Syden terms of use
Last updated November 9, 2026
This is a translation of the original in Portuguese. Syden is run from Brazil, and if the two ever differ, the Portuguese version is the one that applies.
Syden is a free voice, video and chat app for groups of friends. By creating an account, you agree to these terms. They are short on purpose.
- Free and complete: no paid version and no locked features.
- No ads, at all.
- We don't sell your data.
- In 72 languages.
1. Access
Anyone aged 13 or older can create an account, giving their date of birth and confirming an email address (the rules for people under 18 are in section 2); joining a community takes an invite from someone who is already in it. The account is personal: don't share your password. You can delete your account whenever you like, under Settings → My account — it disappears from Syden immediately, and a copy of what you wrote is kept for 90 days outside the app, in case an authority requests it. Nobody reads that copy through Syden, not even whoever administers it; after the 90 days, it is deleted on its own. The details are in the privacy policy.
Joining through a class link. Whoever administers a community can create a link that goes straight to a voice room, valid for a few hours. Anyone who joins through it without an account just types a name and gets a temporary account, which only serves that class and is deleted when the link expires — the same way as any deleted account, including the copy kept for 90 days described above. Whoever is teaching can turn the link off earlier. This account doesn't ask for an age: it can't chat privately, doesn't join any community and only reaches the class room, organized by whoever created it.
2. Age, minors and guardians
Syden is for people aged 13 or older, and was designed to be safe for teenagers too. The rules below follow Brazil's Digital Statute of Children and Adolescents (ECA Digital, Law 15,211/2025).
- The date of birth is asked of everyone, when creating the account (or on first sign-in, for people who already had one). It is only used to know the age range, nobody sees it, and once given it only changes on request to [email protected].
- From 13 to 15, the account is linked to a guardian's — the father, mother or legal guardian, who needs an adult Syden account and declares being the guardian. There are 7 days to do it; after that, the account is paused until it is linked.
- Under 18, everything starts closed: private chat only with friends; screen and camera are shown only to friends; only friends' streams can be watched; and the preview of a room's streams is off. From 13 to 15, only the guardian can open any of these rules; at 16 and 17, the person decides.
- The guardian sees the daily usage time, the adults the teenager talks to or is friends with, and the account's rules, and can set a daily time limit. They don't read the messages.
How age is checked, and our commitment. Today, the age is the one the person gives, with the guardian's declaration and the option of reporting someone who seems to have lied (the account is suspended, with the right to appeal). We know this is not enough. That is why Syden commits here to adopting the gov.br age token as soon as the Brazilian government offers it to apps: with it, the person confirms their age range through their gov.br account, and Syden receives only the confirmation — no CPF, no document, no date. It will be used to confirm the age of accounts and of guardians. Until then, in the Windows app, Syden will also use the age range that Microsoft itself reports for the computer's account, when it is available.
3. Living together
You may not use Syden for:
- harassment, threats, hate speech or discrimination;
- illegal content, including any sexual content involving minors;
- nudity, explicit sexual content or pornography;
- real graphic violence — images or videos of injuries, death or cruelty;
- sharing other people's personal data without permission;
- spam, scams or malicious software;
- trying to break into, overload or get around the security of the service.
4. What you upload
You are responsible for what you post: messages, avatar, emojis, sounds and karaoke songs. Only upload content that is yours or that you have the right to use. The content remains yours; you only authorize Syden to store it and show it to the server's members so the app can work.
About music, a warning: having a file is not the same as having the right to share it. Buying a CD or an MP3 gives you a copy to listen to; playing it for other people is a separate right that doesn't come with the purchase. Syden brings no music library at all, and is not a way to get music — each community uploads what its own members already have.
5. If something of yours was posted here without permission
If you own a work — music, image, video, text — and it is on Syden without your authorization, write to [email protected]. Say what it is, where it is and why the right is yours. You don't need a Syden account for this.
What happens next: the content is taken down, and whoever posted it is told why. If that person says they had the right, they are heard — and while it isn't clear, the content stays down. Doing it again costs the account.
