Update existing category.

PUT

https://firefly.example.com/api/v1/categories/{id}

curl -X PUT 'https://firefly.example.com/api/v1/categories/123' \
  -H 'X-Trace-Id: 40c71bbb-c676-4f24-83cf-cc725d7d7a00' \
  -H 'Authorization: Bearer YOUR_TOKEN' \
  -H 'Content-Type: application/json' \
  --data-raw '{
  "name": "Lunch",
  "notes": "Some example notes",
  "color": "FF0000"
}'

const body = `{
  "name": "Lunch",
  "notes": "Some example notes",
  "color": "FF0000"
}`;

const response = await fetch('https://firefly.example.com/api/v1/categories/123', {
  method: 'PUT',
  headers: {
    'X-Trace-Id': '40c71bbb-c676-4f24-83cf-cc725d7d7a00',
    'Authorization': 'Bearer YOUR_TOKEN',
    'Content-Type': 'application/json',
  },
  body,
});

const data = await response.text();

import requests

body = '''{
  "name": "Lunch",
  "notes": "Some example notes",
  "color": "FF0000"
}'''

response = requests.put(
    'https://firefly.example.com/api/v1/categories/123',
    data=body.encode('utf-8'),
    headers={
        'X-Trace-Id': '40c71bbb-c676-4f24-83cf-cc725d7d7a00',
        'Authorization': 'Bearer YOUR_TOKEN',
        'Content-Type': 'application/json',
    },
)
print(response.text)

Request Body

{
  "name": "Lunch",
  "notes": "Some example notes",
  "color": "FF0000"
}

{
  "name": "Lunch",
  "notes": "Some example notes",
  "color": "FF0000"
}

{
  "data": {
    "type": "categories",
    "id": "2",
    "attributes": {
      "created_at": "2026-10-01T00:00:00+00:00",
      "updated_at": "2026-10-01T00:00:00+00:00",
      "name": "Lunch",
      "color": "FF0000",
      "last_activity": "2026-10-01T00:00:00+00:00",
      "notes": "Some example notes",
      "object_has_currency_setting": false,
      "primary_currency_id": "5",
      "primary_currency_name": "Euro",
      "primary_currency_code": "EUR",
      "primary_currency_symbol": "$",
      "primary_currency_decimal_places": 2,
      "spent": [
        {
          "currency_id": "5",
          "currency_code": "USD",
          "currency_symbol": "$",
          "currency_decimal_places": 2,
          "sum": "123.45"
        }
      ],
      "pc_spent": [
        {
          "currency_id": "5",
          "currency_code": "USD",
          "currency_symbol": "$",
          "currency_decimal_places": 2,
          "sum": "123.45"
        }
      ],
      "earned": [
        {
          "currency_id": "5",
          "currency_code": "USD",
          "currency_symbol": "$",
          "currency_decimal_places": 2,
          "sum": "123.45"
        }
      ],
      "pc_earned": [
        {
          "currency_id": "5",
          "currency_code": "USD",
          "currency_symbol": "$",
          "currency_decimal_places": 2,
          "sum": "123.45"
        }
      ],
      "transferred": [
        {
          "currency_id": "5",
          "currency_code": "USD",
          "currency_symbol": "$",
          "currency_decimal_places": 2,
          "sum": "123.45"
        }
      ],
      "pc_transferred": [
        {
          "currency_id": "5",
          "currency_code": "USD",
          "currency_symbol": "$",
          "currency_decimal_places": 2,
          "sum": "123.45"
        }
      ]
    }
  }
}

{
  "message": "Bad Request",
  "exception": "BadRequestHttpException"
}

{
  "message": "Unauthenticated",
  "exception": "AuthenticationException"
}

{
  "message": "Resource not found",
  "exception": "NotFoundHttpException"
}

{
  "message": "The given data was invalid.",
  "errors": {
    "email": [
      "string"
    ],
    "force": [
      "string"
    ],
    "blocked": [
      "string"
    ],
    "field": [
      "string"
    ],
    "role": [
      "string"
    ],
    "blocked_code": [
      "string"
    ],
    "name": [
      "string"
    ],
    "type": [
      "string"
    ],
    "iban": [
      "string"
    ],
    "start": [
      "string"
    ],
    "end": [
      "string"
    ],
    "date": [
      "string"
    ]
  }
}

{
  "message": "Internal Exception",
  "exception": "InternalException"
}

Body

JSON array with updated category information. See the model for the exact specifications.

application/json,application/x-www-form-urlencodedCategoryUpdate

namestringrequired

Example

Lunch

notesstring | null

Example

Some example notes

colorstring | null

The color of the category in HEX format. Firefly III does not use this field, but your app might.

Example

FF0000

Parameters

idstringrequiredpath

The ID of the category.

