[Solved] Postman API, InstanceNotFoundError on single collection that is visible in the collection list

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1

In our CICD pipeline, we use api requests to retrieve the relevant Collections to run through our tests. Therefore we do first a GET on the collections and do a GET on all collections to retrieve the content as JSON so we can run it with Newman.

Unfortunately, not all collections we get back do return a correct content. For example:
(anonymized with #)

curl -X GET \
  https://api.getpostman.com/collections \
    -H 'X-Api-Key: #############################'

result:

{
    "collections": [
        {
            "id": "######-####-####-####-#######001",
            "name": "Collection ABC",
            "owner": "#######",
            "uid": "######-####-####-####-#######001"
        },
        {
            "id": "######-####-####-####-#######002",
            "name": "Collection DEF",
            "owner": "#######",
            "uid": "######-####-####-####-#######002"
        },
        {
            "id": "######-####-####-####-#######003",
            "name": "Collection XYZ",
            "owner": "#######",
            "uid": "######-####-####-####-#######003"
        }
}

When I do a get of Collection ABC and DEF, it returns a correct JSON. But when I do a get on Collection XYZ, I get the message:

curl -X GET \
  https://api.getpostman.com/collections/######-####-####-####-#######003 \
           -H 'X-Api-Key: #############################' 

{
    "error": {
        "name": "instanceNotFoundError",
        "message": "Instance not found in the database."
    }
}

It is reproducible for this and some other collections. Even when I make changes to their name or content. What am I doing wrong?

2

I could solve it by using the uid instead of id attribute to retrieve the collection. The difference seems to be as follow:

id is the id of the request
uid is the ownerid + id. I think to differentiate between different versions of users if you are working in a team.

When you try to get a collection by id, but it is created by another member it will throw the instanceNotFoundError. If you get the collection with the uid it works fine.