Grist

Grist is a modern relational spreadsheet. It combines the flexibility of a spreadsheet with the robustness of a database.

• grist-core (this repo) has what you need to run a powerful spreadsheet hosting server.
• grist-desktop is a Linux/macOS/Windows desktop app for viewing and editing spreadsheets stored locally.
• grist-static is a fully in-browser build of Grist for displaying spreadsheets on a website without back-end support.

The grist-core repo is the heart of Grist, including the hosted services offered by Grist Labs, an NYC-based company 🇺🇸 and Grist's main developer. The French government agency ANCT Données et Territoires 🇫🇷 has also made significant contributions to the codebase.

The grist-core, grist-desktop, and grist-static repositories are all open source (Apache License, Version 2.0).

Questions? Feedback? Want to share what you're building with Grist? Join our official Discord server or visit our Community forum.

https://user-images.githubusercontent.com/118367/151245587-892e50a6-41f5-4b74-9786-fe3566f6b1fb.mp4

Features

Grist is a hybrid database/spreadsheet, meaning that:

• Columns work like they do in databases: they are named, and they hold one kind of data.
• Columns can be filled by formula, spreadsheet-style, with automatic updates when referenced cells change.

This difference can confuse people coming directly from Excel or Google Sheets. Give it a chance! There's also a Grist for Spreadsheet Users article to help get you oriented. If you're coming from Airtable, you'll find the model familiar (and there's also our Grist vs Airtable article for a direct comparison).

Here are some specific feature highlights of Grist:

• Python formulas.
  • Full Python syntax is supported, including the standard library.
  • Many Excel functions also available.
  • An AI Assistant specifically tuned for formula generation (using OpenAI gpt-3.5-turbo or Llama via llama-cpp-python).
• A portable, self-contained format.
  • Based on SQLite, the most widely deployed database engine.
  • Any tool that can read SQLite can read numeric and text data from a Grist file.
  • Enables backups that you can confidently restore in full.
  • Great for moving between different hosts.
• Can be displayed on a static website with grist-static – no special server needed.
• A self-contained desktop app for viewing and editing locally: grist-desktop.
• Convenient editing and formatting features.
  • Choices and choice lists, for adding colorful tags to records.
  • References and reference lists, for cross-referencing records in other tables.
  • Attachments, to include media or document files in records.
  • Dates and times, toggles, and special numerics such as currency all have specialized editors and formatting options.
  • Conditional Formatting, letting you control the style of cells with formulas to draw attention to important information.
• Drag-and-drop dashboards.
  • Charts, card views and a calendar widget for visualization.
  • Summary tables for summing and counting across groups.
  • Widget linking streamlines filtering and editing data. Grist has a unique approach to visualization, where you can lay out and link distinct widgets to show together, without cramming mixed material into a table.
  • Filter bar for quick slicing and dicing.
• Incremental imports.
  • Import a CSV of the last three months activity from your bank...
  • ...and import new activity a month later without fuss or duplication.
• Integrations.
  • A REST API, Zapier actions/triggers, and support from similar integrators.
  • Import/export to Google drive, Excel format, CSV.
  • Link data with custom widgets, hosted externally.
  • Configurable outgoing webhooks.
• Many templates to get you started, from investment research to organizing treasure hunts.
• Access control options.
  • (You'll need SSO logins set up to make use of these options; grist-omnibus has a prepackaged solution if configuring this feels daunting)
  • Share individual documents, workspaces, or team sites.
  • Control access to individual rows, columns, and tables.
  • Control access based on cell values and user attributes.
• Self-maintainable.
  • Useful for intranet operation and specific compliance requirements.
• Sandboxing options for untrusted documents.
  • On Linux or with Docker, you can enable gVisor sandboxing at the individual document level.
  • On macOS, you can use native sandboxing.
  • On any OS, including Windows, you can use a wasm-based sandbox.
• Translated to many languages.
• F1 key brings up some quick help. This used to go without saying, but in general Grist has good keyboard support.
• We post progress on 𝕏 or Twitter or whatever and publish monthly newsletters.

If you are curious about where Grist is heading, see our roadmap, drop a question in our forum, or browse our extensive documentation.

