Add capacity to a service

A capacity add-on raises one limit of a service you already have, such as the number of ports on a Container Apps server, or turns on its automatic backups. Each add-on is a service of its own that renews with the service it is on, on the same date and billing cycle. You can remove it at any time. The Plan and add-ons card on a Container Apps server's Settings tab lists its add-ons, with Add… for each one you can add (Plan and add-ons). Once account plans open on your account, a Cloud Compute instance, a mail service and an Object Storage service have the same card, and Home offers the add-on that raises a limit you are close to (Home). Otherwise these steps use the API.

The same API can also price an order before you place it, with its add-ons and promo code.

Extra Port, Extra Database and Extra Mailbox take a quantity. A service takes at most 20 units of each kind, counting all its add-ons. Extra Object Storage 250 GB comes one add-on at a time, up to 20 on one service.

Automatic backups are add-ons too. Each service takes one, with no quantity:

The instance add-ons cost a share of the instance's price. Once account plans open on your account, the Business plan pays for them on up to three instances and the Enterprise plan on every instance. On an instance your plan covers, the list shows the add-on with included_by_plan set to true and price.text set to Included with your plan.

More websites come from a websites pack, which goes on your account rather than on a service. Order it on its own, as Order a service describes. GET /products/?product_group=addons lists it with the other add-ons.

Extra Backup Slots is not on sale yet, so a server's list leaves it out. To keep copies of a server, take snapshots by hand or on a schedule, or add automatic backups (Snapshots and backups compared).

• Get an access token for the API. Make your first API request shows how.
• The service must be active and not set to end. service_ref is its service ID, or the UUID of the server behind it.
• For extra mailboxes or storage, set up the included service first (Set up the services your plan includes), and use its id as service_ref.
• Adding an add-on charges the rest of the service's current period. Coritan takes the charge from your credit balance first (Add credit to your balance), and you pay what is left on the invoice.
• A team member working in your account needs the technical or admin role to add or remove an add-on. Any role can list them.

GET /services/{service_ref}/addons lists the add-ons a service has and the ones it can take:

curl https://api.coritan.com/api/v1/services/2210/addons \
  -H "Authorization: Bearer $CORITAN_TOKEN"

This answer for a server is shortened to two add-ons, and its prices may differ from today's:

{
  "parent": {
    "id": 2210,
    "product_name": "CX2",
    "module_name": "container",
    "status": "active",
    "billing_cycle": "monthly",
    "amount": "3.99",
    "next_due_date": "2026-10-14T00:00:00Z"
  },
  "attached": [],
  "available": [
    {
      "product": {"id": 88, "slug": "addon-server-ports", "name": "Extra Port", "description": "One more port on one Container Apps server."},
      "kind": "container_ports",
      "label": "extra ports",
      "adds": "+1 port",
      "unit": 1,
      "unit_label": "port",
      "fits": ["container"],
      "price": {"mode": "per_unit", "amount": "0.50", "cycle": "monthly", "setup_fee": "0.00", "percent": null, "text": "$0.50/mo each"},
      "max_quantity": 20,
      "addable": true,
      "included_by_plan": false,
      "reason_unavailable": null
    },
    {
      "product": {"id": 89, "slug": "addon-server-databases", "name": "Extra Database", "description": "One more database on one Container Apps server."},
      "kind": "container_databases",
      "label": "extra databases",
      "adds": "+1 database",
      "unit": 1,
      "unit_label": "database",
      "fits": ["container"],
      "price": {"mode": "per_unit", "amount": "0.50", "cycle": "monthly", "setup_fee": "0.00", "percent": null, "text": "$0.50/mo each"},
      "max_quantity": 20,
      "addable": true,
      "included_by_plan": false,
      "reason_unavailable": null
    }
  ]
}

parent

The service, with the billing cycle and the date that every add-on on it renews on.

attached

The add-ons the service has that have not ended, each as GET /services/{service_ref} returns a service, plus an addon block. A capacity add-on has addon.type set to capacity, with its quantity, what it adds, whether you can remove it now (removable) and, once you remove it at the end of the term, the date it ends (ends_at). A product bought with the service, such as a floating IP, has addon.type set to product, and you cancel it on its own (Cancel a service).

available

Every add-on for this kind of service, priced on its billing cycle. price.amount is for one unit when price.mode is per_unit, and for the whole add-on when it is fixed. max_quantity is the most one request can add now. When addable is false, reason_unavailable says why (Troubleshooting).

