Synthetic (Privacy-First Free API)

Synthetic runs open-source AI models in private, secure datacenters with both Anthropic-compatible and OpenAI-compatible APIs. 19+ models including MiniMax M2.5, DeepSeek V3.2, Kimi K2, Qwen3 VL, and GLM 4.7 — all at zero cost with a flat prompt-based quota system.

Synthetic is a privacy-first AI inference platform that runs open-source models in private, secure datacenters. The platform's core promise is simple: they never train on your data and never store API prompts or completions. This makes Synthetic uniquely appealing for developers who want access to capable open-source models without sacrificing data privacy. The platform provides dual API compatibility — both Anthropic Messages API and OpenAI Chat Completions API endpoints — meaning it works seamlessly with tools designed for either format. For OpenClaw, Synthetic is configured as an anthropic-messages provider, connecting through the /anthropic endpoint. The model catalog includes 19+ open-source models spanning the best of Chinese and international AI: MiniMax M2.5, DeepSeek V3.2, Kimi K2 Thinking, GLM 4.7, Qwen3 VL 235B, Qwen3 Coder 480B, Llama 3.3, and more. What makes Synthetic stand out is its pricing model: all models consume from a flat prompt-based quota (1.0 prompt per request regardless of model), making cost predictable and simple. There's no per-token billing — whether you use DeepSeek V3.2 or MiniMax M2.5, it's the same quota usage. The platform is GDPR-compliant with zero-retention data policies. Synthetic gained traction in the coding agent community, particularly with Cline and OpenCode users who needed affordable access to frontier open-source models. The founder actively engages with the community, and the platform has been integrated into several popular AI coding tools. For OpenClaw, Synthetic is an excellent free provider for heartbeats, cron jobs, and daily tasks that don't require proprietary model quality. The platform also hosts vision-capable models (Qwen3 VL 235B) and thinking-capable models (Kimi K2 Thinking), providing a broad capability set at zero cost. Models are hosted in US datacenters with providers following zero-retention policies.

Tags: anthropic-compatible, openai-compatible, free, open-source, privacy-first, zero-retention, coding-agent, multi-model

Use Cases

Free AI inference for OpenClaw heartbeats, cron jobs, and background tasks
Privacy-first alternative to direct cloud providers — zero data retention
Access to frontier open-source models (DeepSeek, Kimi, MiniMax, Qwen) without API key management for each
Coding agent workflows with Cline, OpenCode, or OpenClaw using free models
Vision tasks with Qwen3 VL at zero cost
Reasoning tasks with Kimi K2 Thinking for complex problem-solving

Tips

Use the Anthropic endpoint (/anthropic) for OpenClaw's anthropic-messages provider type, or /openai/v1 for openai-completions.
DeepSeek V3.2 on Synthetic is a great daily driver for OpenClaw heartbeats and cron jobs — free with solid quality.
Kimi K2 Thinking is the best free reasoning model on the platform — use it for complex tasks requiring step-by-step thinking.
Pair Synthetic as a free fallback alongside a paid provider like Anthropic. Switch with /model synthetic/hf:deepseek-ai/DeepSeek-V3.2.
Qwen3 VL 235B provides free vision capabilities — useful for screenshot analysis and image-based workflows.
Check dev.synthetic.new for the full model catalog — more models than what's listed in the default OpenClaw config.

Known Issues & Gotchas

All models consume the same flat quota (1.0 prompt per request) regardless of model size — a simple Kimi query costs the same as a large MiniMax M2.5 generation.
Quota is prompt-based, not token-based. Heavy users may hit limits faster than expected if making many small requests.
Only open-source models are available. No Claude, GPT, or Gemini — use direct providers or Venice for proprietary models.
Uses Anthropic Messages API format by default. If your tool expects OpenAI format, use the /openai/v1 endpoint instead.
Model availability depends on Synthetic's hosting capacity. Some models may have higher latency during peak usage.
Vision support is limited to specific models (Qwen3 VL). Not all models support all features.
Being a newer platform, documentation and error messages may be less polished than established providers.

Alternatives

OpenRouter (free models)
Hugging Face Inference
Together AI
Venice AI (Private mode)

Community Feedback

All models on Synthetic consume the same quota (1.0 prompt per request). Strange that Kimi K2.5 and smaller models cost the same, but at least it's predictable.
— Reddit r/vibecoding

I'm the founder of Synthetic: we run most major open-source coding models like Kimi K2, GLM-4.5, Qwen3 Coder 480B, and have a flat prompt quota. Zero retention, GDPR compliant.
— GitHub Cline Discussion

Synthetic.new is great for trying out open-source models without any setup. The Anthropic-compatible API is a nice touch for tools that only speak Anthropic format.
— Reddit r/LocalLLaMA

Frequently Asked Questions

Is Synthetic really free?

Yes, all models on Synthetic are free to use. The platform uses a flat prompt-based quota system where each request consumes 1.0 prompt regardless of which model you use or how many tokens are generated. There are no hidden per-token charges.

Does Synthetic train on my data?

No. Synthetic has a strict zero-retention policy — they never store API prompts or completions and never train on your data. The platform is GDPR-compliant and designed as a privacy-first inference service.

What API format does Synthetic use?

Synthetic supports both Anthropic Messages API (/anthropic endpoint) and OpenAI Chat Completions API (/openai/v1 endpoint). For OpenClaw, it's typically configured as an anthropic-messages provider.

Why does every model cost the same quota on Synthetic?

Synthetic uses a flat prompt-based quota system where each request costs 1.0 prompt regardless of model. This simplifies pricing but means a quick query to a small model costs the same as a long generation from a large model.

Can I use Synthetic with tools other than OpenClaw?

Yes. Synthetic works with any tool that supports OpenAI or Anthropic API formats, including Cline, Continue, TypingMind, and other coding agents. The founder has actively integrated with the Cline community.

Which Synthetic model should I use for coding?

For general coding tasks, DeepSeek V3.2 or MiniMax M2.5 are solid choices. For complex reasoning that benefits from thinking, use Kimi K2 Thinking. For code that needs vision (screenshot analysis), use Qwen3 VL 235B.

Configuration Examples

Basic Synthetic setup (Anthropic API)

providers:
  synthetic:
    apiKey: your-synthetic-api-key
    model: synthetic/hf:deepseek-ai/DeepSeek-V3.2

Synthetic as free fallback

providers:
  anthropic:
    apiKey: sk-ant-xxxxx
    model: anthropic/claude-sonnet-4-6
  synthetic:
    apiKey: your-synthetic-api-key
    model: synthetic/hf:MiniMaxAI/MiniMax-M2.5
    # Free fallback: /model synthetic/hf:MiniMaxAI/MiniMax-M2.5

Synthetic with thinking model

providers:
  synthetic:
    apiKey: your-synthetic-api-key
    model: synthetic/hf:moonshotai/Kimi-K2-Thinking
    # Free reasoning with step-by-step thinking