Using Grist

If you just want a quick demo of Grist:

• You can try Grist out at the hosted service run by Grist Labs at docs.getgrist.com (no registration needed).
• Or you can see a fully in-browser build of Grist at gristlabs.github.io/grist-static.
• Or you can download Grist as a desktop app from github.com/gristlabs/grist-desktop.

To get the default version of grist-core running on your computer with Docker, do:

docker pull gristlabs/grist
docker run -p 8484:8484 -it gristlabs/grist

Then visit http://localhost:8484 in your browser. You'll be able to create, edit, import, and export documents. To preserve your work across docker runs, share a directory as /persist:

docker run -p 8484:8484 -v $PWD/persist:/persist -it gristlabs/grist

Get templates at templates.getgrist.com for payroll, inventory management, invoicing, D&D encounter tracking, and a lot more, or use any document you've created on docs.getgrist.com.

If you need to change the port Grist runs on, set a PORT variable, don't just change the port mapping:

docker run --env PORT=9999 -p 9999:9999 -v $PWD/persist:/persist -it gristlabs/grist

To enable gVisor sandboxing, set --env GRIST_SANDBOX_FLAVOR=gvisor. This should work with default docker settings, but may not work in all environments.

You can find a lot more about configuring Grist, setting up authentication, and running it on a public server in our Self-Managed Grist handbook.

Available Docker images

The default Docker image is gristlabs/grist. This contains all of the standard Grist functionality, as well as extra source-available code for enterprise customers taken from the the grist-ee repository. This extra code is not under a free or open source license. By default, however, the code from the grist-ee repository is completely inert and inactive. This code becomes active only when an administrator enables it by setting either GRIST_ACTIVATION or GRIST_ACTIVATION_FILE.

If you would rather use an image that contains exclusively free and open source code, the gristlabs/grist-oss Docker image is available for this purpose. It is by default functionally equivalent to the gristlabs/grist image.

The administrator panel

You can turn on a special admininistrator panel to inspect the status of your installation. Just visit /admin on your Grist server for instructions. Since it is useful for the admin panel to be available even when authentication isn't set up, you can give it a special access key by setting GRIST_BOOT_KEY.

docker run -p 8484:8484 -e GRIST_BOOT_KEY=secret -it gristlabs/grist

The boot page should then be available at /admin?boot-key=<GRIST_BOOT_KEY>. We are collecting probes for common problems there. If you hit a problem that isn't covered, it would be great if you could add a probe for it in BootProbes. You may instead file an issue so someone else can add it.

Building from source

To build Grist from source, follow these steps:

yarn install
yarn run build:prod
yarn run install:python
yarn start
# Grist will be available at http://localhost:8484/

Grist formulas in documents will be run using Python executed directly on your machine. You can configure sandboxing using a GRIST_SANDBOX_FLAVOR environment variable.

• On macOS, export GRIST_SANDBOX_FLAVOR=macSandboxExec uses the native sandbox-exec command for sandboxing.
• On Linux with gVisor's runsc installed, export GRIST_SANDBOX_FLAVOR=gvisor is an option.
• On any OS including Windows, export GRIST_SANDBOX_FLAVOR=pyodide is available.

These sandboxing methods have been written for our own use at Grist Labs and may need tweaking to work in your own environment - pull requests very welcome here!

Logins

Like git, Grist has features to track document revision history. So for full operation, Grist expects to know who the user modifying a document is. Until it does, it operates in a limited anonymous mode. To get you going, the docker image is configured so that when you click on the "sign in" button Grist will attribute your work to you@example.com. Change this by setting GRIST_DEFAULT_EMAIL:

docker run --env GRIST_DEFAULT_EMAIL=my@email -p 8484:8484 -v $PWD/persist:/persist -it gristlabs/grist

You can change your name in Profile Settings in the User Menu.

For multi-user operation, or if you wish to access Grist across the public internet, you'll want to connect it to your own Single Sign-On service. There are a lot of ways to do this, including SAML and forward authentication. Grist has been tested with Authentik, Auth0, and Google/Microsoft sign-ins via Dex.

Translations

We use Weblate to manage translations. Thanks to everyone who is pitching in. Thanks especially to the ANCT developers who did the hard work of making a good chunk of the application localizable. Merci beaucoup !

Why free and open source software

This repository, grist-core, is maintained by Grist Labs. Our flagship product available at getgrist.com is built from the code you see here, combined with business-specific software designed to scale to many users, handle billing, etc.

