The Problem Every AI API gateway I tried added an invisible margin. OpenRouter, the biggest player, quietly marks up every model. You pay more than the provider charges, and you don't even know how much. The Solution I built aipossword.cn — an open-source AI API gateway with zero markup pricing. 18 models across DeepSeek, Claude, Qwen Zero markup — you pay exactly what providers charge One endpoint — OpenAI compatible, one line code change Open source — AGPLv3, built on New API (18k+ GitHub star