Claude Code MCP images saved to file: Sume returns a media URL

Claude Code 2.1.283 (September 25) now also saves images returned by MCP tools to a file, so Bash and Read can open them. Sume's hosted MCP returns tool results as one text item holding JSON, and generated images in it are media.sume.com URLs, so the durable reference is the URL, not a local file.

Changelog line from Claude Code's docs; Sume behavior from Jobs and results and MCP tools and gates plus the MCP server source, all read 2026-10-01.

What does the Claude Code change do?

The changelog says images returned by MCP tools are now also saved to a file. It does not describe where the file goes or how long it lasts, so check your own session before building on a path.

What does a Sume image tool return?

In the server source I read, the success path builds one content item of type text containing the JSON result. A search of packages/mcp-server/src for image content blocks found none. The job result docs show artifacts with an id starting artf_, a url on media.sume.com, a type and a content_type. Whether Claude Code's new file save kicks in for a text result is not something either source says; I would not assume it does.

How should I report the image?

The playbook says to prefer Sume public ids and media.sume.com URLs in agent reports, and not to paste signed URLs, OAuth tokens or API keys into chat logs. If you need the bytes on disk, ask for a download with assets_download_url and fetch it yourself. Hosted MCP cannot read files from your laptop, so going the other direction needs the upload flow: create an upload URL, PUT the bytes, then assets_complete.

What should I do?

Keep the artf_ id and the URL from the result. Treat any local copy as a convenience. To choose a server for stills, see best MCP for image generation.