janus-ai 0.3.2

The two-faced AI routing gateway

Janus

The two-faced gateway for AI coding tools. Janus sits at the threshold of every AI call — facing the developer on one side and every provider on the other.

Janus is a local-first, single-user AI routing gateway. It exposes OpenAI/Anthropic/Gemini-compatible HTTP endpoints that your coding tools (Claude Code, Codex, Cursor, Cline, ...) talk to, then translates and routes each request to 40+ AI providers — without either side needing to know the other exists.

First-time setup

Janus needs Python 3.11+. Everything lives under ~/.janus/ — a seed config.yaml and a SQLite database (janus.db) that becomes the source of truth after the first startup.

1. Install

From PyPI (recommended):

pip install janus-ai

From source (development):

git clone https://github.com/amanverasia/Janus.git
cd Janus
python -m venv .venv
source .venv/bin/activate   # Windows: .venv\Scripts\activate
pip install -e ".[dev]"

2. Create config

janus config-init

This writes ~/.janus/config.yaml. Open it and add at least one provider with your API keys. Environment variables in ${VAR} form are resolved at startup:

export OPENAI_API_KEY=sk-...
export ANTHROPIC_API_KEY=sk-ant-...

Example provider block:

providers:
  - id: openai
    prefix: openai
    api_type: openai_compat
    base_url: https://api.openai.com/v1
    api_key: ${OPENAI_API_KEY}
    models: [gpt-4o, gpt-4o-mini]

You can also add providers later from the dashboard — no restart required.

3. Start the server

janus serve --port 20128

For access from other machines on your LAN or Tailscale:

janus serve --host 0.0.0.0 --port 20128

Janus serves plain HTTP only. Use http://, not https://, unless you put a reverse proxy with TLS in front.

4. Verify

curl http://localhost:20128/v1/health
# {"status":"ok"}

Open the dashboard at http://localhost:20128/dashboard. The root URL / redirects there.

5. Configure via dashboard

On first startup, Janus imports providers, combos, token_savers, and pricing from YAML into SQLite. After that, the database is authoritative — editing YAML and restarting will not re-apply changes. Use the dashboard instead.

Step	Where	What
Add providers	Providers	Pick from the catalog or add custom; fetch models, test connection
Create a client key	API Keys	sk-janus-... shown once — save it
Enable auth	Settings	Toggle Require API key (recommended for remote access)
Set dashboard login	Settings → Dashboard Login	Username + password for remote browser sign-in
Connect your tools	Tool Setup	Copy-paste env vars for Claude Code, Codex, Cursor, Cline

Dashboard access rules:

• localhost — no sign-in required
• Remote (LAN, Tailscale, Docker on 0.0.0.0) — sign in at /dashboard/login with your dashboard username/password or a Janus API key

Create a key from the CLI instead:

janus keys create --name "my-laptop"

6. Send a test request

curl http://localhost:20128/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/gpt-4o",
    "messages": [{"role": "user", "content": "Hello!"}],
    "max_tokens": 50
  }'

List registered models:

curl http://localhost:20128/v1/models

7. Point your coding tool at Janus

Claude Code / Anthropic tools:

export ANTHROPIC_BASE_URL=http://localhost:20128/v1
export ANTHROPIC_API_KEY=sk-janus-yourkey   # if require_api_key is on

OpenAI-compatible tools (Codex, Cursor, Cline, etc.):

export OPENAI_BASE_URL=http://localhost:20128/v1
export OPENAI_API_KEY=sk-janus-yourkey      # if require_api_key is on

Use prefix/model in requests (e.g. openai/gpt-4o, anthropic/claude-sonnet-4-20250514) or a combo name like best-effort.

📚 Documentation · Contributing · Changelog

Docker

mkdir -p janus-data
janus config-init --path janus-data/config.yaml
# Edit janus-data/config.yaml — add providers and ${ENV_VAR} keys

# Optional: pass API keys via .env in the repo root
echo 'OPENAI_API_KEY=sk-...' >> .env

docker compose up -d

The image binds to 0.0.0.0:20128. SQLite and config persist in ./janus-data/. After first startup, manage providers and settings from the dashboard — not by editing YAML alone.

Remote dashboard: enable Require API key in Settings, create a Janus API key, and set a dashboard username/password under Dashboard Login.

curl http://localhost:20128/v1/health
open http://localhost:20128/dashboard    # macOS; or visit in your browser

Configuration

Janus reads YAML from ~/.janus/config.yaml (or --config) with ${ENV_VAR} token resolution. Generate a template with janus config-init.

