Add vector embedding support for nodes and documents

apps/server/src/data/migrations/00013-create-vector-extension.ts

@@ -0,0 +1,10 @@
+import { Migration, sql } from 'kysely';
+
+export const createVectorExtension: Migration = {
+  up: async (db) => {
+    await sql`CREATE EXTENSION IF NOT EXISTS vector`.execute(db);
+  },
+  down: async (db) => {
+    await sql`DROP EXTENSION IF EXISTS vector`.execute(db);
+  },
+};

apps/server/src/data/migrations/00014-create-node-embeddings-table.ts

@@ -0,0 +1,42 @@
+import { Migration, sql } from 'kysely';
+
+export const createNodeEmbeddingsTable: Migration = {
+  up: async (db) => {
+    await db.schema
+      .createTable('node_embeddings')
+      .addColumn('node_id', 'varchar(30)', (col) => col.notNull())
+      .addColumn('chunk', 'integer', (col) => col.notNull())
+      .addColumn('parent_id', 'varchar(30)')
+      .addColumn('root_id', 'varchar(30)', (col) => col.notNull())
+      .addColumn('workspace_id', 'varchar(30)', (col) => col.notNull())
+      .addColumn('text', 'text', (col) => col.notNull())
+      .addColumn('embedding_vector', sql`vector(2000)`, (col) => col.notNull())
+      .addColumn(
+        'search_vector',
+        sql`tsvector GENERATED ALWAYS AS (to_tsvector('english', text)) STORED`
+      )
+      .addColumn('created_at', 'timestamptz', (col) => col.notNull())
+      .addColumn('updated_at', 'timestamptz')
+      .addPrimaryKeyConstraint('node_embeddings_pkey', ['node_id', 'chunk'])
+      .execute();
+
+    await sql`
+      CREATE INDEX node_embeddings_embedding_vector_idx
+        ON node_embeddings
+        USING hnsw(embedding_vector vector_cosine_ops)
+        WITH (
+          m = 16,            
+          ef_construction = 64  
+        );
+    `.execute(db);
+
+    await sql`
+      CREATE INDEX node_embeddings_search_vector_idx
+        ON node_embeddings
+        USING GIN (search_vector);
+    `.execute(db);
+  },
+  down: async (db) => {
+    await db.schema.dropTable('node_embeddings').execute();
+  },
+};

apps/server/src/data/migrations/00015-create-document-embeddings-table.ts

@@ -0,0 +1,43 @@
+import { Migration, sql } from 'kysely';
+
+export const createDocumentEmbeddingsTable: Migration = {
+  up: async (db) => {
+    await db.schema
+      .createTable('document_embeddings')
+      .addColumn('document_id', 'varchar(30)', (col) => col.notNull())
+      .addColumn('chunk', 'integer', (col) => col.notNull())
+      .addColumn('workspace_id', 'varchar(30)', (col) => col.notNull())
+      .addColumn('text', 'text', (col) => col.notNull())
+      .addColumn('embedding_vector', sql`vector(2000)`, (col) => col.notNull())
+      .addColumn(
+        'search_vector',
+        sql`tsvector GENERATED ALWAYS AS (to_tsvector('english', text)) STORED`
+      )
+      .addColumn('created_at', 'timestamptz', (col) => col.notNull())
+      .addColumn('updated_at', 'timestamptz')
+      .addPrimaryKeyConstraint('document_embeddings_pkey', [
+        'document_id',
+        'chunk',
+      ])
+      .execute();
+
+    await sql`
+      CREATE INDEX document_embeddings_embedding_vector_idx
+        ON document_embeddings
+        USING hnsw(embedding_vector vector_cosine_ops)
+        WITH (
+          m = 16,            
+          ef_construction = 64  
+        );
+    `.execute(db);
+
+    await sql`
+      CREATE INDEX document_embeddings_search_vector_idx
+        ON document_embeddings
+        USING GIN (search_vector);
+    `.execute(db);
+  },
+  down: async (db) => {
+    await db.schema.dropTable('document_embeddings').execute();
+  },
+};

apps/server/src/data/migrations/index.ts

@@ -12,6 +12,9 @@ import { createNodePathsTable } from './00009-create-node-paths-table';
 import { createCollaborationsTable } from './00010-create-collaborations-table';
 import { createDocumentsTable } from './00011-create-documents-table';
 import { createDocumentUpdatesTable } from './00012-create-document-updates-table';
+import { createNodeEmbeddingsTable } from './00014-create-node-embeddings-table';
+import { createDocumentEmbeddingsTable } from './00015-create-document-embeddings-table';
+import { createVectorExtension } from './00013-create-vector-extension';
 
 export const databaseMigrations: Record<string, Migration> = {
   '00001_create_accounts_table': createAccountsTable,
@@ -26,4 +29,7 @@ export const databaseMigrations: Record<string, Migration> = {
   '00010_create_collaborations_table': createCollaborationsTable,
   '00011_create_documents_table': createDocumentsTable,
   '00012_create_document_updates_table': createDocumentUpdatesTable,
+  '00013_create_vector_extension': createVectorExtension,
+  '00014_create_node_embeddings_table': createNodeEmbeddingsTable,
+  '00015_create_document_embeddings_table': createDocumentEmbeddingsTable,
 };

apps/server/src/data/schema.ts

@@ -221,6 +221,38 @@ export type SelectDocumentUpdate = Selectable<DocumentUpdateTable>;
 export type CreateDocumentUpdate = Insertable<DocumentUpdateTable>;
 export type UpdateDocumentUpdate = Updateable<DocumentUpdateTable>;
 
+interface NodeEmbeddingTable {
+  node_id: ColumnType<string, string, never>;
+  chunk: ColumnType<number, number, number>;
+  parent_id: ColumnType<string | null, string | null, string | null>;
+  root_id: ColumnType<string, string, never>;
+  workspace_id: ColumnType<string, string, never>;
+  text: ColumnType<string, string, string>;
+  embedding_vector: ColumnType<number[], number[], number[]>;
+  search_vector: ColumnType<never, never, never>;
+  created_at: ColumnType<Date, Date, never>;
+  updated_at: ColumnType<Date | null, Date | null, Date | null>;
+}
+
+export type SelectNodeEmbedding = Selectable<NodeEmbeddingTable>;
+export type CreateNodeEmbedding = Insertable<NodeEmbeddingTable>;
+export type UpdateNodeEmbedding = Updateable<NodeEmbeddingTable>;
+
+interface DocumentEmbeddingTable {
+  document_id: ColumnType<string, string, never>;
+  chunk: ColumnType<number, number, number>;
+  workspace_id: ColumnType<string, string, never>;
+  text: ColumnType<string, string, string>;
+  embedding_vector: ColumnType<number[], number[], number[]>;
+  search_vector: ColumnType<never, never, never>;
+  created_at: ColumnType<Date, Date, never>;
+  updated_at: ColumnType<Date | null, Date | null, Date | null>;
+}
+
+export type SelectDocumentEmbedding = Selectable<DocumentEmbeddingTable>;
+export type CreateDocumentEmbedding = Insertable<DocumentEmbeddingTable>;
+export type UpdateDocumentEmbedding = Updateable<DocumentEmbeddingTable>;
+
 export interface DatabaseSchema {
   accounts: AccountTable;
   devices: DeviceTable;
@@ -234,4 +266,6 @@ export interface DatabaseSchema {
   collaborations: CollaborationTable;
   documents: DocumentTable;
   document_updates: DocumentUpdateTable;
+  node_embeddings: NodeEmbeddingTable;
+  document_embeddings: DocumentEmbeddingTable;
 }

