Implement hybrid search: Chroma semantic + SQLite temporal

Core implementation:
- Added Chroma MCP client integration to search-server.ts
- Implemented queryChroma() helper with Python dict parsing
- Added VECTOR_DB_DIR constant to paths.ts
- Added SessionStore.getObservationsByIds() method

Search handlers updated:
- search_observations: Semantic-first with 90-day temporal filter
- find_by_concept/type/file: Metadata-first, semantic-enhanced ranking
- All handlers fall back to FTS5 if Chroma unavailable

Technical details:
- Direct MCP client usage (no abstractions)
- Regex parsing of Chroma Python dict responses
- Semantic ranking preserved in final results
- Graceful degradation to FTS5-only search

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>
This commit is contained in:
Alex Newman
2025-10-31 23:00:04 -04:00
parent 867226c19d
commit 309e8a7139
12 changed files with 1189 additions and 149 deletions
+305 -14
View File
@@ -5,6 +5,8 @@
import { Server } from '@modelcontextprotocol/sdk/server/index.js';
import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js';
import { Client } from '@modelcontextprotocol/sdk/client/index.js';
import { StdioClientTransport } from '@modelcontextprotocol/sdk/client/stdio.js';
import {
CallToolRequestSchema,
ListToolsRequestSchema,
@@ -15,10 +17,14 @@ import { basename } from 'path';
import { SessionSearch } from '../services/sqlite/SessionSearch.js';
import { SessionStore } from '../services/sqlite/SessionStore.js';
import { ObservationSearchResult, SessionSummarySearchResult, UserPromptSearchResult } from '../services/sqlite/types.js';
import { VECTOR_DB_DIR } from '../shared/paths.js';
// Initialize search instance
// Initialize search instances
let search: SessionSearch;
let store: SessionStore;
let chromaClient: Client | null = null;
const COLLECTION_NAME = 'cm__claude-mem';
try {
search = new SessionSearch();
store = new SessionStore();
@@ -27,6 +33,95 @@ try {
process.exit(1);
}
/**
* Query Chroma vector database via MCP
* Parses Python dict-like responses from Chroma MCP server
*/
async function queryChroma(
query: string,
limit: number,
whereFilter?: Record<string, any>
): Promise<{ ids: number[]; distances: number[]; metadatas: any[] }> {
if (!chromaClient) {
throw new Error('Chroma client not initialized');
}
const result = await chromaClient.callTool({
name: 'chroma_query_documents',
arguments: {
collection_name: COLLECTION_NAME,
query_texts: [query],
n_results: limit,
include: ['documents', 'metadatas', 'distances'],
where: whereFilter
}
});
const resultText = result.content[0]?.text || '';
// Parse Python dict-like output using regex
// Format: {'ids': [[...]], 'distances': [[...]], 'metadatas': [[...]]}
// Extract IDs (nested array format)
const idsMatch = resultText.match(/'ids':\s*\[\[(.*?)\]\]/s);
const ids: number[] = [];
if (idsMatch) {
const idsContent = idsMatch[1];
// Match quoted strings (Chroma doc IDs like 'obs_123_title')
const idMatches = idsContent.match(/'([^']*(?:\\'[^']*)*)'/g) || [];
for (const idMatch of idMatches) {
const docId = idMatch.slice(1, -1);
// Extract sqlite_id from document ID (format: obs_{id}_title)
const sqliteIdMatch = docId.match(/obs_(\d+)_/);
if (sqliteIdMatch) {
const sqliteId = parseInt(sqliteIdMatch[1], 10);
if (!ids.includes(sqliteId)) {
ids.push(sqliteId);
}
}
}
}
// Extract distances (nested array format)
const distancesMatch = resultText.match(/'distances':\s*\[\[([\d.,\s]+)\]\]/s);
const distances: number[] = [];
if (distancesMatch) {
const distancesContent = distancesMatch[1];
const distanceValues = distancesContent.split(',').map(d => parseFloat(d.trim())).filter(d => !isNaN(d));
distances.push(...distanceValues);
}
// Extract metadatas (nested array format)
const metasMatch = resultText.match(/'metadatas':\s*\[\[(.*?)\]\]/s);
const metadatas: any[] = [];
if (metasMatch) {
const metasContent = metasMatch[1];
// Parse each metadata dict
const metaObjMatches = metasContent.match(/\{[^}]+\}/g) || [];
for (const metaStr of metaObjMatches) {
const meta: any = {};
