: true })
@@ -118,6 +142,8 @@ export class CopilotType {
 
 @Resolver(() => CopilotType)
 export class CopilotResolver {
+  private readonly logger = new Logger(CopilotResolver.name);
+
   constructor(
     private readonly permissions: PermissionService,
     private readonly quota: QuotaService,
@@ -208,7 +234,6 @@ export class CopilotResolver {
     );
   }
 
-  @Public()
   @Mutation(() => String, {
     description: 'Create a chat session',
   })
@@ -222,7 +247,7 @@ export class CopilotResolver {
       options.docId,
       user.id
     );
-    const lockFlag = `session:${user.id}:${options.workspaceId}`;
+    const lockFlag = `${COPILOT_LOCKER}:session:${user.id}:${options.workspaceId}`;
     await using lock = await this.mutex.lock(lockFlag);
     if (!lock) {
       return new TooManyRequestsException('Server is busy');
@@ -241,6 +266,32 @@ export class CopilotResolver {
     });
     return session;
   }
+
+  @Mutation(() => String, {
+    description: 'Create a chat message',
+  })
+  async createCopilotMessage(
+    @CurrentUser() user: CurrentUser,
+    @Args({ name: 'options', type: () => CreateChatMessageInput })
+    options: CreateChatMessageInput
+  ) {
+    const lockFlag = `${COPILOT_LOCKER}:message:${user?.id}:${options.sessionId}`;
+    await using lock = await this.mutex.lock(lockFlag);
+    if (!lock) {
+      return new TooManyRequestsException('Server is busy');
+    }
+    try {
+      const { params, ...rest } = options;
+      const record: SubmittedMessage['params'] = {};
+      new URLSearchParams(params).forEach((value, key) => {
+        record[key] = value;
+      });
+      return await this.chatSession.createMessage({ ...rest, params: record });
+    } catch (e: any) {
+      this.logger.error(`Failed to create chat message: ${e.message}`);
+      throw new Error('Failed to create chat message');
+    }
+  }
 }
 
 @Resolver(() => UserType)

packages/backend/server/src/plugins/copilot/session.ts

@@ -3,43 +3,26 @@ import { randomUUID } from 'node:crypto';
 import { Injectable, Logger } from '@nestjs/common';
 import { PrismaClient } from '@prisma/client';
 
+import { ChatMessageCache } from './message';
 import { ChatPrompt, PromptService } from './prompt';
 import {
   AvailableModel,
   ChatHistory,
   ChatMessage,
   ChatMessageSchema,
+  ChatSessionOptions,
+  ChatSessionState,
   getTokenEncoder,
+  ListHistoriesOptions,
   PromptMessage,
   PromptMessageSchema,
   PromptParams,
+  SubmittedMessage,
 } from './types';
 
-export interface ChatSessionOptions {
-  userId: string;
-  workspaceId: string;
-  docId: string;
-  promptName: string;
-}
-
-export interface ChatSessionState
-  extends Omit<ChatSessionOptions, 'promptName'> {
-  // connect ids
-  sessionId: string;
-  // states
-  prompt: ChatPrompt;
-  messages: ChatMessage[];
-}
-
-export type ListHistoriesOptions = {
-  action: boolean | undefined;
-  limit: number | undefined;
-  skip: number | undefined;
-  sessionId: string | undefined;
-};
-
 export class ChatSession implements AsyncDisposable {
   constructor(
+    private readonly messageCache: ChatMessageCache,
     private readonly state: ChatSessionState,
     private readonly dispose?: (state: ChatSessionState) => Promise<void>,
     private readonly maxTokenSize = 3840
@@ -60,6 +43,29 @@ export class ChatSession implements AsyncDisposable {
     this.state.messages.push(message);
   }
 