Send POST /services/{service_ref}/addons with an add-on from available:

curl -X POST https://api.coritan.com/api/v1/services/2210/addons \
  -H "Authorization: Bearer $CORITAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"product_id": 88, "quantity": 3}'

product_id

The add-on's product.id from available.

quantity

Optional, 1 when left out. How many units to add, up to the add-on's max_quantity. An add-on sold one at a time takes only 1.

billing_cycle

Optional. The add-on renews on the service's cycle, so leave it out or send that cycle.

promo_code

Optional. A promo code for the add-on. A code it cannot use refuses the request (Use a promo code).

The first invoice charges the rest of the service's current period: the add-on's price for the whole days left before the service renews, plus any setup fee. The day in progress counts as used. This server renews on Oct 14, 2026, with 17 of its 30 days left, so 3 extra ports at $0.50/mo each cost $0.85 now. The answer is 201, shortened here:

{
  "service": {
    "id": 2231,
    "product_name": "Extra Port",
    "module_name": "addon",
    "status": "pending",
    "billing_cycle": "monthly",
    "amount": 1.5,
    "config": {"quantity": 3, "addon_of_service_id": 2210, "renews_at": "2026-10-14T00:00:00"},
    "addon": {"type": "capacity", "kind": "container_ports", "label": "extra ports", "quantity": 3, "adds": "+3 ports", "removable": true, "ends_at": null, "included_by_plan": false}
  },
  "invoice_id": 5301,
  "requires_payment": true,
  "charge": "0.85",
  "discount": "0.00",
  "amount_due": "0.85",
  "renews_at": "2026-10-14T00:00:00Z",
  "renewal_amount": "1.50",
  "billing_cycle": "monthly",
  "message": "Pay the invoice to apply the add-on."
}

service

The add-on. Its id is the addon_ref you use to remove it.

charge, discount and amount_due

The first invoice, what a promo code took off it, and what is left to pay after your credit.

renews_at and renewal_amount

When the add-on renews with the service, and what it costs each cycle from then on.

The invoice has a line such as Extra Port, +3 ports (service #2231), to October 14, 2026. When requires_payment is true, pay invoice_id as Pay an invoice shows. message says what happened:

Once the invoice is paid, the add-on's status becomes active and the limit goes up:

• Extra ports and databases raise the server's Port slots and Database slots. In the dashboard, go to Container Apps, open the server, then the Settings tab. The Resources card shows both.
• Extra mailboxes and storage raise mailboxes and object_storage_gb in your plan's limits, and Coritan resizes the included service to match (Read your limits and usage).
• Automatic backups start on the server or the instance, as Automatic backups and How automatic backups run describe.

The add-on renews with the service at renewal_amount, on an invoice of its own.

Send DELETE /services/{service_ref}/addons/{addon_ref}, where addon_ref is the add-on's service ID. By default the add-on stays until the service renews, and nothing more is charged for it:

curl -X DELETE https://api.coritan.com/api/v1/services/2210/addons/2231 \
  -H "Authorization: Bearer $CORITAN_TOKEN"

{
  "service_id": 2231,
  "when": "end_of_term",
  "status": "active",
  "termination_date": "2026-10-14T00:00:00Z",
  "message": "The add-on ends on October 14, 2026, when this server renews. It stays until then."
}

To remove it at once, add ?when=now to the address. The answer's status is then pending_termination, and its message is Add-on removed. Its limit comes off the server in a moment.

When the limit comes off, Coritan deletes nothing. A server with more ports or databases than its slots keeps them, but you cannot add more until it is back under the limit. Extra mailboxes or storage that you use cannot be removed: delete what would be over the limit first.

An add-on whose invoice you have not paid ends at once, whichever when you send, and Coritan cancels its invoice. The message is then Add-on removed. It had not been applied yet.

A service's capacity add-ons end when the service does. When you cancel it, they end on the same date, or at once when you cancel immediately, and Coritan cancels their unpaid invoices. When a service ends for any other reason, such as an unpaid invoice, its add-ons end with it.

Extra ports and databases can also go in the order that creates a server. Put each one in the order's addons, as Add-ons in the order describes, with its product_id and a quantity of up to 20:

curl -X POST https://api.coritan.com/api/v1/services/order \
  -H "Authorization: Bearer $CORITAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "product_id": 12,
    "pricing_id": 34,
    "hostname": "survival-smp",
    "config": {"location": "fra", "name": "survival-smp", "specialization_slug": "minecraft-paper"},
    "addons": [{"product_id": 88, "quantity": 3}]
  }'

• GET /products/?product_group=addons lists the add-on products. Each one's addon block has its kind from What you can add.
• Leave out pricing_id and config. The add-on takes the server's billing cycle.
• List each add-on once. One service holds its whole quantity.
• The first invoice charges a whole billing cycle of the add-on, because the server starts its first cycle with it. A promo code in the order takes nothing off add-ons.
• When the order cannot take an add-on, it refuses the whole order and creates nothing.