// Extract sqlite_id
const sqliteIdMatch = metaStr.match(/'sqlite_id':\s*(\d+)/);
if (sqliteIdMatch) {
meta.sqlite_id = parseInt(sqliteIdMatch[1], 10);
}
// Extract type
const typeMatch = metaStr.match(/'type':\s*'([^']+)'/);
if (typeMatch) {
meta.type = typeMatch[1];
}
// Extract created_at_epoch
const epochMatch = metaStr.match(/'created_at_epoch':\s*(\d+)/);
if (epochMatch) {
meta.created_at_epoch = parseInt(epochMatch[1], 10);
}
metadatas.push(meta);
}
}
return { ids, distances, metadatas };
}
/**
* Format search tips footer
*/
@@ -286,7 +381,45 @@ const tools = [
handler: async (args: any) => {
try {
const { query, format = 'index', ...options } = args;
const results = search.searchObservations(query, options);
let results: ObservationSearchResult[] = [];
// Hybrid search: Try Chroma semantic search first, fall back to FTS5
if (chromaClient) {
try {
console.error('[search-server] Using hybrid semantic search (Chroma + SQLite)');
// Step 1: Chroma semantic search (top 100)
const chromaResults = await queryChroma(query, 100);
console.error(`[search-server] Chroma returned ${chromaResults.ids.length} semantic matches`);
if (chromaResults.ids.length > 0) {
// Step 2: Filter by recency (90 days)
const ninetyDaysAgo = Math.floor(Date.now() / 1000) - (90 * 24 * 60 * 60);
const recentIds = chromaResults.ids.filter((id, idx) => {
const meta = chromaResults.metadatas[idx];
return meta && meta.created_at_epoch > ninetyDaysAgo;
});
console.error(`[search-server] ${recentIds.length} results within 90-day window`);
// Step 3: Hydrate from SQLite in temporal order
if (recentIds.length > 0) {
const limit = options.limit || 20;
results = store.getObservationsByIds(recentIds, { orderBy: 'date_desc', limit });
console.error(`[search-server] Hydrated ${results.length} observations from SQLite`);
}
}
} catch (chromaError: any) {
console.error('[search-server] Chroma query failed, falling back to FTS5:', chromaError.message);
// Fall through to FTS5 fallback
}
}
// Fall back to FTS5 if Chroma unavailable or returned no results
if (results.length === 0) {
console.error('[search-server] Using FTS5 keyword search');
results = search.searchObservations(query, options);
}
if (results.length === 0) {
return {
@@ -400,7 +533,50 @@ const tools = [
handler: async (args: any) => {
try {
const { concept, format = 'index', ...filters } = args;
const results = search.findByConcept(concept, filters);
let results: ObservationSearchResult[] = [];
// Metadata-first, semantic-enhanced search
if (chromaClient) {
try {
console.error('[search-server] Using metadata-first + semantic ranking for concept search');
// Step 1: SQLite metadata filter (get all IDs with this concept)
const metadataResults = search.findByConcept(concept, filters);
console.error(`[search-server] Found ${metadataResults.length} observations with concept "${concept}"`);
if (metadataResults.length > 0) {
// Step 2: Chroma semantic ranking (rank by relevance to concept)
const ids = metadataResults.map(obs => obs.id);
const chromaResults = await queryChroma(concept, Math.min(ids.length, 100));
// Intersect: Keep only IDs that passed metadata filter, in semantic rank order
const rankedIds: number[] = [];
for (const chromaId of chromaResults.ids) {
if (ids.includes(chromaId) && !rankedIds.includes(chromaId)) {
rankedIds.push(chromaId);
}
}
console.error(`[search-server] Chroma ranked ${rankedIds.length} results by semantic relevance`);
// Step 3: Hydrate in semantic rank order
if (rankedIds.length > 0) {
results = store.getObservationsByIds(rankedIds, { limit: filters.limit || 20 });
// Restore semantic ranking order
results.sort((a, b) => rankedIds.indexOf(a.id) - rankedIds.indexOf(b.id));
}
}
} catch (chromaError: any) {
console.error('[search-server] Chroma ranking failed, using SQLite order:', chromaError.message);
// Fall through to SQLite fallback
}
}
// Fall back to SQLite-only if Chroma unavailable or failed
if (results.length === 0) {
console.error('[search-server] Using SQLite-only concept search');
results = search.findByConcept(concept, filters);
