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Your files,
weightless.

CesiumCloud keeps everything you make in one calm place. Drop files in, sort them into folders, preview anything, and find it again in a keystroke.

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FIG. 1 — FREE VAULT

$0 / month

Drop it anywhere

Drag files onto your workspace to upload them to your authenticated cloud account, with resumable transfer support.

Preview in place

Preview supported images and text files in the browser. Star files and folders using your account's saved preferences.

Safe deletes

Move files to Trash, restore them within 48 hours, or choose Delete forever.

Cloud storage,
ready when you are.

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Files

Settings

Manage your account and your files

Account

Name
Email
PlanAccount allocation
End-to-end encryption (original CesiumCloud format)

This optional feature uses CesiumCloud's existing CCENC01 encryption engine. Your recovery key stays in this browser tab only. If lost, encrypted files cannot be recovered.

End-to-end encryption is off.

Danger zone

Delete all data

Permanently removes account files from cloud storage. A password and confirmation are required.

Delete account

Requests irreversible removal of the account and stored data; administrator restrictions may apply.

CesiumCloud / Developer APIAPI v1 · CLI 0.2.9

Storage API

Use the current CesiumCloud CLI and SDK to upload, download and organize your files, or integrate account-scoped operations with the version 1 REST API.

Base URL https://api.cesiummc.space/v1
Account-scoped

Every credential is restricted to one CesiumCloud account and its storage quota.

Device sign-in

Sign in with cesiumcloud authenticate. There are no API keys to create or manage.

Streaming files

Uploads and downloads support reliable streaming transfers.

Quick start — CLI 0.2.9

The current CesiumCloud command-line client is 0.2.9 on npm and PyPI. It supports upload, download, search, file management, transfer progress, and cancellation. Authorize the CLI once with your CesiumCloud account before using file commands.

npm install --global [email protected]
cesiumcloud --version
cesiumcloud authenticate
cesiumcloud upload "C:\Users\you\Documents\notes.txt"
cesiumcloud list -a
cesiumcloud download "notes.txt" --location "C:\Users\you\Downloads"

The npm CLI requires Node.js 22 or newer. Run cesiumcloud --help or cesiumcloud help upload to see the available options. The npm and Python releases share the same core command syntax.

Python SDK and CLI

Install CesiumCloud 0.2.9 with Python 3.10 or newer. On systems that manage Python packages for you, use a virtual environment rather than installing into system Python.

python -m pip install --upgrade cesiumcloud==0.2.9
python -m cesiumcloud --version
python -m cesiumcloud authenticate
python -m cesiumcloud upload "./My Documents"
python -m cesiumcloud download --all "./CesiumCloud Restore"

You can use the same commands with the installed cesiumcloud executable. The Python package also provides programmatic account-scoped file operations.

Linux installation

For Ubuntu and Debian, install Python and create an isolated virtual environment. This works without Node.js.

sudo apt-get update
sudo apt-get install -y python3 python3-venv
python3 -m venv "$HOME/.local/share/cesiumcloud/venv"
"$HOME/.local/share/cesiumcloud/venv/bin/python" -m pip install --upgrade cesiumcloud==0.2.9
"$HOME/.local/share/cesiumcloud/venv/bin/cesiumcloud" authenticate

Windows users can run the command in PowerShell; macOS users can install either the Python CLI or the npm CLI. Always quote paths containing spaces or parentheses.

Account authentication

Run cesiumcloud authenticate and approve the displayed device authorization using your CesiumCloud account. Use cesiumcloud whoami to check the active account and cesiumcloud logout to remove the locally saved authorization. Logging out of one device does not delete your cloud files.

cesiumcloud authenticate
cesiumcloud whoami
cesiumcloud logout

Keep account credentials private. Do not paste authentication codes or saved credentials into public issues, support messages, or shared documents.

Paths and folders

Cloud paths identify files and directories within your own account. A path such as root/photos/holiday.jpg refers to the file in your cloud storage; it is not a local computer path. Use cesiumcloud dir to browse directories and cesiumcloud list -a to see files across your account.