Response

200OKCategorySingle

Updated category stored, result in response

Response fields application/vnd.api+json

dataCategoryReadrequired

Show child attributes

typestringrequired

Immutable value

Example

categories

idstringrequired

Example

attributesCategoryPropertiesrequired

Show child attributes

created_atstring<date-time>read only

Example

2026-10-01T00:00:00+00:00

updated_atstring<date-time>read only

Example

2026-10-01T00:00:00+00:00

namestringrequired

Example

Lunch

colorstring

The color of the category in HEX format. Firefly III does not use this field, but your app might.

Example

FF0000

last_activitystring<date-time> | null

Last activity of the category.

Example

2026-10-01T00:00:00+00:00

notesstring | null

Example

Some example notes

object_has_currency_settingboolean

This object never has its own currency setting, so this value is always false.

Example

false

primary_currency_idstringread only

The currency ID of the administration's primary currency.

Example

primary_currency_namestringread only

The currency name of the administration's primary currency.

Example

Euro

primary_currency_codestringread only

The currency code of the administration's primary currency.

Example

EUR

primary_currency_symbolstringread only

The currency symbol of the administration's primary currency.

Example

primary_currency_decimal_placesinteger<int32>read only

The currency decimal places of the administration's primary currency.

Example

spentArray<ArrayEntryWithCurrencyAndSum>read only

Amount(s) spent in the currencies in the database for this category. ONLY present when start and date are set.

Show child attributes

currency_idstring

Example

currency_codestring

Example

USD

currency_symbolstring

Example

currency_decimal_placesinteger<int32>

Number of decimals supported by the currency

Example

sumstring<amount>

The amount earned, spent or transferred.

Example

123.45

pc_spentArray<ArrayEntryWithCurrencyAndSum>read only

Amount(s) spent in the primary currency in the database for this category. ONLY present when start and date are set.

Show child attributes

currency_idstring

Example

currency_codestring

Example

USD

currency_symbolstring

Example

currency_decimal_placesinteger<int32>

Number of decimals supported by the currency

Example

sumstring<amount>

The amount earned, spent or transferred.

Example

123.45

earnedArray<ArrayEntryWithCurrencyAndSum>read only

Amount(s) earned in the currencies in the database for this category. ONLY present when start and date are set.

Show child attributes

currency_idstring

Example

currency_codestring

Example

USD

currency_symbolstring

Example

currency_decimal_placesinteger<int32>

Number of decimals supported by the currency

Example

sumstring<amount>

The amount earned, spent or transferred.

Example

123.45

pc_earnedArray<ArrayEntryWithCurrencyAndSum>read only

Amount(s) earned in the primary currency in the database for this category. ONLY present when start and date are set.

Show child attributes

currency_idstring

Example

currency_codestring

Example

USD

currency_symbolstring

Example

currency_decimal_placesinteger<int32>

Number of decimals supported by the currency

Example

sumstring<amount>

The amount earned, spent or transferred.

Example

123.45

transferredArray<ArrayEntryWithCurrencyAndSum>read only

Amount(s) transferred in the currencies in the database for this category. ONLY present when start and date are set.

Show child attributes

currency_idstring

Example

currency_codestring

Example

USD

currency_symbolstring

Example

currency_decimal_placesinteger<int32>

Number of decimals supported by the currency

Example

sumstring<amount>

The amount earned, spent or transferred.

Example

123.45

pc_transferredArray<ArrayEntryWithCurrencyAndSum>read only

Amount(s) transferred in primary currency in the database for this category. ONLY present when start and date are set.

Show child attributes

currency_idstring

Example

currency_codestring

Example

USD

currency_symbolstring

Example

currency_decimal_placesinteger<int32>

Number of decimals supported by the currency

Example

sumstring<amount>

The amount earned, spent or transferred.

Example

123.45

400Bad RequestBadRequestResponse

Bad request

Response fields application/json

messagestring

Example

Bad Request

exceptionstring

Example

BadRequestHttpException

401UnauthorizedUnauthenticatedResponse

Unauthenticated

Response fields application/json

messagestring

Example

Unauthenticated

exceptionstring

Example

AuthenticationException

404Not FoundNotFoundResponse

Page not found

Response fields application/json

messagestring

Example

Resource not found

exceptionstring

Example

NotFoundHttpException

422Unprocessable EntityValidationErrorResponse

Validation error. The body will have the exact details.

Response fields application/json

messagestring

Example

The given data was invalid.

errorsobject

Show child attributes

emailArray<string>

forceArray<string>

blockedArray<string>

fieldArray<string>

roleArray<string>

blocked_codeArray<string>

nameArray<string>

typeArray<string>

ibanArray<string>

startArray<string>

endArray<string>

dateArray<string>

500Internal Server ErrorInternalExceptionResponse

Internal exception

Response fields application/json

messagestring

Example

Internal Exception

exceptionstring

Example

InternalException

Authorization

firefly_iii_authoauth2

OAuth2 authorization code flow. Create a client on your installation's /profile page; it authorizes at /oauth/authorize and issues tokens at /oauth/token there. The URLs below are the demo site's. How to use the API walks through it.

local_bearer_authhttp (bearer)

A Personal Access Token, sent as a bearer token. Create one on your installation under Options > Profile > OAuth > Personal Access Tokens.