> ## Documentation Index
> Fetch the complete documentation index at: https://docs.saasybill.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Create a subscription
> Creates the subscription and its first invoice, and sends the invoice to Xero, under the same rules as the New Subscription form. **`Idempotency-Key` is required**: a repeat of this request would otherwise be a second subscription and a second bill. A retry with the same key and body returns the first response. If Xero refuses the invoice the subscription still exists and the response is 201 with `invoice.xero.sync_status` of `failed`.
Requires the `subscriptions:write` scope. See [Authentication](/api-reference/authentication#scopes).
## OpenAPI
````yaml /api-reference/openapi.json post /v1/subscriptions
openapi: 3.1.0
info:
title: Saasybill API
version: 1.0.0
description: >-
Create and manage subscriptions in Saasybill from your own platform.
**Authentication.** `Authorization: Bearer saasybill_live_…`. Create keys
under Developer Settings.
**Idempotency.** Send an `Idempotency-Key` on writes. It is required to
create a subscription.
**Webhooks.** Saasybill calls your URL when something changes. Events:
`customer.created`, `customer.updated`, `customer.deleted`,
`subscription.created`, `subscription.updated`, `subscription.ended`,
`subscription.restored`, `subscription.deleted`, `invoice.created`,
`invoice.updated`, `invoice.paid`, `invoice.voided`, `invoice.deleted`,
`credit_note.created`, `credit_note.updated`, `credit_note.voided`,
`credit_note.deleted`. Each request is signed: `Saasybill-Signature: t=,v1=`, where `v1` is `HMAC-SHA256(secret, ".")`.
Reject a `t` more than five minutes old. Deliveries are at-least-once,
retried for about 20 hours, and unordered: de-duplicate on the event `id`.
Changes are detected about once a minute, so an event can arrive up to a
minute late, and changes inside one minute are combined.
**Testing.** Create a sandbox under Developer Settings → Configuration,
connect it to a Xero Demo Company, and use a test key (`saasybill_test_…`)
created inside it. A test key works only in its sandbox, which sends no
emails and is never billed. Your plans, customers and subscriptions can be
copied into the sandbox when it is created or reset, and its test clock can
be advanced to see renewals without waiting. `GET /v1/organisation` returns
`livemode: false` for a sandbox.
servers:
- url: https://api.saasybill.com
description: Production
security: []
tags:
- name: Organisation
description: The organisation an API key belongs to.
- name: Customers
description: >-
Customers are synced from Xero. Create one only where the organisation
allows it.
- name: Plans
description: Read the pricing plans you can sell.
- name: Charges
description: Read the one-off fees that can be added to a new subscription.
- name: Subscriptions
description: Create subscriptions, change units, and end or restore them.
- name: Invoices
description: Read the invoices Saasybill raises in Xero.
- name: Credit notes
description: >-
Read the credit notes Saasybill raises in Xero, and where their credit was
applied.
- name: Usage
description: Report the usage that is billed in arrears against a subscription.
paths:
/v1/subscriptions:
post:
tags:
- Subscriptions
summary: Create a subscription
description: >-
Creates the subscription and its first invoice, and sends the invoice to
Xero, under the same rules as the New Subscription form.
**`Idempotency-Key` is required**: a repeat of this request would
otherwise be a second subscription and a second bill. A retry with the
same key and body returns the first response. If Xero refuses the
invoice the subscription still exists and the response is 201 with
`invoice.xero.sync_status` of `failed`.
operationId: post_v1_subscriptions
parameters:
- name: Idempotency-Key
in: header
required: true
description: >-
1 to 255 printable characters. A retry with the same key and body
returns the first response.
schema:
type: string
minLength: 1
maxLength: 255
example: signup_8f3a2c1d
requestBody:
required: true
content:
application/json:
schema:
type: object
properties:
customer:
description: The Saasybill customer id. Give this or `customer_code`.