File names and directory names are preserved where supported. If a command reports an ambiguous path, use a more specific path rather than guessing which file it will select.

Complete CLI command reference — 0.2.9

cesiumcloud authenticate
cesiumcloud whoami
cesiumcloud logout

cesiumcloud upload SOURCE [and SOURCE...] [--replace] [-simultaneous N]
cesiumcloud upload cancel
cesiumcloud cancel-upload UPLOAD_ID

cesiumcloud download CLOUDPATH [and CLOUDPATH...] [--location DIR] [-simultaneous N]
cesiumcloud download --all LOCALDIR [-simultaneous N]
cesiumcloud download cancel

cesiumcloud list [options] [CLOUDDIR]
cesiumcloud search TERM
cesiumcloud dir [CLOUDDIR|..|-|/]
cesiumcloud rename OLD NEW
cesiumcloud move SOURCE [and SOURCE...] [to] DESTINATION
cesiumcloud delete CLOUDPATH [and CLOUDPATH...]

cesiumcloud e2ee help
cesiumcloud help COMMAND

The literal separators [and] and [to] allow multiple source paths and a move destination. Use quotes around each path when necessary.

Upload files and folders

Upload a single file or a directory recursively. Multiple files may upload concurrently, and the CLI reports progress and errors. To replace an existing file with the same cloud path, use --replace.

cesiumcloud upload "./photos"
cesiumcloud upload "./notes.txt" --replace
cesiumcloud upload "./photos" -simultaneous 20

Uploads are subject to your account's available storage and service availability. A completed file stays available even if a later file in the same operation fails or is cancelled.

Multiple sources and concurrency

Supply several local files or folders in a single command by separating them with the literal [and] argument. Set -simultaneous N to specify a concurrency preference; the current CLI supports up to 40 active uploads.

cesiumcloud upload "./Folder A" [and] "./Folder B" -simultaneous 20
cesiumcloud upload "./first.txt" [and] "./second.txt"

The number of simultaneous transfers is a limit, not a guaranteed upload speed. The server may temporarily ask clients to wait or retry.

Download named files

Download one or more named cloud files. Without --location, files are saved to your operating system's Downloads folder. If an output filename already exists, the CLI uses an available numbered name rather than silently overwriting it.

cesiumcloud download "root/photos/holiday.jpg"
cesiumcloud download "first.txt" [and] "second.txt" --location "./Restored"
cesiumcloud download "root/videos/clip.mp4" --location "E:\Videos"

Quote the entire cloud path when it contains spaces or parentheses.

Restore all files

Use download --all to restore every file in your account to a chosen local directory. This is different from downloading a single named file.

cesiumcloud download --all "./CesiumCloud Restore"
cesiumcloud download --all "E:\RestoreAll" -simultaneous 20

The CLI supports up to 64 simultaneous downloads. Completed downloads are retained if a later transfer fails; verify important backups before removing their source copies.

Transfer progress and cancellation

Uploads and downloads show live progress as transfers occur. To stop active CLI transfers, open a second terminal on the same computer and run the matching cancel command.

cesiumcloud upload cancel
cesiumcloud download cancel

To cancel a particular incomplete server upload, use cesiumcloud cancel-upload UPLOAD_ID where supported. The two general cancel commands affect active local CLI transfers on that computer; they do not cancel website uploads or transfers started on other devices. Already completed files remain stored.

List files, sort, and paginate

Use list for a directory, -a for recursive listing, and -next to continue a paginated listing.

cesiumcloud list -a
cesiumcloud list -n 20
cesiumcloud list -next 20
cesiumcloud list -sort name
cesiumcloud list -sort size
cesiumcloud list -sort lastmodified
cesiumcloud list -long

The supported sort values are size, name, datecreated, lastmodified and reset. Large accounts may return results in multiple pages.

