Overview

Cumbersome is a free native LLM API client from Folding Sky that connects directly to OpenAI, Anthropic, OpenRouter, Google AI Studio, Z.ai, Vercel AI Gateway, and any OpenAI-compatible endpoint including local Ollama servers. Built for people who want to know exactly which model answered them, it exposes model selection, sampling parameters, token counts, and prompt caching instead of silently routing requests to cheaper models. Its standout Face/Off mode streams one prompt to three models in parallel for head-to-head comparison, with an optional judging pass. Conversations, folders, and system-message presets sync over iCloud, API keys live in the Keychain, and there is no Folding Sky server in the middle — you pay your providers directly and nothing else.

Pricing: Free (bring your own API keys)

Minimum macOS: 15.0 (Sequoia)

Architecture: Apple Silicon, Intel

Key Features

Bring your own API keys - direct connections to OpenAI, Anthropic, OpenRouter, Google AI Studio, Z.ai, and Vercel AI Gateway
Any OpenAI-compatible endpoint works, including self-hosted and local Ollama servers
Face/Off mode streams a single prompt to three models in parallel, with an optional judging pass
Explicit model selection per conversation - no hidden routing to cheaper models
Full parameter control with custom API parameters, system instructions, and token inspection
Prompt caching inspection and conversation compaction to keep context costs down
MCP tool support over remote HTTPS servers
Built-in headless browser for local web automation and research
Web search, reasoning, and image generation tools
Python data analysis plus in-app JavaScript and HTML execution with live preview
Markdown and LaTeX rendering with rich in-place message editing
Synced folders and reusable system-message presets for organizing conversations
iCloud sync across Mac, iPhone, iPad, and Vision Pro with API keys stored in the Keychain
No Folding Sky backend - requests go straight from your device to the provider
Data export for full conversation transcripts
Siri and Shortcuts integration
Accessibility support with VoiceOver, Dynamic Type, and full keyboard navigation
Theme options and English plus Simplified Chinese localization
Completely free with no subscriptions or in-app purchases