}
if (results.length === 0) {
return {
@@ -457,9 +633,59 @@ const tools = [
handler: async (args: any) => {
try {
const { filePath, format = 'index', ...filters } = args;
const results = search.findByFile(filePath, filters);
let observations: ObservationSearchResult[] = [];
let sessions: SessionSummarySearchResult[] = [];
const totalResults = results.observations.length + results.sessions.length;
// Metadata-first, semantic-enhanced search for observations
if (chromaClient) {
try {
console.error('[search-server] Using metadata-first + semantic ranking for file search');
// Step 1: SQLite metadata filter (get all results with this file)
const metadataResults = search.findByFile(filePath, filters);
console.error(`[search-server] Found ${metadataResults.observations.length} observations, ${metadataResults.sessions.length} sessions for file "${filePath}"`);
// Sessions: Keep as-is (already summarized, no semantic ranking needed)
sessions = metadataResults.sessions;
// Observations: Apply semantic ranking
if (metadataResults.observations.length > 0) {
// Step 2: Chroma semantic ranking (rank by relevance to file path)
const ids = metadataResults.observations.map(obs => obs.id);
const chromaResults = await queryChroma(filePath, Math.min(ids.length, 100));
// Intersect: Keep only IDs that passed metadata filter, in semantic rank order
const rankedIds: number[] = [];
for (const chromaId of chromaResults.ids) {
if (ids.includes(chromaId) && !rankedIds.includes(chromaId)) {
rankedIds.push(chromaId);
}
}
console.error(`[search-server] Chroma ranked ${rankedIds.length} observations by semantic relevance`);
// Step 3: Hydrate in semantic rank order
if (rankedIds.length > 0) {
observations = store.getObservationsByIds(rankedIds, { limit: filters.limit || 20 });
// Restore semantic ranking order
observations.sort((a, b) => rankedIds.indexOf(a.id) - rankedIds.indexOf(b.id));
}
}
} catch (chromaError: any) {
console.error('[search-server] Chroma ranking failed, using SQLite order:', chromaError.message);
// Fall through to SQLite fallback
}
}
// Fall back to SQLite-only if Chroma unavailable or failed
if (observations.length === 0 && sessions.length === 0) {
console.error('[search-server] Using SQLite-only file search');
const results = search.findByFile(filePath, filters);
observations = results.observations;
sessions = results.sessions;
}
const totalResults = observations.length + sessions.length;
if (totalResults === 0) {
return {
@@ -476,13 +702,13 @@ const tools = [
const formattedResults: string[] = [];
// Add observations
results.observations.forEach((obs, i) => {
observations.forEach((obs, i) => {
formattedResults.push(formatObservationIndex(obs, i));
});
// Add sessions
results.sessions.forEach((session, i) => {
formattedResults.push(formatSessionIndex(session, i + results.observations.length));
sessions.forEach((session, i) => {
formattedResults.push(formatSessionIndex(session, i + observations.length));
});
combinedText = header + formattedResults.join('\n\n') + formatSearchTips();
@@ -490,13 +716,13 @@ const tools = [
const formattedResults: string[] = [];
// Add observations
results.observations.forEach((obs, i) => {
observations.forEach((obs, i) => {
formattedResults.push(formatObservationResult(obs, i));
});
// Add sessions
results.sessions.forEach((session, i) => {
formattedResults.push(formatSessionResult(session, i + results.observations.length));
sessions.forEach((session, i) => {
formattedResults.push(formatSessionResult(session, i + observations.length));
});
combinedText = formattedResults.join('\n\n---\n\n');
@@ -540,10 +766,53 @@ const tools = [
handler: async (args: any) => {
try {
const { type, format = 'index', ...filters } = args;
const results = search.findByType(type, filters);
const typeStr = Array.isArray(type) ? type.join(', ') : type;
let results: ObservationSearchResult[] = [];
// Metadata-first, semantic-enhanced search
if (chromaClient) {
try {
console.error('[search-server] Using metadata-first + semantic ranking for type search');