Search and navigate

Search by file name or another supported term, and use dir to change the CLI's current cloud directory.

cesiumcloud search "report"
cesiumcloud dir root/photos
cesiumcloud dir ..
cesiumcloud dir -

The website also provides account-wide search. Search results depend on account permissions and currently indexed files.

Rename, move, and delete

Rename files, move one or more files, or permanently delete a selected cloud path. CLI deletion is a permanent operation and is not the same as moving an item to website Trash.

cesiumcloud rename "root/old.txt" "new.txt"
cesiumcloud move "root/a.txt" [and] "root/b.txt" [to] root/archive
cesiumcloud delete "root/archive/old.txt"

Double-check deletion targets. Completed permanent deletions cannot be restored through the website Trash view.

SDK use in applications

The Python and JavaScript packages provide methods for working with authenticated account files, including uploads, listings, downloads, renames and deletions. For reliable transfers, prefer the official SDK's supported methods instead of implementing transfer retries or upload state management yourself.

See the installed package reference and cesiumcloud help for the client version you are using. Obtain an account credential through the supported authentication flow, and store it securely rather than embedding it in browser code or publishing it in a repository.

REST API authentication

The public REST API base URL is https://api.cesiummc.space/v1. Account endpoints require a valid account-scoped bearer credential; unauthenticated requests generally return HTTP 401.

curl "https://api.cesiummc.space/v1/me" \
  -H "Authorization: Bearer YOUR_ACCOUNT_CREDENTIAL"

Use credentials only over HTTPS. For browser application sign-in and file operations, use the supported CesiumCloud website session and official clients instead of exposing a credential to untrusted page scripts.

API account and health endpoints

These version 1 routes are available to clients with the appropriate permissions.

MethodPathPurpose
GET/v1/healthService availability (public).
GET/v1/meCurrent account and storage information.
GET/v1/filesList account-accessible files.
GET/v1/transfersAccount transfer status and limits.

The examples use an illustrative bearer credential placeholder. Your SDK may provide a richer, paginated account catalog than the simple v1 file-list response.

API uploads and transfer grants

For uploads, use the current official SDK or CLI. The API includes authenticated transfer authorization and upload-session routes for compatible clients. Requests can be delayed, rejected or retried depending on account permissions, available quota, and current transfer state.

MethodPathPurpose
POST/v1/transfer/grantRequest short-lived transfer authorization.
POST/v1/transfer/client-queue/batchRegister upload requests.
GET/v1/transfer/client-queue/{ticketId}Check a transfer request's current status.
POST/v1/transfer/client-queue/{ticketId}/finishReport an upload outcome.
DELETE/v1/transfer/client-queue/{ticketId}Cancel a pending request.

Use the supported client implementation for detailed request formats and sequencing. Do not treat a registration acknowledgment as proof that file data has finished uploading.

Downloads and integrity

Use the CLI or SDK to download files reliably. Clients support streaming, recovery of interrupted transfers where possible, and final completion checks. For a named download, specify the cloud path and optional local destination.

cesiumcloud download "root/docs/report.pdf" --location "./Restored"
cesiumcloud download --all "./Complete Restore"

A successful download should reproduce the complete original file. An interrupted download is not a finished backup; retry it and verify any important data before removing other copies.

HTTP errors and retries

API requests may return HTTP 400 for malformed input, 401 for missing or expired authentication, 403 for insufficient permission, 404 for unavailable or inaccessible items, 409 for a conflicting operation, and 429 or 5xx for temporary restrictions or service errors.

Read the response body when available. For temporary errors, honor a returned Retry-After header and retry with bounded backoff. Do not retry a destructive request blindly if its previous outcome is uncertain; check the operation's current status first.

Storage allocation and performance

Your account's allocated storage and remaining space determine whether new files can be accepted. A file upload may wait briefly when other transfers are active. Uploads and downloads have separate client concurrency controls, and increasing concurrency does not guarantee better speed.

For large batches, use the CLI's progress output and check final success and failure counts. A partial batch is not a complete backup; retry only files that did not finish.

Website file manager

Use Files to create folders and text files, upload files or folders, preview supported files, search, download, star, rename and move items. Starred collects items you have marked for quick access.

