`budgets.save`

Create or edit a monthly, quarterly or yearly spending budget, for all expenses or one category. Actuals use ledger entries and splits, with refunds deducted and transfers excluded. Requires current expectedRevision or zero for a new budget and an idempotencyKey. Does not change bookkeeping entries.

POST/api/v1/accounting/budgets.save

Permissions

accounting:readaccounting:write

Who can call it

admin, finance

Retries

Idempotency key required, with expectedRevision

MCP

accounting_budgets_save

Fields

idstring (ID)
The record's ID.
expectedRevisionintegerRequired
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.
0 to 9007199254740991
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
namestringRequired
A display name.
1–160 characters
categoryIdstring (ID) or nullRequired
The ID of a category, from categories.list.
currencystringRequired
Three-letter currency code, such as CAD or USD.
amountMinorstringRequired
An amount in cents (the currency's smallest unit), written as a whole-number string such as "1250" for $12.50.
Matches ^\d{1,15}$
periodenumRequired
The period to cover.
monthlyquarterlyyearly
startsOnstring (date)Required
A date, as YYYY-MM-DD.
endsOnstring (date) or nullRequired
activebooleanRequired
Whether the record is turned on.

curl https://app.getoatmilk.com/api/v1/accounting/budgets.save \
  -H "Authorization: Bearer $OATMILK_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
  "expectedRevision": 3,
  "name": "Synthetic Ventures Inc.",
  "categoryId": "7f0f6c1e-1c1f-4b5e-9c8d-2f5e8e3c1a10",
  "currency": "CAD",
  "amountMinor": "1250",
  "period": "monthly",
  "startsOn": "2026-09-01",
  "endsOn": "2026-09-01",
  "active": true,
  "id": "9a8b7c6d-5e4f-4a3b-8c2d-1e0f9a8b7c6d"
}'

const response = await fetch("https://app.getoatmilk.com/api/v1/accounting/budgets.save", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.OATMILK_API_KEY}`,
    "Content-Type": "application/json",
    "Idempotency-Key": crypto.randomUUID(),
  },
  body: JSON.stringify({
    "expectedRevision": 3,
    "name": "Synthetic Ventures Inc.",
    "categoryId": "7f0f6c1e-1c1f-4b5e-9c8d-2f5e8e3c1a10",
    "currency": "CAD",
    "amountMinor": "1250",
    "period": "monthly",
    "startsOn": "2026-09-01",
    "endsOn": "2026-09-01",
    "active": true,
    "id": "9a8b7c6d-5e4f-4a3b-8c2d-1e0f9a8b7c6d"
  }),
});
const { data, error } = await response.json();
if (!response.ok) throw new Error(`${error.code}: ${error.message}`);
console.log(data);

import os
import uuid

import requests

response = requests.post(
    "https://app.getoatmilk.com/api/v1/accounting/budgets.save",
    headers={
        "Authorization": f"Bearer {os.environ['OATMILK_API_KEY']}",
        "Idempotency-Key": str(uuid.uuid4()),
    },
    json={
        "expectedRevision": 3,
        "name": "Synthetic Ventures Inc.",
        "categoryId": "7f0f6c1e-1c1f-4b5e-9c8d-2f5e8e3c1a10",
        "currency": "CAD",
        "amountMinor": "1250",
        "period": "monthly",
        "startsOn": "2026-09-01",
        "endsOn": "2026-09-01",
        "active": True,
        "id": "9a8b7c6d-5e4f-4a3b-8c2d-1e0f9a8b7c6d",
    },
    timeout=30,
)
payload = response.json()
if not response.ok:
    raise RuntimeError(f"{payload['error']['code']}: {payload['error']['message']}")
print(payload["data"])

Response

{
  "data": { … }
}

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.

Input

POST/api/v1/accounting/budgets.save

curl https://app.getoatmilk.com/api/v1/accounting/budgets.save \
  -H "Authorization: Bearer $OATMILK_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
  "expectedRevision": 3,
  "name": "Synthetic Ventures Inc.",
  "categoryId": "7f0f6c1e-1c1f-4b5e-9c8d-2f5e8e3c1a10",
  "currency": "CAD",
  "amountMinor": "1250",
  "period": "monthly",
  "startsOn": "2026-09-01",
  "endsOn": "2026-09-01",
  "active": true,
  "id": "9a8b7c6d-5e4f-4a3b-8c2d-1e0f9a8b7c6d"
}'

const response = await fetch("https://app.getoatmilk.com/api/v1/accounting/budgets.save", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.OATMILK_API_KEY}`,
    "Content-Type": "application/json",
    "Idempotency-Key": crypto.randomUUID(),
  },
  body: JSON.stringify({
    "expectedRevision": 3,
    "name": "Synthetic Ventures Inc.",
    "categoryId": "7f0f6c1e-1c1f-4b5e-9c8d-2f5e8e3c1a10",
    "currency": "CAD",
    "amountMinor": "1250",
    "period": "monthly",
    "startsOn": "2026-09-01",
    "endsOn": "2026-09-01",
    "active": true,
    "id": "9a8b7c6d-5e4f-4a3b-8c2d-1e0f9a8b7c6d"
  }),
});
const { data, error } = await response.json();
if (!response.ok) throw new Error(`${error.code}: ${error.message}`);
console.log(data);

import os
import uuid

import requests

response = requests.post(
    "https://app.getoatmilk.com/api/v1/accounting/budgets.save",
    headers={
        "Authorization": f"Bearer {os.environ['OATMILK_API_KEY']}",
        "Idempotency-Key": str(uuid.uuid4()),
    },
    json={
        "expectedRevision": 3,
        "name": "Synthetic Ventures Inc.",
        "categoryId": "7f0f6c1e-1c1f-4b5e-9c8d-2f5e8e3c1a10",
        "currency": "CAD",
        "amountMinor": "1250",
        "period": "monthly",
        "startsOn": "2026-09-01",
        "endsOn": "2026-09-01",
        "active": True,
        "id": "9a8b7c6d-5e4f-4a3b-8c2d-1e0f9a8b7c6d",
    },
    timeout=30,
)
payload = response.json()
if not response.ok:
    raise RuntimeError(f"{payload['error']['code']}: {payload['error']['message']}")
print(payload["data"])

Fields

Example

Try it