apps/server/src/jobs/assistant-response.ts

@@ -0,0 +1,198 @@
+import {
+  generateId,
+  IdType,
+  extractBlockTexts,
+  MessageAttributes,
+  NodeAttributes,
+} from '@colanode/core';
+import { Document } from '@langchain/core/documents';
+import { database } from '@/data/database';
+import { eventBus } from '@/lib/event-bus';
+import { configuration } from '@/lib/configuration';
+import { fetchNode } from '@/lib/nodes';
+import { nodeRetrievalService } from '@/services/node-retrieval-service';
+import { documentRetrievalService } from '@/services/document-retrieval-service';
+import { JobHandler } from '@/types/jobs';
+import {
+  rewriteQuery,
+  rerankDocuments,
+  generateFinalAnswer,
+  generateNoContextAnswer,
+  assessUserIntent,
+} from '@/services/llm-service';
+
+export type AssistantResponseInput = {
+  type: 'assistant_response';
+  nodeId: string;
+  workspaceId: string;
+};
+
+declare module '@/types/jobs' {
+  interface JobMap {
+    assistant_response: {
+      input: AssistantResponseInput;
+    };
+  }
+}
+
+export const assistantResponseHandler = async (
+  input: AssistantResponseInput
+) => {
+  const { nodeId, workspaceId } = input;
+  console.log('Starting assistant response handler', { nodeId, workspaceId });
+  if (!configuration.ai.enabled) return;
+
+  const node = await fetchNode(nodeId);
+  if (!node) return;
+  // Assume nodes of type 'message' carry the user query.
+  const userInputText = extractBlockTexts(
+    node.id,
+    (node.attributes as MessageAttributes).content
+  );
+  if (!userInputText || userInputText.trim() === '') return;
+
+  // Fetch user details (assuming created_by is the user id)
+  const user = await database
+    .selectFrom('users')
+    .where('id', '=', node.created_by)
+    .selectAll()
+    .executeTakeFirst();
+  if (!user) return;
+
+  // Get conversation history: for example, sibling nodes (other messages with the same parent)
+  const chatHistoryNodes = await database
+    .selectFrom('nodes')
+    .selectAll()
+    .where('parent_id', '=', node.parent_id)
+    .where('id', '!=', node.id)
+    .orderBy('created_at', 'asc')
+    .limit(10)
+    .execute();
+
+  const chatHistory = chatHistoryNodes.map(
+    (n) =>
+      new Document({
+        pageContent:
+          extractBlockTexts(
+            n.id,
+            (n.attributes as MessageAttributes).content
+          ) || '',
+        metadata: { id: n.id, type: n.type, createdAt: n.created_at },
+      })
+  );
+
+  const formattedChatHistory = chatHistory
+    .map((doc) => {
+      const ts = doc.metadata.createdAt
+        ? new Date(doc.metadata.createdAt).toLocaleString()
+        : 'Unknown';
+      return `- [${ts}] ${doc.metadata.id}: ${doc.pageContent}`;
+    })
+    .join('\n');
+
+  const intent = await assessUserIntent(userInputText, formattedChatHistory);
+
+  let finalAnswer: string;
+  let citations: Array<{ sourceId: string; quote: string }>;
+
+  if (intent === 'no_context') {
+    finalAnswer = await generateNoContextAnswer(
+      userInputText,
+      formattedChatHistory
+    );
+    citations = [];
+  } else {
+    const rewrittenQuery = await rewriteQuery(userInputText);
+    const nodeDocs = await nodeRetrievalService.retrieve(
+      rewrittenQuery,
+      workspaceId,
+      user.id
+    );
+    const documentDocs = await documentRetrievalService.retrieve(
+      rewrittenQuery,
+      workspaceId
+    );
+    const allContext = [...nodeDocs, ...documentDocs];
+    const reranked = await rerankDocuments(
+      allContext.map((doc, idx) => ({
+        content: doc.pageContent,
+        type: doc.metadata.type,
+        sourceId: doc.metadata.id,
+      })),
+      rewrittenQuery
+    );
+    const topContext = reranked.slice(0, 5);
+    const formattedMessages = allContext
+      .filter((doc) => doc.metadata.type === 'message')
+      .map((doc) => {
+        const ts = doc.metadata.createdAt
+          ? new Date(doc.metadata.createdAt).toLocaleString()
+          : 'Unknown';
+        return `- [${ts}] ${doc.metadata.id}: ${doc.pageContent}`;
+      })
+      .join('\n');
+    const formattedDocuments = allContext
+      .filter(
+        (doc) =>
+          doc.metadata.type === 'page' || doc.metadata.type === 'document'
+      )
+      .map((doc) => {
+        const ts = doc.metadata.createdAt
+          ? new Date(doc.metadata.createdAt).toLocaleString()
+          : 'Unknown';
+        return `- [${ts}] ${doc.metadata.id}: ${doc.pageContent}`;
+      })
+      .join('\n');
+    const promptArgs = {
+      currentTimestamp: new Date().toISOString(),
+      workspaceName: workspaceId, // Or retrieve workspace details
+      userName: user.name || 'User',
+      userEmail: user.email || 'unknown@example.com',
+      formattedChatHistory,
+      formattedMessages,
+      formattedDocuments,
+      question: userInputText,
+    };
+    const result = await generateFinalAnswer(promptArgs);
+    finalAnswer = result.answer;
+    citations = result.citations;
+  }
+
+  // Create a response node (answer message)
+  const responseNodeId = generateId(IdType.Node);
+  const responseAttributes = {
+    type: 'message',
+    subtype: 'standard',
+    content: {
+      [generateId(IdType.Block)]: {
+        id: generateId(IdType.Block),
+        type: 'paragraph',
+        parentId: responseNodeId,
+        index: 'a',
+        content: [{ type: 'text', text: finalAnswer }],
+      },
+    },
+    parentId: node.parent_id,
+    referenceId: node.id,
+  };
+
+  await database
+    .insertInto('nodes')
+    .values({
+      id: responseNodeId,
+      root_id: node.root_id,
+      workspace_id: workspaceId,
+      attributes: JSON.stringify(responseAttributes),
+      state: Buffer.from(''), // Initial empty state
+      created_at: new Date(),
+      created_by: 'colanode_ai',
+    })
+    .executeTakeFirst();
+
+  eventBus.publish({
+    type: 'node_created',
+    nodeId: responseNodeId,
+    rootId: node.root_id,
+    workspaceId,
+  });
+};