Select multiple files using their checkboxes. Hold Shift while clicking another checkbox to select the range between them. Dragging one of the selected files to a folder moves the selected group. Upload progress, cancellation, completed operations and errors are displayed within the application.

The top bar also includes Plans and Docs. The CesiumCloud logo returns to the “Your files, weightless” homepage.

Trash and automatic deletion

Items moved into Trash are automatically scheduled for permanent deletion 48 hours (2 days) after being placed there. Restore an item before that deadline to keep it. After the deadline or after choosing Delete forever, recovery through Trash is not available.

The interface removes an item once a permanent deletion has been accepted, although completion may still be in progress. Closing your browser does not cancel the accepted deletion. Verify that you have selected the correct items before deleting them.

Optional end-to-end encryption

Optional end-to-end encryption is available through cesiumcloud e2ee and the website's encryption controls. Encryption must be explicitly enabled: normal uploads are not automatically end-to-end encrypted. Filenames, folder paths, sizes and timestamps may remain visible.

cesiumcloud e2ee help
cesiumcloud e2ee keygen
cesiumcloud e2ee upload "./private-notes.txt"
cesiumcloud e2ee download "private-notes.txt.ccenc" --location "./Restored"
cesiumcloud e2ee migrate "root/docs/old.txt"

Save the recovery key offline. CesiumCloud cannot recover encrypted content if you lose the key. Migration leaves the original file intact unless you explicitly choose and confirm the documented removal options.

Plans, support, and troubleshooting

Check Plans for advertised plan information. Paid checkout is not yet available as an automated in-site purchase; paid plan buttons submit a genuine inquiry instead of activating a subscription. For assistance with access, password recovery, a failed transfer, or billing questions, use Contact.

Before reporting a transfer issue, note the client version (cesiumcloud --version), command attempted, approximate time, and the customer-facing error message. Do not include your account password, recovery key, authorization tokens, or other private credentials.

Terms of Service

Last updated October 25, 2026

1. What CesiumCloud provides

Cloud Storage by CesiumCloud provides registered account holders with a browser-based interface for uploading, retrieving, and managing files within an assigned storage quota. CesiumCloud uses third-party providers for storage and application operations as detailed in the Privacy Policy. Users can register with an email address and password; administrator-issued accounts may have different storage allocations. There is no public checkout or automatic subscription enrollment.

2. Access and accounts

You may create an account directly or receive one from the service administrator. You are responsible for your account credentials and for activity conducted through the account. Contact the operator using the contact form if you believe access has been compromised.

3. Storage limits and acceptable use

Each account has an assigned quota and must not intentionally evade limits, interfere with other users, or store material it is not authorized to possess or distribute. The service may refuse requests that exceed your quota or upstream provider limits. Uploads, downloads and session-based transfers may be interrupted or fail.

4. Availability, loss and backups

Service availability and transfer performance depend on third-party services and the user’s internet connection. CesiumCloud targets 99.9% uptime but does not provide a guaranteed uptime service level or independently verified historical uptime measurements. Customer data is backed up periodically to offsite storage as part of CesiumCloud’s data-protection operations. Backups improve recoverability but do not guarantee that every file or version can be restored, or promise a specific recovery time. Users should still keep independent copies of irreplaceable files. Storage availability remains subject to the service’s underlying storage entitlement.

5. Deletion and closure

When you request to delete a file, the application may permanently delete it from the connected Drive and remove its app metadata. Such deletions may not be reversible. The service administrator may suspend an account for misuse or discontinue service access, subject to applicable law and any agreement with the account holder. Account removal can be requested through the contact form.

6. Privacy and third parties

The Privacy Policy describes CesiumCloud’s processing of account details, file data and storage-provider API access. The service depends on third-party systems operated by infrastructure providers, each with their own limitations and terms.

7. Payments and plans

CesiumCloud permits self-service Starter registration and administrator-provisioned accounts. This website does not process payments or enroll visitors in paid plans. Any paid offering will display its applicable price, billing and cancellation conditions before accepting a purchase.