// Step 1: SQLite metadata filter (get all IDs with this type)
const metadataResults = search.findByType(type, filters);
console.error(`[search-server] Found ${metadataResults.length} observations with type "${typeStr}"`);
if (metadataResults.length > 0) {
// Step 2: Chroma semantic ranking (rank by relevance to type)
const ids = metadataResults.map(obs => obs.id);
const chromaResults = await queryChroma(typeStr, Math.min(ids.length, 100));
// Intersect: Keep only IDs that passed metadata filter, in semantic rank order
const rankedIds: number[] = [];
for (const chromaId of chromaResults.ids) {
if (ids.includes(chromaId) && !rankedIds.includes(chromaId)) {
rankedIds.push(chromaId);
}
}
console.error(`[search-server] Chroma ranked ${rankedIds.length} results by semantic relevance`);
// Step 3: Hydrate in semantic rank order
if (rankedIds.length > 0) {
results = store.getObservationsByIds(rankedIds, { limit: filters.limit || 20 });
// Restore semantic ranking order
results.sort((a, b) => rankedIds.indexOf(a.id) - rankedIds.indexOf(b.id));
}
}
} catch (chromaError: any) {
console.error('[search-server] Chroma ranking failed, using SQLite order:', chromaError.message);
// Fall through to SQLite fallback
}
}
// Fall back to SQLite-only if Chroma unavailable or failed
if (results.length === 0) {
console.error('[search-server] Using SQLite-only type search');
results = search.findByType(type, filters);
}
if (results.length === 0) {
const typeStr = Array.isArray(type) ? type.join(', ') : type;
return {
content: [{
type: 'text' as const,
@@ -553,7 +822,6 @@ const tools = [
}
// Format based on requested format
const typeStr = Array.isArray(type) ? type.join(', ') : type;
let combinedText: string;
if (format === 'index') {
const header = `Found ${results.length} observation(s) with type "${typeStr}":\n\n`;
@@ -827,6 +1095,29 @@ server.setRequestHandler(CallToolRequestSchema, async (request) => {
// Start the server
async function main() {
// Initialize Chroma client
try {
console.error('[search-server] Initializing Chroma client...');
const chromaTransport = new StdioClientTransport({
command: 'uvx',
args: ['chroma-mcp', '--client-type', 'persistent', '--data-dir', VECTOR_DB_DIR]
});
chromaClient = new Client({
name: 'claude-mem-search-chroma-client',
version: '1.0.0'
}, {
capabilities: {}
});
await chromaClient.connect(chromaTransport);
console.error('[search-server] Chroma client connected successfully');
} catch (error: any) {
console.error('[search-server] Failed to initialize Chroma client:', error.message);
console.error('[search-server] Falling back to FTS5-only search');
chromaClient = null;
}
const transport = new StdioServerTransport();
await server.connect(transport);
console.error('[search-server] Claude-mem search server started');
+27
View File
@@ -616,6 +616,33 @@ export class SessionStore {
return stmt.all(sdkSessionId) as any[];
}
/**
* Get observations by array of IDs with ordering and limit
*/
getObservationsByIds(
ids: number[],
options: { orderBy?: 'date_desc' | 'date_asc'; limit?: number } = {}
): any[] {
if (ids.length === 0) return [];
const { orderBy = 'date_desc', limit } = options;
const orderClause = orderBy === 'date_asc' ? 'ASC' : 'DESC';
const limitClause = limit ? `LIMIT ${limit}` : '';
// Build placeholders for IN clause
const placeholders = ids.map(() => '?').join(',');
const stmt = this.db.prepare(`
SELECT *
FROM observations
WHERE id IN (${placeholders})
ORDER BY created_at_epoch ${orderClause}
${limitClause}
`);
return stmt.all(...ids) as any[];
}
/**
* Get summary for a specific session
*/
+1
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@@ -32,6 +32,7 @@ export const TRASH_DIR = join(DATA_DIR, 'trash');
export const BACKUPS_DIR = join(DATA_DIR, 'backups');
export const USER_SETTINGS_PATH = join(DATA_DIR, 'settings.json');
export const DB_PATH = join(DATA_DIR, 'claude-mem.db');
export const VECTOR_DB_DIR = join(DATA_DIR, 'vector-db');
// Claude integration paths
export const CLAUDE_SETTINGS_PATH = join(CLAUDE_CONFIG_DIR, 'settings.json');