# Host

> Upload files to Cloudflare R2 and return a shareable public URL. Supports any file type (HTML, images, PDFs, etc.) with automatic slug generation, clipboard copy, and hosting history tracking. Use when the user says "host", "host this", "host file", "publish", "publish this", "share this file", "upload to R2", "make this public", "get a shareable link", "deploy this file", "put this online", or any variation of wanting to make a file publicly accessible via URL.

- Skill: `jcottam/host` (Agent Skill, multi-file: 5 files)
- Install (CLI): `npx skillmds@latest add jcottam/host`
- Raw SKILL.md: https://api.skillmd.com/api/skills/jcottam/host/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Web & Frontend
- License: MIT
- Author: jcottam (https://skillmd.com/u/jcottam)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/jcottam/host

---


# Host

Upload any file to Cloudflare R2 and get back a shareable public URL.

`SCRIPTS` below refers to the `scripts/` directory next to this file.

## Prerequisites

- **Wrangler CLI** — the Cloudflare developer CLI used for all R2 operations
- **Cloudflare account** with an R2 bucket that has public access enabled (r2.dev subdomain or custom domain)
- **Wrangler authenticated** via one of:
  - `wrangler login` (interactive OAuth — run once, token persists in `~/.wrangler`)
  - `CLOUDFLARE_API_TOKEN` environment variable

## Step 1 — Check prerequisites

### Wrangler installation

Check if `wrangler` is available:

```bash
wrangler --version
```

If not installed, install it globally:

```bash
npm install -g wrangler
```

### Wrangler authentication

Verify auth status:

```bash
wrangler whoami
```

If not authenticated, the user must run `wrangler login` interactively (opens a browser for OAuth). This is a one-time step.

### Host configuration

Look for `~/.publish.json`. If it doesn't exist, run `$SCRIPTS/setup.sh` and walk the user through the prompts. The setup script creates the config file with:

```json
{
  "bucket": "my-bucket-name",
  "publicBaseUrl": "https://pub-xxx.r2.dev"
}
```

If the file exists, read it and parse the `bucket` and `publicBaseUrl` values. Both are required.

## Step 2 — Identify the asset

Determine what file to host from context:

1. If the user specified a file path, use that.
2. If the user said "host this" without a path, check for:
   - A file the user is currently viewing or recently created
   - A `.canvas.tsx` output or generated HTML file from the current session
3. Verify the file exists before proceeding. If ambiguous, ask the user to clarify.

## Step 3 — Generate the key

Decide the R2 object key (the path within the bucket):

- **Default**: derive a readable slug from the filename.
  - Strip extension, lowercase, replace spaces and special characters with hyphens
  - Append today's date: `my-report-2026-05-15`
  - Re-attach the original file extension
  - Example: `Sales Report Q1.html` becomes `sales-report-q1-2026-05-15.html`
- **User override**: if the user provided a custom name, use it instead (sanitized).
- **Collision check**: scan `~/.publish-history.json` for the key. If it exists, ask the user whether to overwrite or append a suffix (`-2`, `-3`, etc.).

## Step 4 — Upload

Run the host script:

```bash
$SCRIPTS/host.sh <file-path> [--key <custom-key>]
```

The script:
1. Reads `~/.publish.json` for bucket name and public URL base
2. Detects the content type from the file extension
3. Uploads via `wrangler r2 object put <bucket>/<key> --file <path> --content-type <type> --remote`
4. Constructs the public URL: `<publicBaseUrl>/<key>`
5. Copies the URL to the clipboard (`pbcopy` on macOS, `xclip`/`xsel` on Linux)
6. Appends an entry to `~/.publish-history.json`
7. Outputs JSON with `url`, `key`, `contentType`, `size`, and `publishedAt`

**Important:** The `--remote` flag is required. Without it, Wrangler uploads to a local R2 simulator instead of the actual Cloudflare R2 bucket.

If the script exits non-zero, report the error to the user. Common issues:
- **Wrangler not installed**: suggest `npm install -g wrangler`
- **Not authenticated**: suggest running `wrangler login`
- **Bucket not found**: confirm the bucket name in `~/.publish.json` and that public access is enabled
- **File not found**: re-check the file path

## Step 5 — Report

After a successful upload:

1. Print the public URL prominently.
2. Confirm the URL was copied to the clipboard.
3. Mention the entry was added to history.

Example output:

```
Hosted: https://pub-xxx.r2.dev/sales-report-q1-2026-05-15.html
Copied to clipboard.
```

## History

Use `$SCRIPTS/history.sh` to interact with the local hosting history at `~/.publish-history.json`.

| Command | Description |
|---------|-------------|
| `history.sh list` | Show the 10 most recent uploads |
| `history.sh list --all` | Show all uploads |
| `history.sh search <query>` | Filter entries by key or local path |
| `history.sh prune` | Remove entries whose R2 objects no longer exist |

When the user asks to see their hosting history, list recent uploads, or find a previously hosted file, use the appropriate history command.

## Custom domains

For setting up a custom domain instead of the default `r2.dev` URL, see [references/custom-domain.md](references/custom-domain.md).