For the results and scope of the latest security checks, read the security testing report.

8. Questions

For service, security, account, and privacy inquiries, contact [email protected] or use the contact form.

Privacy Policy for Cloud Storage by CesiumCloud

Effective date: October 27, 2026Service: Cloud Storage by CesiumCloudWebsite: cloud.cesiummc.space

Service identity. Cloud Storage by CesiumCloud is a browser-based file storage service. Registered account holders can upload, organize, list, download, and delete files through individually authenticated accounts. Uploaded content is held on managed storage drives and transferred through CesiumCloud’s website and API, with support from third-party hosting, network, and storage infrastructure providers.

Privacy contact: [email protected]. You may also submit privacy and deletion requests through our contact form. These are the published contact channels for the CesiumCloud service.

1. What we collect

CesiumCloud account data: your email address, assigned account identifier, role, storage quota, how much quota you use, and the date your account was created. Passwords are not stored in plain text; the system stores password salts and keyed password hashes. We also store session hashes and expiration timestamps for authentication and login-attempt records for abuse prevention.

Files and metadata: the content you upload, the file name, content type, file size, upload date, storage-object and file-segment identifiers, and the CesiumCloud account to which each file belongs. We record upload-session information (including offsets and temporary upload session URLs) while processing large or resumable transfers.

Support inquiries: your email, contact category, subject, message, and a hashed network identifier used to limit automated abuse if you use our contact form. Third-party hosting, network, and storage providers may independently process technical request information under their own policies.

2. How managed storage is accessed

CesiumCloud operates service-managed storage infrastructure. Customers are not required to connect their personal cloud-storage accounts or grant access to files outside their CesiumCloud account. Service operations are limited to the managed storage objects and metadata needed to deliver the requested storage features.

The service organizes stored content by account, keeps the identifiers necessary to locate files and their segments, and reads or deletes those objects when an authorized customer requests a download or permanent deletion. Credentials used by CesiumCloud to access its underlying infrastructure are restricted to service operations and are encrypted when stored. Customers are not given those service credentials.

3. How we use the data

We use account information to authenticate users, enforce quotas, prevent abuse, and respond to requests. We use file contents and metadata to provide the storage functionality users request: uploading, organizing by account, listing, downloading, and deleting their files. To provide these functions, data passes between your device, CesiumCloud’s servers and network infrastructure, and the managed drives on which files are held.

Customer file contents and information received through infrastructure integrations are not used for advertising, personalized marketing, sale to data brokers, creditworthiness determinations, resale of data, or training, developing, or improving generalized artificial intelligence or machine-learning models.

Limited use of service data: Information received from third-party infrastructure integrations is used only as necessary to operate, secure, or improve the user-facing storage service, and is not transferred for unrelated advertising or resale. Where a third-party API imposes additional limited-use obligations, CesiumCloud follows those obligations.

4. Storage, sharing, and who can access information

Managed drives: uploaded content is held on drives used by CesiumCloud to operate the storage service. Network and hosting infrastructure: customer requests and file-transfer streams are processed by infrastructure providers supporting CesiumCloud. Service database: CesiumCloud stores account records, file metadata, quotas, authentication sessions, support inquiries, and encrypted credentials required for service operations. These providers process data on CesiumCloud’s behalf to deliver the service.

Files are accessible through CesiumCloud only after the backend checks the signed-in user’s file ownership and account permissions. The service administrator and the storage/platform providers may have technical access to file contents in their respective systems. Existing files and ordinary uploads are not end-to-end encrypted. Account holders may explicitly enable client-side E2EE for file contents. When selected, only encrypted content is transferred to the service, and the recovery key remains on the customer device. File names, folder paths, sizes, dates, and other account metadata remain visible. CesiumCloud cannot restore a lost recovery key.

We disclose data to our storage, network, and hosting providers only as needed to operate the service, to the authorized account holder to fulfill file requests, or where legally required. We do not sell uploaded files or file metadata, and we do not share them with advertisers or data brokers.