type: string
minLength: 1
maxLength: 100
customer_code:
type: string
description: >-
The organisation's own reference for the customer. Unique
per organisation.
create_customer:
description: >-
Create the customer in Xero if no customer has
`customer_code`. Needs the organisation to have allowed it.
type: object
properties:
name:
type: string
minLength: 1
maxLength: 255
description: The name the contact is created under in Xero.
first_name:
description: The contact person's first name, in Xero.
anyOf:
- type: string
maxLength: 255
- type: 'null'
last_name:
description: The contact person's last name, in Xero.
anyOf:
- type: string
maxLength: 255
- type: 'null'
email:
anyOf:
- type: string
maxLength: 255
format: email
pattern: >-
^(?:[A-Za-z0-9_'+\-]+\.)*[A-Za-z0-9_'+\-]*[A-Za-z0-9_+-]@(?:[A-Za-z0-9][A-Za-z0-9\-]*\.)+[A-Za-z]{2,}$
- type: 'null'
required:
- name
additionalProperties: false
plan:
description: The plan id. Give this or `plan_code`.
type: string
minLength: 1
maxLength: 100
plan_code:
type: string
minLength: 1
maxLength: 100
units:
description: >-
Not for a plan with no units: a flat fee plan, or one with
no recurring fee.
type: integer
minimum: 0
maximum: 999999999
flat_fee_price:
description: Only where the plan allows its price to be overridden.
anyOf:
- type: string
minLength: 1
maxLength: 20
- type: number
start_date:
description: Defaults to today in the organisation's timezone.
type: string
pattern: ^\d{4}-\d{2}-\d{2}$
end_after_cycles:
anyOf:
- type: integer
minimum: 1
maximum: 1000
- type: 'null'
discount_percent:
description: 0 to 100. Defaults to 0.
anyOf:
- type: string
minLength: 1
maxLength: 20
- type: number
label:
anyOf:
- type: string
maxLength: 255
- type: 'null'
invoice_reference:
anyOf:
- type: string
maxLength: 255
- type: 'null'
minimum_units:
anyOf:
- type: integer
minimum: 0
maximum: 999999999
- type: 'null'
minimum_invoice_amount:
anyOf:
- anyOf:
- type: string
minLength: 1
maxLength: 20
- type: number
- type: 'null'
invoice_due_days:
anyOf:
- type: integer
minimum: 1
maximum: 365
- type: 'null'
meter_minimums:
description: >-
Raise the minimum of meters the plan bills, for this
subscription only. A meter the plan does not bill is
refused, and a meter named twice.
maxItems: 50
type: array
items:
type: object
properties:
meter:
description: The Saasybill meter id. Give this or `meter_code`.
type: string
minLength: 1
maxLength: 100
meter_code:
type: string
description: >-
The meter's ID as shown in Saasybill, such as
`api_calls`.
minimum_units:
type: integer
minimum: 0
maximum: 999999999
description: >-
The least a period bills for this meter on this
subscription. Not below the plan's minimum for it.
required:
- minimum_units
additionalProperties: false
cpi_enabled:
type: boolean
description: >-
Raise the plan price, and the rates of any meters the plan
bills, by the consumer price index at each renewal. Usage is
billed at the rates of the period it was used in. Annual
plans only, and only where the organisation's country has a
CPI figure or a manual rate. Defaults to false. Cannot be
changed through the API after creation.
charges:
maxItems: 50
type: array
items:
type: object
properties:
charge:
type: string
minLength: 1
maxLength: 100
price:
description: >-
Only where the charge allows its price to be
overridden.
anyOf:
- type: string
minLength: 1
maxLength: 20
- type: number
apply_discount:
type: boolean
required:
- charge
additionalProperties: false
additionalProperties: false
examples:
Per unit plan, by code:
summary: Per unit plan, by code
description: >-
The usual signup: find the customer and the plan by your own
codes.
