Hey medplum team- we had a question about what's the proper way to handle compartments in the current version of medplum (v4.1.5 as of writing). We recently aborted an upgrade from v3.2.24 -> v4.1.4 after discovering the removal of [user defined compartments](https://github.com/medplum/medplum/issues/5124). We have a use where we would add an

Organization

compartment on a

Task

resource so that it could be used as a filter in a graphql query. It appears that was removed in [4.0.4](https://github.com/medplum/medplum/pull/6145) in favor of using the

meta.accounts

key to apply arbitrary compartments wherever the [patient compartment](https://hl7.org/fhir/R4/compartmentdefinition-patient.html) is also applied. Since `Task`s don't have an inclusion criteria for the patient compartment, is there a recommended way to achieve the same functionality? If I recall correctly, we had at one time used

_tag

as a filter for graphql queries but noticed relatively slow performance. Memory of that is a bit hazy though.

Hey @nathan-watkins-unityai , good question! The desired behavior of compartments and accounts is something we are actively working on and trying to make more clear, so it is interesting to hear your approach. Let me try to answer parts of this one at a time. "we had at one time used _tag as a filter for graphql queries but noticed relatively slow performance. Memory of that is a bit hazy though" [Here](https://www.medplum.com/docs/search/advanced-search-parameters#_tag) are some docs about the _tag search param. One solution could be to just add the Organization as a tag, and then you could filter as intended. It will be less performant than _compartment because _tag searching over any type of text where _compartment is searching over ids (resource references). The current behavior of writing to the meta.compartment of a Task resource would be to just specify the references that you want in the meta.accounts when updating that resource. ex.

R4/Task/123

PUT

{
  "resourceType": "Task",
  "status": "accepted",
  "intent": "unknown",
  "id": "123",
  "meta": {
    "project": "123",
    "compartment": [
      {
        "reference": "Project/123"
      }
    ],
    "accounts": [
      {
        "reference": "Organization/123"
      }
    ],
//...
}

and then that Organization will be added to meta.compartment Please let me know if I am wrong here, but I assume that the ideal behavior for you would be for you to add the Organization to the compartment of the Patient, and then it automatically updates all the compartment of the resources in the [patient compartment ](https://hl7.org/fhir/R4/compartmentdefinition-patient.html). Then, you could manage the compartments for all the other resources by just updating the Patient, and your queries would all look the same:

await medplum.searchResources('<ResourceType>', {
  _compartment: 'Organization/<your-org-id>',
});

This is currently achievable for all the resources in the Patient's compartment definition using the patient [$set-accounts](https://www.medplum.com/docs/api/fhir/operations/patient-set-accounts) operation. As you noted, unfortunately, the Task resource is not in the Patient compartment definition. Interestingly, it did get included in the [Patient R5 CompartmentDefinition](https://hl7.org/fhir/R5/compartmentdefinition-patient.html), so this must be a use case that others have come across. In the future, this is something we could add to the automatic propagation.

Thank you for the thorough response! This helps us significantly on how to approach this. Your assumption is correct on what we would view as the ideal behavior. One last point of clarification- does the

$set-accounts

operation always have to be called to propagate a patient's accounts -> compartments? Or is that for retroactively applying them? In other words, if the

Patient.accounts

is populated with an

Organization

reference (for example), do subsequently created resources within the compartment definition automatically add it to the compartments or only after the

$set-accounts

operation is run?

"do subsequently created resources within the compartment definition automatically add it to the compartments or only after the $set-accounts operation is run?" On new resource creations within the compartment , yes they are automatically applied. No need to call $set-accounts (Ex. creating a DiagnosticReport that's subject field points to a patient. The DiagnosticReport.meta.accounts will be automatically inherited from the Patient.meta.accounts For updates, this is where most of the confusion comes from, and please note, this behavior may change very soon. If you are updating a resource in the Patient's compartment as an admin, and do not specify the meta field, it will inherit the meta.accounts, but if you do specify the meta field, then it will overwrite them. This is why we suggest the $set-accounts when you need to change something in the meta.accounts of a resource within the Patient's compartment.