Requests and responses

Request and response format of the vynst (inwendo ERP) REST API, headers and wrapper objects.

The API speaks JSON. Requests with a body send content-type: application/json, responses come as application/json. Only file uploads use multipart/form-data.

Paths and methods

Method	Meaning
`GET`	read a list or a single entry
`POST`	create an entry or trigger an action
`PUT`	change an entry with all fields sent
`PATCH`	change only the fields sent
`DELETE`	delete or archive an entry

Wrapper in the request body

When creating or changing an entry, the object sits in a wrapper named after the resource. A new person looks like this:

{
  "crmperson": {
    "first_name": "Lena",
    "last_name": "Hartmann"
  }
}

The Request body section of every API page shows which wrapper an endpoint expects. The code samples already build it correctly.

Field names

The API uses snake_case. If you prefer camelCase, set these headers:

Header	Effect
`x-iw-convert-to-camel-case: 1`	translate field names in the body from `camelCase` to `snake_case`
`x-iw-convert-object-to-id: field,field`	reduce these fields to the inner ID when an object arrives
`x-iw-convert-string-to-date-time: field,field`	read these fields as dates, also when sent as text or timestamp

Client identification

Every endpoint optionally takes iw-build-id and iw-package-id. Your own apps can send their build and package with it, which helps support. The API pages therefore do not list these two parameters one by one.

Dates and times

Dates and times use ISO 8601 with a time zone, for example 2026-10-15T09:30:00+02:00.