Writing a client

Windows · macOS · Android · home

A complete updater, in the order the calls should be made. The shape below is what a host keeping a Roblox client up to date actually needs; adapt the install step to your target.

The loop

  1. Ask what should be installed.
  2. Compare against what is installed. Stop if equal.
  3. Download, following redirects.
  4. Verify the sha256.
  5. Install according to kind.
  6. Record the version you installed.

Compare version, not displayVersion in step 2. The dotted string is not unique, so two different desktop builds can carry the same one and an updater keyed on it will skip a real update.

bash

#!/usr/bin/env bash
set -euo pipefail

API="https://www.rbxoffsets.com"
PLATFORM="${1:-windows}"           # windows | macos | android
STATE="/var/lib/roblox-tracker/$PLATFORM-version"
mkdir -p "$(dirname "$STATE")"

# 1. what should be installed
meta="$(curl -fsS "$API/api/v1/$PLATFORM/files/latest")"
version="$(printf '%s' "$meta" | jq -r .version)"
kind="$(printf '%s' "$meta" | jq -r .kind)"
name="$(printf '%s' "$meta" | jq -r .fileName)"
want_sha="$(printf '%s' "$meta" | jq -r .sha256)"

# 2. already there?  (compare the identity, never displayVersion)
if [ -f "$STATE" ] && [ "$(cat "$STATE")" = "$version" ]; then
  echo "up to date: $version"; exit 0
fi

# 3. download - -L is required, the endpoint redirects to Cloudflare
out="/tmp/$name"
curl -fL --retry 3 --retry-delay 5 -o "$out" "$API/download/$PLATFORM/$version"

# 4. verify
if [ -n "$want_sha" ]; then
  got="$(sha256sum "$out" | cut -d' ' -f1)"
  [ "$got" = "$want_sha" ] || { echo "sha256 mismatch, refusing"; rm -f "$out"; exit 1; }
else
  echo "warning: this build is unpinned (no published sha256)"
fi

# 5. install
case "$kind" in
  apk)  adb install -r "$out" ;;
  xapk) tmp="$(mktemp -d)"; unzip -q "$out" -d "$tmp"
        adb install-multiple "$tmp"/*.apk ;;
  zip)  unzip -oq "$out" -d /opt/roblox ;;
esac

# 6. remember
printf '%s' "$version" > "$STATE"
rm -f "$out"
echo "installed $version"

python

import hashlib, requests

API = "https://www.rbxoffsets.com"
PLATFORM = "windows"

meta = requests.get(f"{API}/api/v1/{PLATFORM}/files/latest", timeout=15).json()

with requests.get(f"{API}/download/{PLATFORM}/{meta['version']}", stream=True,
                  allow_redirects=True, timeout=(15, 600)) as r:
    r.raise_for_status()
    digest = hashlib.sha256()
    with open(meta["fileName"], "wb") as f:
        for chunk in r.iter_content(1 << 20):
            f.write(chunk)
            digest.update(chunk)

if meta["sha256"] and digest.hexdigest() != meta["sha256"]:
    raise SystemExit("sha256 mismatch")

Watching every platform at once

curl -s https://www.rbxoffsets.com/api/v1/platforms \
  | jq -r '.platforms[] | "\(.label)\t\(.displayVersion)\t\(.releasedAt)"'

Polling politely

The tracker itself checks upstream every 60 seconds, so asking more often than that learns nothing new. Once every 5 to 15 minutes is plenty for an updater. The metadata endpoints are database reads and cost this server almost nothing; /api/v1/{platform}/current may reach upstream, so prefer /files/latest in a loop and keep /current for the moment you actually intend to install.

Responses are sent with Cache-Control: no-store. There is no rate limit today. Set a real User-Agent so an unexpected traffic pattern can be traced to its owner rather than blocked.

Things that will bite you

  • Treating displayVersion as the identity. It is not unique. Key everything on version.
  • Not following redirects. You get a 302 body, not a file, and it looks like a corrupt download.
  • Caching the signed URL. It expires in about 60 minutes. Always start from the /download/ path.
  • Assuming latest equals the newest Roblox release. It is the newest stored build. When they differ, /api/v1/{platform}/current explains why in heldBack.
  • Falling back to latest offsets. Offsets for a neighbouring build are not approximately right. Fail instead.
  • Ignoring kind. An xapk installed as a plain APK fails every time.
  • Treating an empty sha256 as verified. Empty means unknown. Log it.
  • Sorting Android versions as strings. 2.734.99 sorts above 2.734.917 lexically and is older. Compare the dotted segments as integers, or compare versionCode. Desktop identities do not sort at all — use releasedAt.