Polylog

Multi-agent chatbot platform with RAG, flow builder and widget

A multi-tenant, multi-agent chatbot platform. Clients sign up, upload knowledge, design conversation flows visually, embed a widget on their site, and route captured leads to Telegram, WhatsApp, email, or a webhook — all from one dashboard.

Sector: AI · SaaS
Stack: Next.js 15 · FastAPI · Elasticsearch · Stripe

In numbers

Languages (cross-lingual RAG): 100+
Dockerized services: 9
Tenant + multi-agent: Multi
Grounded, cited answers: RAG

01 — About the Project

One widget, many agents, every language

Polylog lets a business stand up a grounded, on-brand chatbot in minutes: upload PDFs, crawl a site, or paste text, design the conversation visually, and drop one script tag on the page. Every row and query is scoped by tenant, and a single widget can host several agents — say a travel consultant and a sales consultant side by side.

Answers are retrieved with hybrid search (BM25 + dense vectors + RRF) over Elasticsearch, reranked by a cross-encoder, with bge-m3 embeddings that work across 100+ languages. A grounding verifier checks every answer against the retrieved sources and blocks ungrounded claims before the visitor ever sees them.

02 — The Challenge

Ship a SaaS where non-technical clients build a trustworthy chatbot themselves — accurate, multilingual, and safe from hallucinations — while keeping every tenant's data strictly isolated and the whole thing self-hostable.

03 — The Solution

A FastAPI backend with tenant-scoped Postgres + Elasticsearch, a Next.js dashboard with an @xyflow visual flow builder, a Shadow-DOM widget that streams over SSE, Stripe billing with server-side limits, and a grounding/citation trust layer. Nine services orchestrated with Docker Compose.

04 — Key Features

Everything you need in one platform

01
Hybrid RAG knowledge
Upload files, crawl URLs, or paste text. BM25 + dense vectors + RRF on Elasticsearch, cross-encoder rerank, bge-m3 cross-lingual embeddings.
02
Visual flow builder
Message, choice, capture, condition, API-call, AI-answer, handoff and intent nodes on an @xyflow canvas, with a live test-run.
03
Embeddable widget
Shadow-DOM isolated, streams answers over SSE, renders choice buttons, lead forms, citations, and product cards — localized to the visitor.
04
Multi-tenant + multi-agent
Every row and query scoped by tenant_id; knowledge and flows scoped by agent_id. One widget can host several agents.
05
Channels & leads
Route captured leads to Telegram, WhatsApp, email, or webhook — credentials encrypted at rest, never in env.
06
Grounding trust layer
A verifier checks each answer against retrieved chunks and blocks ungrounded claims, with inline citations and a guardrail audit log.