apps/server/src/jobs/embed-document.ts

@@ -0,0 +1,121 @@
+// Updated embed-document.ts
+import { OpenAIEmbeddings } from '@langchain/openai';
+import { ChunkingService } from '@/services/chunking-service';
+import { database } from '@/data/database';
+import { configuration } from '@/lib/configuration';
+import { CreateDocumentEmbedding } from '@/data/schema';
+import { sql } from 'kysely';
+import { fetchNodeWithContext } from '@/services/node-retrieval-service';
+import { DocumentContent, extractBlockTexts } from '@colanode/core';
+import { JobHandler } from '@/types/jobs';
+
+export type EmbedDocumentInput = {
+  type: 'embed_document';
+  documentId: string;
+};
+
+export const embedDocumentHandler: JobHandler<EmbedDocumentInput> = async (
+  input
+) => {
+  if (!configuration.ai.enabled) return;
+  const { documentId } = input;
+
+  // Retrieve document along with its associated node in one query
+  const document = await database
+    .selectFrom('documents')
+    .select(['id', 'content', 'workspace_id', 'created_at'])
+    .where('id', '=', documentId)
+    .executeTakeFirst();
+  if (!document) return;
+
+  // Fetch associated node for context (page node, etc.)
+  const nodeContext = await fetchNodeWithContext(documentId);
+  // If available, include node type and parent (space) name in the context.
+  let header = '';
+  if (nodeContext) {
+    const { node, parent, root } = nodeContext;
+    header = `${node.attributes.type} "${(node.attributes as any).name || ''}"`;
+    if (parent && parent.attributes.name) {
+      header += ` in "${parent.attributes.name}"`;
+    }
+    if (root && root.attributes.name) {
+      header += ` [${root.attributes.name}]`;
+    }
+  }
+
+  // Extract text using document content. (For pages and rich–text, use extractBlockTexts.)
+  const docText = extractBlockTexts(documentId, document.content.blocks) || '';
+  const fullText = header ? `${header}\n\nContent:\n${docText}` : docText;
+  if (!fullText.trim()) {
+    await database
+      .deleteFrom('document_embeddings')
+      .where('document_id', '=', documentId)
+      .execute();
+    return;
+  }
+
+  const chunkingService = new ChunkingService();
+  const chunks = await chunkingService.chunkText(fullText, {
+    type: 'document',
+    id: documentId,
+  });
+  const embeddings = new OpenAIEmbeddings({
+    apiKey: configuration.ai.embedding.apiKey,
+    modelName: configuration.ai.embedding.modelName,
+    dimensions: configuration.ai.embedding.dimensions,
+  });
+
+  const existingEmbeddings = await database
+    .selectFrom('document_embeddings')
+    .select(['chunk', 'text'])
+    .where('document_id', '=', documentId)
+    .execute();
+
+  const embeddingsToUpsert: CreateDocumentEmbedding[] = [];
+  for (let i = 0; i < chunks.length; i++) {
+    const chunk = chunks[i];
+    const existing = existingEmbeddings.find((e) => e.chunk === i);
+    if (existing && existing.text === chunk) continue;
+    embeddingsToUpsert.push({
+      document_id: documentId,
+      chunk: i,
+      workspace_id: document.workspace_id,
+      text: chunk,
+      embedding_vector: [],
+      created_at: new Date(),
+    });
+  }
+
+  const batchSize = configuration.ai.embedding.batchSize;
+  for (let i = 0; i < embeddingsToUpsert.length; i += batchSize) {
+    const batch = embeddingsToUpsert.slice(i, i + batchSize);
+    const textsToEmbed = batch.map((item) => item.text);
+    const embeddingVectors = await embeddings.embedDocuments(textsToEmbed);
+    for (let j = 0; j < batch.length; j++) {
+      batch[j].embedding_vector = embeddingVectors[j] ?? [];
+    }
+  }
+
+  for (const embedding of embeddingsToUpsert) {
+    await database
+      .insertInto('document_embeddings')
+      .values({
+        document_id: embedding.document_id,
+        chunk: embedding.chunk,
+        workspace_id: embedding.workspace_id,
+        text: embedding.text,
+        embedding_vector: sql.raw(
+          `'[${embedding.embedding_vector.join(',')}]'::vector`
+        ),
+        created_at: embedding.created_at,
+      })
+      .onConflict((oc) =>
+        oc.columns(['document_id', 'chunk']).doUpdateSet({
+          text: sql.ref('excluded.text'),
+          embedding_vector: sql.ref('excluded.embedding_vector'),
+          updated_at: new Date(),
+        })
+      )
+      .execute();
+  }
+};

apps/server/src/jobs/embed-node.ts

@@ -0,0 +1,183 @@
+import { OpenAIEmbeddings } from '@langchain/openai';
+import { extractBlockTexts, NodeAttributes, FieldValue } from '@colanode/core';
+import { ChunkingService } from '@/services/chunking-service';
+import { database } from '@/data/database';
+import { configuration } from '@/lib/configuration';
+import { CreateNodeEmbedding } from '@/data/schema';
+import { sql } from 'kysely';
+import { fetchNode } from '@/lib/nodes';
+import { JobHandler } from '@/types/jobs';
+
+export type EmbedNodeInput = {
+  type: 'embed_node';
+  nodeId: string;
+};
+
+declare module '@/types/jobs' {
+  interface JobMap {
+    embed_node: {
+      input: EmbedNodeInput;
+    };
+  }
+}
+
+const formatFieldValue = (fieldValue: FieldValue): string => {
+  switch (fieldValue.type) {
+    case 'boolean':
+      return `${fieldValue.value ? 'Yes' : 'No'}`;
+    case 'string_array':
+      return (fieldValue.value as string[]).join(', ');
+    case 'number':
+    case 'string':
+    case 'text':
+      return String(fieldValue.value);
+    default:
+      return '';
+  }
+};
+
+const extractNodeText = async (
+  nodeId: string,
+  attributes: NodeAttributes
+): Promise<string> => {
+  switch (attributes.type) {
+    case 'message':
+      return extractBlockTexts(nodeId, attributes.content) ?? '';
+    case 'record': {
+      const sections: string[] = [];
+
+      // Fetch the database node to get its name
+      const databaseNode = await fetchNode(attributes.databaseId);
+      const databaseName =
+        databaseNode?.attributes.type === 'database'
+          ? databaseNode.attributes.name
+          : attributes.databaseId;
+
+      // Add field context with database name
+      sections.push(`Field "${attributes.name}" in database "${databaseName}"`);
+
+      // Process field value
+      Object.entries(attributes.fields).forEach(([fieldName, fieldValue]) => {
+        if (!fieldValue || !('type' in fieldValue)) {
+          return;
+        }
+
+        const value = formatFieldValue(fieldValue as FieldValue);
+        if (value) {
+          sections.push(value);
+        }
+      });
+
+      return sections.join('\n');
+    }
+    default:
+      return '';
+  }
+};
+
+export const embedNodeHandler = async (input: {
+  type: 'embed_node';
+  nodeId: string;
+}) => {
+  if (!configuration.ai.enabled) {
+    return;
+  }
+
+  const { nodeId } = input;
+  const node = await fetchNode(nodeId);
+  if (!node) {
+    return;
+  }
+
+  // Skip page nodes (document content is handled separately in the embed document job)
+  if (node.type === 'page') {
+    return;
+  }
+
+  const text = await extractNodeText(node.id, node.attributes);
+  if (!text || text.trim() === '') {
+    await database
+      .deleteFrom('node_embeddings')
+      .where('node_id', '=', nodeId)
+      .execute();
+    return;
+  }
+
+  const chunkingService = new ChunkingService();
+  const chunks = await chunkingService.chunkText(text, {
+    type: 'node',
+    id: nodeId,
+  });
+  const embeddings = new OpenAIEmbeddings({
+    apiKey: configuration.ai.embedding.apiKey,
+    modelName: configuration.ai.embedding.modelName,
+    dimensions: configuration.ai.embedding.dimensions,
+  });
+
+  const existingEmbeddings = await database
+    .selectFrom('node_embeddings')
+    .select(['chunk', 'text'])
+    .where('node_id', '=', nodeId)
+    .execute();
+
+  const embeddingsToCreateOrUpdate: CreateNodeEmbedding[] = [];
+  for (let i = 0; i < chunks.length; i++) {
+    const chunk = chunks[i];
+    if (!chunk) continue;
+    const existing = existingEmbeddings.find((e) => e.chunk === i);
+    if (existing && existing.text === chunk) continue;
+    embeddingsToCreateOrUpdate.push({
+      node_id: nodeId,
+      chunk: i,
+      parent_id: node.parent_id,
+      root_id: node.root_id,
+      workspace_id: node.workspace_id,
+      text: chunk,
+      embedding_vector: [],
+      created_at: new Date(),
+    });
+  }
+
+  const batchSize = configuration.ai.embedding.batchSize;
+  for (let i = 0; i < embeddingsToCreateOrUpdate.length; i += batchSize) {
+    const batch = embeddingsToCreateOrUpdate.slice(i, i + batchSize);
+    const textsToEmbed = batch.map((item) => item.text);
+    const embeddingVectors = await embeddings.embedDocuments(textsToEmbed);
+    for (let j = 0; j < batch.length; j++) {
+      const vector = embeddingVectors[j];
+      const batchItem = batch[j];
+      if (batchItem) {
+        batchItem.embedding_vector = vector ?? [];
+      }
+    }
+  }
+
+  if (embeddingsToCreateOrUpdate.length === 0) {
+    return;
+  }
+
+  for (const embedding of embeddingsToCreateOrUpdate) {
+    await database
+      .insertInto('node_embeddings')
+      .values({
+        node_id: embedding.node_id,
+        chunk: embedding.chunk,
+        parent_id: embedding.parent_id,
+        root_id: embedding.root_id,
+        workspace_id: embedding.workspace_id,
+        text: embedding.text,
+        embedding_vector: sql.raw(
+          `'[${embedding.embedding_vector.join(',')}]'::vector`
+        ),
+        created_at: embedding.created_at,
+      })
+      .onConflict((oc) =>
+        oc.columns(['node_id', 'chunk']).doUpdateSet({
+          text: sql.ref('excluded.text'),
+          embedding_vector: sql.ref('excluded.embedding_vector'),
+          updated_at: new Date(),
+        })
+      )
+      .execute();
+  }
+};