Grist Labs is an open-core company. We offer Grist hosting as a service, with free and paid plans. We also develop and sell features related to Grist using a proprietary license, targeted at the needs of enterprises with large self-managed installations.

We see data portability and autonomy as a key value, and grist-core is an essential part of that. We are committed to maintaining and improving the grist-core codebase, and to be thoughtful about how proprietary offerings impact data portability and autonomy.

By opening its source code and offering an OSI-approved free license, Grist benefits its users:

• Developer community. The freedom to examine source code, make bug fixes, and develop new features is a big deal for a general-purpose spreadsheet-like product, where there is a very long tail of features vital to someone somewhere.
• Increased trust. Because anyone can examine the source code, “security by obscurity” is not an option. Vulnerabilities in the code can be found by others and reported before they cause damage.
• Independence. Grist is available to you regardless of the fortunes of the Grist Labs business, since it is open source and can be self-hosted. Using our hosted solution is convenient, but you are not locked in.
• Price flexibility. If you are low on funds but have time to invest, self-hosting is a great option to have. And DIY users may have the technical savvy and motivation to delve in and make improvements, which can benefit all users of Grist.
• Extensibility. For developers, having the source open makes it easier to build extensions (such as Custom Widgets). You can more easily include Grist in your pipeline. And if a feature is missing, you can just take the source code and build on top of it.

For more on Grist Labs' history and principles, see our About Us page.

Sponsors

Reviews

• Grist on ProductHunt
• Grist on AppSumo (life-time deal is sold out)
• Capterra, G2, TrustRadius

Environment variables

Grist can be configured in many ways. Here are the main environment variables it is sensitive to:

