itch-publish — Claude Code skill: publish builds to itch.io

---
name: itch-publish
description: >
  Publish and update a game on itch.io: create the project page and upload builds with the
  butler CLI (butler push) to named channels. Use for itch.io publishing, butler push,
  channel naming for Windows/macOS/Linux/HTML5, versioning uploads, or shipping a jam or
  release build to itch.io.
---

# itch.io Publish (butler)

Get a build onto an itch.io page and keep it updated. The page is created in the browser; all
uploads go through **butler**, itch.io's command-line tool, with one command you'll use
forever: `butler push`. butler diffs against the previous build and uploads only what
changed. Deep CI/CD and flag detail lives in `references/butler-ci.md`.

## When to use

- Use when creating/updating an itch.io project page, installing or logging in to butler,
  uploading a build with `butler push`, choosing channel names, versioning uploads, or
  shipping a jam/demo/release build to itch.io.
- Triggers: `butler push`, `butler login`, channels, `.itch.toml`, "publish on itch",
  "upload to itch".

**When *not* to use:** publishing on Steam (use `steam-publish`); jam *scope/planning* (use
`game-jam` — this skill is only the upload mechanics); building the game itself (engine
skills).

## Core workflow

1. **Create the project page** at `itch.io/game/new` — butler pushes only to a page that
   already exists. Set the **Kind of project**: keep *Downloadable* for native builds, or
   choose **HTML** for a browser-playable game (this is required for web builds — see
   Pitfalls). Set pricing and keep visibility at **Draft** (or Restricted for testers) until
   the page is finished: the first public publish puts it on *Most Recent* once, and it
   cannot go back to the top later.
2. **Install butler and log in.** Download from `itchio.itch.io/butler`, add it to `PATH`,
   then `butler login` (opens a browser to authorize). Verify with `butler version`. For
   CI, use `BUTLER_API_KEY` instead — see the reference. (The itch desktop app also has a
   graphical push screen that uses its own bundled butler, if the user prefers no CLI.)
3. **Prepare a portable build folder** — the exact files a player runs, nothing extra. Push a
   **folder** (or a single `.zip` *of* that folder), **not an installer** and **not a
   pre-compressed archive of archives** (hurts patching; see Pitfalls).
4. **Push to a channel:** `butler push <dir> <user>/<game>:<channel>`. `<user>/<game>` is
   the lowercase page address (`finji.itch.io/overland` → `finji/overland`). The channel name
   determines the platform tag (see Patterns). The first push uploads everything; later
   pushes to the same channel upload only the diff.
5. **Fill in the *Edit game* page, then Save.** Fix platform tags if a channel wasn't
   auto-tagged correctly — tick only platforms you have actually run the build on. For
   browser games also flip the page to **HTML** and tag the channel *playable in browser*.
   Answer the **AI generation disclosure** section if any shipped content was made with
   generative AI (mandatory for asset pages, which are delisted without it), and mark adult
   content under *Metadata → Classification*.
6. **Version your builds** (optional but recommended): `--userversion 1.2.0` or
   `--userversion-file build.txt` so you control the version string players and the update
   API see.
7. **Update later** by pushing to the *same* channel again. Use `butler status <user>/<game>`
   to see channels/builds and `butler push-preview` to see what a push would change before
   sending it.

## Patterns

### 1. The one command you need — `butler push`

```bash
# butler push <directory-or-zip> <user>/<game>:<channel>
butler push ./build/windows leafy/my-game:windows
butler push ./build/mac     leafy/my-game:osx
butler push ./build/linux   leafy/my-game:linux
butler push ./web           leafy/my-game:html   # browser build (also set page Kind = HTML)
```

### 2. Channel naming controls the platform tag (kebab-case, lowercase)

```text
Substring in channel name -> auto-applied tag:
  win / windows  -> Windows        linux -> Linux
  mac / osx      -> macOS          android -> Android
Multiple platforms in one channel are allowed: e.g. a Java jar:
  butler push ./jar leafy/my-game:win-linux-mac
Convention: lowercase words separated by dashes (windows-beta, osx-demo, soundtrack).
Tags are only the INITIAL guess — fix them anytime on the Edit game page (then Save).
There is no tag for CPU architecture: name the channel (windows-arm64) if you ship several.
```

