# Contribution in general and how to post them in EHRBase
**URL:** https://discourse.openehr.org/t/contribution-in-general-and-how-to-post-them-in-ehrbase/1241
**Category:** Platform
**Tags:** ehrbase
**Created:** [20 January 2021 15:57 UTC](https://discourse.openehr.org/t/contribution-in-general-and-how-to-post-them-in-ehrbase/1241 "2021-01-20T15:57:20Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@surfer](https://discourse.openehr.org/u/surfer)
#### Post date: [20 January 2021 15:57 UTC](https://discourse.openehr.org/t/contribution-in-general-and-how-to-post-them-in-ehrbase/1241/1 "2021-01-20T15:57:20Z")
Hi,
I’d like to learn how/when to use the contributions. Due to my ignorance my questions are very basic and maybe naive.
1)The first thing is that I don’t have any example of contribution, to learn from, other than the one in the API openEHR specification [[EHR API](https://specifications.openehr.org/releases/ITS-REST/latest/ehr.html#contribution)] .
Do you have a meaningful example of a contribution?
2)Then I was wondering what’s the difference between posting a composition and posting a contribution with the same composition inside or as well if I should use the REST put to update a composition or should I update it through a contribution. What’s the recommended approach?
3)How do you post a contribution to EHRBase? I tried with the contribution I mentioned before with no success.
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### Author:  [@thomas.beale](https://discourse.openehr.org/u/thomas.beale)
#### Post date: [20 January 2021 16:16 UTC](https://discourse.openehr.org/t/contribution-in-general-and-how-to-post-them-in-ehrbase/1241/2 "2021-01-20T16:16:53Z")
Here is a bit of explanatory background on Contributions:
- [openEHR Architecture Overview - Versioning](https://specifications.openehr.org/releases/BASE/latest/architecture_overview.html#_versioning_2)
- [EHR spec](https://specifications.openehr.org/releases/RM/latest/ehr.html#_change_control_in_the_ehr)
Short summary of the concepts:
- a Contribution is the same idea as a [change set](https://en.wikipedia.org/wiki/Changeset) in versioning theory - a collection of all changes to be committed at one time to some repository or file system.
- whenever anything is committed to the openEHR EHR, a Contribution is created, whether you are explicitly aware of it or not.
- ideally, a repository should advance from one valid state to the next in contribution steps - i.e. no commit should create an invalid state.
An API that supports Contributions should enable you to commit multiple changes in one set, i.e.
- updated Compositions - e.g. Medications list, Problem List.
- new Encounter Composition
- even logical deletes (rare in openEHR)
hope this helps.
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### Author:  [@surfer](https://discourse.openehr.org/u/surfer)
#### Post date: [20 January 2021 17:10 UTC](https://discourse.openehr.org/t/contribution-in-general-and-how-to-post-them-in-ehrbase/1241/3 "2021-01-20T17:10:26Z")
thank you Mr Beale,
I just read them and returning to point 2) in the original post if i understood it correctly there’s no difference in the two approaches. I mean if I have only a composition to create I can do it through the composition API or through the contribution API with AUDIT\_DETAILS.change\_type set to create. There’s not a preferred approach.
But what happens if I post a contribution where multiple action occur and one fails? Being change-set means that everything in the contribution is rejected or the action that fails is removed and the rest form an accepted contribution?
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### Author:  [@thomas.beale](https://discourse.openehr.org/u/thomas.beale)
#### Post date: [20 January 2021 17:22 UTC](https://discourse.openehr.org/t/contribution-in-general-and-how-to-post-them-in-ehrbase/1241/4 "2021-01-20T17:22:44Z")
If you just want to commit a single Composition, which is a common thing to need to do in many situations, then the Composition API will be easier. It will cause a Contribution to be created for you.
If you try to commit a Contribution, and it contains one item that doesn’t validate against its template, the Contribution will fail. But the same can happen with just a single Composition.
It might be useful for us to think about an additional API that can validate structures before trying to do a commit.
