| name | cdn-upload |
| description | Upload local files (figures, images, any asset) to the user's public CDN at cdn.hails.info (Cloudflare R2) and get back public https URLs. Use when an image/file needs a public URL — e.g. embedding a figure inline in a PRIVATE-repo GitHub PR/issue description (private-repo raw/blob links do NOT render; a public cdn.hails.info URL does, via GitHub's camo proxy), sharing a screenshot, or any "host this so it has a URL" need. Backed by the kb project's R2 scheme. |
cdn-upload — public URLs for local files via cdn.hails.info
cdn.hails.info is a public Cloudflare R2 bucket (r2:cdn-hails-info). Upload a file and it is
reachable at https://cdn.hails.info/<key>. Because the URL is public, GitHub renders it inline in
markdown even for private repos (where committed/raw.githubusercontent.com image links 404 or
are blocked by the camo proxy).
Use it
~/.agents/skills/cdn-upload/scripts/cdn-upload path/to/figure.png [more.png ...]
The script (mirrors DJRHails/kb bin/r2_upload.py):
- Content-addressed: key is
img/<sha256[:32]><ext>, so identical bytes collapse to one object
and re-uploads are idempotent (same URL every time).
- Immutable cache header on upload (
Cache-Control: public, max-age=31536000, immutable).
- Routing: a local
rclone r2: remote if configured; else, inside a gantry worker
(the gantry CLI is on PATH and $GANTRY_API_KEY is injected), it runs gantry attach —
which POSTs to gantry's /agent/attachments, since gantry holds the R2 creds the sandboxed
worker lacks, and returns the same cdn.hails.info/img/<sha> URL (images only); else it scps to
trifle (the user's Mac, where rclone + the r2: remote live) and uploads from there. So it
works from a maintainer host, a gantry worker, or any tailnet host.
Embedding in a GitHub PR/issue (the common case)
url=$(.../scripts/cdn-upload figures/foo.png)- Put
 in the PR/issue body.
- Update an existing PR body with the REST API (avoids a
gh pr edit bug that fails on
Projects-classic GraphQL): gh api --method PATCH repos/<owner>/<repo>/pulls/<n> -F body=@body.md.
Notes
- Verify a URL is live:
curl -s -o /dev/null -w '%{http_code} %{content_type}' "$url" → 200 image/png.
- The full
kb flow (bin/r2_upload.py <dir>) also rewrites markdown image refs in-place and keeps
a content registry; this skill is just the upload primitive for one-off files.