+  async getMessageById(messageId: string) {
+    const message = await this.messageCache.get(messageId);
+    if (!message || message.sessionId !== this.state.sessionId) {
+      throw new Error(`Message not found: ${messageId}`);
+    }
+    return message;
+  }
+
+  async pushByMessageId(messageId: string) {
+    const message = await this.messageCache.get(messageId);
+    if (!message || message.sessionId !== this.state.sessionId) {
+      throw new Error(`Message not found: ${messageId}`);
+    }
+
+    this.push({
+      role: 'user',
+      content: message.content,
+      attachments: message.attachments,
+      params: message.params,
+      createdAt: new Date(),
+    });
+  }
+
   pop() {
     this.state.messages.pop();
   }
@@ -109,6 +115,7 @@ export class ChatSessionService {
 
   constructor(
     private readonly db: PrismaClient,
+    private readonly messageCache: ChatMessageCache,
     private readonly prompt: PromptService
   ) {}
 
@@ -326,6 +333,10 @@ export class ChatSessionService {
     });
   }
 
+  async createMessage(message: SubmittedMessage): Promise<string | undefined> {
+    return await this.messageCache.set(message);
+  }
+
   /**
    * usage:
    * ``` typescript
@@ -342,7 +353,7 @@ export class ChatSessionService {
   async get(sessionId: string): Promise<ChatSession | null> {
     const state = await this.getSession(sessionId);
     if (state) {
-      return new ChatSession(state, async state => {
+      return new ChatSession(this.messageCache, state, async state => {
         await this.setSession(state);
       });
     }

packages/backend/server/src/plugins/copilot/types.ts

@@ -8,10 +8,12 @@ import {
 } from 'tiktoken';
 import { z } from 'zod';
 
+import type { ChatPrompt } from './prompt';
+
 export interface CopilotConfig {
   openai: OpenAIClientOptions;
   fal: {
-    secret: string;
+    apiKey: string;
   };
 }
 
@@ -27,6 +29,8 @@ export enum AvailableModels {
   // moderation
   TextModerationLatest = 'text-moderation-latest',
   TextModerationStable = 'text-moderation-stable',
+  // text to image
+  DallE3 = 'dall-e-3',
 }
 
 export type AvailableModel = keyof typeof AvailableModels;
@@ -53,8 +57,7 @@ export const ChatMessageRole = Object.values(AiPromptRole) as [
   'user',
 ];
 
-export const PromptMessageSchema = z.object({
-  role: z.enum(ChatMessageRole),
+const PureMessageSchema = z.object({
   content: z.string(),
   attachments: z.array(z.string()).optional(),
   params: z
@@ -63,6 +66,10 @@ export const PromptMessageSchema = z.object({
     .nullable(),
 });
 
+export const PromptMessageSchema = PureMessageSchema.extend({
+  role: z.enum(ChatMessageRole),
+}).strict();
+
 export type PromptMessage = z.infer<typeof PromptMessageSchema>;
 
 export type PromptParams = NonNullable<PromptMessage['params']>;
@@ -73,6 +80,12 @@ export const ChatMessageSchema = PromptMessageSchema.extend({
 
 export type ChatMessage = z.infer<typeof ChatMessageSchema>;
 
+export const SubmittedMessageSchema = PureMessageSchema.extend({
+  sessionId: z.string(),
+}).strict();
+
+export type SubmittedMessage = z.infer<typeof SubmittedMessageSchema>;
+
 export const ChatHistorySchema = z
   .object({
     sessionId: z.string(),
@@ -84,6 +97,32 @@ export const ChatHistorySchema = z
 
 export type ChatHistory = z.infer<typeof ChatHistorySchema>;
 
+// ======== Chat Session ========
+
+export interface ChatSessionOptions {
+  // connect ids
+  userId: string;
+  workspaceId: string;
+  docId: string;
+  promptName: string;
+}
+
+export interface ChatSessionState
+  extends Omit<ChatSessionOptions, 'promptName'> {
+  // connect ids
+  sessionId: string;
+  // states
+  prompt: ChatPrompt;
+  messages: ChatMessage[];
+}
+
+export type ListHistoriesOptions = {
+  action: boolean | undefined;
+  limit: number | undefined;
+  skip: number | undefined;
+  sessionId: string | undefined;
+};
+
 // ======== Provider Interface ========
 
 export enum CopilotProviderType {
@@ -96,6 +135,7 @@ export enum CopilotCapability {
   TextToEmbedding = 'text-to-embedding',
   TextToImage = 'text-to-image',
   ImageToImage = 'image-to-image',
+  ImageToText = 'image-to-text',
 }
 
 export interface CopilotProvider {
@@ -137,13 +177,71 @@ export interface CopilotTextToEmbeddingProvider extends CopilotProvider {
   ): Promise<number[][]>;
 }
 