Variable	Purpose
ALLOWED_WEBHOOK_DOMAINS	comma-separated list of permitted domains to use in webhooks (e.g. webhook.site,zapier.com). You can set this to * to allow all domains, but if doing so, we recommend using a carefully locked-down proxy (see GRIST_HTTPS_PROXY) if you do not entirely trust users. Otherwise services on your internal network may become vulnerable to manipulation.
APP_DOC_URL	doc worker url, set when starting an individual doc worker (other servers will find doc worker urls via redis)
APP_DOC_INTERNAL_URL	like APP_DOC_URL but used by the home server to reach the server using an internal domain name resolution (like in a docker environment). It only makes sense to define this value in the doc worker. Defaults to APP_DOC_URL.
APP_HOME_URL	url prefix for home api (home and doc servers need this)
APP_HOME_INTERNAL_URL	like APP_HOME_URL but used by the home and the doc servers to reach any home workers using an internal domain name resolution (like in a docker environment). Defaults to APP_HOME_URL
APP_STATIC_URL	url prefix for static resources
APP_STATIC_INCLUDE_CUSTOM_CSS	set to "true" to include custom.css (from APP_STATIC_URL) in static pages
APP_UNTRUSTED_URL	URL at which to serve/expect plugin content.
GRIST_ADAPT_DOMAIN	set to "true" to support multiple base domains (careful, host header should be trustworthy)
GRIST_APP_ROOT	directory containing Grist sandbox and assets (specifically the sandbox and static subdirectories).
GRIST_BACKUP_DELAY_SECS	wait this long after a doc change before making a backup
GRIST_BOOT_KEY	if set, offer diagnostics at /boot/GRIST_BOOT_KEY
GRIST_DATA_DIR	Directory in which to store documents. Defaults to docs/ relative to the Grist application directory. In Grist's default Docker image, its default value is /persist/docs so that it will be used as a mounted volume.
GRIST_DEFAULT_EMAIL	if set, login as this user if no other credentials presented
GRIST_DEFAULT_PRODUCT	if set, this controls enabled features and limits of new sites. See names of PRODUCTS in Product.ts.
GRIST_DEFAULT_LOCALE	Locale to use as fallback when Grist cannot honour the browser locale.
GRIST_DOMAIN	in hosted Grist, Grist is served from subdomains of this domain. Defaults to "getgrist.com".
GRIST_EXPERIMENTAL_PLUGINS	enables experimental plugins
GRIST_ENABLE_REQUEST_FUNCTION	enables the REQUEST function. This function performs HTTP requests in a similar way to requests.request. This function presents a significant security risk, since it can let users call internal endpoints when Grist is available publicly. This function can also cause performance issues. Unset by default.
GRIST_HIDE_UI_ELEMENTS	comma-separated list of UI features to disable. Allowed names of parts: helpCenter,billing,templates,createSite,multiSite,multiAccounts,sendToDrive,tutorials,supportGrist. If a part also exists in GRIST_UI_FEATURES, it will still be disabled.
GRIST_HOST	hostname to use when listening on a port.
GRIST_HTTPS_PROXY	if set, use this proxy for webhook payload delivery.
GRIST_ID_PREFIX	for subdomains of form o-, expect or produce o-${GRIST_ID_PREFIX}.
GRIST_IGNORE_SESSION	if set, Grist will not use a session for authentication.
GRIST_INCLUDE_CUSTOM_SCRIPT_URL	if set, will load the referenced URL in a <script> tag on all app pages.
GRIST_INST_DIR	path to Grist instance configuration files, for Grist server.
GRIST_LIST_PUBLIC_SITES	if set to true, sites shared with the public will be listed for anonymous users. Defaults to false.
GRIST_MANAGED_WORKERS	if set, Grist can assume that if a url targeted at a doc worker returns a 404, that worker is gone
GRIST_MAX_UPLOAD_ATTACHMENT_MB	max allowed size for attachments (0 or empty for unlimited).
GRIST_MAX_UPLOAD_IMPORT_MB	max allowed size for imports (except .grist files) (0 or empty for unlimited).
GRIST_OFFER_ALL_LANGUAGES	if set, all translated langauages are offered to the user (by default, only languages with a special 'good enough' key set are offered to user).
GRIST_ORG_IN_PATH	if true, encode org in path rather than domain
GRIST_PAGE_TITLE_SUFFIX	a string to append to the end of the <title> in HTML documents. Defaults to " - Grist". Set to _blank for no suffix at all.
~GRIST_PROXY_AUTH_HEADER~	Deprecated, and interpreted as a synonym for GRIST_FORWARD_AUTH_HEADER.
GRIST_ROUTER_URL	optional url for an api that allows servers to be (un)registered with a load balancer
GRIST_SERVE_SAME_ORIGIN	set to "true" to access home server and doc workers on the same protocol-host-port as the top-level page, same as for custom domains (careful, host header should be trustworthy)
GRIST_SERVERS	the types of server to setup. Comma separated values which may contain "home", "docs", static" and/or "app". Defaults to "home,docs,static".
GRIST_SESSION_COOKIE	if set, overrides the name of Grist's cookie
GRIST_SESSION_DOMAIN	if set, associates the cookie with the given domain - otherwise defaults to GRIST_DOMAIN
GRIST_SESSION_SECRET	a key used to encode sessions
GRIST_SKIP_BUNDLED_WIDGETS	if set, Grist will ignore any bundled widgets included via NPM packages.
GRIST_ANON_PLAYGROUND	When set to 'false' deny anonymous users access to the home page
GRIST_FORCE_LOGIN	Much like GRIST_ANON_PLAYGROUND but don't support anonymous access at all (features like sharing docs publicly requires authentication)
GRIST_SINGLE_ORG	set to an org "domain" to pin client to that org
GRIST_TEMPLATE_ORG	set to an org "domain" to show public docs from that org
GRIST_HELP_CENTER	set the help center link ref
GRIST_TERMS_OF_SERVICE_URL	if set, adds terms of service link
FREE_COACHING_CALL_URL	set the link to the human help (example: email adress or meeting scheduling tool)
GRIST_CONTACT_SUPPORT_URL	set the link to contact support on error pages (example: email adress or online form)
GRIST_SUPPORT_ANON	if set to 'true', show UI for anonymous access (not shown by default)
GRIST_SUPPORT_EMAIL	if set, give a user with the specified email support powers. The main extra power is the ability to share sites, workspaces, and docs with all users in a listed way.
GRIST_TELEMETRY_LEVEL	the telemetry level. Can be set to: off (default), limited, or full.
GRIST_THROTTLE_CPU	if set, CPU throttling is enabled
GRIST_TRUST_PLUGINS	if set, plugins are expect to be served from the same host as the rest of the Grist app, rather than from a distinct host. Ordinarily, plugins are served from a distinct host so that the cookies used by the Grist app are not automatically available to them. Enable this only if you understand the security implications.
GRIST_USER_ROOT	an extra path to look for plugins in - Grist will scan for plugins in $GRIST_USER_ROOT/plugins.
GRIST_UI_FEATURES	comma-separated list of UI features to enable. Allowed names of parts: helpCenter,billing,templates,createSite,multiSite,multiAccounts,sendToDrive,tutorials,supportGrist. If a part also exists in GRIST_HIDE_UI_ELEMENTS, it won't be enabled.
GRIST_UNTRUSTED_PORT	if set, plugins will be served from the given port. This is an alternative to setting APP_UNTRUSTED_URL.
GRIST_WIDGET_LIST_URL	a url pointing to a widget manifest, by default https://github.com/gristlabs/grist-widget/releases/download/latest/manifest.json is used
COOKIE_MAX_AGE	session cookie max age, defaults to 90 days; can be set to "none" to make it a session cookie
HOME_PORT	port number to listen on for REST API server; if set to "share", add API endpoints to regular grist port.
PORT	port number to listen on for Grist server
REDIS_URL	optional redis server for browser sessions and db query caching
GRIST_SNAPSHOT_TIME_CAP	optional. Define the caps for tracking buckets. Usage: {"hour": 25, "day": 32, "isoWeek": 12, "month": 96, "year": 1000}
GRIST_SNAPSHOT_KEEP	optional. Number of recent snapshots to retain unconditionally for a document, regardless of when they were made
GRIST_PROMCLIENT_PORT	optional. If set, serve the Prometheus metrics on the specified port number. ⚠️ Be sure to use a port which is not publicly exposed ⚠️.