apps/server/src/jobs/index.ts

@@ -2,7 +2,9 @@ import { cleanNodeDataHandler } from '@/jobs/clean-node-data';
 import { cleanWorkspaceDataHandler } from '@/jobs/clean-workspace-data';
 import { JobHandler, JobMap } from '@/types/jobs';
 import { sendEmailVerifyEmailHandler } from '@/jobs/send-email-verify-email';
-
+import { embedNodeHandler } from './embed-node';
+import { embedDocumentHandler } from './embed-document';
+import { assistantResponseHandler } from './assistant-response';
 type JobHandlerMap = {
   [K in keyof JobMap]: JobHandler<JobMap[K]['input']>;
 };
@@ -11,4 +13,7 @@ export const jobHandlerMap: JobHandlerMap = {
   send_email_verify_email: sendEmailVerifyEmailHandler,
   clean_workspace_data: cleanWorkspaceDataHandler,
   clean_node_data: cleanNodeDataHandler,
+  embed_node: embedNodeHandler,
+  embed_document: embedDocumentHandler,
+  assistant_response: assistantResponseHandler,
 };

apps/server/src/lib/configuration.ts

@@ -69,26 +69,63 @@ export interface SmtpConfiguration {
   };
 }
 
+export type AIProvider = 'openai' | 'google';
+
+export interface AIProviderConfiguration {
+  apiKey: string;
+  enabled?: boolean;
+}
+
+export interface AIModelConfiguration {
+  provider: AIProvider;
+  modelName: string;
+  temperature: number;
+}
+
 export interface AiConfiguration {
   enabled: boolean;
   entryEmbedDelay: number;
-  openai: OpenAiConfiguration;
+  providers: {
+    openai: AIProviderConfiguration;
+    google: AIProviderConfiguration;
+  };
+  langfuse: {
+    publicKey: string;
+    secretKey: string;
+    baseUrl: string;
+  };
+  models: {
+    queryRewrite: AIModelConfiguration;
+    response: AIModelConfiguration;
+    rerank: AIModelConfiguration;
+    summarization: AIModelConfiguration;
+    contextEnhancer: AIModelConfiguration;
+    noContext: AIModelConfiguration;
+    intentRecognition: AIModelConfiguration;
+  };
+  embedding: {
+    provider: AIProvider;
+    apiKey: string;
+    modelName: string;
+    dimensions: number;
+    batchSize: number;
+  };
   chunking: ChunkingConfiguration;
-}
+  retrieval: RetrievalConfiguration;
-
-export interface OpenAiConfiguration {
-  apiKey: string;
-  embeddingModel: string;
-  embeddingDimensions: number;
-  embeddingBatchSize: number;
 }
 
 export interface ChunkingConfiguration {
   defaultChunkSize: number;
   defaultOverlap: number;
   enhanceWithContext: boolean;
-  contextEnhancerModel: string;
+}
-  contextEnhancerTemperature: number;
+
+export interface RetrievalConfiguration {
+  hybridSearch: {
+    semanticSearchWeight: number;
+    keywordSearchWeight: number;
+    maxResults: number;
+  };
 }
 
 const getRequiredEnv = (env: string): string => {
@@ -172,15 +209,84 @@ export const configuration: Configuration = {
     entryEmbedDelay: parseInt(
       getOptionalEnv('AI_ENTRY_EMBED_DELAY') || '60000'
     ),
-    openai: {
+    providers: {
-      apiKey: getOptionalEnv('OPENAI_API_KEY') || '',
+      openai: {
-      embeddingModel: getOptionalEnv('OPENAI_EMBEDDING_MODEL') || '',
+        apiKey: getOptionalEnv('OPENAI_API_KEY') || '',
-      embeddingDimensions: parseInt(
+        enabled: getOptionalEnv('OPENAI_ENABLED') === 'true',
-        getOptionalEnv('OPENAI_EMBEDDING_DIMENSIONS') || '2000'
+      },
-      ),
+      google: {
-      embeddingBatchSize: parseInt(
+        apiKey: getOptionalEnv('GOOGLE_API_KEY') || '',
-        getOptionalEnv('OPENAI_EMBEDDING_BATCH_SIZE') || '50'
+        enabled: getOptionalEnv('GOOGLE_ENABLED') === 'true',
-      ),
+      },
+    },
+    langfuse: {
+      publicKey: getOptionalEnv('LANGFUSE_PUBLIC_KEY') || '',
+      secretKey: getOptionalEnv('LANGFUSE_SECRET_KEY') || '',
+      baseUrl:
+        getOptionalEnv('LANGFUSE_BASE_URL') || 'https://cloud.langfuse.com',
+    },
+    models: {
+      queryRewrite: {
+        provider: (getOptionalEnv('QUERY_REWRITE_PROVIDER') ||
+          'openai') as AIProvider,
+        modelName: getOptionalEnv('QUERY_REWRITE_MODEL') || 'gpt-4o-mini',
+        temperature: parseFloat(
+          getOptionalEnv('QUERY_REWRITE_TEMPERATURE') || '0.3'
+        ),
+      },
+      response: {
+        provider: (getOptionalEnv('RESPONSE_PROVIDER') ||
+          'openai') as AIProvider,
+        modelName: getOptionalEnv('RESPONSE_MODEL') || 'gpt-4o-mini',
+        temperature: parseFloat(
+          getOptionalEnv('RESPONSE_TEMPERATURE') || '0.3'
+        ),
+      },
+      rerank: {
+        provider: (getOptionalEnv('RERANK_PROVIDER') || 'openai') as AIProvider,
+        modelName: getOptionalEnv('RERANK_MODEL') || 'gpt-4o-mini',
+        temperature: parseFloat(getOptionalEnv('RERANK_TEMPERATURE') || '0.3'),
+      },
+      summarization: {
+        provider: (getOptionalEnv('SUMMARIZATION_PROVIDER') ||
+          'openai') as AIProvider,
+        modelName: getOptionalEnv('SUMMARIZATION_MODEL') || 'gpt-4o-mini',
+        temperature: parseFloat(
+          getOptionalEnv('SUMMARIZATION_TEMPERATURE') || '0.3'
+        ),
+      },
+      contextEnhancer: {
+        provider: (getOptionalEnv('CHUNK_CONTEXT_PROVIDER') ||
+          'openai') as AIProvider,
+        modelName: getOptionalEnv('CHUNK_CONTEXT_MODEL') || 'gpt-4o-mini',
+        temperature: parseFloat(
+          getOptionalEnv('CHUNK_CONTEXT_TEMPERATURE') || '0.3'
+        ),
+      },
+      noContext: {
+        provider: (getOptionalEnv('NO_CONTEXT_PROVIDER') ||
+          'openai') as AIProvider,
+        modelName: getOptionalEnv('NO_CONTEXT_MODEL') || 'gpt-4o-mini',
+        temperature: parseFloat(
+          getOptionalEnv('NO_CONTEXT_TEMPERATURE') || '0.3'
+        ),
+      },
+      intentRecognition: {
+        provider: (getOptionalEnv('INTENT_RECOGNITION_PROVIDER') ||
+          'openai') as AIProvider,
+        modelName: getOptionalEnv('INTENT_RECOGNITION_MODEL') || 'gpt-4o-mini',
+        temperature: parseFloat(
+          getOptionalEnv('INTENT_RECOGNITION_TEMPERATURE') || '0.3'
+        ),
+      },
+    },
+    embedding: {
+      provider: (getOptionalEnv('EMBEDDING_PROVIDER') ||
+        'openai') as AIProvider,
+      modelName: getOptionalEnv('EMBEDDING_MODEL') || 'text-embedding-3-large',
+      dimensions: parseInt(getOptionalEnv('EMBEDDING_DIMENSIONS') || '2000'),
+      apiKey: getOptionalEnv('EMBEDDING_API_KEY') || '',
+      batchSize: parseInt(getOptionalEnv('EMBEDDING_BATCH_SIZE') || '50'),
     },
     chunking: {
       defaultChunkSize: parseInt(
@@ -191,11 +297,19 @@ export const configuration: Configuration = {
       ),
       enhanceWithContext:
         getOptionalEnv('CHUNK_ENHANCE_WITH_CONTEXT') === 'true',
-      contextEnhancerModel:
+    },
-        getOptionalEnv('CHUNK_CONTEXT_ENHANCER_MODEL') || 'gpt-4o-mini',
+    retrieval: {
-      contextEnhancerTemperature: parseFloat(
+      hybridSearch: {
-        getOptionalEnv('CHUNK_CONTEXT_ENHANCER_TEMPERATURE') || '0.3'
+        semanticSearchWeight: parseFloat(
-      ),
+          getOptionalEnv('RETRIEVAL_HYBRID_SEARCH_SEMANTIC_WEIGHT') || '0.7'
+        ),
+        keywordSearchWeight: parseFloat(
+          getOptionalEnv('RETRIEVAL_HYBRID_SEARCH_KEYWORD_WEIGHT') || '0.3'
+        ),
+        maxResults: parseInt(
+          getOptionalEnv('RETRIEVAL_HYBRID_SEARCH_MAX_RESULTS') || '20'
+        ),
+      },
     },
   },
 };