5. Security controls

CesiumCloud uses HTTPS for web and API traffic; HttpOnly, Secure, SameSite session cookies; server-side authentication and per-file account access checks; per-account quotas; and encrypted storage of service-level access credentials. The service separates account and file metadata in its database. E2EE is optional and never applied retroactively. Existing storage copies and ordinary backups remain unencrypted until customers separately encrypt and replace them. E2EE key loss can make encrypted files permanently unrecoverable. No system can promise absolute security or uninterrupted availability. Customer data is periodically backed up as part of CesiumCloud’s storage operations. Backups do not guarantee restoration of every file version or a specific recovery time, so users should still keep an independent copy of important files.

Optional migration: Customers may individually migrate older plaintext files into client-side encrypted copies. Migration verifies a fresh ciphertext download and decrypted file hash before any explicitly authorized permanent deletion of the active plaintext source. Existing files are not silently encrypted or deleted; historical backups and infrastructure retention may remain subject to separate schedules.

6. Data retention and deletion

Files: uploaded files remain on the managed storage drives while associated with a CesiumCloud account, unless deleted or affected by storage availability. When an authorized user permanently deletes a file, CesiumCloud removes its active storage objects, rebuilding shared storage packs where necessary to preserve unrelated files, and updates its file index and storage quota. CesiumCloud does not provide an undo option. Separately retained backups or infrastructure logs may be subject to different retention or deletion schedules.

Account information: account records are retained while accounts are administered. Login sessions expire after approximately seven days, although expired database records may be cleaned up later. Upload session records expire after approximately one day; incomplete transfer data may persist temporarily under storage-provider retention practices. Support messages are stored in the restricted operator dashboard until reviewed and removed by the administrator; no fixed automated deletion schedule is currently implemented.

Your choices: you can download and remove files from your account. To request account removal, access to personal information, or correction of account information, contact [email protected] or use the privacy request contact form. Storage and hosting providers may apply their own technical log or backup retention practices, which can differ from CesiumCloud’s active-file deletion process.

CesiumCloud depends on a time-limited third-party storage entitlement and cannot promise that files will be available indefinitely. Users should download important files and keep their own backups.

7. Changes to this policy and age restrictions

This policy will be updated when the service’s material data-collection, use, sharing, or retention practices change. The effective date on this page will be revised to reflect such changes. The service is not intended for children under 13.

For questions about how CesiumCloud handles uploaded files, storage information, or personal data, contact [email protected] or the contact form.

Contact & privacy requests

This form submits an inquiry to the private CesiumCloud operator dashboard. You can request data access, account deletion, help with your storage account or report a security concern. Do not include passwords, OAuth tokens or other credentials. You can also email [email protected].

Requests are retained in the service’s administrative database and are accessible only through the operator’s authenticated controls. Support requests are handled through this contact form.

Start free.
Grow when you do.

Six plans, one calm interface. Pick the room your files need.

Questions, answered.

How does the Free plan renew?

Free gives you 5 GB for one week at a time. Renew before the deadline to keep your files, and a new week begins. The cycle repeats for as long as you keep renewing.

What is the grace period?

If you miss a renewal, the grace period gives you extra time to sort it out: 4 days on Free and 14 days on every paid plan.

Why do plans show how many are available?

Paid plans are offered in limited numbers, and the count adjusts as demand and capacity change. If a plan sells out, choose another or check back later.

What happens if I run out of space?

Uploads that don’t fit are skipped with a message, and nothing you’ve already stored is touched. Empty the trash, delete something, or move up a plan.

Which plans include the API and team management?

Every plan includes API access. Free is limited to 300 requests a day, Plus to 10,000 and Premium to 100,000, and Pro and above are unlimited. Team management comes with Premium and above.

Welcome back

Log in to pick up where you left off.

Accounts are authenticated by the CesiumCloud server. New passwords must be at least 12 characters. By continuing you agree to the Terms of Service and Privacy Policy.

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