Ons APIAPI Properties
Our APIs are provided as a REST service. New resources are added without notice. Deprecations are published as a news article and listed on the deprecations page 6 months before the resources are removed. The rest of this page explains the general workings and behaviour of our APIs. The list of available APIs and their documentation can be found here.
Environments
We have three different environments.
| environment | use | URL |
|---|---|---|
| DEVELOPMENT | Developing your connector using fictional data | https://api-development.ons.io |
| STAGING | Test your connector on a customer’s test environment | https://api-staging.ons.io |
| PRODUCTION | Run your connector on a customer’s production environment | https://api.ons.io |
Contexts
In the past, Ons API was offered in different contexts resulting in different base paths. Only the technical context, with base path /t/ is being used now. For backwards compatability, all endpoints must still be prepended with the /t/ base path (except for the /ping endpoint). Thus, the /clients/{id} endpoint on development will look like api-development.ons.io/t/clients/3.
HTTP Methods
Our APIs support the REST verbs as expected.
GET
Used to retrieve resources and related data. Query parameters are used to select a sub-set or apply some sort of filtering. Query parameters are almost always optional. Requests do not change server state. Common urls include:
| Format | Use |
|---|---|
/resource | request all entries |
/resource/42 | request a particular entry |
/resource/42/sub_resource | request all entries related to an entry |
/resource/x-stream-connect/data.xml | request all entries in a streaming matter |
POST
Used to create new resources or perform some kind of action. POST requests are also used when sensitive data is transferred (like a login). For a 200 return status the same resource is returned with some updated fields. Requests change server state.
| Format | Use |
|---|---|
/resource | create a new resource |
/resource/42/sub_resource | create a new sub-resource for resource |
/resource/42/action | perform action for resource |
PUT
Used to update an existing resource. The behaviour for POST also applies to PUT.
| Format | Use |
|---|---|
/resource/42 | update resource |
DELETE
Removes a particular resource or removes a relation between resources.
| Format | Use |
|---|---|
/resource/42 | delete resource |
Headers
It is possible to add headers to HTTP requests to our API. There are three headers that are of interest.
Accept
This header is required and defines the returned format. For most cases requesting json or xml will be enough. Some APIs return octet-streams (bytes) and the /ping returns text/plain. If you request something that can’t be given, you’ll receive a 406 status code. You can enter multiple formats. The first one indicates your preference. Weights should also be supported.
Accept: application/json,application/xml
Content-Type
Required for POST and PUT calls. This header indicates the format used in the http body. You can only have one. The charset is optional but recommended.
Content-Type: application/xml;charset=utf-8
User-Agent
The User-Agent header is optional but it would help us to identify your requests when something goes wrong.
User-Agent: connector/1.1+http://your-domain.com
Where connector should be replaced with the name of your connector.
HTTP Response codes
Below you can find a table with http response codes you can expect.
| Status | Text | Description |
|---|---|---|
| 200 | OK | GET: valid response with your requested data in the response body. POST/PUT: valid response with your given resource enriched with some extra data in the response body. |
| 201 | Created | POST: object created, response has no body. There’s a Location header with the path where you can find the resource. |
| 202 | Accepted | PUT: changes are accepted, no response body. |
| 204 | No Content | POST: used for actions which were successful. GET: resource requested had no content. |
| 400 | Bad request | GET: the combination of query params is invalid. POST/PUT: the given content is incorrect. You’ll receive an ErrorResponse body indicating what was wrong. |
| 401 | Unauthorized | You have insufficient rights to access the resource. |
| 402 | Payment required | Reserved for future use. |
| 403 | Forbidden | Authentication unsuccessful. |
| 404 | Not found | The requested resource was not found. |
| 406 | Not acceptable | Wrong Accept header. |
| 409 | Conflict | POST: The given resource already exists or was changed by another call. |
| 423 | Locked | GET: The given resource is not yet ready. This is the case for delayed jobs that take some time to process. |
| 429 | Too many requests | You are being rate limited. |
| 500 | Internal server error | Something blew up on our side. We most likely got an error report, but it doesn’t hurt to report it. |
| 502 | Bad gateway | invalid upstream, this happens during updates. |
| 503 | Service unavailable | A service is down, this happens during updates. |
| 504 | Gateway timeout | A timeout somewhere in our infrastructure. This could happen due to updates or when our network is congested. It can also happen when your network is congested or broken. |
Rate limiting
Currently we limit requests per connector to the following:
- 4 requests in parallel
- 100 requests per second
- 10.000 seconds of request time per day
The latest is measured as a sum for all requests being done. This can be 100.000 requests that take 100 milliseconds each or 1 request that takes 10.000 seconds. This is currently not enforced but will be in the future. If you go over the limit, you’ll receive a 429 status code.
Versioning
Our APIs are not versioned. Rather, we rely on marking resources as deprecated 6 months prior to removal. Keep an eye on the deprecation article and be prepared to adjust your connector. New resources are added as they become available, without further notice.