value:
customer_code: ACME-001
plan_code: TEAM-MONTHLY
units: 10
start_date: '2026-09-30'
discount_percent: '10'
label: Acme � Team plan
invoice_reference: PO-4471
With a one-off charge:
summary: With a one-off charge
description: >-
Bill a charge once, on the first invoice. Charges are sent by
id. The second charge overrides its price.
value:
customer_code: ACME-001
plan_code: TEAM-MONTHLY
units: 25
charges:
- charge: e2a7d5c8-91b3-4d16-a0f4-7c8b6e5d3a22
apply_discount: false
- charge: a8c4e1f7-3d92-4b05-8e6a-1c7f9d2b5e30
price: '300.00'
apply_discount: true
Flat fee, fixed term:
summary: Flat fee, fixed term
description: >-
A flat fee plan takes no units. Set flat_fee_price only where
the plan allows its price to be overridden.
value:
customer: 3b9f1c1e-6a52-4c0e-9d7e-1f6f2f0b7a11
plan: 2f6b9d3a-8c14-4e75-a0b2-6d1e7f3c9a48
flat_fee_price: '2400.00'
end_after_cycles: 12
invoice_due_days: 14
Annual plan with CPI increases:
summary: Annual plan with CPI increases
description: >-
Sets cpi_enabled to raise the plan price by CPI at each
renewal. Annual plans only, and the organisation must have CPI
price adjustments switched on.
value:
customer_code: ACME-001
plan_code: TEAM-ANNUAL
units: 10
cpi_enabled: true
Create the customer if missing:
summary: Create the customer if missing
description: >-
Uses customer_code, and creates the customer in Xero if no
customer has that code. Needs the organisation to have allowed
it.
value:
customer_code: NORTH-100
create_customer:
name: Northwind Traders
email: ap@northwind.example
plan_code: TEAM-MONTHLY
units: 5
Usage plan with a raised meter minimum:
summary: Usage plan with a raised meter minimum
description: >-
For a plan that bills meters. Raises the minimum of one meter
for this subscription only, never below the plan’s own. A plan
with no recurring fee takes no units.
value:
customer_code: ACME-001
plan_code: API-USAGE
meter_minimums:
- meter_code: api_calls
minimum_units: 10000
responses:
'201':
description: Success.
content:
application/json:
schema:
type: object
properties:
id:
type: string
object:
type: string
const: subscription
customer:
type: string
customer_code:
type:
- string
- 'null'
plan:
type: string
status:
type: string
enum:
- pending
- active
- complete
- ended
currency:
type: string
interval:
type: object
properties:
unit:
type: string
enum:
- day
- week
- month
- year
count:
type: integer
required:
- unit
- count
additionalProperties: false
timezone:
type: string
start_date:
type: string
description: YYYY-MM-DD, in the subscription's own timezone.
renewal_date:
anyOf:
- type: string
description: YYYY-MM-DD, in the subscription's own timezone.
- type: 'null'
end_date:
anyOf:
- type: string
description: YYYY-MM-DD, in the subscription's own timezone.
- type: 'null'
units:
type: integer
minimum_units:
type: integer
discount_percent:
type: string
description: A decimal string, e.g. "19.9900".
cancel_at_period_end:
type: boolean
end_after_cycles:
anyOf:
- type: integer
- type: 'null'
label:
type:
- string
- 'null'
invoice_reference:
type:
- string
- 'null'
renewal_value:
type: string
description: >-
What the next period is certain to bill: the plan at its
current units, the add-ons, and the minimum units of each
meter the plan bills, net of the discount. Usage above the
meter minimums is not included; see `usage_value`.
usage_value:
type: string
description: >-
The average, over the last three closed usage periods, of
what each billed for usage above the meter minimums, net
of the discount. An estimate at the plan's current meter
prices, and never part of `renewal_value`. 0 until a usage
period has closed, and for a plan that bills no meter.
