Organizations (groups, classes)

An organization groups users (a class, a school team, a club) so they get their own ranking and members-only problems, contests, quizzes and posts. This page is for members and organization managers alike.

⏱ ~20 min · 👤 Teachers, club leaders, members · 🔑 None to join; judge.add_organization to create one

Before you start

• You have an LCOJ account and are logged in (see Account).
• To join: you know the organization's name or link (like https://luyencode.net/organization/<slug>).
• To manage: you are an admin of the organization, or you have asked an LCOJ administrator to create one for you.

What an organization is

Each organization has its own page at /organization/<slug> with the tabs Home, Users, Problems list, Contests list and Submissions.

Use	Example
Class	A teacher assigns problems and tests to class 10A1 and checks which problems each student has solved.
School team	The school's informatics team runs private mock contests with an internal ranking.
Club	Club news is posted as members-only posts.

What members and visitors can see:

Content	Visitors / non-members	Members	Organization admins
About page, member list	✅	✅	✅
Organization posts	❌	✅ (published posts)	✅ (including their own drafts)
Organization problems, contests, submissions	❌	✅	✅
Review requests, kick, edit, view costs	❌	❌	✅

Joining and leaving

There are two kinds of organization, set by the Is open organization? box (is_open):

• Open (is_open on): click Join organization and you are in.
• Closed (is_open off): click Request membership, give a reason, and wait for an admin to approve.

Joining an open organization

1. Go to /organizations/ (or the organization link you were given).
2. Open the organization and click Join organization in the Controls box.

You can also pick open organizations in the organizations box on your profile edit page /edit/profile/.

Organization limit

Each user can be in at most DMOJ_USER_MAX_ORGANIZATION_COUNT open organizations (3 on luyencode.net). Closed organizations do not count toward this limit.

Requesting to join a closed organization

1. Open the organization page and click Request membership.
2. Fill in Your reason for joining: (required), for example "I'm Nguyen Van A from class 10A1", then click Request!.
3. You land on the Join request detail page (/organization/<slug>/request/<id>), which shows its State: Pending, Approved or Rejected. LCOJ does not notify you when it is approved; check the organization page again later.

While one request is pending you cannot send another. If it is rejected, you can request again.

Leaving

Click Leave organization on the organization page. Admins cannot leave their own organization (You cannot leave an organization you own.).

Creating an organization

Organizations are usually created by an LCOJ administrator. There are two ways:

Way	Path	Permission
On the site	/organizations/create (the Create new organization tab on /organizations/)	judge.add_organization
Django admin	/admin/judge/organization/add/	Staff + judge.add_organization

Main fields:

Field	English label	Meaning
name	Organization title	Display name, up to 128 characters.
slug	Organization slug	Used in the URL /organization/<slug> and as the key prefix for problems and contests. Unique, must start with a letter; only letters, digits, -, _.
short_name	Short name	Up to 20 characters, shown beside usernames in contests. When created on the site, LCOJ sets it to the first 20 characters of the slug; it can only be changed in the admin.
about	Organization description	Required. Markdown shown on the organization home page.
is_open	Is open organization?	Open or closed (see above).
is_unlisted	Is unlisted organization?	(Admin only) Hides it from the /organizations/ list. On by default, so a new organization is not listed until someone unticks this in the admin.
slots	Maximum size	(Admin only) Member limit, only checked when approving requests to a closed organization.
admins	Administrators	The people who manage the organization.
logo_override_image	Logo override image	Image URL that replaces the site logo while viewing the organization.
paid_credit, monthly_free_credit_limit	—	Judging credit, see Storage, quotas and credit.

The creator does not become an admin automatically

The Administrators box (and the two credit boxes) on the site form is only shown to users with judge.organization_admin. If you create an organization without that permission, it ends up with no admins at all, not even you. Ask an LCOJ administrator to add you in the admin. Likewise, in the admin, Administrators, Is open organization? and Maximum size are only editable with organization_admin.

Limits and the "Org Admin" group

• Users who already administer VNOJ_ORGANIZATION_ADMIN_LIMIT organizations (3 on luyencode.net) cannot create more on the site. The spam_organization permission lifts this limit, but currently only for superusers (see Permissions).
• Whenever the organization form is saved on the site, every admin is added to the Django group named by GROUP_PERMISSION_FOR_ORG_ADMIN (default Org Admin). Operators must create this group beforehand and give it the permissions organization admins need, such as create_organization_problem, create_private_contest, edit_organization_post. If the group does not exist, saving the form fails. Admins added in the Django admin are not added to the group; add them by hand.

Organization admin tasks

Organization admins are the users in the Administrators list (or users with edit_all_organization). The management links are in the Controls box on the organization home page and in the tabs on the right.

