What
The Artifact tool now documents four new actions for artifacts whose page declares an assets capability:
upload_asset— push a local file into the artifact's asset storelist_assets— enumerate what's storedread_asset— pull a stored file back down to diskdelete_asset— remove a stored file
Why
This gives an artifact its own persistent file storage that Claude can manage directly, useful for artifacts that need to keep data, uploads, or generated files around between sessions rather than only living in the page itself.
Names in the bundleassets
Documented inapi/build-with-claude/citations
The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.
Confirmed since
Anthropic's documentation has since written up assets, on environments.
| Code hosting | `github.com`, `api.github.com`, `codeload.github.com`, `raw.githubusercontent.com`, `objects.githubusercontent.com`, `release-assets.githubusercontent.com`, `gitlab.com`, `bitbucket.org` |managed-agents/environments see the edit
Added since
A small documentation edit on Skills in Claude Desktop touched a line naming assets after this was published.
**Mind the text-only rule.** A skill delivered through the admin portal can contain only text files, in these formats: `.md`, `.txt`, `.json`, `.yaml`, `.yml`, `.csv`. The skill authoring guide describes scripts and binary assets such as i…government/desktop/skills see the edit
One source agreesOne thing we can check says the same as this entry.
Anthropic's documentation agrees
A small documentation edit on Skills in Claude Desktop touched a line naming assets after this was published.