feat(core): stream persistable article bodies as NDJSON

Add POST /articles/bodies so clients can batch-fetch post and note bodies with paywall, language, and unchanged-version lines.

Author: Innei

apps/core/src/app.module.ts

@@ -25,6 +25,7 @@ import { ActivityModule } from './modules/activity/activity.module'
 import { AggregateModule } from './modules/aggregate/aggregate.module'
 import { AiModule } from './modules/ai/ai.module'
 import { AnalyzeModule } from './modules/analyze/analyze.module'
+import { ArticleBodyModule } from './modules/article-body/article-body.module'
 import { AuthModule } from './modules/auth/auth.module'
 import { ReviewDemoModule } from './modules/auth/review-demo.module'
 import { BackupModule } from './modules/backup/backup.module'
@@ -92,6 +93,7 @@ import { SampleResponseInterceptor } from './shared/sample/sample-response.inter
     AckModule,
     ActivityModule,
     AggregateModule,
+    ArticleBodyModule,
     AnalyzeModule,
     EnrichmentModule,
     AuthModule.forRoot(),

apps/core/src/modules/ai/ai-insights/ai-insights.adapter.ts

@@ -10,7 +10,10 @@ import { ConfigsService } from '../../configs/configs.service'
 import { EntitlementService } from '../../membership/entitlement.service'
 import { AI_PROMPTS } from '../ai.prompts'
 import { AiService } from '../ai.service'
-import { isGlobalArticleVisible } from '../ai-article-visibility.util'
+import {
+  type ArticleViewer,
+  isArticleVisibleToViewer,
+} from '../ai-article-visibility.util'
 import type { GenerationUsage } from '../ai-generation-metrics/ai-generation-metrics.types'
 import {
   emptyUsage,
@@ -97,7 +100,7 @@ export class AiInsightsAdapter implements MultilangAdapter<
     ) {
       throw createAppException(AppErrorCode.CONTENT_NOT_FOUND_CANT_PROCESS)
     }
-    if (!isGlobalArticleVisible(article)) {
+    if (!isArticleVisibleToViewer(article, options ?? {})) {
       throw createAppException(AppErrorCode.CONTENT_NOT_FOUND_CANT_PROCESS)
     }
     if (
@@ -127,8 +130,12 @@ export class AiInsightsAdapter implements MultilangAdapter<
 
   async resolveArticle(
     refId: string,
+    viewer?: ArticleViewer,
   ): Promise<MultilangResolvedArticle<ArticleForInsights>> {
-    const { article, sourceLang } = await this.resolveArticleDetailed(refId)
+    const { article, sourceLang } = await this.resolveArticleDetailed(
+      refId,
+      viewer,
+    )
     return { article, text: article.text, sourceLang }
   }
 

apps/core/src/modules/ai/ai-multilang/ai-multilang.service.ts

@@ -208,6 +208,7 @@ export class MultilangGenerationService {
 
     const { article, text, sourceLang } = await adapter.resolveArticle(
       payload.refId,
+      { isOwner: true },
     )
     const targets = normalizeTargetLangs(payload.targetLanguages).filter(
       (lang) => lang !== sourceLang,

apps/core/src/modules/ai/ai-multilang/ai-multilang.types.ts

@@ -1,3 +1,4 @@
+import type { ArticleViewer } from '../ai-article-visibility.util'
 import type { GenerationUsage } from '../ai-generation-metrics/ai-generation-metrics.types'
 import type { AiStreamEvent } from '../ai-inflight/ai-inflight.types'
 
@@ -30,7 +31,10 @@ export interface MultilangResolvedArticle<TArticle> {
 export interface MultilangAdapter<TArticle, TDoc> {
   readonly feature: MultilangFeature
   assertEnabled: () => Promise<void>
-  resolveArticle: (refId: string) => Promise<MultilangResolvedArticle<TArticle>>
+  resolveArticle: (
+    refId: string,
+    viewer?: ArticleViewer,
+  ) => Promise<MultilangResolvedArticle<TArticle>>
   generate: (
     article: TArticle,
     lang: string,

apps/core/src/modules/ai/ai-summary/ai-summary.adapter.ts

@@ -10,7 +10,10 @@ import { DatabaseService } from '~/processors/database/database.service'
 import { ConfigsService } from '../../configs/configs.service'
 import { AI_PROMPTS } from '../ai.prompts'
 import { AiService } from '../ai.service'
-import { isGlobalArticleVisible } from '../ai-article-visibility.util'
+import {
+  type ArticleViewer,
+  isArticleVisibleToViewer,
+} from '../ai-article-visibility.util'
 import type { GenerationUsage } from '../ai-generation-metrics/ai-generation-metrics.types'
 import {
   emptyUsage,
@@ -71,7 +74,10 @@ export class AiSummaryAdapter implements MultilangAdapter<
     }
   }
 
