OatmilkDevelopers

Invoicing

invoices.groups.save

Create or revise a shared billing group. Give project, context and currency. Optional plan allocates selected items or phases to 2–50 independent businesses by explicit percentages or fixed minor units. Every item must reconcile exactly. No default split or inferred tax. Does not change existing invoices.

POST/api/v1/accounting/invoices.groups.save

Permissions

accounting:readaccounting:write

Who can call it

admin, finance

Retries

Idempotency key required, with expectedRevision

MCP

accounting_invoices_groups_save

Fields

  • projectIdstring (ID)Required

    The ID of the related record.

  • namestringRequired

    A display name.

    1–200 characters

  • contextstring

    at most 500 characters · Default ""

  • currencystringRequired

    Three-letter currency code, such as CAD or USD.

  • planobject or nullRequired

  • idstring (ID)

    The record's ID.

  • expectedRevisioninteger

    The record's current revision, from the last time you read it. If someone changed the record since, the request is refused with a conflict so you can reload and check before trying again.

    at most 9007199254740991 · greater than 0

  • idempotencyKeystringRequired

    Any unique text you generate once per intended change, so a retried request only happens once. Send it as the Idempotency-Key header instead if you prefer; if you send both they must match.

    8–200 characters

Example

curl https://app.getoatmilk.com/api/v1/accounting/invoices.groups.save \
  -H "Authorization: Bearer $OATMILK_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
  "projectId": "4d5e6f7a-8b9c-4d0e-8f1a-2b3c4d5e6f7a",
  "name": "Synthetic Ventures Inc.",
  "currency": "CAD",
  "plan": {
    "items": [
      {
        "id": "example",
        "line": {
          "description": "Synthetic example from the docs",
          "unitAmountMinor": "1250"
        }
      }
    ],
    "allocations": [
      {
        "itemIds": [
          "example"
        ],
        "method": "percent",
        "shares": [
          {
            "partyId": "7f0f6c1e-1c1f-4b5e-9c8d-2f5e8e3c1a10",
            "value": "1"
          },
          {
            "partyId": "7f0f6c1e-1c1f-4b5e-9c8d-2f5e8e3c1a10",
            "value": "1"
          }
        ]
      }
    ],
    "payers": [
      {
        "partyId": "7f0f6c1e-1c1f-4b5e-9c8d-2f5e8e3c1a10",
        "taxTreatment": "hst"
      },
      {
        "partyId": "7f0f6c1e-1c1f-4b5e-9c8d-2f5e8e3c1a10",
        "taxTreatment": "hst"
      }
    ]
  }
}'
Response
{
  "data": { … }
}

Try it

Try it

Checks your input with this action’s real schema and answers like the API, with synthetic data. No key needed, and nothing changes.

POST/api/v1/accounting/invoices.groups.save
curl https://app.getoatmilk.com/api/v1/accounting/invoices.groups.save \
  -H "Authorization: Bearer $OATMILK_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
  "projectId": "4d5e6f7a-8b9c-4d0e-8f1a-2b3c4d5e6f7a",
  "name": "Synthetic Ventures Inc.",
  "currency": "CAD",
  "plan": {
    "items": [
      {
        "id": "example",
        "line": {
          "description": "Synthetic example from the docs",
          "unitAmountMinor": "1250"
        }
      }
    ],
    "allocations": [
      {
        "itemIds": [
          "example"
        ],
        "method": "percent",
        "shares": [
          {
            "partyId": "7f0f6c1e-1c1f-4b5e-9c8d-2f5e8e3c1a10",
            "value": "1"
          },
          {
            "partyId": "7f0f6c1e-1c1f-4b5e-9c8d-2f5e8e3c1a10",
            "value": "1"
          }
        ]
      }
    ],
    "payers": [
      {
        "partyId": "7f0f6c1e-1c1f-4b5e-9c8d-2f5e8e3c1a10",
        "taxTreatment": "hst"
      },
      {
        "partyId": "7f0f6c1e-1c1f-4b5e-9c8d-2f5e8e3c1a10",
        "taxTreatment": "hst"
      }
    ]
  }
}'

More in Invoicing.