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AI Providers & Models
There are no API keys to manage. You pick a provider and model for each AI capability in Settings, and FeynmanLM bills the usage to your prepaid balance at that provider's own API list price plus a 15% margin — metered on the exact cost the provider reports, not an estimate. New accounts start with $5 of credit.
You can also skip the built-in AI entirely and drive FeynmanLM from a Claude, ChatGPT, Gemini, or Grok subscription you already pay for, connected via MCP at 1¢ per tool call. Sources, Schedule, and semantic search work either way. Most people mix the two.
Chat and reviews (text models)
In-app Chat, Feynman reviews, and background tasks (like paper metadata extraction) use the text provider and model selected in Settings → AI Provider. The default is Anthropic with Claude Sonnet 5.
| Provider | Models | Default |
|---|---|---|
| Anthropic | Claude Sonnet 5, Claude Fable 5, Claude Opus 4.8, Claude Haiku 4.5 | Claude Sonnet 5 |
| OpenAI | GPT-5.6 Sol, GPT-5.6 Terra, GPT-5.6 Luna | GPT-5.6 Sol |
| Google (Gemini) | Gemini 3.5 Flash, Gemini 3 Pro Preview, Gemini 2.5 Flash Lite | Gemini 3.5 Flash |
| xAI (Grok) | Grok 4.3, Grok 4.5 | Grok 4.3 |
| OpenRouter | DeepSeek V4 Flash, DeepSeek V4 Pro, Kimi K3, GPT OSS 120B, GPT OSS 20B, Qwen3 32B, Qwen3 235B, GLM 5.2, Muse Spark 1.1, Nemotron 3 Ultra, Nemotron 3 Super, Nemotron 3 Nano | DeepSeek V4 Flash |
| Together AI | Inkling | Inkling |
Notes:
- All open-weight models — DeepSeek, Kimi, Qwen, GLM, GPT OSS, Muse Spark, and Nemotron — are served through OpenRouter. The picker groups them by the lab that trained them, and you can add any other model from OpenRouter's directory. Together AI remains a chat provider solely for Thinking Machines' Inkling, which isn't listed on OpenRouter.
- DeepSeek and Kimi are offered only through OpenRouter's US-routed inference; the labs' own APIs are deliberately not integrated.
- The model picker shows a curated list; you can hide models you never use in Settings → Chat Models.
- Each provider remembers its own model choice, so switching providers doesn't reset your selection.
Read Aloud (text-to-speech)
Read Aloud generates audio with the provider selected in Settings → Text-to-Speech. The default is OpenAI.
| Provider | Models | Voices |
|---|---|---|
| OpenAI (default) | GPT-4o mini TTS (default), TTS-1, TTS-1 HD | 13 voices (default: Sage) |
| Google (Gemini) | Gemini 3.1 Flash TTS (default), Gemini 2.5 Flash TTS, Gemini 2.5 Pro TTS | 30 voices (default: Kore) |
| Groq | Orpheus | 6 English voices |
| Together AI | Orpheus (default), Kokoro, Cartesia Sonic 3.5/3/2 | Orpheus, Kokoro, Cartesia, Rime, and Minimax voice banks |
| ElevenLabs | Multilingual v2 (default), Flash v2.5, Turbo v2.5, v3 | 10 preset voices |
| xAI | Grok TTS | 5 voices |
| Local | Qwen3-TTS on your own local server | Free — runs on your own machine |
Gemini also supports overnight batch audio: queue a source in the evening and FeynmanLM generates the audio through Gemini's Batch API at half the live-request price.
Voice input (speech-to-text)
Voice dictation in Chat uses the provider selected in Settings → Speech-to-Text:
- Groq (default): Whisper Large v3 Turbo
- OpenAI: GPT-4o mini Transcribe
Audio is sent only to your configured provider and is not persisted after transcription.
Image generation
- Apple Image Playground (default): on-device, free, nothing billed
- Google (Gemini): Gemini 3.1 Flash Image
- OpenAI: GPT Image 2
Semantic search
Semantic source search runs entirely on-device using Apple's NaturalLanguage contextual embeddings. It costs nothing and sends nothing over the network.
Costs
- Every provider above is available immediately — nothing is behind a tier, and there is no key to obtain. Signing in with your Apple account is the only setup.
- Settings → AI Usage tracks every request against the provider's list price plus the 15% margin, so you can see exactly what your learning costs, to the cent. Models without a published rate are shown as unpriced rather than guessed.
- Your balance carries over — credits don't expire and don't reset monthly. Top up when you run out.
- Background tasks (paper metadata extraction, transcript cleanup, search embeddings) draw on the same balance and are itemised per task in the ledger. Each one's model is configurable in Settings → AI Models → Background Tasks, so you can point the noisy ones at something cheap.
- If a provider or model can't complete a request, FeynmanLM surfaces the error — it never silently falls back to a different model or to heuristic grading.