-  async resolveArticleDetailed(articleId: string): Promise<{
+  async resolveArticleDetailed(
+    articleId: string,
+    viewer: ArticleViewer = {},
+  ): Promise<{
     article: ArticleForSummary
     sourceLang: string
     type: CollectionRefTypes.Post | CollectionRefTypes.Note
@@ -86,9 +92,7 @@ export class AiSummaryAdapter implements MultilangAdapter<
     ) {
       throw createAppException(AppErrorCode.CONTENT_NOT_FOUND_CANT_PROCESS)
     }
-    // Never expose summaries for draft / password-protected / future-dated
-    // content. Public endpoints and background tasks both flow through here.
-    if (!isGlobalArticleVisible(article)) {
+    if (!isArticleVisibleToViewer(article, viewer)) {
       throw createAppException(AppErrorCode.CONTENT_NOT_FOUND_CANT_PROCESS)
     }
     const doc = article.document as { title: string; text: string }
@@ -103,8 +107,12 @@ export class AiSummaryAdapter implements MultilangAdapter<
 
   async resolveArticle(
     refId: string,
+    viewer?: ArticleViewer,
   ): Promise<MultilangResolvedArticle<ArticleForSummary>> {
-    const { article, sourceLang } = await this.resolveArticleDetailed(refId)
+    const { article, sourceLang } = await this.resolveArticleDetailed(
+      refId,
+      viewer,
+    )
     return { article, text: article.text, sourceLang }
   }
 

apps/core/src/modules/article-body/article-body.controller.ts

@@ -0,0 +1,39 @@
+import { Body, Post, Req, Res } from '@nestjs/common'
+import type { FastifyReply, FastifyRequest } from 'fastify'
+
+import { ApiController } from '~/common/decorators/api-controller.decorator'
+import { CurrentReaderId } from '~/common/decorators/current-user.decorator'
+import { HTTPDecorators } from '~/common/decorators/http.decorator'
+import { Lang } from '~/common/decorators/lang.decorator'
+import { HasAdminAccess } from '~/common/decorators/role.decorator'
+import { applyNdjsonHeaders, subscribeNdjson } from '~/utils/ndjson.util'
+
+import { ArticleBodiesDto } from './article-body.schema'
+import { ArticleBodyService } from './article-body.service'
+
+@ApiController('articles')
+export class ArticleBodyController {
+  constructor(private readonly articleBodyService: ArticleBodyService) {}
+
+  @Post('/bodies')
+  @HTTPDecorators.RawResponse
+  @HTTPDecorators.SkipLogging
+  async streamBodies(
+    @Body() body: ArticleBodiesDto,
+    @Lang() lang: string | undefined,
+    @HasAdminAccess() isOwner: boolean,
+    @CurrentReaderId() readerId: string | undefined,
+    @Req() request: FastifyRequest,
+    @Res() reply: FastifyReply,
+  ) {
+    applyNdjsonHeaders(reply, request)
+    await subscribeNdjson(
+      reply,
+      this.articleBodyService.streamBodies(body.items, {
+        isOwner,
+        lang,
+        readerId,
+      }),
+    )
+  }
+}

apps/core/src/modules/article-body/article-body.module.ts

@@ -0,0 +1,14 @@
+import { Module } from '@nestjs/common'
+
+import { MembershipModule } from '../membership/membership.module'
+import { NoteModule } from '../note/note.module'
+import { PostModule } from '../post/post.module'
+import { ArticleBodyController } from './article-body.controller'
+import { ArticleBodyService } from './article-body.service'
+
+@Module({
+  imports: [PostModule, NoteModule, MembershipModule],
+  controllers: [ArticleBodyController],
+  providers: [ArticleBodyService],
+})
+export class ArticleBodyModule {}

apps/core/src/modules/article-body/article-body.schema.ts

@@ -0,0 +1,20 @@
+import { createZodDto } from 'nestjs-zod'
+import { z } from 'zod'
+
+import { zEntityId } from '~/common/zod'
+
+export const ARTICLE_BODY_BATCH_LIMIT = 20
+
+export const ArticleBodyItemSchema = z.object({
+  bodyVersion: z.number().int().nonnegative().optional(),
+  id: zEntityId,
+  kind: z.enum(['note', 'post']),
+})
+
+export const ArticleBodiesSchema = z.object({
+  items: z.array(ArticleBodyItemSchema).min(1).max(ARTICLE_BODY_BATCH_LIMIT),
+})
+
+export class ArticleBodiesDto extends createZodDto(ArticleBodiesSchema) {}
+
+export type ArticleBodyItem = z.infer<typeof ArticleBodyItemSchema>