Privacy Policy
How Sachess handles local analysis, Photo-FEN uploads, multiplayer rooms, peer calls, and cloud-book requests.
Sachess keeps core tools usable without an account and is designed to minimize data collection. Optional email accounts sync selected settings, puzzle progress, and saved games; this policy distinguishes browser-only features from data that must be processed remotely.
Author: Sachess Development Team
·
Updated: 2026-08-29
·
0 Sources
Details
Local Processing and Browser Storage
Pikafish AI analysis runs locally in your browser. When you use Photo-FEN upload or paste, the selected image is sent to Sachess Worker for size/type validation and server-side inference; do not submit sensitive or identifying photos. Sachess does not require an account, email address, password, or payment information.
Sachess uses localStorage for settings such as theme, language, application preferences, and saved game state. Optional accounts use a passwordless Smart Link and can store selected preferences, puzzle progress, and saved games. Multiplayer credentials use sessionStorage. A service worker caches public application assets for performance and offline use.
- Pikafish analysis remains on the device; Photo-FEN recognition is a remote Worker-assisted feature.
- Browser storage can be cleared through your browser settings.
- Service-worker caches contain public site and engine assets, not account records.
Photo-FEN Image Processing and Peer Calls
Photo-FEN uploads and pasted images are sent to Sachess Worker for validation and inference. The image is processed to return a board/FEN result; Sachess does not expose it as a public asset or require an account. Avoid uploading photos containing people, documents, or other sensitive information.
Audio/video calls are available only to the two players, not spectators. They request the microphone only when a player chooses to join, and the camera stays off until enabled. Media is exchanged peer-to-peer when possible. If a direct connection cannot be established, encrypted media may pass through Cloudflare TURN using a short-lived 30-minute credential issued only after joining the call. The room service carries signaling and room state, and Sachess does not record or store call media. ICE connectivity checks may reveal network information to the peer and to the relay provider when relay is used.
- Photo-FEN sends the selected image to Sachess Worker for processing.
- Microphone and camera are opt-in; camera starts disabled.
- Peer calls may expose network information and may fail on restrictive networks.
- Sachess does not record or store peer-call media.
Multiplayer Rooms and Cloud Book
When you create or join a multiplayer room, Cloudflare Workers and a room Durable Object process the room code, player credential, settings, FEN, move history, clocks, chat messages, draw or rematch state, and result until the room is cleaned up under the room-expiry rules. Anyone holding a valid room link or credential may be able to access that room, so do not place sensitive information in chat.
Cloudflare processes ordinary network information needed to deliver and protect the service. For room-creation abuse prevention, Sachess converts the connecting IP address to a one-way hash and temporarily stores creation timestamps, waiting-room reservations, cooldowns, and abuse blocks in a Durable Object. Frequent creators may be asked to complete Cloudflare Turnstile; the verification token is checked by the Worker and is not used as a player profile. If you open the cloud-book feature, the current FEN is sent to the ChessDB service to retrieve moves.
- Multiplayer positions, moves, timers, and chat are server-processed temporarily.
- Room credentials are stored in sessionStorage and should be treated as private links.
- ChessDB receives a FEN only when you use cloud-book lookup.
Service Providers and Your Choices
Cloudflare hosts and protects Sachess and provides the room, STUN, and TURN relay infrastructure. Google may provide STUN discovery. ChessDB provides cloud-book results only when requested. Brevo delivers optional Smart Link email messages. These providers process data under their own terms and privacy policies.
You may clear site data in your browser, avoid multiplayer chat, and choose not to use cloud-book lookup.
- Sachess does not sell personal information.
- Clearing browser site data removes local preferences, cached assets, and saved session credentials.
FAQ
Does Sachess require registration?No. Core tools do not require an account, email address, password, or payment information. An optional email account enables synchronization and saved-game storage.
Is game data uploaded?Local Pikafish analysis stays on your device. Photo-FEN sends the selected image to Sachess Worker for processing. Multiplayer room state and signaling are temporarily processed by Cloudflare, peer-call media is exchanged directly when possible, and cloud-book lookup sends the current FEN to ChessDB when requested.
Does Sachess use my microphone or camera?Only the two players can join an audio/video call. Microphone access is requested only when a player chooses to join; camera access remains off until enabled. Spectators cannot join calls. Calls may fail on restrictive networks and are not recorded by Sachess.
Does Sachess use cookies?Sachess uses browser storage for preferences and sessions. The daily puzzle and optional account session use secure, HttpOnly cookies where needed.
Which third parties process data?Cloudflare provides hosting, room infrastructure, STUN discovery, and TURN relay; Google may provide STUN discovery; Sachess Worker processes Photo-FEN uploads; ChessDB receives FEN positions only for requested cloud-book lookups.