This address is for copyright. For any other matter, including reporting someone's conduct, [email protected] — and inside the app, the fastest way is to report (section 6).
6. Moderation
The server's administrator can delete messages, emojis, sounds and channels, and remove members who break these terms. Removing a member deletes their account and their messages. In a call, they can also cut someone's screen share and camera without removing them from the room.
Anyone can report: a message (with the flag next to it), a person and a screen share (through the right-click menu on them), and the age of someone who seems to be under 13. A screen-share report carries the image of that moment, which only the Syden team sees. Whoever reports can mark that it involves a risk to a child or teenager, and those reports are looked at first. The report keeps a copy of what was reported and goes to whoever looks after Syden, who decides what to do and records the decision. Reporting in bad faith, to bother someone, also breaks these terms.
Bans and suspensions. The Syden team can ban an account from all of Syden, or suspend it on suspicion of age. The decision is always made by a person, never automatically, and comes with the reason: whoever was banned or suspended sees the reason when opening Syden and can appeal right there, or at [email protected]. A banned account keeps existing, so the same email can't open another one.
Serious cases. Exploitation, abuse or grooming of a child or teenager: the content is taken down immediately, the evidence is kept for as long as the law requires, and the case is reported to the authorities (such as SaferNet Brasil and the Federal Police), with or without a report, as ECA Digital requires.
Every moderation action — deleting another person's message, removing a member, deleting an account, granting a role — is logged with name and time, so that you can ask for an explanation later.
7. The service
Syden is offered free of charge and "as is", by a personal project. We do our best to keep it running, but it may become unavailable, change or be shut down. There is no guarantee of availability and no liability for losses caused by using the service or by its absence, to the extent permitted by law.
8. Privacy
What we store and how is explained in the privacy policy.
9. Governing law
These terms are governed by the laws of Brazil.
10. Credits
Part of what appears in Syden was made by other people and is used under free licenses. Their credits are gathered here, instead of being spread across the screens.
- Fantasy monsters (mini-game): This work includes material taken from the System Reference Document 5.1 ("SRD 5.1") by Wizards of the Coast LLC and available at https://dnd.wizards.com/resources/systems-reference-document. The SRD 5.1 is licensed under the Creative Commons Attribution 4.0 International License available at https://creativecommons.org/licenses/by/4.0/legalcode. The names and data were selected, translated and adapted by Syden.
- Chess puzzles (mini-game): from the Lichess puzzle database, in the public domain (CC0).
- Countries (mini-game): data from Natural Earth, in the public domain. Mythology: the list is ours, with names in each language from Wikidata (CC0).
- Bunny session (mini-game): the skate park and the board come from Mini Skate; the park around it (trees, flowers, benches and stalls), from the Coaster Kit; and the houses of the neighbourhood, from City Kit Suburban, all three by Kenney, in the public domain (CC0).
- Burrow Toy Cars (mini-game): the track and the cars come from the Toy Car Kit by Kenney, in the public domain (CC0).
- Burrow Obstacle Course (mini-game): the platforms, conveyor belts, saws, sweepers, cannons, springs, flags and the finish sign come from the Platformer Pack by Kay Lousberg, in the public domain (CC0).
- Burrow Bridge (mini-game): the car and the truck come from the Car Kit by Kenney, and the cart from Halloween Bits by Kay Lousberg, all in the public domain (CC0).
- Target practice (Bunny Party microgame): the stall, the curtains, the targets, the crosshair and the bullet holes come from Shooting Gallery by Kenney, in the public domain (CC0).
- Garden Brawl (mini-game): the creatures of the garden, the forest, the desert, the snow and the castle were redrawn as pixel art from the Ultimate Monsters models by Quaternius, and the forest trees come from Parallax Forest by Luis Zuno (ansimuz), both in the public domain (CC0).
- Burrow Traffic (mini-game): the buildings come from Isometric Buildings and the cars from Isometric Vehicles, both by Kenney, in the public domain (CC0).