### 3. Version, verify, and preview

```bash
butler version                              # print version; confirms install + PATH
butler login                                # authorize this machine (opens browser)

# Set an explicit version string instead of itch's auto-incrementing integer:
butler push ./build leafy/my-game:windows --userversion 1.2.0
butler push ./build leafy/my-game:windows --userversion-file build_number.txt

butler status leafy/my-game                 # list channels + latest builds/versions
butler push-preview ./build leafy/my-game:windows   # NEW/MODIFIED/DELETED/SAME, uploads nothing
```

### 4. First-time, hidden, and filtered pushes

```bash
# Hide a brand-new channel from the page until you're ready (NEW channels only):
butler push ./build leafy/my-game:windows-beta --hidden

# Exclude files from the upload without copying the folder (--ignore is repeatable):
butler push ./build leafy/my-game:windows --ignore '*.pdb' --ignore '*.dSYM'

# Preview exactly what would be sent, without sending it:
butler push ./build leafy/my-game:windows --dry-run
```

## Pitfalls

- **Pushing an installer.** itch.io patches *portable* builds; an installer (`.exe`/`.msi`)
  defeats patching and the itch app's auto-update, and may need admin rights players don't
  have. Push the extracted, runnable folder instead.
- **Pre-compressed builds.** Pushing a heavily compressed archive (or an archive of archives)
  makes patches huge — a tiny change rewrites the whole compressed blob. Push uncompressed
  files; itch.io compresses on its side.
- **A folder containing only one `.zip`.** butler auto-unzips it and pushes the contents
  (to avoid a "zip in a zip"). Pass `--no-auto-unzip` only if you truly want the zip uploaded
  as one opaque file.
- **HTML5 game shows as a download.** Two switches are required: set the page **Kind** to
  *HTML* and tag the channel *playable in browser* on the *Edit game* page after the first
  push — neither happens automatically from the channel name.
- **HTML5 build loads a blank page or 403s.** The upload needs `index.html` at its root and
  must stay within itch.io's limits: at most 1,000 files, 500 MB extracted, 200 MB per file,
  240 characters per path. The CDN is case-sensitive, serves the game from a subfolder (so
  paths starting with `/` break — use relative paths), returns 403 for folder URLs, and only
  allows HTTPS requests to other domains. HTML5 pages take payment only as donations; sell a
  web game by making the page *Downloadable*.
- **`invalid target (bad user)` / `(bad game)`.** The target must match the page address
  exactly — subdomain for the user, URL slug for the game, all lowercase — and the page must
  exist already.
- **macOS `.app` loses its structure.** Push the `.app` folder itself (or the folder that
  contains it); butler keeps the bundle as the top-level directory and marks Mac/Linux
  executables as executable by default.
- **`--hidden` on an existing channel errors.** It only applies when the push *creates* a new
  channel. Unhide later from *Edit game*.
- **Channel typos make duplicate slots.** `windows` and `win-final` are different channels and
  create separate downloads. Decide your channel names up front and reuse them.
- **30 GB cap.** itch.io rejects builds whose total *uncompressed* size exceeds 30 GB.
- **Paid page delisted or payouts frozen.** Selling requires following the payment
  processors' rules (itch.io's creator FAQ lists themes card networks will not process), and
  adult content must be classified as such. Check before setting a price.
- **Secrets in CI logs.** A `BUTLER_API_KEY` printed in a public log is compromised — revoke
  it immediately on the API keys page. See the reference for safe CI usage.

## References

- For CI/CD (GitHub Actions/GitLab) with `BUTLER_API_KEY`, automated install via `broth`, the
  full flag list, and the update-check API, read `references/butler-ci.md`.
- Primary docs: the butler manual — `itch.io/docs/butler` (installing, login, pushing);
  itch.io creator docs — `itch.io/docs/creators/html5` (web build limits) and
  `itch.io/docs/creators/quality-guidelines` (tagging, AI disclosure, delisting rules).

## Related skills

- `steam-publish` — the same game on Steam via SteamPipe (often shipped alongside itch.io).
- `game-jam` — most jams are hosted on itch.io; this skill handles the upload step.
- `prototype-fast` — share an early prototype on a Draft/restricted itch page for playtesting.