AI Formula Assistant related variables (all optional):

Variable	Purpose
ASSISTANT_API_KEY	optional. An API key to pass when making requests to an external AI conversational endpoint.
ASSISTANT_CHAT_COMPLETION_ENDPOINT	optional. A chat-completion style endpoint to call. Not needed if OpenAI is being used.
ASSISTANT_MODEL	optional. If set, this string is passed along in calls to the AI conversational endpoint.
ASSISTANT_LONGER_CONTEXT_MODEL	optional. If set, requests that fail because of a context length limitation will be retried with this model set.
OPENAI_API_KEY	optional. Synonym for ASSISTANT_API_KEY that assumes an OpenAI endpoint is being used. Sign up for an account on OpenAI and then generate a secret key here.

At the time of writing, the AI Assistant is known to function against OpenAI chat completion endpoints for gpt-3.5-turbo and gpt-4. It can also function against the chat completion endpoint provided by llama-cpp-python.

Sandbox related variables:

Variable	Purpose
GRIST_SANDBOX_FLAVOR	can be gvisor, pynbox, unsandboxed, docker, or macSandboxExec. If set, forces Grist to use the specified kind of sandbox.
GRIST_SANDBOX	a program or image name to run as the sandbox. See NSandbox.ts for nerdy details.
PYTHON_VERSION	can be 2 or 3. If set, documents without an engine setting are assumed to use the specified version of python. Not all sandboxes support all versions.
PYTHON_VERSION_ON_CREATION	can be 2 or 3. If set, newly created documents have an engine setting set to python2 or python3. Not all sandboxes support all versions.

Forward authentication variables:

Variable	Purpose
GRIST_FORWARD_AUTH_HEADER	if set, trust the specified header (e.g. "x-forwarded-user") to contain authorized user emails, and enable "forward auth" logins.
GRIST_FORWARD_AUTH_LOGIN_PATH	if GRIST_FORWARD_AUTH_HEADER is set, Grist will listen at this path for logins. Defaults to /auth/login.
GRIST_FORWARD_AUTH_LOGOUT_PATH	if GRIST_FORWARD_AUTH_HEADER is set, Grist will forward to this path when user logs out.

Forward authentication supports two modes, distinguished by GRIST_IGNORE_SESSION:

1. With sessions, and forward-auth on login endpoints.

   For example, using traefik reverse proxy with traefik-forward-auth middleware:

   • GRIST_IGNORE_SESSION: do NOT set, or set to a falsy value.
   • Make sure your reverse proxy applies the forward auth middleware to GRIST_FORWARD_AUTH_LOGIN_PATH and GRIST_FORWARD_AUTH_LOGOUT_PATH.
   • If you want to allow anonymous access in some cases, make sure all other paths are free of the forward auth middleware. Grist will trigger it as needed by redirecting to GRIST_FORWARD_AUTH_LOGIN_PATH. Once the user is logged in, Grist will use sessions to identify the user until logout.