apps/server/src/lib/nodes.ts

@@ -35,6 +35,7 @@ import {
   checkCollaboratorChanges,
 } from '@/lib/collaborations';
 import { jobService } from '@/services/job-service';
+import { configuration } from '@/lib/configuration';
 
 const debug = createDebugger('server:lib:nodes');
 
@@ -169,6 +170,18 @@ export const createNode = async (
       });
     }
 
+    // Schedule node embedding
+    await jobService.addJob(
+      {
+        type: 'embed_node',
+        nodeId: input.nodeId,
+      },
+      {
+        jobId: `embed_node:${input.nodeId}`,
+        delay: configuration.ai.entryEmbedDelay,
+      }
+    );
+
     return {
       node: createdNode,
     };
@@ -290,6 +303,18 @@ export const tryUpdateNode = async (
       });
     }
 
+    // Schedule node embedding
+    await jobService.addJob(
+      {
+        type: 'embed_node',
+        nodeId: input.nodeId,
+      },
+      {
+        jobId: `embed_node:${input.nodeId}`,
+        delay: configuration.ai.entryEmbedDelay,
+      }
+    );
+
     return {
       type: 'success',
       output: {
@@ -396,6 +421,18 @@ export const createNodeFromMutation = async (
       });
     }
 
+    // Schedule node embedding
+    await jobService.addJob(
+      {
+        type: 'embed_node',
+        nodeId: mutation.id,
+      },
+      {
+        jobId: `embed_node:${mutation.id}`,
+        delay: configuration.ai.entryEmbedDelay,
+      }
+    );
+
     return {
       node: createdNode,
     };
@@ -527,6 +564,18 @@ const tryUpdateNodeFromMutation = async (
       });
     }
 
+    // Schedule node embedding
+    await jobService.addJob(
+      {
+        type: 'embed_node',
+        nodeId: mutation.id,
+      },
+      {
+        jobId: `embed_node:${mutation.id}`,
+        delay: configuration.ai.entryEmbedDelay,
+      }
+    );
+
     return {
       type: 'success',
       output: {

apps/server/src/services/chunking-service.ts

@@ -1,68 +1,98 @@
+// Updated chunking-service.ts
 import { RecursiveCharacterTextSplitter } from 'langchain/text_splitter';
-import { ChatOpenAI } from '@langchain/openai';
-import { SystemMessage } from '@langchain/core/messages';
-
 import { configuration } from '@/lib/configuration';
+import { database } from '@/data/database';
+import { addContextToChunk } from '@/services/llm-service';
+
+export type ChunkingMetadata = {
+  nodeId: string;
+  type: string;
+  name?: string;
+  parentName?: string;
+  spaceName?: string;
+  createdAt: Date;
+};
 
 export class ChunkingService {
-  public async chunkText(text: string): Promise<string[]> {
+  // Unified chunkText that optionally enriches the chunk with context metadata.
+  public async chunkText(
+    text: string,
+    metadataInfo?: { type: 'node' | 'document'; id: string }
+  ): Promise<string[]> {
     const chunkSize = configuration.ai.chunking.defaultChunkSize;
     const chunkOverlap = configuration.ai.chunking.defaultOverlap;
-
     const splitter = new RecursiveCharacterTextSplitter({
       chunkSize,
       chunkOverlap,
     });
-
     const docs = await splitter.createDocuments([text]);
-    let chunks = docs.map((doc) => doc.pageContent);
+    let chunks = docs
-
+      .map((doc) => doc.pageContent)
-    chunks = chunks.filter((c) => c.trim().length > 10);
+      .filter((c) => c.trim().length > 10);
-
     if (configuration.ai.chunking.enhanceWithContext) {
-      const enriched: string[] = [];
+      // Fetch unified metadata (using a single query if possible)
-      for (const chunk of chunks) {
+      const metadata = metadataInfo
-        const c = await this.addContextToChunk(chunk, text);
+        ? await this.fetchMetadata(metadataInfo)
-        enriched.push(c);
+        : undefined;
-      }
+      chunks = await Promise.all(
-      return enriched;
+        chunks.map(async (chunk) => {
+          return addContextToChunk(chunk, text, metadata);
+        })
+      );
     }
-
     return chunks;
   }
 
