# Charge a payer on a schedule from a saved method

`POST /subscriptions` · Skerry · Payers, saved methods and subscriptions

Charge a payer on a schedule from a saved method. Needs an Idempotency-Key. Under a mandate that covers `subscription.create`, the amount of one period (integer minor units) is checked against the mandate and counted once.

- Scope: payments:write
- Moves money: yes
- Idempotency: required
- Untrusted: reference, external_ref, metadata

## Parameters

- `Idempotency-Key` (header, required), string: A repeat with the same key and body returns the first answer instead of acting twice.

## Request body

`application/json`

```json
{
  "type": "object",
  "required": [
    "customer_id",
    "payer_id",
    "payment_method_id",
    "currency",
    "interval",
    "items"
  ],
  "properties": {
    "customer_id": {
      "type": "string",
      "maxLength": 200
    },
    "payer_id": {
      "type": "string",
      "maxLength": 200
    },
    "payment_method_id": {
      "type": "string",
      "maxLength": 200
    },
    "currency": {
      "type": "string",
      "pattern": "^[A-Za-z]{3}$"
    },
    "interval": {
      "type": "string",
      "maxLength": 40
    },
    "interval_count": {
      "type": "integer",
      "minimum": 1
    },
    "items": {
      "type": "array",
      "minItems": 1,
      "items": {
        "type": "object",
        "required": [
          "name",
          "amount"
        ],
        "properties": {
          "name": {
            "type": "string",
            "maxLength": 500
          },
          "amount": {
            "type": "integer",
            "minimum": 1,
            "description": "Integer minor units of `currency`, for one unit."
          },
          "quantity": {
            "type": "integer",
            "minimum": 1
          }
        }
      }
    },
    "trial_days": {
      "type": "integer",
      "minimum": 0
    },
    "reference": {
      "type": "string",
      "maxLength": 500
    },
    "external_ref": {
      "type": "string",
      "maxLength": 200,
      "description": "The document this belongs to in your own system."
    },
    "external_kind": {
      "type": "string",
      "enum": [
        "invoice",
        "bill",
        "order",
        "booking",
        "other"
      ]
    },
    "dry_run": {
      "type": "boolean",
      "description": "Check the request and report what would happen, without doing it."
    }
  }
}
```

## Responses

- `200`: Success.
- `202`: requires_approval — Not an error: the operation is held for a person. The body names the approval.
- `400`: price_below_minimum — The price is below the smallest single payment for a method (`detail.method`, `detail.minimum`), or has a part of a cent. Set `credit_only`, raise the price, or drop the method.
- `401`: dpop_invalid — The token is bound to a key and the DPoP proof was missing, wrong for this request, or already used.
- `402`: payment_failed — The payer's bank or card refused. `detail.reason` says why in plain terms.
- `403`: agent_payment_over_max — The merchant asks for more than `max_amount`. Nothing was signed. `detail.asked_minor` is the lowest price asked, in US cents.
- `404`: not_found — No such object in this project — including one that belongs to somebody else.
- `409`: token_not_issued — A delegated payment token could not be issued ready to use, for instance because the payer would have to act. Nothing was sent to the merchant.
- `429`: too_many_waiters — This key already has as many requests waiting (`?wait=`) as it may. Let one finish, or read without wait.
- `500`: internal_error — Ours. Quote the `request_id` and we can find the call.
- `502`: platform_error — A provider failed. Safe to retry with the same Idempotency-Key.
- `503`: oauth_unavailable — The authorisation server's keys could not be read, so tokens cannot be checked. API keys still work.

## Example

```sh
curl -X POST 'https://api.skerry.xyz/subscriptions' \
  -H 'Authorization: Bearer $KEY' \
  -H 'Content-Type: application/json' \
  -d '"{ customer_id, payer_id, payment_method_id, currency, interval, interval_count?, items: [{ name, amount, quantity? }], trial_days?, reference?, external_ref?, external_kind?, dry_run? }"'
```