2. With no sessions, and forward-auth on all endpoints.

   For example, using HTTP Basic Auth and server configuration that sets the header (specified in GRIST_FORWARD_AUTH_HEADER) to the logged-in user.

• GRIST_IGNORE_SESSION: set to true. Grist sessions will not be used.
• Make sure your reverse proxy sets the header you specified for all requests that may need login information. It is imperative that this header cannot be spoofed by the user, since Grist will trust whatever is in it.

When using forward authentication, you may wish to also set the following variables:

• GRIST_FORCE_LOGIN=true to disable anonymous access.

Plugins:

Grist has a plugin system, used internally. One useful thing you can do with it is include custom widgets in a build of Grist. Custom widgets are usually made available just by setting GRIST_WIDGET_LIST_URL, but that has the downside of being an external dependency, which can be awkward for offline use or for archiving. Plugins offer an alternative.

To "bundle" custom widgets as a plugin:

• Add a subdirectory of plugins, e.g. plugins/my-widgets. Alternatively, you can set the GRIST_USER_ROOT environment variable to any path you want, and then create plugins/my-widgets within that.
• Add a manifest.yml file in that subdirectory that looks like this:

name: My Widgets
components:
  widgets: widgets.json

• The widgets.json file should be in the format produced by the grist-widget repository, and should be placed in the same directory as manifest.yml. Any material in plugins/my-widgets will be served by Grist, and relative URLs can be used in widgets.json.
• Once all files are in place, restart Grist. Your widgets should now be available in the custom widgets dropdown, along with any others from GRIST_WIDGET_LIST_URL.
• If you like, you can add multiple plugin subdirectories, with multiple sets of widgets, and they'll all be made available.

Google Drive integrations:

Variable	Purpose
GOOGLE_CLIENT_ID	set to the Google Client Id to be used with Google API client
GOOGLE_CLIENT_SECRET	set to the Google Client Secret to be used with Google API client
GOOGLE_API_KEY	set to the Google API Key to be used with Google API client (accessing public files)
GOOGLE_DRIVE_SCOPE	set to the scope requested for Google Drive integration (defaults to drive.file)

Database variables:

Variable	Purpose
TYPEORM_DATABASE	database filename for sqlite or database name for other db types
TYPEORM_HOST	host for db
TYPEORM_LOGGING	set to 'true' to see all sql queries
TYPEORM_PASSWORD	password to use
TYPEORM_PORT	port number for db if not the default for that db type
TYPEORM_TYPE	set to 'sqlite' or 'postgres'
TYPEORM_USERNAME	username to connect as
TYPEORM_EXTRA	any other properties to pass to TypeORM in JSON format

Testing:

Variable	Purpose
GRIST_TESTING_SOCKET	a socket used for out-of-channel communication during tests only.
GRIST_TEST_HTTPS_OFFSET	if set, adds https ports at the specified offset. This is useful in testing.
GRIST_TEST_SSL_CERT	if set, contains filename of SSL certificate.
GRIST_TEST_SSL_KEY	if set, contains filename of SSL private key.
GRIST_TEST_LOGIN	allow fake unauthenticated test logins (suitable for dev environment only).
GRIST_TEST_ROUTER	if set, then the home server will serve a mock version of router api at /test/router
GREP_TESTS	pattern for selecting specific tests to run (e.g. env GREP_TESTS=ActionLog yarn test).

Tests

Tests are run automatically as part of CI when a PR is opened. However, it can be helpful to run tests locally before pushing your changes to GitHub. First, you'll want to make sure you've installed all dependencies:

yarn install
yarn install:python

Then, you can run the main test suite like so:

yarn test

Python tests may also be run locally. (Note: currently requires Python 3.9 - 3.11.)

yarn test:python

For running specific tests, you can specify a pattern with the GREP_TESTS variable:

env GREP_TESTS=ChoiceList yarn test
env GREP_TESTS=summary yarn test:python

License

This repository, grist-core, is released under the Apache License, Version 2.0, which is an OSI-approved free software license. See LICENSE.txt and NOTICE.txt for more information.