-  private async addContextToChunk(
+  // A unified metadata fetch which uses a join to gather node and parent (space) details.
-    chunk: string,
+  private async fetchMetadata(info: {
-    fullText: string
+    type: 'node' | 'document';
-  ): Promise<string> {
+    id: string;
-    try {
+  }): Promise<ChunkingMetadata | undefined> {
-      const chat = new ChatOpenAI({
+    if (info.type === 'node') {
-        openAIApiKey: configuration.ai.openai.apiKey,
+      // Fetch node along with parent (if exists) and the root (assumed to be the space)
-        modelName: configuration.ai.chunking.contextEnhancerModel,
+      const result = await database
-        temperature: configuration.ai.chunking.contextEnhancerTemperature,
+        .selectFrom('nodes')
-        maxTokens: 200,
+        .leftJoin('nodes as parent', 'nodes.parent_id', 'parent.id')
-      });
+        .leftJoin('nodes as root', 'nodes.root_id', 'root.id')
-
+        .select([
-      const prompt = `
+          'nodes.id as nodeId',
-<document>
+          'nodes.type',
-${fullText}
+          "nodes.attributes->>'name' as name",
-</document>
+          "parent.attributes->>'name' as parentName",
-
+          "root.attributes->>'name' as spaceName",
-Here is the chunk we want to situate in context:
+          'nodes.created_at as createdAt',
-<chunk>
+        ])
-${chunk}
+        .where('nodes.id', '=', info.id)
-</chunk>
+        .executeTakeFirst();
-
+      if (!result) return undefined;
-Generate a short (50-100 tokens) contextual prefix that seamlessly provides background or location info for the chunk. Then include the original chunk text below it without any extra separator.
+      return {
-      `;
+        nodeId: result.nodeId,
-
+        type: result.type,
-      const response = await chat.invoke([new SystemMessage(prompt)]);
+        name: result.name,
-      const context = (response.content.toString() ?? '').trim();
+        parentName: result.parentName,
-
+        spaceName: result.spaceName,
-      return `${context} ${chunk}`;
+        createdAt: result.createdAt,
-    } catch (err) {
+      };
-      console.error('Error adding context to chunk:', err);
+    } else {
-      return chunk;
+      // For documents, assume similar metadata based on associated node.
+      const result = await database
+        .selectFrom('documents')
+        .innerJoin('nodes', 'documents.id', 'nodes.id')
+        .select([
+          'nodes.id as nodeId',
+          'nodes.type',
+          "nodes.attributes->>'name' as name",
+          'nodes.created_at as createdAt',
+        ])
+        .where('documents.id', '=', info.id)
+        .executeTakeFirst();
+      if (!result) return undefined;
+      return {
+        nodeId: result.nodeId,
+        type: result.type,
+        name: result.name,
+        createdAt: result.createdAt,
+      };
     }
   }
 }

apps/server/src/services/document-retrieval-service.ts

@@ -0,0 +1,189 @@
+import { OpenAIEmbeddings } from '@langchain/openai';
+import { Document } from '@langchain/core/documents';
+import { database } from '@/data/database';
+import { configuration } from '@/lib/configuration';
+import { sql } from 'kysely';
+
+type SearchResult = {
+  id: string;
+  text: string;
+  score: number;
+  type: 'semantic' | 'keyword';
+  createdAt?: Date;
+  chunkIndex: number;
+};
+
+export class DocumentRetrievalService {
+  private embeddings = new OpenAIEmbeddings({
+    apiKey: configuration.ai.embedding.apiKey,
+    modelName: configuration.ai.embedding.modelName,
+    dimensions: configuration.ai.embedding.dimensions,
+  });
+
+  public async retrieve(
+    query: string,
+    workspaceId: string,
+    limit = configuration.ai.retrieval.hybridSearch.maxResults
+  ): Promise<Document[]> {
+    const embedding = await this.embeddings.embedQuery(query);
+    if (!embedding) return [];
+    const semanticResults = await this.semanticSearch(
+      embedding,
+      workspaceId,
+      limit
+    );
+    const keywordResults = await this.keywordSearch(query, workspaceId, limit);
+    return this.combineSearchResults(semanticResults, keywordResults);
+  }
+
+  private async semanticSearch(
+    embedding: number[],
+    workspaceId: string,
+    limit: number
+  ): Promise<SearchResult[]> {
+    const results = await database
+      .selectFrom('document_embeddings')
+      .innerJoin('documents', 'documents.id', 'document_embeddings.document_id')
+      .select((eb) => [
+        'document_embeddings.document_id as id',
+        'document_embeddings.text',
+        'documents.created_at',
+        'document_embeddings.chunk as chunk_index',
+        sql<number>`('[${embedding.join(',')}]'::vector) <=> document_embeddings.embedding_vector`.as(
+          'similarity'
+        ),
+      ])
+      .where('document_embeddings.workspace_id', '=', workspaceId)
+      .groupBy([
+        'document_embeddings.document_id',
+        'document_embeddings.text',
+        'documents.created_at',
+        'document_embeddings.chunk',
+      ])
+      .orderBy('similarity', 'asc')
+      .limit(limit)
+      .execute();
+
+    return results.map((result) => ({
+      id: result.id,
+      text: result.text,
+      score: result.similarity,
+      type: 'semantic',
+      createdAt: result.created_at,
+      chunkIndex: result.chunk_index,
+    }));
+  }
+
+  private async keywordSearch(
+    query: string,
+    workspaceId: string,
+    limit: number
+  ): Promise<SearchResult[]> {
+    const results = await database
+      .selectFrom('document_embeddings')
+      .innerJoin('documents', 'documents.id', 'document_embeddings.document_id')
+      .select((eb) => [
+        'document_embeddings.document_id as id',
+        'document_embeddings.text',
+        'documents.created_at',
+        'document_embeddings.chunk as chunk_index',
+        sql<number>`ts_rank(document_embeddings.search_vector, websearch_to_tsquery('english', ${query}))`.as(
+          'rank'
+        ),
+      ])
+      .where('document_embeddings.workspace_id', '=', workspaceId)
+      .where(
+        (eb) =>
+          sql`document_embeddings.search_vector @@ websearch_to_tsquery('english', ${query})`
+      )
+      .groupBy([
+        'document_embeddings.document_id',
+        'document_embeddings.text',
+        'documents.created_at',
+        'document_embeddings.chunk',
+      ])
+      .orderBy('rank', 'desc')
+      .limit(limit)
+      .execute();
+
+    return results.map((result) => ({
+      id: result.id,
+      text: result.text,
+      score: result.rank,
+      type: 'keyword',
+      createdAt: result.created_at,
+      chunkIndex: result.chunk_index,
+    }));
+  }
+
+  private combineSearchResults(
+    semanticResults: SearchResult[],
+    keywordResults: SearchResult[]
+  ): Document[] {
+    const { semanticSearchWeight, keywordSearchWeight } =
+      configuration.ai.retrieval.hybridSearch;
+    const maxSemanticScore = Math.max(
+      ...semanticResults.map((r) => r.score),
+      1
+    );
+    const maxKeywordScore = Math.max(...keywordResults.map((r) => r.score), 1);
+    const combined = new Map<string, SearchResult & { finalScore: number }>();
+    const createKey = (result: SearchResult) =>
+      `${result.id}-${result.chunkIndex}`;
+    const calculateRecencyBoost = (
+      createdAt: Date | undefined | null
+    ): number => {
+      if (!createdAt) return 1;
+      const now = new Date();
+      const ageInDays =
+        (now.getTime() - createdAt.getTime()) / (1000 * 60 * 60 * 24);
+      return ageInDays <= 7 ? 1 + (1 - ageInDays / 7) * 0.2 : 1;
+    };
+
+    semanticResults.forEach((result) => {
+      const key = createKey(result);
+      const recencyBoost = calculateRecencyBoost(result.createdAt);
+      const normalizedScore =
+        ((maxSemanticScore - result.score) / maxSemanticScore) *
+        semanticSearchWeight;
+      combined.set(key, {
+        ...result,
+        finalScore: normalizedScore * recencyBoost,
+      });
+    });
+
+    keywordResults.forEach((result) => {
+      const key = createKey(result);
+      const recencyBoost = calculateRecencyBoost(result.createdAt);
+      const normalizedScore =
+        (result.score / maxKeywordScore) * keywordSearchWeight;
+      if (combined.has(key)) {
+        const existing = combined.get(key)!;
+        existing.finalScore += normalizedScore * recencyBoost;
+      } else {
+        combined.set(key, {
+          ...result,
+          finalScore: normalizedScore * recencyBoost,
+        });
+      }
+    });
+
+    return Array.from(combined.values())
+      .sort((a, b) => b.finalScore - a.finalScore)
+      .map(
+        (result) =>
+          new Document({
+            pageContent: result.text,
+            metadata: {
+              id: result.id,
+              score: result.finalScore,
+              createdAt: result.createdAt,
+              type: 'document',
+              chunkIndex: result.chunkIndex,
+            },
+          })
+      );
+  }
+}
+
+export const documentRetrievalService = new DocumentRetrievalService();