On first startup only, YAML seeds the SQLite database. Subsequent changes should be made via the dashboard or Export Config / Reset to Defaults on the Settings page.

server:
  port: 20128
  host: 127.0.0.1
  require_api_key: false

providers:
  - id: openai
    prefix: openai
    api_type: openai_compat
    base_url: https://api.openai.com/v1
    api_key: ${OPENAI_API_KEY}
    models: [gpt-4o, gpt-4o-mini, o3, o4-mini]

  - id: anthropic
    prefix: anthropic
    api_type: anthropic
    base_url: https://api.anthropic.com
    api_key: ${ANTHROPIC_API_KEY}
    models: [claude-sonnet-4-20250514, claude-opus-4-20250514]

combos:
  - name: best-effort
    models: [anthropic/claude-sonnet-4-20250514, openai/gpt-4o]

Supported Provider Types

api_type	Use For
openai_compat	Any OpenAI-compatible API (OpenAI, Groq, Together, DeepSeek, OpenRouter, Mistral, Fireworks, Perplexity, xAI, ...)
anthropic	Direct Anthropic API
gemini	Direct Google Gemini API
opencode_free	OpenCode Zen free tier

Known Provider Base URLs

Provider	base_url
OpenAI	https://api.openai.com/v1
Groq	https://api.groq.com/openai/v1
Together AI	https://api.together.xyz/v1
DeepSeek	https://api.deepseek.com/v1
OpenRouter	https://openrouter.ai/api/v1
Mistral	https://api.mistral.ai/v1
Fireworks	https://api.fireworks.ai/inference/v1
Perplexity	https://api.perplexity.ai
xAI (Grok)	https://api.x.ai/v1
Qwen/DashScope	https://dashscope.aliyuncs.com/compatible-mode/v1

Client Setup

See step 7 in First-time setup for the basics. The dashboard Tool Setup page (/dashboard/tools) generates copy-paste env vars for your exact server URL and auth settings.

Claude Code / Anthropic tools:

export ANTHROPIC_BASE_URL=http://localhost:20128/v1

OpenAI tools (Codex, Cursor, etc.):

export OPENAI_BASE_URL=http://localhost:20128/v1
export OPENAI_API_KEY=sk-janus-yourkey  # if require_api_key is on

Features

• Fallback routing — multi-account rotation with cooldowns (429->60s, 5xx->30s, auth->300s, network->15s)
• Combos — named ordered model sequences (e.g., "model": "best-effort")
• Token savers — RTK compression (default ON), Caveman terse prompt, Ponytail lazy-dev prompt
• Budgets — daily spending limits per API key or global, with warn/block thresholds
• Analytics — cost tracking, spend trends, success rates, per-model/provider/key breakdowns
• Pricing — 28 builtin model prices, YAML-overridable, cache token rates
• Dashboard — HTMX UI at /dashboard with charts, budget management, usage stats, and remote username/password login
• Upstream key inventory — validate, monitor, and route through a multi-key pool for 29 providers (/dashboard/inventory)

Upstream Key Inventory

Built-in dashboard for upstream provider API keys: health checks, credit tracking, and automatic routing through the best available key.

Dashboard: http://127.0.0.1:20128/dashboard/inventory

• Overview stats, paginated/sortable keys table, key detail modal, best-keys widget
• Add keys, bulk submit, import from Dashboard export JSON, re-identify misclassified keys
• Encryption at rest; routable keys wired into gateway fallback rotation
• Background recheck scheduler (twice daily by default)

Variable	Purpose
INVENTORY_ENCRYPTION_KEY	Fernet key for encrypting upstream keys at rest
INVENTORY_PUSH_TOKEN	Auth token for POST /dashboard/api/inventory/push
INVENTORY_SCHEDULER_ENABLED	Set to false to disable background rechecks (default: true)

janus inventory generate-encryption-key          # create Fernet key
janus inventory migrate export.json --verify     # import Dashboard export + summary
janus inventory verify                           # cutover verification summary
janus inventory encrypt-keys                       # encrypt plaintext keys in DB

CLI Reference

Command	Description
janus serve	Start the gateway server
janus config-init	Generate default config YAML
janus config-path	Print config file path
janus keys create/list/revoke	Manage API keys
janus usage stats/cost/by-key	Usage and cost reports
janus budgets list/set/delete	Manage spending budgets
janus pricing list/show	View model pricing
janus inventory migrate/verify/encrypt-keys/generate-encryption-key	Upstream key inventory and cutover

Development

git clone https://github.com/amanverasia/Janus.git
cd Janus
python -m venv .venv
pip install -e ".[dev]"

# Run tests
.venv/bin/python -m pytest

# Lint + typecheck
.venv/bin/ruff check src/janus/ tests/
.venv/bin/mypy src/janus/

# Start dev server
.venv/bin/janus serve --port 20128 --reload

Tech Stack

Python 3.11+ / FastAPI / httpx / Pydantic v2 / aiosqlite / Jinja2 / HTMX / Chart.js

License

GPL-3.0 © 2026 Aman Verasia