Reviewing join requests

1. On the organization page, click View requests (the badge shows the number of pending requests). The page is /organization/<slug>/requests/pending.
2. For each request, read the Reason (click the time to see details), then set the State to Approved or Rejected, or tick Delete? to remove it.
3. Click Update. Approved users become members immediately.
4. Review the history in the Log, Approved and Rejected tabs.

If the organization has a Maximum size and you approve more people than the free slots, LCOJ rejects the whole update and tells you how many slots are left.

INFO

Only users in the Administrators list can open the request pages; edit_all_organization is not enough.

Kicking members

1. Open the Users tab (/organization/<slug>/users/).
2. Click Kick on the member's row and confirm.

Other admins cannot be kicked.

Editing the organization

Click Edit organization (/organization/<slug>/edit). On the site, admins can change the title, slug, Is open organization?, description and logo. Users with organization_admin can also change the admin list and credit. Users with add_organizationquota also see a Quota Grants section (see below). The other fields (short name, unlisted, maximum size) can only be changed via Admin organization (the admin page).

Changing the slug

Changing the slug changes the organization URL and the key prefix for new problems and contests. Existing problems and contests keep their keys, but they cannot be edited on the site until their keys match the new prefix.

Key prefix

Problems and contests created in an organization must have a key that starts with the organization prefix: the slug in lowercase with every non-alphanumeric character removed, followed by _. For example, the slug THPT-Chuyen-A gives the prefix thptchuyena_. The key box on the create forms is prefilled with the prefix.

Organization problems

1. On the organization page, click the Create new problem tab (/organization/<slug>/problem-create). Requires create_organization_problem.
2. Keep the prefix in the problem code. A wrong prefix shows Problem id code must starts with <prefix>.
3. The problem is marked organization-private. Tick public so all members can see it, or leave it private and pick the Private users who may see it.
4. Attach organization tags to it (see Organization problem tags).

Members see the organization's public problems in the Problems list tab, plus problems they author, curate or test. For writing statements and tests, see Managing problems.

Organization contests

Click the Create new contest tab (/organization/<slug>/contest-create, requires create_private_contest). The contest is automatically private to organizations; remember to turn on Publicly visible so members can see it. Organization contests appear in the Contests list tab and also on /contests/ (users can tick Hide private contests to hide them). Details: see Creating and managing contests.

Organization quizzes

There is no quiz create page inside organizations. When authoring a quiz, tick Publicly visible and Private to organizations, then pick the organization. See Creating and managing quizzes.

Organization posts

1. Click Create blog post in the Controls box (/organization/<slug>/post/new). Requires edit_organization_post.
2. Write the post and set the publish time (defaults to now).

Posts appear on the organization home page and only members can read them. Unlike personal blog posts, there is no minimum solved-problem count.

Organization problem tags

Each organization has its own tag set, separate from LCOJ's global problem tags.

1. Click the Manage tags tab (/organization/<slug>/tags/).
2. Click Create new tag, enter a name (unique within the organization) and save. Rename or delete tags in the Actions column; the Problems column shows how many problems use each tag.
3. Attach tags when creating or editing organization problems.

Members can filter problems by tag (or show untagged problems) in the Problems list tab.

Member solved problems

In the Users tab, admins see an extra Solved problems column; click View (/organization/<slug>/user/<username>/solved) to see which organization problems that member has solved, grouped by organization tag (untagged problems last).

Member ranking and organization points

The Users tab is an internal ranking, sorted by performance points by default; it can also be sorted by points, solved count or rating. Users who set themselves as unlisted do not appear. The link /organization/<slug>/users/find?handle=<username> jumps straight to that user's page of the ranking.

An organization's Points (the Points column on /organizations/) come from the performance points of its top 100 members:

org points = VNOJ_ORG_PP_SCALE × (pp[0] + 0.95 × pp[1] + 0.95² × pp[2] + … + 0.95⁹⁹ × pp[99])

where pp[i] is the performance points of the member ranked i (starting at 0). The constants are VNOJ_ORG_PP_STEP = 0.95, VNOJ_ORG_PP_ENTRIES = 100, VNOJ_ORG_PP_SCALE = 1 (luyencode.net uses the defaults). Points update when members join or leave; the admin has a Recalculate scores action.

Storage, quotas and credit

Admins click Organization cost (/organization/<slug>/usage) to see:

• Quotas: problem count and test data storage used versus the limits, plus the active quota packages (Active Quota Grants).
• Pie charts of problem count and storage by last submission time (no submissions, 12+ months, 9–12, 6–9, 3–6, under 3 months), to find old problems to clean up.
• A problem table sorted by test data size, filterable by author (among the admins) or last submission time.
• Bulk delete: tick problems and click Delete Selected (up to 200 at a time). Non-superusers can only delete problems they author or curate. Problems are only marked as deleted (soft delete); the periodic garbage collector removes them for good after VNOJ_PROBLEM_DELETION_GRACE_PERIOD (7 days).
• Judging credit: the Organization Monthly Credit usage and Organization Monthly cost charts, plus the remaining free and paid credit.

