01.AI Yi family
Kai-Fu Lee's 01.AI (founded 2023, Beijing). Yi family open-weights — Yi-34B (2023), Yi-Large (proprietary 2024), Yi-Lightning (2024-10, frontier-tier, matched GPT-4o on LMSYS chatbot arena). Apache 2.0 (Yi-34B and base sizes). Important second Chinese open-weights option alongside DeepSeek + Qwen.
At a glance
- Type
- Open-weights frontier-tier Chinese model family (Yi-Lightning / Yi-34B)
- Tier
- T2
- Created
- 2023-07 (01.AI founded); 2023-11 (Yi-34B); 2024-05 (Yi-Large); 2024-10 (Yi-Lightning)
- Latest release
- Yi-Lightning (2024-10)
- License
- Apache 2.0 (Yi-34B + base sizes); proprietary (Yi-Large, Yi-Lightning)
- Pricing
- API: Yi-Lightning $0.14 per 1M tokens (vendor-claimed lowest among frontier-tier); Yi-34B weights free under Apache 2.0
- Funding
- $1B+ raised; >$1B valuation 2024 (Alibaba, Lightspeed China, Tencent investors)
Taxonomy
- storage
- parametric
- retrieval
- parametric-recall
- persistence
- parametric-permanent
- update
- read-only
- unit
- weight
- governance
- opaque
- conflict
- n/a
When to use
Optimised for: cost-efficient frontier inference; Chinese-language native; Apache 2.0 for Yi-34B tier
Anti-fit: China data-residency for regulated Western workloads; Yi-Lightning closed weights; less mindshare in West than Qwen / DeepSeek
Pros & cons
Pros
Kai-Fu Lee founder pedigree; Yi-Lightning matched GPT-4o on LMSYS at fraction of cost; Apache 2.0 Yi-34B is broadly deployable.
Cons
Less Western mindshare than DeepSeek / Qwen; Yi-Lightning closed-weights; smaller OSS ecosystem; China data-residency concerns.
Claims & capabilities
Yi-Lightning matched GPT-4o on LMSYS Arena Oct-2024 at fraction of training cost; Yi-34B Apache 2.0; trained at $3M total compute claimed; Kai-Fu Lee founder pedigree (ex-Microsoft Research Asia, Google China)
Technical surface
- API surface
- REST + SDK; HuggingFace Transformers for Yi-34B
- Backend storage
- not applicable — substrate foundation model
- Deployment
- Self-hostable (Yi-34B Apache 2.0) + 01.AI API for Yi-Large / Yi-Lightning; Together AI hosts Yi-34B
- Embedding model
- not applicable — not a memory product
- Multi-tenancy
- not applicable — substrate foundation model
- MCP
- not applicable — substrate foundation model
- A2A
- not applicable — substrate foundation model
- OpenTelemetry
- not applicable — substrate foundation model
Similar systems
Other foundation models (substrate reference) in the catalog, ranked by inbound references.
- Anthropic Claude (foundation models) T1
Claude family of frontier foundation models — Sonnet 4 (workhorse), Opus 4.5 (frontier capability), Haiku 4.5 (fast/cheap). Frontier model used as substrate by Claude Code, Anthropic Memory tool, Cline, Aider, Continue.dev, Cursor, Goose, and dozens of other catalog entries. Memory in Claude is parametric (in weights) — discrete episodic memory lives outside the model in the Claude Memory tool (see Platform-provider memory section).
- OpenAI GPT family (GPT-5 / GPT-4o / o3 / o4) T1
OpenAI's foundation model family — GPT-5 (2025-08 flagship), GPT-4o (multimodal workhorse), o3/o4 reasoning series. Substrate for ChatGPT, the OpenAI API, Microsoft Copilot, Azure OpenAI, and many downstream agents in this catalog (Devin, Codex CLI, Operator, Cursor mode). Parametric memory in weights; discrete user memory ships in ChatGPT Memory feature (separate row).
- Google Gemini 3 family T1
Google DeepMind's Gemini 3 frontier model family — Gemini 3 Pro (top tier), 3 Flash (fast), 3 Nano (on-device). Substrate for Google Workspace AI, Vertex AI Agent Platform, Gemini Code Assist, Project Mariner, and Project Astra. Multimodal-native; 1M-10M context window. Largest context window of any frontier model. Used by Gemini Enterprise Agent Platform Memory Bank (separate row).
- Mistral Large 2 / Mixtral family T1
French frontier-model lab (Paris). Family includes Mistral Large 2 (123B dense, Jul-2024), Mixtral 8x22B (open-weights MoE), Mistral Small 3 (24B, open-weights Jan-2025), Codestral (code specialist). EU-headquartered alternative to US/China model labs; GDPR-friendly data residency. Distinct from the Mistral Le Chat memory feature (already in catalog) — this row covers the model family itself as substrate.
- Meta Llama 4 family T1
Meta's Llama 4 family (released 2025-04) — Scout (109B MoE, 17B active), Maverick (400B MoE, 17B active), Behemoth (2T MoE, 288B active; preview). First Llama generation to use mixture-of-experts and to be multimodal-native. Substrate for many OSS agents (Open-Interpreter, Ollama-served local agents, vLLM-served enterprise inference). Llama community license (commercial use permitted under 700M MAU threshold).
- xAI Grok 4 T1
Elon Musk's xAI frontier model — Grok 4 launched 2025-07. Trained on Colossus (100k+ GPU supercluster in Memphis). Deeply integrated with X/Twitter (real-time tweet data access). Grok 4 Heavy variant for premium tier. No frontier-tier open-weights — Grok 1 (314B MoE) is the only weight release.