A capacity add-on needs the service it goes on, so never order one on its own.

POST /checkout/quote takes the body of an order and answers what it would cost, without placing it. It works for any order, with or without add-ons and a promo code:

curl -X POST https://api.coritan.com/api/v1/checkout/quote \
  -H "Authorization: Bearer $CORITAN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "product_id": 12,
    "pricing_id": 34,
    "hostname": "survival-smp",
    "config": {"location": "fra", "name": "survival-smp", "specialization_slug": "minecraft-paper"},
    "addons": [{"product_id": 88, "quantity": 3}],
    "promo_code": "SPRING25"
  }'

This code gives 25% off the first 3 invoices:

{
  "lines": [
    {"label": "CX2", "amount": "3.99", "cycle": "monthly", "kind": "recurring"},
    {"label": "Extra Port, +3 ports", "amount": "1.50", "cycle": "monthly", "kind": "addon"}
  ],
  "subtotal": "5.49",
  "discount": "1.00",
  "due_now": "4.49",
  "requires_payment": true,
  "currency": "USD",
  "renews": [
    {"label": "CX2", "amount": "2.99", "cycle": "monthly"},
    {"label": "Extra Port, +3 ports", "amount": "1.50", "cycle": "monthly"}
  ],
  "promo": {
    "valid": true,
    "code": "SPRING25",
    "message": "SPRING25 applied: 25% off the first 3 invoices.",
    "reason": null,
    "summary": "25% off the first 3 invoices",
    "duration": "repeating",
    "cycles": 3
  }
}

lines

The lines of the order's first invoice. kind is recurring for the product you order, setup for its setup fee, and addon for anything bought with it. Each floating IP or Shield Custom Profile that your account plan would pay for has its own line, with an amount of 0.00 and a label that adds , included with your plan to the product's name, such as IPv4 Address, included with your plan. This holds when it is the order itself and when it is an add-on. Coritan waives its setup fee, so the quote has no setup fee line for it.

discount and due_now

What the promo code takes off the first invoice, and what is left to pay before the order starts. When you place the order, Coritan takes that from your credit first (How the first payment works). When nothing is due first, because the order costs nothing or your account is billed in arrears, due_now is 0.00 and requires_payment is false.

renews

What each renewal charges. When the code also covers renewals, the product's line shows the price after its discount. The code covers as many invoices as promo.cycles says, the first one included.

promo

null when the order has no promo_code. A code the order cannot use does not refuse the quote: valid is false, and reason is one of the words under Use a promo code.

Each code the quote refuses counts as one check towards the limit on POST /billing/promo/validate, which is 30 checks in ten minutes. Once your account reaches it, reason is rate_limited for every code. Wait a few minutes, then quote again. A code the quote accepts counts nothing.

The quote refuses what the order would refuse, with the same status and message (Troubleshooting and Order a service). It leaves out only the checks made as an order is placed: those on an order that costs $0, the same order sent twice, and a floating IP order's idempotency_key. A quote holds nothing for you, and the order checks everything again.

When a service cannot take an add-on, adding it answers 422 with {"detail": {"errors": ["<message>"]}}. The list shows the same message as the add-on's reason_unavailable, and an order or a quote gives it when the new server cannot take the add-on:

Adding an add-on can also answer 422 for what the request asks:

An order or a quote can also answer 422 with one of these:

Other answers when you add an add-on:

404 with Service not found, or 403 with Access denied

No service has that service_ref, or it belongs to another account.

404 with There is no product with id 99. Choose an add-on from this service's list.

product_id is wrong. Take it from available.

422 with promo beside errors

The promo code cannot be used on this add-on. promo is one of the reason words in Use a promo code. Send the request again without promo_code to pay the full price.

429 with "error": "rate_limited"

Your account added or removed add-ons 20 times in an hour. retry_after_seconds and the Retry-After header give the length of the window.

Removing an add-on can answer with one of these. A 422 holds its message in {"detail": {"errors": [...]}}, and the others hold it in detail:

• Order a service
• Use a promo code
• Cancel a service
• How account plans work