apps/server/src/services/llm-service.ts

@@ -0,0 +1,278 @@
+// Updated llm-service.ts
+import { ChatOpenAI } from '@langchain/openai';
+import { ChatGoogleGenerativeAI } from '@langchain/google-genai';
+import { PromptTemplate, ChatPromptTemplate } from '@langchain/core/prompts';
+import { StringOutputParser } from '@langchain/core/output_parsers';
+import { HumanMessage } from '@langchain/core/messages';
+import { configuration } from '@/lib/configuration';
+import { Document } from '@langchain/core/documents';
+import { z } from 'zod';
+import { NodeAttributes } from '@colanode/core';
+
+// Use proper Zod schemas and updated prompt templates
+
+const rerankedDocumentsSchema = z.object({
+  rankings: z.array(
+    z.object({
+      index: z.number(),
+      score: z.number().min(0).max(1),
+      type: z.enum(['node', 'document']),
+      sourceId: z.string(),
+    })
+  ),
+});
+type RerankedDocuments = z.infer<typeof rerankedDocumentsSchema>;
+
+const citedAnswerSchema = z.object({
+  answer: z.string(),
+  citations: z.array(
+    z.object({
+      sourceId: z.string(),
+      quote: z.string(),
+    })
+  ),
+});
+type CitedAnswer = z.infer<typeof citedAnswerSchema>;
+
+export function getChatModel(
+  task: keyof typeof configuration.ai.models
+): ChatOpenAI | ChatGoogleGenerativeAI {
+  const modelConfig = configuration.ai.models[task];
+  if (!configuration.ai.enabled) {
+    throw new Error('AI is disabled.');
+  }
+  const providerConfig = configuration.ai.providers[modelConfig.provider];
+  if (!providerConfig.enabled) {
+    throw new Error(`${modelConfig.provider} provider is disabled.`);
+  }
+  switch (modelConfig.provider) {
+    case 'openai':
+      return new ChatOpenAI({
+        modelName: modelConfig.modelName,
+        temperature: modelConfig.temperature,
+        openAIApiKey: providerConfig.apiKey,
+      });
+    case 'google':
+      return new ChatGoogleGenerativeAI({
+        modelName: modelConfig.modelName,
+        temperature: modelConfig.temperature,
+        apiKey: providerConfig.apiKey,
+      });
+    default:
+      throw new Error(`Unsupported AI provider: ${modelConfig.provider}`);
+  }
+}
+
+// Updated prompt templates using type-safe node types and context
+const queryRewritePrompt = PromptTemplate.fromTemplate(
+  `You are an expert at rewriting queries for information retrieval within Colanode.
+  
+Guidelines:
+1. Extract the core information need.
+2. Remove filler words.
+3. Preserve key technical terms and dates.
+  
+Original query:
+{query}
+  
+Rewrite the query and return only the rewritten version.`
+);
+
+const summarizationPrompt = PromptTemplate.fromTemplate(
+  `Summarize the following text focusing on key points relevant to the user's query.
+If the text is short (<100 characters), return it as is.
+  
+Text: {text}
+User Query: {query}`
+);
+
+const rerankPrompt = PromptTemplate.fromTemplate(
+  `Re-rank the following list of documents by their relevance to the query.
+For each document, provide:
+- Original index (from input)
+- A relevance score between 0 and 1
+- Document type (node or document)
+- Source ID
+  
+User query:
+{query}
+  
+Documents:
+{context}
+  
+Return an array of rankings in JSON format.`
+);
+
+const answerPrompt = ChatPromptTemplate.fromTemplate(
+  `You are Colanode's AI assistant.
+  
+CURRENT TIME: {currentTimestamp}
+WORKSPACE: {workspaceName}
+USER: {userName} ({userEmail})
+  
+CONVERSATION HISTORY:
+{formattedChatHistory}
+  
+RELATED CONTEXT:
+Messages:
+{formattedMessages}
+Documents:
+{formattedDocuments}
+  
+USER QUERY:
+{question}
+  
+Provide a clear, professional answer. Then, in a separate citations array, list exact quotes (with source IDs) used to form your answer.
+Return the result as JSON with keys "answer" and "citations".`
+);
+
+const intentRecognitionPrompt = PromptTemplate.fromTemplate(
+  `Determine if the following user query requires retrieving additional context.
+Return exactly one value: "retrieve" or "no_context".
+
+Conversation History:
+{formattedChatHistory}
+
+User Query:
+{question}`
+);
+
+const noContextPrompt = PromptTemplate.fromTemplate(
+  `Answer the following query concisely using general knowledge, without retrieving additional context.
+
+Conversation History:
+{formattedChatHistory}
+
+User Query:
+{question}
+
+Return only the answer.`
+);
+
+export async function rewriteQuery(query: string): Promise<string> {
+  const task = 'queryRewrite';
+  const model = getChatModel(task);
+  return queryRewritePrompt
+    .pipe(model)
+    .pipe(new StringOutputParser())
+    .invoke({ query });
+}
+
+export async function summarizeDocument(
+  document: Document,
+  query: string
+): Promise<string> {
+  const task = 'summarization';
+  const model = getChatModel(task);
+  return summarizationPrompt
+    .pipe(model)
+    .pipe(new StringOutputParser())
+    .invoke({ text: document.pageContent, query });
+}
+
+export async function rerankDocuments(
+  documents: { content: string; type: string; sourceId: string }[],
+  query: string
+): Promise<
+  Array<{ index: number; score: number; type: string; sourceId: string }>
+> {
+  const task = 'rerank';
+  const model = getChatModel(task).withStructuredOutput(
+    rerankedDocumentsSchema
+  );
+  const formattedContext = documents
+    .map(
+      (doc, idx) =>
+        `${idx}. Type: ${doc.type}, Content: ${doc.content}, ID: ${doc.sourceId}\n`
+    )
+    .join('\n');
+  const result = (await rerankPrompt
+    .pipe(model)
+    .invoke({ query, context: formattedContext })) as RerankedDocuments;
+  return result.rankings;
+}
+
+export async function generateFinalAnswer(promptArgs: {
+  currentTimestamp: string;
+  workspaceName: string;
+  userName: string;
+  userEmail: string;
+  formattedChatHistory: string;
+  formattedMessages: string;
+  formattedDocuments: string;
+  question: string;
+}): Promise<{
+  answer: string;
+  citations: Array<{ sourceId: string; quote: string }>;
+}> {
+  const task = 'response';
+  const model = getChatModel(task).withStructuredOutput(citedAnswerSchema);
+  return (await answerPrompt.pipe(model).invoke(promptArgs)) as CitedAnswer;
+}
+
+export async function generateNoContextAnswer(
+  query: string,
+  chatHistory: string = ''
+): Promise<string> {
+  const task = 'noContext';
+  const model = getChatModel(task);
+  return noContextPrompt
+    .pipe(model)
+    .pipe(new StringOutputParser())
+    .invoke({ question: query, formattedChatHistory: chatHistory });
+}
+
+export async function assessUserIntent(
+  query: string,
+  chatHistory: string
+): Promise<'retrieve' | 'no_context'> {
+  const task = 'intentRecognition';
+  const model = getChatModel(task);
+  const result = await intentRecognitionPrompt
+    .pipe(model)
+    .pipe(new StringOutputParser())
+    .invoke({ question: query, formattedChatHistory: chatHistory });
+  return result.trim().toLowerCase() === 'no_context'
+    ? 'no_context'
+    : 'retrieve';
+}
+
+export async function addContextToChunk(
+  chunk: string,
+  fullText: string,
+  metadata?: any
+): Promise<string> {
+  try {
+    const task = 'contextEnhancer';
+    const model = getChatModel(task);
+    // Choose a prompt variant based on metadata type (node/document) if available.
+    const promptTemplate = PromptTemplate.fromTemplate(
+      `Using the following context information:
+{contextInfo}
+
+Full content:
+{fullText}
+
+Given this chunk:
+{chunk}
+
+Generate a short (50–100 tokens) contextual prefix (do not repeat the chunk) and prepend it to the chunk.`
+    );
+    const contextInfo = metadata
+      ? `Type: ${metadata.type}, Name: ${metadata.name || 'N/A'}, Parent: ${metadata.parentName || 'N/A'}, Space: ${metadata.spaceName || 'N/A'}`
+      : 'No additional context available.';
+    const prompt = await promptTemplate.format({
+      contextInfo,
+      fullText,
+      chunk,
+    });
+    const response = await model.invoke([
+      new HumanMessage({ content: prompt }),
+    ]);
+    const prefix = (response.content.toString() || '').trim();
+    return prefix ? `${prefix}\n\n${chunk}` : chunk;
+  } catch (err) {
+    console.error('Error in addContextToChunk:', err);
+    return chunk;
+  }
+}