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### Author:  [@surfer](https://discourse.openehr.org/u/surfer)
#### Post date: [20 January 2021 19:10 UTC](https://discourse.openehr.org/t/contribution-in-general-and-how-to-post-them-in-ehrbase/1241/5 "2021-01-20T19:10:55Z")
and for point 1) and 3) that is I would need an example of a contribution accepted by EHRBase, @birger.haarbrandt can you help me? As I tried the example composition from the openEHR specification and tried to overcome the errors that comes out with no success.
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### Author:  [@birger.haarbrandt](https://discourse.openehr.org/u/birger.haarbrandt)
#### Post date: [20 January 2021 19:36 UTC](https://discourse.openehr.org/t/contribution-in-general-and-how-to-post-them-in-ehrbase/1241/6 "2021-01-20T19:36:07Z")
Hi @surfer,
you will find some examples in our integration tests: [https://github.com/ehrbase/ehrbase/tree/develop/tests/robot/\_resources/test\_data\_sets/contributions/valid](https://github.com/ehrbase/ehrbase/tree/develop/tests/robot/_resources/test_data_sets/contributions/valid)
If I remember correctly there were still some variations between the serializations. This should hopefully be resolved and completely standardized. Hope this helps!
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### Author:  [@surfer](https://discourse.openehr.org/u/surfer)
#### Post date: [20 January 2021 20:27 UTC](https://discourse.openehr.org/t/contribution-in-general-and-how-to-post-them-in-ehrbase/1241/7 "2021-01-20T20:27:52Z")
yeah. It sure helps. thanks
And the parameters and headers are the ones in [https://specifications.openehr.org/releases/ITS-REST/latest/ehr.html#contribution](https://specifications.openehr.org/releases/ITS-REST/latest/ehr.html#contribution) , aren’t they?
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### Author:  [@jake.smolka](https://discourse.openehr.org/u/jake.smolka)
#### Post date: [21 January 2021 15:15 UTC](https://discourse.openehr.org/t/contribution-in-general-and-how-to-post-them-in-ehrbase/1241/8 "2021-01-21T15:15:44Z")
Hey @surfer!
Here’s a working example from our integration tests to get you started, if it didn’t work out yet.
Precondition: Create an EHR and remember the `EHR_ID`.
To get EHRbase prepared for this example contribution and the compositions it contains you first need to upload the required template. Create a POST request to `http://localhost:8080/ehrbase/rest/openehr/v1/definition/template/adl1.4` and set the headers
- `Content-Type` = `application/xml` because the body payload will be XML.
- `prefer` = `return=representation` if you want the uploaded template directly returned to you.
Add the following body payload to the request:
[obs\_eva.en.v1.xml](https://discourse.openehr.org/uploads/short-url/iD9wFTGSX7JhfkNP8ror7CjTKwU.xml) (17.2 KB)
Execute the request. The response should have a `201 Created` status and the template as body.
(Note: This step obviously depends on the content of the contribution. For instance, if a contribution modifies an EHR\_STATUS objects no specific template is required. If it adds or modifies a different kind of composition the matching template is required, instead of the one I provided.)
For the contribution itself:
Create a `POST` request pointing at the endpoint URI `http://localhost:8080/ehrbase/rest/openehr/v1/ehr/{{ehrId}}/contribution`.
The following headers are important
- `Content-Type` = `application/json` because the body payload is json.
- `prefer` = `return=representation` if you want the created objects directly returned to you.
Add the following body payload to the request:
[request-body-payload.json](https://discourse.openehr.org/uploads/short-url/g7xhhqejyzk7RtOrg53Z6rAo1GO.json) (15.5 KB)
This example contains two compositions, which should now be successfully created, after executing the request. The response should have a `201 Created` status and an overview of the objects in the body.
Hope this helps you getting started!
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### Author:  [@surfer](https://discourse.openehr.org/u/surfer)
#### Post date: [22 January 2021 07:57 UTC](https://discourse.openehr.org/t/contribution-in-general-and-how-to-post-them-in-ehrbase/1241/9 "2021-01-22T07:57:32Z")
thank you. it should help a lot indeed