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. By 2026 01.AI's site leads with enterprise AI products (WorldWise Enterprise LLM Platform, 2025-03; Boss AI; TopSales AI) and lists Yi-Lightning (2024-10) as its latest Yi model. 01.AI's international API platform (platform.01.ai) is suspended: it says API services are temporarily unavailable from August 25 due to business adjustments and points users to the Chinese platform at platform.lingyiwanwu.com.
Active · Verified 2026-10-31 · fresh as of 2026-10-31 · 35 cited facts, 0 with a third-party source · 1 recorded change · Suggest a correction
At a glance
- Tier
- T2
- Created
- 2023-07 (01.AI founded); 2023-11 (Yi-34B); 2024-05 (Yi-Large); 2024-10 (Yi-Lightning) vendor fix
- Latest release
- Yi-Lightning (2024-10) vendor fix
- GitHub
- github.com/01-ai/Yi ~7k+ stars vendor fix
- Pricing
- API: Yi-Lightning $0.14 per 1M tokens (vendor-claimed lowest among frontier-tier); Yi-34B weights free under Apache 2.0 (international API at platform.01.ai suspended; API access now only via platform.lingyiwanwu.com) vendor fix
- Freshness
- 2026-10-31 fix
- Layer
- large-models repo fix
- Licensing
- open-core (estimate) fix
- Maintainer health
- 2 issues in 90 days · 0 releases in 12 months · bus factor 4 — as of 2026-10-31 repo
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.
- 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. The x.ai site now brands itself SpaceXSI (page title, checked 2026-10-29).
- Cohere Command R+ / Command A T1
Toronto-based foundation-model lab (Aidan Gomez, ex-Google Brain 'Attention Is All You Need' co-author). Command family is enterprise / RAG-optimised: Command A (Mar-2025, 111B dense, 256k ctx), Command R+ (104B MoE), Command R7B (smallest tier). Announced merger with Aleph Alpha April-2026. Open weights via CC-BY-NC (non-commercial); Cohere-hosted for commercial.
Sources (34 cited facts, 0 third-party)
Each fact links to the page it came from; the badge says who published it (how to read sources).
- What it is Open-weights frontier-tier Chinese model family (Yi-Lightning / Yi-34B) vendor
- What it does & what's distinct Kai-Fu Lee's 01.AI (founded 2023, Beijing). Yi family open-weights — Yi-34B (2023), Yi-L… vendor
- Claims / benefits Yi-Lightning matched GPT-4o on LMSYS Arena Oct-2024 at fraction of training cost; Yi-34B… vendor
- Modalities text, code; Yi-VL (vision) variant vendor
- Created 2023-07 (01.AI founded); 2023-11 (Yi-34B); 2024-05 (Yi-Large); 2024-10 (Yi-Lightning) vendor
- Latest release Yi-Lightning (2024-10) vendor
- License Apache 2.0 (Yi-34B + base sizes); proprietary (Yi-Large, Yi-Lightning) vendor
- GitHub github.com/01-ai/Yi ~7k+ stars vendor
- Mindshare Top-3 Chinese model lab; LMSYS arena visibility from Yi-Lightning launch Oct-2024; meani… vendor
- Funding $1B+ raised; >$1B valuation 2024 (Alibaba, Lightspeed China, Tencent investors) vendor
- Customers / scale Chinese enterprise via 01.AI API; some Western OSS via HuggingFace (Yi-34B) vendor
- Pricing API: Yi-Lightning $0.14 per 1M tokens (vendor-claimed lowest among frontier-tier); Yi-34… vendor
- Compliance China-based; not US-certified vendor
- Data handling Self-hosting recommended for Western sensitive data; Apache 2.0 weights for Yi-34B remov… vendor
- Deployment Self-hostable (Yi-34B Apache 2.0) + 01.AI API for Yi-Large / Yi-Lightning; Together AI h… vendor
- HQ Beijing, China vendor
- Founders / pedigree Kai-Fu Lee (CEO; ex-Microsoft Research Asia President, ex-Google China President, Sinova… vendor
- Performance LMSYS Chatbot Arena: Yi-Lightning matched GPT-4o (Oct-2024); MMLU ~78% (Yi-Large); MMLU-… vendor
- Code/weights release open weights for Yi-34B/9B/6B/Coder; proprietary for Yi-Large/Lightning vendor
- API surface REST + SDK; HuggingFace Transformers for Yi-34B vendor
- LLM lock open (Apache 2.0 for Yi-34B); single-vendor for Yi-Lightning vendor
- Runtimes any (HuggingFace, vLLM, llama.cpp) vendor
- Validated verticals Chinese enterprise; cost-sensitive OSS deployers globally vendor
- Time to running <10min via 01.AI API; <1hr self-host (Yi-34B Ollama / vLLM) vendor
- Anti-fit China data-residency for regulated Western workloads; Yi-Lightning closed weights; less … vendor
- Optimised for cost-efficient frontier inference; Chinese-language native; Apache 2.0 for Yi-34B tier vendor
- Adjacent infrastructure HuggingFace; Together AI hosting; Sinovation Ventures alumni network vendor
- Pros Kai-Fu Lee founder pedigree; Yi-Lightning matched GPT-4o on LMSYS at fraction of cost; A… vendor
- Cons Less Western mindshare than DeepSeek / Qwen; Yi-Lightning closed-weights; smaller OSS ec… vendor
- Project & sources www.01.ai/ vendor
- capability-benchmark-sources humaneval: 83.5% (Yi-Lightning, 0-shot, 2025-01-22) https://arxiv.org/abs/2412.01253 · a… paper
- architecture-deployment-locus hybrid repo
- positioning-platform-vs-product platform vendor
- taxonomy-three-layer-rollup large-models repo
What changed
Changes to this record's lifecycle, licence, release, pricing and hosting facts, from the catalog's git history. Subscribe (Atom)
- 2026-10-29
- Pricing “API: Yi-Lightning $0.14 per 1M tokens (vendor-claimed lowest among frontier-tier); Yi-34B weights free under Apache 2.0” → “API: Yi-Lightning $0.14 per 1M tokens (vendor-claimed lowest among frontier-tier); Yi-34B weights free under Apache 2.0 (international API at platform.01.ai suspended; API access now only via platform.lingyiwanwu.com)” source
Related systems
Referenced by (2)
- LlamaIndex (framework) integrates with — LlamaIndex has an official LLM integration package llama-index-llms-yi in its repo. (verified 2026-10-29)
- Portkey AI integrates with — Portkey docs have a Lingyi (01.ai) LLM provider integration page. (verified 2026-10-29)