Transaction links

Create a new link between transactions

POST

https://firefly.example.com/api/v1/transaction-links

Store a new link between two transactions. For this end point you need the journal_id from a transaction.

curl -X POST 'https://firefly.example.com/api/v1/transaction-links' \
  -H 'X-Trace-Id: 40c71bbb-c676-4f24-83cf-cc725d7d7a00' \
  -H 'Authorization: Bearer YOUR_TOKEN' \
  -H 'Content-Type: application/json' \
  --data-raw '{
  "link_type_id": "5",
  "link_type_name": "Is paid by",
  "inward_id": "131",
  "outward_id": "131",
  "notes": "Some example notes"
}'

const body = `{
  "link_type_id": "5",
  "link_type_name": "Is paid by",
  "inward_id": "131",
  "outward_id": "131",
  "notes": "Some example notes"
}`;

const response = await fetch('https://firefly.example.com/api/v1/transaction-links', {
  method: 'POST',
  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 = '''{
  "link_type_id": "5",
  "link_type_name": "Is paid by",
  "inward_id": "131",
  "outward_id": "131",
  "notes": "Some example notes"
}'''

response = requests.post(
    'https://firefly.example.com/api/v1/transaction-links',
    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

{
  "link_type_id": "5",
  "link_type_name": "Is paid by",
  "inward_id": "131",
  "outward_id": "131",
  "notes": "Some example notes"
}

{
  "link_type_id": "5",
  "link_type_name": "Is paid by",
  "inward_id": "131",
  "outward_id": "131",
  "notes": "Some example notes"
}

{
  "data": {
    "type": "transactionLinks",
    "id": "2",
    "attributes": {
      "created_at": "2026-10-01T00:00:00+00:00",
      "updated_at": "2026-10-01T00:00:00+00:00",
      "inward_id": "131",
      "outward_id": "131",
      "notes": "Some example notes"
    },
    "links": {
      "0": {
        "rel": "self",
        "uri": "/OBJECTS/1"
      },
      "self": "https://demo.firefly-iii.org/api/v1/OBJECTS/1"
    }
  }
}

{
  "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 the necessary link type information or key=value pairs. See the model for the exact specifications.

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

link_type_idstringrequiredwrite only

The link type ID to use. You can also use the link_type_name field.

Example

link_type_namestringwrite only

The link type name to use. You can also use the link_type_id field.

Example

Is paid by

inward_idstringrequired

The inward transaction transaction_journal_id for the link. This becomes the 'is paid by' transaction of the set.

Example

outward_idstringrequired

The outward transaction transaction_journal_id for the link. This becomes the 'pays for' transaction of the set.

Example

notesstring | null

Optional. Some notes.

Example

Some example notes

Parameters

X-Trace-Idstring<uuid>header

Unique identifier associated with this request.

Response

200OKTransactionLinkSingle

New transaction link stored, result in response.

Response fields application/vnd.api+json

dataTransactionLinkReadrequired

Show child attributes

typestringrequired

Immutable value

Example

transactionLinks

idstringrequired

Example

attributesTransactionLinkrequired

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

inward_idstringrequired

The inward transaction transaction_journal_id for the link. This becomes the 'is paid by' transaction of the set.

Example

outward_idstringrequired

The outward transaction transaction_journal_id for the link. This becomes the 'pays for' transaction of the set.

Example

notesstring | null

Optional. Some notes.

Example

Some example notes

linksObjectLinkrequired

Show child attributes

0object

Show child attributes

relstring

Example

self

uristring

Example

/OBJECTS/1

selfstring<uri>

Example

https://demo.firefly-iii.org/api/v1/OBJECTS/1

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.