usage_value_annual:
type: string
description: '`usage_value` times the periods in a year.'
minimum_usage_value:
type: string
description: >-
The part of `renewal_value` that is the meter minimums,
net of the discount. 0 for a plan that bills no meter.
meters:
type: array
items:
type: object
properties:
meter:
type: string
description: The Saasybill meter id.
meter_code:
type: string
name:
type: string
minimum_units:
type: integer
description: >-
The minimum in force: this subscription's own where
it set one, never below the plan's.
plan_minimum_units:
type: integer
description: The plan's minimum for the meter.
required:
- meter
- meter_code
- name
- minimum_units
- plan_minimum_units
additionalProperties: false
description: >-
The meters the subscription's plan bills for, with the
minimum each is billed at.
cpi_enabled:
type: boolean
description: Whether the price rises with CPI at each renewal.
created:
type: string
format: date-time
description: ISO 8601, UTC.
invoice:
anyOf:
- type: object
properties:
id:
type: string
object:
type: string
const: invoice
customer:
type: string
subscription:
type:
- string
- 'null'
number:
description: Xero's invoice number, once it is in Xero.
type:
- string
- 'null'
reference:
type:
- string
- 'null'
status:
type: string
enum:
- draft
- awaiting_approval
- approved
- paid
- voided
- deleted
- not_in_external
currency:
type: string
invoice_date:
type: string
format: date-time
description: ISO 8601, UTC.
due_date:
anyOf:
- type: string
format: date-time
description: ISO 8601, UTC.
- type: 'null'
subtotal:
type: string
description: Excluding tax.
total:
type: string
description: Including tax, as Xero returns it.
credit_note_amount:
type: string
description: A decimal string, e.g. "19.9900".
amount_paid:
anyOf:
- type: string
description: A decimal string, e.g. "19.9900".
- type: 'null'
sent:
type: boolean
xero:
type: object
properties:
sync_status:
type: string
enum:
- synced
- failed
- pending
description: >-
`failed` means the invoice exists here and
Xero refused it; the subscription that raised
it was still created.
invoice_id:
type:
- string
- 'null'
sync_error:
type:
- string
- 'null'
required:
- sync_status
- invoice_id
- sync_error
additionalProperties: false
lines:
type: array
items:
type: object
properties:
id:
type: string
type:
anyOf:
- type: string
enum:
- subscription
- addon
- charge
- usage
- type: 'null'
description: >-
What the line bills for. `usage` is metered
usage, one line per meter per billing
period.
revenue_type:
anyOf:
- type: string
enum:
- new_subscription
- expansion
- renewal
- usage
- type: 'null'
description: >-
The revenue bucket the line falls in.
Metered usage is `usage`, never `renewal`.
Null where it was not recorded.
meter:
description: >-
The Saasybill meter id a `usage` line bills.
Null on every other line.
type:
- string
- 'null'
usage_quantity:
description: >-
The quantity a `usage` line was priced for,
as a decimal string, after the meter's
minimum. `units` is this rounded up. Null on
every other line.
type:
- string
- 'null'
name:
type:
- string
- 'null'
description:
type:
- string
- 'null'
units:
anyOf:
- type: integer
- type: 'null'
amount:
type: string
description: A decimal string, e.g. "19.9900".
discount_amount:
type: string
description: A decimal string, e.g. "19.9900".
charge_amount:
type: string
description: >-
What is billed: `amount` less
`discount_amount`.
effective_date:
anyOf:
- type: string
format: date-time
description: ISO 8601, UTC.
