OpenChat

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Your AI assistant. Your rules. Your experience.

Today you can access models that answer your questions — but the experience is always someone else's. Fixed UI. Fixed prompts. Fixed personality. OpenChat is different: it gives you full ownership of the chat experience, running on whatever model you choose, deployed wherever you want, shaped exactly how you want it.

OpenChat is a free, open source chat UI with persistent session management, multi-provider LLM support, and cited sources built in. Bring your own model — Groq, OpenAI, Anthropic, Google Gemini, or a local Ollama instance — and get a production-quality research assistant that you fully control. Configure the personality, swap the model, deploy to your own infrastructure. No locked-in subscriptions, no data sent to third parties you didn't choose.

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How it works

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Screenshots

Overview

Chat — cited sources

Settings

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Why OpenChat?

Most chat products give you a great experience — until they change it. You have no say in the model, the personality, or where your conversations go. OpenChat flips that:

• You pick the model. OpenAI, Anthropic, Gemini, Ollama, Groq — swap with one env var.
• You own the experience. Override the system prompt to tune the AI's personality, tone, and focus.
• You own your data. Conversations live in your own PostgreSQL database. Nothing leaves your infrastructure.
• You control the deployment. Run locally, on Docker, or in the cloud. SAP BTP Cloud Foundry guide included.

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Features

• Multi-provider LLM support — Groq, OpenAI, Anthropic, Google Gemini, Ollama — zero code changes to switch
• Persistent sessions — full chat history stored in PostgreSQL; survives restarts and reloads
• Session sidebar — browse, switch, and create conversations from the sidebar
• Real-time streaming — responses stream live with a typing cursor indicator
• Cited sources — every AI response includes a collapsible sources banner; no unverified claims
• Configurable personality — override the default system prompt via LLM_SYSTEM_PROMPT
• Dark-mode UI — clean, minimal interface built with Next.js 16 and Tailwind CSS v4
• Cloud Foundry ready — manifest and deployment guide for SAP BTP

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Quick Start

Prerequisites

• Node.js ≥ 20
• PostgreSQL ≥ 14 (running locally or via Docker)
• An API key for your chosen LLM provider

1. Clone and install

git clone https://github.com/SentorLabs/openchat.git
cd openchat
npm install

2. Configure environment

Copy the example and fill in your values:

cp .env.example .env.local

# Choose your provider: groq | openai | anthropic | gemini | ollama
LLM_PROVIDER=groq

# Model name for your chosen provider
LLM_MODEL=llama-3.3-70b-versatile

# API key (not required for Ollama)
LLM_API_KEY=your_api_key_here

# PostgreSQL connection string
DATABASE_URL=postgresql://postgres:password@localhost:5432/openchat

# Optional: override the default system prompt
# LLM_SYSTEM_PROMPT="You are a helpful assistant focused on software engineering."

3. Create the database

createdb openchat

OpenChat automatically creates the required tables on first run — no manual migrations needed.

4. Run

npm run dev

Open http://localhost:3000.

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LLM Provider Configuration

Provider	LLM_PROVIDER	Example LLM_MODEL	Key required
Groq	groq	llama-3.3-70b-versatile	Yes
OpenAI	openai	gpt-4o	Yes
Anthropic	anthropic	claude-opus-4-6	Yes
Google Gemini	gemini	gemini-2.0-flash	Yes
Ollama (local)	ollama	llama3.2	No

For Ollama, also set OLLAMA_BASE_URL if your instance isn't on http://localhost:11434.

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Environment Variables

Variable	Required	Default	Description
LLM_PROVIDER	Yes	groq	LLM backend to use
LLM_MODEL	Yes	—	Model name for your provider
LLM_API_KEY	Yes*	—	API key (*not needed for Ollama)
DATABASE_URL	Yes	—	PostgreSQL connection string
LLM_SYSTEM_PROMPT	No	Built-in	Override the AI's system prompt
OLLAMA_BASE_URL	No	http://localhost:11434	Ollama base URL

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Customising the AI Personality

The most powerful feature of OpenChat is the ability to define exactly what kind of assistant you want. Set LLM_SYSTEM_PROMPT to anything:

# A focused coding assistant
LLM_SYSTEM_PROMPT="You are a senior software engineer. Answer only technical questions with code examples. Be concise."

# A research assistant with strict citation rules
LLM_SYSTEM_PROMPT="You are a research analyst. Always cite primary sources. Never state unverified facts."