-export interface CopilotTextToImageProvider extends CopilotProvider {}
+export interface CopilotTextToImageProvider extends CopilotProvider {
+  generateImages(
+    messages: PromptMessage[],
+    model: string,
+    options: {
+      signal?: AbortSignal;
+      user?: string;
+    }
+  ): Promise<Array<string>>;
+  generateImagesStream(
+    messages: PromptMessage[],
+    model?: string,
+    options?: {
+      signal?: AbortSignal;
+      user?: string;
+    }
+  ): AsyncIterable<string>;
+}
 
-export interface CopilotImageToImageProvider extends CopilotProvider {}
+export interface CopilotImageToTextProvider extends CopilotProvider {
+  generateText(
+    messages: PromptMessage[],
+    model: string,
+    options: {
+      temperature?: number;
+      maxTokens?: number;
+      signal?: AbortSignal;
+      user?: string;
+    }
+  ): Promise<string>;
+  generateTextStream(
+    messages: PromptMessage[],
+    model: string,
+    options: {
+      temperature?: number;
+      maxTokens?: number;
+      signal?: AbortSignal;
+      user?: string;
+    }
+  ): AsyncIterable<string>;
+}
+
+export interface CopilotImageToImageProvider extends CopilotProvider {
+  generateImages(
+    messages: PromptMessage[],
+    model: string,
+    options: {
+      signal?: AbortSignal;
+      user?: string;
+    }
+  ): Promise<Array<string>>;
+  generateImagesStream(
+    messages: PromptMessage[],
+    model?: string,
+    options?: {
+      signal?: AbortSignal;
+      user?: string;
+    }
+  ): AsyncIterable<string>;
+}
 
 export type CapabilityToCopilotProvider = {
   [CopilotCapability.TextToText]: CopilotTextToTextProvider;
   [CopilotCapability.TextToEmbedding]: CopilotTextToEmbeddingProvider;
   [CopilotCapability.TextToImage]: CopilotTextToImageProvider;
+  [CopilotCapability.ImageToText]: CopilotImageToTextProvider;
   [CopilotCapability.ImageToImage]: CopilotImageToImageProvider;
 };

packages/backend/server/src/schema.gql

@@ -37,6 +37,13 @@ type CopilotQuota {
   used: SafeInt!
 }
 
+input CreateChatMessageInput {
+  attachments: [String!]
+  content: String!
+  params: String
+  sessionId: String!
+}
+
 input CreateChatSessionInput {
   """An mark identifying which view to use to display the session"""
   action: String
@@ -167,6 +174,9 @@ type Mutation {
   """Create a subscription checkout link of stripe"""
   createCheckoutSession(input: CreateCheckoutSessionInput!): String!
 
+  """Create a chat message"""
+  createCopilotMessage(options: CreateChatMessageInput!): String!
+
   """Create a chat session"""
   createCopilotSession(options: CreateChatSessionInput!): String!
 

packages/frontend/graphql/src/schema.ts

@@ -34,6 +34,13 @@ export interface Scalars {
   Upload: { input: File; output: File };
 }
 
+export interface CreateChatMessageInput {
+  attachments: InputMaybe<Array<Scalars['String']['input']>>;
+  content: Scalars['String']['input'];
+  params: InputMaybe<Scalars['String']['input']>;
+  sessionId: Scalars['String']['input'];
+}
+
 export interface CreateChatSessionInput {
   /** An mark identifying which view to use to display the session */
   action: InputMaybe<Scalars['String']['input']>;