- type: 'null'
required:
- id
- type
- revenue_type
- meter
- usage_quantity
- name
- description
- units
- amount
- discount_amount
- charge_amount
- effective_date
additionalProperties: false
created:
type: string
format: date-time
description: ISO 8601, UTC.
required:
- id
- object
- customer
- subscription
- number
- reference
- status
- currency
- invoice_date
- due_date
- subtotal
- total
- credit_note_amount
- amount_paid
- sent
- xero
- created
additionalProperties: false
- type: 'null'
description: >-
The first invoice. Null in setup mode, where none is
raised, and for a plan with no recurring fee sold with no
add-ons or charges, which has nothing to bill for its
first period. Check `xero.sync_status`.
required:
- id
- object
- customer
- customer_code
- plan
- status
- currency
- interval
- timezone
- start_date
- renewal_date
- end_date
- units
- minimum_units
- discount_percent
- cancel_at_period_end
- end_after_cycles
- label
- invoice_reference
- renewal_value
- usage_value
- usage_value_annual
- minimum_usage_value
- meters
- cpi_enabled
- created
- invoice
additionalProperties: false
example:
id: 9d4e2b7a-13c5-4f8e-b6a0-2e1d7c9f5b33
object: subscription
customer: 3b9f1c1e-6a52-4c0e-9d7e-1f6f2f0b7a11
customer_code: ACME-001
plan: b6c1e0a4-2f7d-4a61-8f0c-5d3e9a7b2c44
status: active
currency: AUD
interval:
unit: month
count: 1
timezone: Australia/Sydney
start_date: '2026-09-30'
renewal_date: '2026-10-30'
end_date: null
units: 10
minimum_units: 5
discount_percent: '10.00'
cancel_at_period_end: false
end_after_cycles: null
label: Acme � Team plan
invoice_reference: PO-4471
renewal_value: '108.0000'
usage_value: '0.0000'
usage_value_annual: '0.0000'
minimum_usage_value: '0.0000'
meters: []
cpi_enabled: false
created: '2026-09-30T04:12:00.000Z'
invoice:
id: 5f8a3c9d-7e21-4b04-9c6d-0a2b4e8f1d55
object: invoice
customer: 3b9f1c1e-6a52-4c0e-9d7e-1f6f2f0b7a11
subscription: 9d4e2b7a-13c5-4f8e-b6a0-2e1d7c9f5b33
number: INV-0042
reference: PO-4471
status: awaiting_approval
currency: AUD
invoice_date: '2026-09-29T14:00:00.000Z'
due_date: '2026-10-29T13:00:00.000Z'
subtotal: '558.0000'
total: '613.8000'
credit_note_amount: '0.0000'
amount_paid: null
sent: false
xero:
sync_status: synced
invoice_id: f0e9d8c7-b6a5-4f43-9210-fedcba987654
sync_error: null
lines:
- id: 0a1b2c3d-4e5f-4a6b-8c7d-9e0f1a2b3c77
type: subscription
revenue_type: new_subscription
meter: null
usage_quantity: null
name: Team
description: Team � 10 seats
units: 10
amount: '120.0000'
discount_amount: '12.0000'
charge_amount: '108.0000'
effective_date: '2026-09-29T14:00:00.000Z'
- id: 1b2c3d4e-5f6a-4b7c-9d8e-0f1a2b3c4d88
type: charge
revenue_type: new_subscription
meter: null
usage_quantity: null
name: Onboarding
description: One-off setup and training
units: null
amount: '450.0000'
discount_amount: '0.0000'
charge_amount: '450.0000'
effective_date: '2026-09-29T14:00:00.000Z'
created: '2026-09-30T04:12:01.000Z'
headers:
Request-Id:
$ref: '#/components/headers/Request-Id'
RateLimit-Limit:
$ref: '#/components/headers/RateLimit-Limit'
RateLimit-Remaining:
$ref: '#/components/headers/RateLimit-Remaining'
RateLimit-Reset:
$ref: '#/components/headers/RateLimit-Reset'
'401':
description: The key is missing, malformed, revoked or expired.