- 3D room (on the home screen, for those who choose the 3D style): the furniture, the walls, the window and the door come from Furniture Bits and Restaurant Bits by Kay Lousberg, and the bookcase, the wardrobe, the plants, the rugs and the box from the Furniture Kit by Kenney; in the colorful theme, the furniture, the walls, the window, the floor, the plants, the frames, the clock, the shelves and the trinkets (the teddy bear, the alarm clock, the record player, the piggy bank, the duck mug, the cake) come from the Playful Bedroom, Lovely Living Room, House Plants, Charming Kitchen, Pleasant Picnic and Baked Goods sets of the Tiny Treats collection by Isa Lousberg; and the juice, the soda, the popcorn, the chips and the cake of the classic theme from the Food Kit by Kenney; all in the public domain (CC0).
- 3D hall (on the community home, for those who choose the 3D style): the furniture comes from Furniture Bits and Restaurant Bits by Kay Lousberg and from the Furniture Kit by Kenney; the Christmas decoration (the tree, the presents, the toy train, the gingerbread house, the snowman and the armchair) from Holiday Bits by Kay Lousberg; the bathroom (the bathtub, the rubber duck, the sink, the mirror, the toilet, the towels, the bottles, the floor and the door) from Bubbly Bathroom, in the Tiny Treats collection by Isa Lousberg; all in the public domain (CC0).
- Burrow kitchen (mini-game): the kitchen and the food come from Restaurant Bits by Kay Lousberg and the Food Kit by Kenney; the bacon, the steak and the fried and burnt egg come from the LowPoly Models food pack by Quaternius, converted to another format and with the colours lightened; all in the public domain (CC0).
- 3D minigolf (mini-game): the course pieces come from the Minigolf Kit, and the park around it (flowers, benches, trees and stalls) from the Coaster Kit, both by Kenney, in the public domain (CC0).
- Bunny soccer (mini-game): the players and the ball come from the Sports Pack by Kenney, in the public domain (CC0).
- Burrows and Towers (mini-game): the buildings, the wall, the construction sites, the catapult, the weapons, the arrows, the banners, the trees and the rocks come from the Medieval Hexagon Pack, and the resource piles and the gold nuggets of the mines, from Resource Bits, both by Kay Lousberg, in the public domain (CC0).
- Call reactions: the little balloons come from the Emotes Pack by Kenney, in the public domain (CC0).
- Chess, Checkers, Truco, Dominoes and the Capitals dice (mini-games): the 3D board, pieces, cards, tiles and dice come from Board Game Bits by Kay Lousberg, in the public domain (CC0); the rules, from the chess.js library (Jeff Hlywa), under the 2-clause BSD license.
- Mini-games: the key, mouse and touch gesture figures are the Input Prompts; and the in-game icons (playing alone, the group, the computer, pause and others) come from Game Icons and its expansion, all by Kenney, in the public domain (CC0).
- How big is it? (mini-game): figures from Microsoft's Fluent Emoji, under the MIT License.
- Capitals (mini-game): the buildings, trees, trains, cars and boats on the 3D board come from the City Kit Commercial, City Kit Suburban, Train Kit, Car Kit and Watercraft Pack packs by Kenney, in the public domain (CC0).
- Battleship (mini-game): the ships on the 3D sea come from the Pirate Kit by Kenney, in the public domain (CC0).
- Sticker background removal (in the desktop app): the BiRefNet model (Zheng Peng et al.), under the MIT License, in the 512 px conversion by shozebDev. It runs on your computer: the image is not sent to Syden to be cut out.
- Secret word (mini-game): the words accepted as guesses come from VERO, the LibreOffice spell checker, by Raimundo Santos Moura and team, under the LGPLv3 and the MPL.
- Fonts chosen by communities: free fonts under the SIL Open Font License, each with its license next to the file.
What changed, and when
Changing terms of use is the kind of thing done quietly when nobody is looking. Here is the list, newest first, so you can check whether what you agreed to is still what is written.
