{"schema":"postcutoff/model@1","as_of":"2026-11-13T13:49:00+01:00","url":"https://postcutoff.com/m/pi-0-fast/","md":"https://postcutoff.com/m/pi-0-fast/index.md","disclosure":{"written_by":"AI agents (Claude Opus 5.5 in Claude Code)","editor":"human editor","policy":"https://postcutoff.com/about/"},"license":null,"id":"pi-0-fast","name":"π0-FAST","org":"Physical Intelligence","family":"π (pi)","released":"2025-01-16","status":"legacy","type":"robotics","modality_in":["text","image"],"modality_out":["action"],"open_weights":true,"model_license":"apache-2.0 (openpi code); weights built on PaliGemma, Gemma terms apply","context_window":null,"max_output":null,"knowledge_cutoff":null,"pricing":null,"price_line":"Price not published","access":[{"provider":"GitHub (openpi)","url":"https://github.com/Physical-Intelligence/openpi","model_id":"gs://openpi-assets/checkpoints/pi0_fast_base"},{"provider":"Hugging Face (LeRobot port)","url":"https://huggingface.co/lerobot/pi0fast-base","model_id":"lerobot/pi0fast-base","docs":"https://huggingface.co/docs/lerobot/pi0fast"}],"capabilities":[{"name":"FAST action tokenizer (autoregressive VLA)","detail":"Frequency-space Action Sequence Tokenization (DCT + BPE) compresses action chunks ~10x, letting an autoregressive VLA learn dexterous high-frequency tasks and train up to 5x faster than diffusion/flow π0.","first":false,"discovered":"launch","source":"https://huggingface.co/blog/pi0"},{"name":"DROID generalist checkpoint","detail":"pi0_fast_droid runs zero-shot on Franka DROID setups for many table-top instructions (openpi).","first":false,"discovered":"later","source":"https://github.com/Physical-Intelligence/openpi"}],"entry":null,"notes":"FAST tokenizer released and open-sourced mid-January 2025 (X post by @physical_int, 2025-01-16 approx.); π0-FAST weights open-sourced in openpi on 2025-02-04. Not marked first: no explicit 'first' claim verified.","verified":"2026-09-29","body_md":"Autoregressive sibling of π0 built on the FAST tokenizer.\n\nSources: [HF blog: π0 and π0-FAST](https://huggingface.co/blog/pi0), [PI on X](https://x.com/physical_int/status/1879963467836453067), [openpi](https://github.com/Physical-Intelligence/openpi).","page_url":"https://postcutoff.com/m/pi-0-fast/","standing":{"kind":"robotics","newer_count":30,"newer":[{"id":"praxis-1","name":"Praxis-1","org":"Runway","released":"2026-09-30","page_url":"https://postcutoff.com/m/praxis-1/"},{"id":"figure-helix-2-5","name":"Helix 2.5","org":"Figure AI","released":"2026-09-17","page_url":"https://postcutoff.com/m/figure-helix-2-5/"},{"id":"unifolm-wla-1-0","name":"UnifoLM-WLA-1.0","org":"Unitree Robotics","released":"2026-09-10","page_url":"https://postcutoff.com/m/unifolm-wla-1-0/"},{"id":"skild-s1","name":"Skild S1 (Skild Brain)","org":"Skild AI","released":"2026-08-25","page_url":"https://postcutoff.com/m/skild-s1/"},{"id":"generalist-gen-1-5","name":"Generalist GEN-1.5","org":"Generalist AI","released":"2026-08-19","page_url":"https://postcutoff.com/m/generalist-gen-1-5/"}],"before":{"id":"pi-0","name":"π0 (pi-zero)","org":"Physical Intelligence","released":"2024-10-31","page_url":"https://postcutoff.com/m/pi-0/"},"after":{"id":"pi-0-5","name":"π0.5","org":"Physical Intelligence","released":"2025-04-22","page_url":"https://postcutoff.com/m/pi-0-5/"},"weights":"public","licence":"apache-2.0 (openpi code); weights built on PaliGemma, Gemma terms apply","licence_permissive":false,"summary":"Weights are public. Licence: apache-2.0; weights built on PaliGemma, Gemma terms apply. See the licence for commercial terms."}}