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
example:
error:
type: authentication_error
code: invalid_api_key
message: 'Provide a valid API key as `Authorization: Bearer `.'
request_id: req_4f1a9c2e7b8d3a605e1c9f02
headers:
Request-Id:
$ref: '#/components/headers/Request-Id'
'403':
description: >-
The key lacks the scope, is a test key, or the organisation has not
allowed this.
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
example:
error:
type: permission_error
code: insufficient_scope
message: This API key does not have the `subscriptions:write` scope.
request_id: req_4f1a9c2e7b8d3a605e1c9f02
headers:
Request-Id:
$ref: '#/components/headers/Request-Id'
'404':
description: No such object.
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
example:
error:
type: not_found
code: subscription_not_found
message: There is no subscription with that id.
request_id: req_4f1a9c2e7b8d3a605e1c9f02
headers:
Request-Id:
$ref: '#/components/headers/Request-Id'
'409':
description: >-
The request conflicts with the current state, or with an earlier
request using the same `Idempotency-Key`.
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
example:
error:
type: conflict
code: idempotency_conflict
message: >-
This `Idempotency-Key` was used with a different request.
Use a new key for a different request.
request_id: req_4f1a9c2e7b8d3a605e1c9f02
headers:
Request-Id:
$ref: '#/components/headers/Request-Id'
'422':
description: A field is missing or invalid. `error.param` names it.
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
example:
error:
type: invalid_request_error
code: invalid_parameter
message: '`units`: Invalid input: expected number, received string'
param: units
request_id: req_4f1a9c2e7b8d3a605e1c9f02
headers:
Request-Id:
$ref: '#/components/headers/Request-Id'
'429':
description: 'Rate limited: 120 requests a minute per key. See `Retry-After`.'
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
example:
error:
type: rate_limit_error
code: rate_limited
message: Too many requests. Try again in 12 seconds.
request_id: req_4f1a9c2e7b8d3a605e1c9f02
headers:
Request-Id:
$ref: '#/components/headers/Request-Id'
'500':
description: >-
Something went wrong on our side. Retry; quote `error.request_id` if
it persists.
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
example:
error:
type: api_error
code: internal_error
message: >-
Something went wrong on our side. Retry the request; if it
keeps failing, quote the request id.
request_id: req_4f1a9c2e7b8d3a605e1c9f02
headers:
Request-Id:
$ref: '#/components/headers/Request-Id'
security:
- bearerAuth:
- subscriptions:write
components:
headers:
Request-Id:
description: A unique id for the request. Quote it when you contact support.
schema:
type: string
example: req_4f1a9c2e7b8d3a605e1c9f02
RateLimit-Limit:
description: Requests allowed per minute for this key.
schema:
type: integer
example: 120
RateLimit-Remaining:
description: Requests left in the current window.
schema:
type: integer
example: 117
RateLimit-Reset:
description: Seconds until the oldest counted request stops counting.
schema:
type: integer
example: 41
schemas:
Error:
type: object
properties:
error:
type: object
properties:
type:
type: string
enum:
- authentication_error
- permission_error
- invalid_request_error
- not_found
- conflict
- rate_limit_error
- api_error
code:
type: string
description: Stable. Branch on this, never on `message`.
message:
type: string
param:
type: string
request_id:
type: string
required:
- type
- code
- message
- request_id
additionalProperties: false
required:
- error
additionalProperties: false
description: >-
Every failed request answers with this shape. Branch on `error.code`,
never on `error.message`.
securitySchemes:
bearerAuth:
type: http
scheme: bearer
description: >-
An API key. Its scopes decide what it may call: `customers:read` (List
and look up customers.) `customers:write` (Create customers, and Xero
contacts where the organisation allows it.) `catalogue:read` (List plans
and charges.) `subscriptions:read` (List and look up subscriptions.)
`subscriptions:write` (Create subscriptions, change units, end and
restore them.) `invoices:read` (List and look up invoices.)
`credit_notes:read` (List and look up credit notes, and where their
credit was applied.)
````
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