# A customer support agent for your product
LLM_SYSTEM_PROMPT="You are a support agent for Acme Corp. Only answer questions about our product. Be friendly and brief."

No redeploy needed — just update the env var and restart.

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Deployment

Docker (local or server)

docker build -t openchat .
docker run -p 3000:3000 \
  -e LLM_PROVIDER=groq \
  -e LLM_MODEL=llama-3.3-70b-versatile \
  -e LLM_API_KEY=your_key \
  -e DATABASE_URL=postgresql://... \
  openchat

SAP BTP Cloud Foundry

See DEPLOY.md for the complete step-by-step guide including PostgreSQL deployment as a CF app and network policy configuration.

Quick summary:

# 1. Push Postgres as an internal CF app
cf push -f deploy-postgres.yml

# 2. Create the service binding
cf create-user-provided-service openchat-db -p '{"uri":"postgresql://..."}'

# 3. Push OpenChat
cf push -f manifest.yml

# 4. Network policy + env vars
cf add-network-policy openchat --destination-app postgres-db --port 5432 --protocol tcp
cf set-env openchat LLM_PROVIDER groq
cf set-env openchat LLM_MODEL llama-3.3-70b-versatile
cf set-env openchat LLM_API_KEY your_key
cf restage openchat

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Project Structure

src/
├── app/
│   ├── api/
│   │   ├── chat/route.ts          # Streaming chat endpoint
│   │   ├── sessions/route.ts      # List & create sessions
│   │   └── sessions/[id]/
│   │       └── messages/route.ts  # Load session messages
│   ├── about/page.tsx             # About page
│   ├── releases/page.tsx          # Changelog
│   ├── page.tsx                   # Main chat UI
│   ├── layout.tsx
│   └── globals.css
├── components/
│   ├── Nav.tsx                    # Top navigation bar
│   ├── Sidebar.tsx                # Session list panel
│   └── SourcesBanner.tsx         # Collapsible sources banner
└── lib/
    ├── db.ts                      # PostgreSQL pool + schema init
    ├── llm.ts                     # Unified multi-provider LLM adapter
    ├── sources.ts                 # Parse & strip [SOURCES] blocks
    └── types.ts                   # Shared TypeScript interfaces

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Contributing

Contributions are welcome and appreciated. OpenChat is built for the community — if you run your own AI assistant, you know what's missing.

Getting started

1. Fork the repository
2. Create a feature branch: git checkout -b feat/your-feature
3. Make your changes and add tests where relevant
4. Ensure the build passes: npm run build
5. Open a pull request with a clear description of the change

What we're looking for

• New LLM providers — add support for Mistral, Cohere, Together AI, etc.
• UI improvements — message formatting, markdown rendering, code highlighting
• Export features — download chat history as PDF or Markdown
• Auth support — multi-user mode with authentication
• Docker Compose — a ready-to-run compose file with Postgres included
• Bug fixes — check the issues tab

Code style

• TypeScript strict mode — no any without a comment explaining why
• Keep components focused — one responsibility per file
• Environment-driven configuration — no hardcoded credentials or model names
• Test your provider integration locally before submitting

Reporting issues

Please open an issue with:

• Steps to reproduce
• Expected vs actual behaviour
• Your LLM_PROVIDER and Node.js version
• Any relevant log output

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Database Schema

OpenChat auto-creates these tables on first run:

CREATE TABLE sessions (
  id         UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  title      TEXT NOT NULL DEFAULT 'New Chat',
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE TABLE messages (
  id         UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  session_id UUID NOT NULL REFERENCES sessions(id) ON DELETE CASCADE,
  role       TEXT NOT NULL CHECK (role IN ('user','assistant')),
  content    TEXT NOT NULL,
  sources    JSONB,
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

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Tech Stack

Layer	Technology
Framework	Next.js 16 (App Router)
Language	TypeScript 5
Styling	Tailwind CSS v4
Database	PostgreSQL (via node-postgres)
LLM providers	Groq, OpenAI, Anthropic, Google Gemini, Ollama
Runtime	Node.js ≥ 20

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License

Apache 2.0 — see LICENSE for details.

You are free to use, modify, and distribute OpenChat for any purpose, including commercial use. If you distribute derivative works, include a copy of the license and preserve attribution notices. If you build something great on top of it, we'd love to hear about it.

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Acknowledgements

OpenChat is a community project. Thank you to everyone who has contributed ideas, bug reports, and code. Built with Next.js, Tailwind CSS, and the open source AI ecosystem.

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Take control of your AI experience.