# Artifacts by 041

> Artifacts by 041 makes the buckets you own in AWS, GCP, Azure or any S3 endpoint look like one global store of versioned file sets. Every write lands in a bucket in the writer's own region, so a spot training run can hop clouds, resume the latest checkpoint once across clouds, and keep writing locally. A control plane that hands out signed URLs and never touches the bytes.

Every link below is a markdown page. Any docs page also answers with markdown when asked for `Accept: text/markdown` or fetched with curl.

## Start

- [Getting started](https://artifacts.041.io/docs/getting-started.md): An organization, a fallback location, an API key, and a run pointed at `o41://`.
- [The model](https://artifacts.041.io/docs/model.md): Artifacts, versions, the latest, and the one writer that opens from the latest, from nothing, or as a fork.
- [Checkpointing a run](https://artifacts.041.io/docs/checkpointing.md): SexpGPU and any other trainer on `o41://`: resume the latest, save locally, fork.

## Setup

- [Connecting clouds](https://artifacts.041.io/docs/connecting-clouds.md): AWS, GCP and Azure by OIDC federation: the app is the issuer, your cloud trusts one subject.
- [S3 endpoints](https://artifacts.041.io/docs/s3-endpoints.md): Tigris, R2, a neocloud's object store or an existing bucket, added with a key and a placement tag.
- [Locations and placement](https://artifacts.041.io/docs/placement.md): Where a write goes: cloud and region, then the cloud's default, then the fallback. How a box finds its place.

## Reference

- [HTTP API](https://artifacts.041.io/docs/api.md): Every endpoint under `/api/v1`, with request and response examples from the contract.
- [Command line](https://artifacts.041.io/docs/cli.md): `npx @o41/artifacts`: login, locations, API keys, listing, signed URLs, get and put.
- [o41-checkpoint](https://artifacts.041.io/docs/o41-checkpoint.md): The Rust crate: resume, save, fork and load on a directory, a raw bucket, or `o41://`.
- [Bucket layout](https://artifacts.041.io/docs/bucket-layout.md): What sits in your bucket: one prefix per version, `_manifest.json` written last.

## Optional

- [Landing page](https://artifacts.041.io/index.md): the cost argument, checkpointing across clouds, the four ways in