Harbangan

A multi-user Rust proxy gateway. Use OpenAI and Anthropic client libraries with Kiro, Anthropic, OpenAI Codex, GitHub Copilot, and custom providers. Both Proxy-Only Mode and Full Deployment support all providers — a single container is all you need to get started. Per-user auth, content guardrails, and real-time streaming.

Rust Axum 0.7 OpenAI Compatible Anthropic Compatible Streaming Multi-User RBAC Content Guardrails Kiro Multi-Provider

The Name

In Batak Toba culture, the harbangan is the gate of the traditional house — a threshold between the ordered world of family and community, and the open world beyond. In Batak cosmology, the universe is divided into three realms, and every threshold mirrors that cosmic boundary. To cross a harbangan is to move between states of being.

This gateway embodies the same philosophy:

• Cosmic boundary — The harbangan separates the three realms of Batak cosmology. This gateway sits at the boundary between your client code and multiple provider backends (Kiro, Anthropic, OpenAI Codex, Copilot, Custom), translating between OpenAI and Anthropic formats on either side.
• Guardian of social order — The Batak gate enforces Dalihan Na Tolu, the three-pillar kinship system that governs who may enter and how. Harbangan enforces multi-user RBAC: Google SSO, per-user API keys, admin/user roles, and domain allowlisting decide what passes through.
• Ritual transition — Crossing a harbangan signals a shift in status. Requests crossing this gateway undergo their own transformation: format conversion, content guardrails (CEL rules + AWS Bedrock), and provider routing before reaching the other side.
• Openness as moral virtue — In Batak ethics, a gate that is always open signals generosity and communal spirit. This one is open source, and in proxy-only mode, a single container is all you need to open the gate.

Further reading on Batak Toba philosophy: Form and Meaning of Batak Toba House · Dalihan Na Tolu: Vision of Integrity · Batak Cultural Values

How It Works

Harbangan sits between your existing AI client code and multiple provider backends. Send requests in OpenAI or Anthropic format – the gateway translates them on the fly, handles per-user authentication with role-based access control, applies content guardrails, and streams responses back in the format your client expects.

flowchart TD
    subgraph Clients
        OAI["OpenAI Client"]
        ANT["Anthropic Client"]
    end

    subgraph Docker["Docker Compose"]
        subgraph GW["Backend"]
            MW["Middleware\n(CORS, Auth)"]
            GUARD["Guardrails\n(CEL + Bedrock)"]
            CONV["Format Converters"]
            STREAM["Stream Parser"]
        end
    end

    subgraph Providers["Provider Backends"]
        KIRO["Kiro API\n(CodeWhisperer)"]
        ANTHROPIC["Anthropic API"]
        OPENAI["OpenAI API"]
        COPILOT["GitHub Copilot"]
        CUSTOM["Custom Endpoint"]
    end

    subgraph Auth["Authentication"]
        SSO["Google SSO / Password+2FA"]
    end

    OAI --> MW
    ANT --> MW
    MW --> GUARD
    GUARD --> CONV
    CONV --> KIRO
    CONV --> ANTHROPIC
    CONV --> OPENAI
    CONV --> COPILOT
    CONV --> CUSTOM
    KIRO --> STREAM
    ANTHROPIC --> STREAM
    OPENAI --> STREAM
    COPILOT --> STREAM
    CUSTOM --> STREAM
    STREAM --> OAI
    STREAM --> ANT
    GW -.-> SSO

Features

↔ OpenAI Compatible

Drop-in replacement for the OpenAI API. Use any OpenAI client library -- just point it at the gateway.

↔ Anthropic Compatible

Full support for the Anthropic Messages API, including system prompts, tool use, and content blocks.

◆ Multi-Provider

Connect to Kiro (AWS CodeWhisperer), Anthropic, OpenAI Codex, GitHub Copilot, and custom endpoints with per-user credentials and automatic token refresh. All providers work in both deployment modes.

∼ Real-time Streaming

Parses provider-specific binary formats and converts to standard SSE in real time. Supports AWS Event Stream and chunked transfer.

⚫ Multi-User RBAC

Google SSO or password + TOTP 2FA for web UI, per-user API keys for programmatic access. Admin and User roles with domain allowlisting.

✧ Extended Thinking

Extracts reasoning blocks from model responses and maps them to native thinking/reasoning content fields.

◑ Content Guardrails

AWS Bedrock-powered content validation with CEL rule engine. Validate input and output with configurable sampling and fail-open design.

▦ Web Dashboard

Built-in CRT-styled web UI for configuration, user management, API keys, provider setup, and usage tracking.

▶ Proxy-Only Mode

Single-container deployment with no database or Web UI. Supports all providers via environment variables. AWS SSO device code flow for Kiro on first start; credentials cached to a Docker volume for automatic restarts.

Quick Start

# Clone and configure
git clone https://github.com/if414013/harbangan.git
cd harbangan
cp .env.example .env
# Edit .env — set POSTGRES_PASSWORD (and optionally INITIAL_ADMIN_* for password auth)

# Start all services
docker compose up -d --build

Then open https://your-domain.com/_ui/ to complete setup via Google SSO.

For proxy-only mode (single container, no database):

cp .env.proxy.example .env.proxy
# Edit .env.proxy and set PROXY_API_KEY (min 16 chars)
docker compose -f docker-compose.gateway.yml --env-file .env.proxy up -d

On first start, the container prints an AWS device code URL — open it in a browser to authenticate with Kiro. Credentials are cached to a Docker volume for automatic restarts.

Documentation

> Getting Started # Architecture / API Reference ~ Client Setup $ Deployment ? Troubleshooting

API Endpoints

Endpoint	Method	Description
/v1/chat/completions	POST	OpenAI-compatible chat completions
/v1/messages	POST	Anthropic-compatible messages
/v1/models	GET	List available models
/health	GET	Health check
/_ui/	GET	Web dashboard