Quotas: maximum problems = VNOJ_ORGANIZATION_DEFAULT_MAX_PROBLEMS + active packages; maximum storage = VNOJ_ORGANIZATION_DEFAULT_MAX_STORAGE + packages. Storage is the total size of the test data zip files of non-deleted problems. Users with add_organizationquota add packages on the Edit organization page (the Add Quota Grant section: start date, Number of packages, end date, one year by default) or in the admin (storage in GB).

Credit: every submission to an organization-private problem, or inside an organization-private contest, consumes credit equal to its total judging time. The monthly free credit is used first, then paid credit. The cost chart computes (seconds used − VNOJ_MONTHLY_FREE_CREDIT) / 3600 × VNOJ_PRICE_PER_HOUR thousand VND.

Setting	Default	luyencode.net	Meaning
VNOJ_ENABLE_ORGANIZATION_CREDIT_LIMITATION	False	False	When on, blocks submissions once the organization is out of credit. luyencode.net does not block; credit is tracked only.
VNOJ_MONTHLY_FREE_CREDIT	10800 (3 hours)	3 hours	Free credit per month (seconds).
VNOJ_PRICE_PER_HOUR	50	50	Price per judging hour above the free amount (thousand VND), used only for the chart.
VNOJ_ORGANIZATION_DEFAULT_MAX_PROBLEMS	1000	1000	Default problem limit.
VNOJ_ORGANIZATION_DEFAULT_MAX_STORAGE	5 GB	5 GB	Default test data storage limit.
VNOJ_QUOTA_ENFORCEMENT_ENABLED	False	False	When on, blocks creating problems/uploading tests over quota. luyencode.net only warns.
VNOJ_QUOTA_WARNING_THRESHOLD	0.8	0.8	Warn from 80% of the quota.
VNOJ_QUOTA_WARNING_SUFFIX	''	''	HTML appended to quota warnings (for example a link to a guide).
VNOJ_QUOTA_PACKAGE_PROBLEMS, VNOJ_QUOTA_PACKAGE_STORAGE	1000, 5 GB	default	Problems and storage added by each quota package.

For operators

Closing the month's figures and refilling free credit on the 1st of each month is the organization_monthly_reset periodic task, run by Celery beat. LCOJ's Docker setup only runs a Celery worker, so this task (like the deleted-problem garbage collector) does not run unless you add beat. The backfill_current_credit and backfill_monthly_credit commands recompute credit figures.

Organization subdomains

LCOJ ships an OrganizationSubdomainMiddleware for opening organizations on subdomains (like <slug>.example.com), but it is not enabled in the default MIDDLEWARE, so the feature is inactive on luyencode.net. To enable it, an operator must add the middleware, set up DNS/proxy for the subdomains, and list non-organization subdomains in VNOJ_IGNORED_ORGANIZATION_SUBDOMAINS (default ['oj', 'www', 'localhost']). For luyencode.net the first host label is luyencode, so luyencode (and dev) must be added to that list, or every page returns 404.

Verify

• The organization is listed at /organizations/ (once Is unlisted organization? is off) or opens at /organization/<slug>.
• A member account sees the Problems list and Contests list tabs; a non-member gets Cannot view organization's private data.
• A test join request shows up under View requests and can be approved.
• The Organization cost page shows the right problem count and storage.

Troubleshooting

Symptom	Cause and fix
The organization is not listed at /organizations/	It is unlisted (the default). Ask an administrator to untick Is unlisted organization? in the admin, or share the direct link.
You may not be part of more than 3 public organizations.	You are already in 3 open organizations. Leave one.
No Join organization button, only Request membership	The organization is closed. Send a request and wait.
A second request is refused	You already have a pending request. Wait for an admin.
Approving says the organization can only receive N more members	Maximum size is reached. Raise it in the admin or approve fewer people.
Created an organization but cannot manage it	The creator is not made an admin automatically. Ask an LCOJ administrator to add you to Administrators.
A Can't create organization page lists the organizations you manage	You already administer 3 organizations (VNOJ_ORGANIZATION_ADMIN_LIMIT). Ask a superuser to create it.
Saving the organization form on the site gives a server error	The Org Admin group does not exist. An operator creates it at /admin/auth/group/.
Admins do not see Create new problem / Create new contest / Create blog post	Missing create_organization_problem / create_private_contest / edit_organization_post. Grant them via the Org Admin group or directly.
Problem id code must starts with …	Wrong problem code prefix. See Key prefix.
Kick says the user is an admin of the organization	Admins cannot be kicked. Remove them from Administrators in the admin first.
Members cannot see an organization problem	The problem is private. Make it public, or add them to Private users.

Next steps

• Creating and managing contests: private contests for a class.
• Managing problems: writing problems for the organization.
• Creating and managing quizzes: organization-only quizzes.
• Permissions: permissions for organization admins.