- November 9, 2026 — section 10 now says that, in Garden Brawl, the garden creatures too are redrawn as pixel art from the Ultimate Monsters models (Quaternius, public domain).
- November 6, 2026 — section 10 now credits, in Bunny session, the park and the neighbourhood around the skate park (Coaster Kit and City Kit Suburban, Kenney, public domain), and, in the mini-games, the Game Icons icons (Kenney, public domain), and, in Target practice in the Bunny Party, the stall and the targets (Shooting Gallery, Kenney, public domain), and, in Burrow Traffic, the buildings and the cars (Isometric Buildings and Isometric Vehicles, Kenney, public domain), and, in Burrow Toy Cars, the track and the cars (Toy Car Kit, Kenney, public domain), and, in Garden Brawl, the creatures of the new stages, redrawn as pixel art (Ultimate Monsters, Quaternius, public domain), and the forest trees (Parallax Forest, ansimuz, public domain), and, in the 3D room, the furniture (Furniture Bits and Restaurant Bits, Kay Lousberg, and Furniture Kit, Kenney, public domain), the colorful theme (Tiny Treats, Isa Lousberg, public domain) and the food on top of the furniture (Food Kit, Kenney, public domain), and, in Burrow kitchen, the bacon, the steak and the fried and burnt egg (LowPoly Models, Quaternius, public domain), and, in the 3D hall, the furniture (Furniture Bits and Restaurant Bits, Kay Lousberg, and Furniture Kit, Kenney, public domain), the Christmas decoration (Holiday Bits, Kay Lousberg, public domain) and the bathroom (Tiny Treats, Isa Lousberg, public domain), and, in Burrows and Towers, the buildings, the wall, the catapult, the weapons, the projectiles, the trees and the rocks, which now come from the Medieval Hexagon Pack (Kay Lousberg, public domain), replacing the Quaternius and Kenney ones, and, in Burrow Obstacle Course, the course pieces (Platformer Pack, Kay Lousberg, public domain), and, in Burrow Bridge, the vehicles (Car Kit, Kenney, and Halloween Bits, Kay Lousberg, public domain).
- November 5, 2026 — section 10 now credits the 3D models on the Capitals board and the Battleship ships, the mini-game control figures (Kenney, public domain), chess (Kay Lousberg, public domain, and the chess.js library, BSD), and the 3D of Checkers, Truco, Dominoes and the dice, the skate park and the kitchen, 3D minigolf (the course and the park around it), Bunny soccer, Burrows and Towers and the call reactions (Kay Lousberg, Kenney and Quaternius, public domain).
- November 4, 2026 — section 10 now credits the model that removes sticker backgrounds in the app. Nothing changed in what you agreed to.
- October 25, 2026 — section 10 was added, with the credits for third-party material used under free licenses (mini-game data, figures and fonts). Nothing changed in what you agreed to.
- October 17, 2026 — section 2 was added, on age, minors and guardians: Syden is for people aged 13 or older and asks everyone's date of birth; from 13 to 15 the account is linked to a guardian; under 18, everything starts closed; and the commitment to adopt the gov.br age token. Moderation (now section 6) gained reporting a message with the flag, reporting a screen share and someone's age, cutting a screen share in a call, bans and suspensions with reason and appeal, and reporting serious cases to the authorities. The other sections were renumbered.
- October 10, 2026 — section 1 no longer says that signing up requires an invite code: anyone creates an account by confirming their email, and the invite is for joining a community (this had been the case since September 27, and the text had fallen behind). The opening no longer speaks of a "closed group". And this English version was published.
- October 5, 2026 — section 1 now explains joining through a class link: the temporary account, with just a name, that is deleted when the link expires.
- October 2, 2026 — section 1 now says that, when you delete your account, a copy of what you wrote is kept for 90 days outside the app, in case an authority requests it.
- September 28, 2026 — section 4 was added, with the address for anyone who holds copyright over something posted here.
- September 27, 2026 — first version published.