apps/server/src/services/node-retrieval-service.ts

@@ -0,0 +1,199 @@
+import { OpenAIEmbeddings } from '@langchain/openai';
+import { Document } from '@langchain/core/documents';
+import { database } from '@/data/database';
+import { configuration } from '@/lib/configuration';
+import { sql } from 'kysely';
+
+type SearchResult = {
+  id: string;
+  text: string;
+  score: number;
+  type: 'semantic' | 'keyword';
+  createdAt?: Date;
+  chunkIndex: number;
+};
+
+export class NodeRetrievalService {
+  private embeddings = new OpenAIEmbeddings({
+    apiKey: configuration.ai.embedding.apiKey,
+    modelName: configuration.ai.embedding.modelName,
+    dimensions: configuration.ai.embedding.dimensions,
+  });
+
+  public async retrieve(
+    query: string,
+    workspaceId: string,
+    userId: string,
+    limit = configuration.ai.retrieval.hybridSearch.maxResults
+  ): Promise<Document[]> {
+    const embedding = await this.embeddings.embedQuery(query);
+    if (!embedding) return [];
+    const semanticResults = await this.semanticSearch(
+      embedding,
+      workspaceId,
+      userId,
+      limit
+    );
+    const keywordResults = await this.keywordSearch(
+      query,
+      workspaceId,
+      userId,
+      limit
+    );
+    return this.combineSearchResults(semanticResults, keywordResults);
+  }
+
+  private async semanticSearch(
+    embedding: number[],
+    workspaceId: string,
+    userId: string,
+    limit: number
+  ): Promise<SearchResult[]> {
+    const results = await database
+      .selectFrom('node_embeddings')
+      .innerJoin('nodes', 'nodes.id', 'node_embeddings.node_id')
+      .select((eb) => [
+        'node_embeddings.node_id as id',
+        'node_embeddings.text',
+        'nodes.created_at',
+        'node_embeddings.chunk as chunk_index',
+        // Wrap raw expression to satisfy type:
+        sql<number>`('[${embedding.join(',')}]'::vector) <=> node_embeddings.embedding_vector`.as(
+          'similarity'
+        ),
+      ])
+      .where('node_embeddings.workspace_id', '=', workspaceId)
+      .groupBy([
+        'node_embeddings.node_id',
+        'node_embeddings.text',
+        'nodes.created_at',
+        'node_embeddings.chunk',
+      ])
+      .orderBy('similarity', 'asc')
+      .limit(limit)
+      .execute();
+
+    return results.map((result) => ({
+      id: result.id,
+      text: result.text,
+      score: result.similarity,
+      type: 'semantic',
+      createdAt: result.created_at,
+      chunkIndex: result.chunk_index,
+    }));
+  }
+
+  private async keywordSearch(
+    query: string,
+    workspaceId: string,
+    userId: string,
+    limit: number
+  ): Promise<SearchResult[]> {
+    const results = await database
+      .selectFrom('node_embeddings')
+      .innerJoin('nodes', 'nodes.id', 'node_embeddings.node_id')
+      .select((eb) => [
+        'node_embeddings.node_id as id',
+        'node_embeddings.text',
+        'nodes.created_at',
+        'node_embeddings.chunk as chunk_index',
+        sql<number>`ts_rank(node_embeddings.search_vector, websearch_to_tsquery('english', ${query}))`.as(
+          'rank'
+        ),
+      ])
+      .where('node_embeddings.workspace_id', '=', workspaceId)
+      .where(
+        (eb) =>
+          sql`node_embeddings.search_vector @@ websearch_to_tsquery('english', ${query})`
+      )
+      .groupBy([
+        'node_embeddings.node_id',
+        'node_embeddings.text',
+        'nodes.created_at',
+        'node_embeddings.chunk',
+      ])
+      .orderBy('rank', 'desc')
+      .limit(limit)
+      .execute();
+
+    return results.map((result) => ({
+      id: result.id,
+      text: result.text,
+      score: result.rank,
+      type: 'keyword',
+      createdAt: result.created_at,
+      chunkIndex: result.chunk_index,
+    }));
+  }
+
+  private combineSearchResults(
+    semanticResults: SearchResult[],
+    keywordResults: SearchResult[]
+  ): Document[] {
+    const { semanticSearchWeight, keywordSearchWeight } =
+      configuration.ai.retrieval.hybridSearch;
+    const maxSemanticScore = Math.max(
+      ...semanticResults.map((r) => r.score),
+      1
+    );
+    const maxKeywordScore = Math.max(...keywordResults.map((r) => r.score), 1);
+    const combined = new Map<string, SearchResult & { finalScore: number }>();
+    const createKey = (result: SearchResult) =>
+      `${result.id}-${result.chunkIndex}`;
+    const calculateRecencyBoost = (
+      createdAt: Date | undefined | null
+    ): number => {
+      if (!createdAt) return 1;
+      const now = new Date();
+      const ageInDays =
+        (now.getTime() - createdAt.getTime()) / (1000 * 60 * 60 * 24);
+      return ageInDays <= 7 ? 1 + (1 - ageInDays / 7) * 0.2 : 1;
+    };
+
+    semanticResults.forEach((result) => {
+      const key = createKey(result);
+      const recencyBoost = calculateRecencyBoost(result.createdAt);
+      const normalizedScore =
+        ((maxSemanticScore - result.score) / maxSemanticScore) *
+        semanticSearchWeight;
+      combined.set(key, {
+        ...result,
+        finalScore: normalizedScore * recencyBoost,
+      });
+    });
+
+    keywordResults.forEach((result) => {
+      const key = createKey(result);
+      const recencyBoost = calculateRecencyBoost(result.createdAt);
+      const normalizedScore =
+        (result.score / maxKeywordScore) * keywordSearchWeight;
+      if (combined.has(key)) {
+        const existing = combined.get(key)!;
+        existing.finalScore += normalizedScore * recencyBoost;
+      } else {
+        combined.set(key, {
+          ...result,
+          finalScore: normalizedScore * recencyBoost,
+        });
+      }
+    });
+
+    return Array.from(combined.values())
+      .sort((a, b) => b.finalScore - a.finalScore)
+      .map(
+        (result) =>
+          new Document({
+            pageContent: result.text,
+            metadata: {
+              id: result.id,
+              score: result.finalScore,
+              createdAt: result.createdAt,
+              type: 'node',
+              chunkIndex: result.chunkIndex,
+            },
+          })
+      );
+  }
+}
+
+export const nodeRetrievalService = new NodeRetrievalService();