Test any model. Right from your browser.
An interactive playground for 240+ models. Chat, tweak parameters, compare responses, watch cost + latency in real time, and export integration code in 15 languages — without writing a single line of integration code.
Active session
- Server-side key storage
- 0
- Models you can test
- 240+
- Streaming + non-stream
- Both
- Code-gen languages
- 15
Your key lives in sessionStorage only
Alibaba US, OpenAI, AWS Bedrock, Azure Foundry, Google Vertex AI & Anthropic
Real-time tokens or full-response mode
8 SDKs + 7 frameworks
Chat, swap models, watch the cost — per message.
The customer reports a billing mismatch after upgrading mid-cycle. Suggested tone: empathetic and direct. Confirm the proration math first, then offer the credit…
218 tokens · $0.0008 · TTFT 120 ms
The same path as production: no sandboxing
Every playground request uses your real virtual key and traverses the same auth, credit-reserve, guardrail, and provider chain as your SDK. No fake responses, no mock providers, no silent shortcuts.
Playground request flow
Paste key
sessionStorage only
Cleared on tab close; never sent to nRouter servers.
Frontend (Next.js)
Cloud Run
Forwards request with the user-pasted virtual key.
Nemo Backend
nRouter
Auth, credit reserve, guardrails: same as production.
Nemo routing core
Routing engine
Cost & usage tracking, rate limits, provider fallback.
Provider
Vertex / Anthropic / OpenAI
Real LLM call. No sandboxing, no fake responses.
Your key never leaves the browser
Virtual key only
sessionStorage scope, master key isolated
Every LLM call (playground, SDK, or production API) must authenticate with a virtual key (sk-nemo-...). The playground enforces this by holding the key only in browser sessionStorage. Refresh the tab and you re-paste; close the tab and the key is gone.
- Browser sessionStorage scope (cleared on tab close)
- Never POSTed to nRouter for persistent storage
- Master key never enters the playground flow
- Per-key spend, RPM, TPM enforced exactly as in production
Storage + auth posture
Full playground reference: chat, streaming, parameters, code-gen
- Full chat interface
- System prompts, multi-turn history, model swap mid-conversation, and a side-by-side compare model. Latest-response tokens, cost, and latency in the Metrics tab. Cancel mid-stream to stop token spend.
- Streaming + non-streaming
- SSE streaming (default) with a live token-rate counter, or full-response mode for batch / eval workflows. Identical billing. Both modes use the same pipeline.
- Parameter pass-through
- temperature, top_p, max_tokens, and a system prompt. Every parameter you set is forwarded as-is to the provider, with no silent defaults.
- Code generation — 15 languages
- Python (native + OpenAI-compatible), Node.js, Go, Ruby, Java, PHP, cURL, plus 7 frameworks (LangChain, LlamaIndex, CrewAI, AutoGen, Google ADK, more). Drawn from the canonical SDK examples package: embeds your exact prompt + parameter set.
- Error surfacing
- 402 (out of credits) surfaced with an inline top-up CTA. 429 with a retry-after timer. Provider 4xx errors shown verbatim. Streaming aborts cleanly on mid-stream errors.
- Model catalog access
- Every model in your account, one dropdown. Filter by capability (chat, vision, embedding, image, video), provider, latency budget, or cost ceiling. Switch models mid-conversation; price-per-1k tokens visible per model.
Common playground questions
Is the playground free?
Yes. There is no additional fee for using the playground itself. You pay only for the tokens consumed at the same per-token rate as API calls. Cost and latency are displayed in real time as you test, so there are no surprises.
What models can I test?
All 240+ models live on nRouter today across Anthropic (Claude), Google Vertex AI (Gemini, Imagen, Veo, embeddings), and OpenAI (GPT, o-series). Every model available through the nRouter API is available in the playground. AWS Bedrock (Claude, Llama, DeepSeek, Nova, Qwen) is live too.
Where is my API key stored?
Browser sessionStorage only. The key is cleared on tab close, never sent to nRouter servers for storage, and never persisted across sessions. This is a critical security requirement: all LLM calls must use virtual keys (not master keys), and the playground deliberately holds zero server-side state.
Does the playground support streaming?
Yes. Server-sent-events streaming is the default. You see tokens appear as the model generates them, with a live token-rate counter. Cancel mid-stream to save on cost. A non-streaming mode is also available for batch and eval workflows.
Can I export code from the playground?
Yes. Auto-generated integration code in 15 languages: Python (native + OpenAI-compatible), Node.js, Go, PHP, Java, Ruby, cURL, plus 7 frameworks including LangChain, LlamaIndex, CrewAI, AutoGen, and Google ADK. The generated code uses your exact prompt, model selection, and parameter configuration, ready to paste into your project.
240+ models · 15 code generators · 0 server-side keys
From idea to working prototype in under a minute
No SDK to install, no provider account to manage. Sign up, paste your virtual key, start chatting.