How chamfer handles your data
This is an English translation provided for convenience. The Japanese version is the authoritative text, and if the two differ, the Japanese version prevails. Read the Japanese version
This page is written by the operator, takushio2525 (“we”), to explain what information chamfer (https://chamfer.takushio2525.com, “the service”) handles.
Analytics (Google Analytics 4) and cookie consent are covered by the privacy policy shared by all takushio2525.com sites (https://takushio2525.com/privacy/), which applies to the service as it is. This page explains everything else that is specific to the service.
1. Using the service without signing in
HTML files and folders you open (including CSS, images and fonts) are processed only inside your browser and are never sent to our servers.
Folders you open are kept in storage inside your browser (IndexedDB, chamfer-projects), up to the 8 most recent imports; older ones are removed the next time you open a folder. HTML and PDF files you export are saved on your device.
2. Signing in with Google
You sign in with a Google account. Sign-in runs on Amazon Cognito (AWS Tokyo region). Of the information we receive from Google, we store only the two items below. We do not store your name or profile picture.
- Your email address (shown while you are signed in, and checked against share links limited to specific accounts)
- The identifier Google uses to tell accounts apart (used to recognize the documents you store as yours)
3. Cloud save
While you are signed in, a document you open and edit is saved to the cloud automatically once you stop working on it for a moment. Opening a document alone does not save it. You can also save at any time with “Save to cloud now”.
We store the document’s content (one HTML file, including its images), its file name, its size, and when it was created and last updated. It is stored in Amazon S3 and Amazon DynamoDB (both in the AWS Tokyo region), up to 20 MB per document and 50 documents per person.
Documents you store can be read and written only from your account; other users cannot see them. The exceptions are when you use link sharing or connect an AI tool.
We do not view or use the content of stored documents. However, we may check them, only to the extent necessary, (1) when required by law, (2) when we receive a report of infringement of rights or of content that violates the terms of use and need to verify it, or (3) when it is strictly necessary to deal with a failure.
4. Storing documents that contain other people’s information
If a document you store or share contains other people’s personal information (such as a roster or contact details), or text and images to which others hold the rights, it is up to you to confirm that you may store it in the service and share it (for example under your employer’s rules, or with the rights holder’s permission).
5. Link sharing
- With an “Anyone with the link” link, anyone who knows the link can see the document’s content, file name and last-updated time without signing in. Your email address is not shown.
- With an “Only the accounts you name” link, we store the email addresses you enter (up to 20). When someone opens the link and signs in with Google, we compare their email address (as verified by Google) with that list. The viewer’s email address is used only for this check and is not stored. The addresses you enter are other people’s personal information, so let them know you are sharing with them before you enter them.
- A link stays valid until you revoke it or delete the document.
- Viewers can save or copy whatever appears on their screen. Do not share documents containing information you would not want seen.
6. Connecting AI tools
You can connect AI tools such as Claude to your chamfer account. A connection is made only when you choose “Allow” on the connection screen. A tool you allow can read the list and the content of the documents you saved to the cloud and, if you allowed it, create, rewrite and delete documents and create and revoke share links.
How the tool handles the documents it receives is governed by the tool provider’s policy. We record the URL and name of the connected tool, the scope you allowed, and your identifier and email address. This permission remains after you sign out of chamfer; to revoke it, disconnect chamfer in the tool. Permissions that go unused expire after 30 days.
7. What we keep on your device
| Name | Type | Purpose | How long |
|---|---|---|---|
chamfer_locale | Cookie | Remembers your display language | 1 year |
chamfer.printGuide.dismissed | localStorage | Records that you chose not to see the printing tips again | Until you clear it |
chamfer-projects | IndexedDB | Holds folders you opened (CSS, images) | The 8 most recent |
chamfer.auth.session | localStorage | A key that keeps you signed in (only while signed in) | Until you sign out (the key is valid for 5 days) |
chamfer.auth.pending | sessionStorage | A temporary value used during sign-in | Until sign-in completes |
chamfer.share.token | sessionStorage | A temporary copy kept when you sign in with a share link open | Until sign-in completes |
cognito | Cookie (Amazon Cognito domain) | The session of the sign-in screen | Until you sign out |
When you sign out, we delete the sign-in key from your device, make that key unusable, and end the session of the sign-in screen.
8. Third parties that handle information
| Company | Location | Role | Information they receive |
|---|---|---|---|
Amazon Web Services Japan G.K. (AWS) | Japan (servers in the Tokyo region) | Delivery (CloudFront), sign-in (Cognito), storage (S3, DynamoDB), processing (Lambda) | The information in sections 2 to 6, and your IP address and browser information when you access the service |
Google LLC | United States | Sign-in with a Google account; analytics (under the common policy) | Sign-in authentication; browsing information (as described in the common policy) |
Vercel Inc. | United States | Only redirecting the former URL (chamfer-sandy.vercel.app) to the current one | Your IP address and browser information when you open the former URL |
The provider of an AI tool you connect | Depends on the provider | As described in section 6 | The documents you allowed |
CloudFront delivers the service through locations around the world. We do not use delivery access logs (such as IP addresses) to identify individuals. Processing records (Lambda execution logs) keep the type and reason of errors and are deleted after 90 days. They do not contain document content, email addresses or IP addresses.
9. Retention and deletion
- You can delete cloud documents and share links from the screen at any time. They are removed immediately and cannot be restored (we keep no backups).
- To delete the account itself (your email address and identifier), contact us. Deleting your account also deletes your cloud documents, share links and the permissions you granted to AI tools.
- Anything kept in your browser (the table in section 7) can be cleared from your browser settings.
10. How we keep information safe
- All communication is encrypted (HTTPS).
- Document storage is not public. Documents are retrieved only through signed URLs that expire within minutes.
- Storage keys are built only from verified sign-in information, so no request can point to another user’s documents.
- Share links are random values too long to guess.
- Data is stored in Japan (AWS Tokyo region) and managed under Japan’s Act on the Protection of Personal Information.
11. Requests for disclosure, correction, deletion and more
To request disclosure, correction, suspension of use or deletion of your information, or to make a complaint about how it is handled, contact us. We will respond without undue delay after confirming that you are the person concerned. There is no fee.
We will tell you the operator’s name and address without delay on request.
12. Changes to this page
When we change this page, we will show the new content and the date it takes effect here. Before collecting a new kind of information, or using it for a purpose other than the current ones, we will tell signed-in users on screen and ask for their consent.
13. Contact
Contact: contact@takushio2525.com
Established: September 30, 2026