AI Potluck
Model components / Fine-tuning code

Tinker

Thinking Machines Lab

Tinker is Thinking Machines Lab's managed training API for researchers, launched October 1, 2025. It lets teams control the training loop through four primitives (forward_backward, optim_step, sample, and save_state) while Thinking Machines runs the distributed infrastructure underneath. The API covers LoRA fine-tuning and RL sampling on open-weight models from several vendors, including large mixture-of-experts checkpoints, alongside Thinking Machines' own Inkling models.

The supported-model roster changes often (Llama was dropped in June 2026), so the linked product page is the current list rather than this entry. Verified 2026-08-09 via the Tinker product page, the Service Terms of Use, and Thinking Machines' news archive.

Openness

1 high confidence
1.0
license
Proprietary
source
closed
engine
closed(hosted distributed-training service on TML infra)
cookbook
open(Apache-2.0, thinking-machines-lab/tinker-cookbook)
api
public-but-proprietary(forward_backward/optim_step/sample/save_state)
method
LoRA(+RL via sample)
access
paid+account-gated

The core training service is a proprietary hosted API, and only the example cookbook is OSI-licensed, so the product is closed. It is not open core either, because no self-hostable engine exists to be the core.

  • https://thinkingmachines.ai/tinker/ recorded 2026-08-09

    Describes Tinker as "a training API for researchers" where users "Control every aspect of model training and fine-tuning while we handle the infrastructure." Offers sign-up/sign-in, docs, and per-token/per-GB-month pricing; no self-host or download path exists for the training engine itself, only a link out to the separate tinker-cookbook example repo.

  • https://thinkingmachines.ai/legal/terms/ recorded 2026-08-09

    The Service Terms of Use (last updated January 10, 2026) grants Authorized Users "a non-exclusive, limited, non-transferable, non-sublicensable, worldwide right to access and use the Services" - a proprietary terms-of-use grant over the hosted platform, not an open-source license to the underlying engine.

  • https://github.com/thinking-machines-lab/tinker-cookbook/blob/main/LICENSE recorded 2026-08-09

    Full text of the Apache License, Version 2.0 - the tinker-cookbook repository's own license, unchanged from the prior read (fetched via the raw.githubusercontent.com redirect).

  • https://github.com/thinking-machines-lab/tinker-cookbook recorded 2026-08-09

    GitHub repository page for thinking-machines-lab/tinker-cookbook, described in its own metadata as 'Post-training with Tinker' - example and recipe code that calls the hosted Tinker API rather than the training engine itself.

  • https://thinkingmachines.ai/news/ recorded 2026-08-09

    News archive lists "Oct 1, 2025 Announcing Tinker" as its own dated entry, confirming the product's launch date cited in prose.

Adoption

2 low confidence
2.0

Thinking Machines' own Tinker page names Glean/Waldo, Chroma, Lightning Rod Labs, Mantic, Trajectory, MIT, Stanford and Axiom Math among users of the API. Level 2 on named adopters rather than a download or seat count, none being published for a hosted training API.

  • https://thinkingmachines.ai/tinker/ recorded 2026-08-09

    Case-study section now names Glean (Waldo), Chroma (Context-1), Lightning Rod Labs, Mantic, and Trajectory as customers, plus research collaborations credited to MIT, Stanford, and Axiom Math; no aggregate user count, download count, or revenue figure appears anywhere on the page.

Capability

4 medium confidence
4.0

Tinker hides distributed multi-GPU training behind a four-function API, covering LoRA training plus sampling for reinforcement learning and evaluation, across a wide model range from 1B up to large mixture-of-experts checkpoints. The largest it lists is NVIDIA Nemotron-3-Ultra-550B-A55B-BF16, at 550B total and 55B active parameters. It stays one band below the top because the service is LoRA-centric, with no full fine-tuning and no full RL stack, and because the judgment rests on that feature comparison rather than on any MLPerf Training result.

  • https://thinkingmachines.ai/tinker/ recorded 2026-08-09

    FAQ still states "Tinker is a flexible API for efficiently fine-tuning open source models with LoRA." Current model tiles top out at NVIDIA Nemotron-3-Ultra-550B-A55B-BF16; no full-fine-tuning or full-RL-stack option is described anywhere on the page.

  • https://tinker-docs.thinkingmachines.ai/tinker/models/ recorded 2026-08-09

    Retired Models page lists a June 12, 2026 retirement batch including Qwen3-235B-A22B-Instruct-2507 and six Llama checkpoints (Llama-3.3-70B-Instruct, Llama-3.1-70B, Llama-3.1-8B, Llama-3.1-8B-Instruct, Llama-3.2-3B, Llama-3.2-1B), confirming the model roster the score's value field cites has shifted since it was last read.

Verified 2026-08-09