Cumbersome: LLM AI API Client

IMPORTANT: Requires your own API keys from OpenAI, Anthropic, OpenRouter, Google AI Studio, Z.ai, or Vercel AI Gateway, or your own OpenAI-compatible endpoint.

I built Cumbersome because consumer AI apps kept dumbing things down. Cumbersome is the manual transmission of AI apps: more complex, but with far greater control.

WHY I BUILT THIS

Consumer AI providers like ChatGPT and Claude route requests to cheaper models to keep their costs down. They charge monthly subscriptions whether you use them once or a thousand times. They hide the technical controls that let you tune how models respond. And they lock you into one provider.

I wanted an AI client that connects directly to AI provider APIs. I wanted to pick exactly which model I use and know I'm getting it. I wanted to compare different models on the same prompt. I wanted to pay per use instead of subscriptions. So I built it.

SUPPORTED PROVIDERS

Bring your API keys, or add your own OpenAI-compatible endpoint, for any of the following:

— ChatGPT / OpenAI
— Claude / Anthropic
— Gemini / Google AI Studio
— OpenRouter multi-provider
— Vercel AI Gateway multi-provider
— Z.ai
— OpenAI-compatible custom endpoints (beta), including Ollama, Azure, LM Studio, Groq, Together, and self-hosted backends

WHAT YOU GET

— A simple API client.
— Switch providers or AI models mid-conversation.
— iCloud sync across devices. (Nothing saved to our servers.)
— Face/Off Mode. Three responses generated at once. An AI judge picks the best.
— Extended thinking. Turn on model reasoning for OpenAI and OpenRouter.
— Full parameter control. Temperature, tokens, system prompts. API playground controls on your phone.
— Concurrent chats. Multiple conversations streaming in parallel.
— Edit any message. Remove tangents, fix mistakes, reshape your conversation history.
— Rich content. Markdown, LaTeX math, code blocks with copy, attachments.
— Local browser tool use for OpenAI (beta). Open pages with your own device browser context for better compatibility.
— Export everything. Copy conversations, export JSON, or share deep links to specific chats.
— Collapse long messages. Fold them to keep your place in deep conversations.
— Siri and Shortcuts. Ask questions hands-free or build automations in the Shortcuts app.
— Accessible. VoiceOver, Dynamic Type, Voice Control, full keyboard navigation,