You can update an existing Decision Optimization model using the watsonx.ai Runtime REST API. This can be useful, for example, if in your model you have explicitly specified a Python version that has now become deprecated.

To change Python version for an existing deployed model:

1. Create a revision to your Decision Optimization model

   All API requests require a version parameter that takes a date in the format version=YYYY-MM-DD. This code example posts a model that uses the file update_model.json. The URL will vary according to the chosen region/location for your machine learning service.

   curl --location --request POST \
     "https://us-south.ml.cloud.ibm.com/ml/v4/models/MODEL-ID-HERE/revisions?version=2021-12-01" \
     -H "Authorization: bearer TOKEN-HERE" \
     -H "Content-Type: application/json" \
     -d @revise_model.json

   The revise_model.json file contains the following code:

   {
     "commit_message": "Save current model",
     "space_id": "SPACE-ID-HERE"
   }

   Note the model revision number "rev" that is provided in the output for use in the next step.
2. Update an existing deployment so that current jobs will not be impacted:

   curl --location --request PATCH \
     "https://us-south.ml.cloud.ibm.com/ml/v4/deployments/DEPLOYMENT-ID-HERE?version=2021-12-01&space_id=SPACE-ID-HERE" \
     -H "Authorization: bearer TOKEN-HERE" \
     -H "Content-Type: application/json" \
     -d @revise_deploy.json

   The revise_deploy.json file contains the following code:

   [
     {
     "op": "add",
     "path": "/asset",
     "value": {
       "id":"MODEL-ID-HERE",
       "rev":"MODEL-REVISION-NUMBER-HERE"
      }
     }
   ]

3. Patch an existing model to explicitly specify Python version 3.11

   curl --location --request PATCH \
     "https://us-south.ml.cloud.ibm.com/ml/v4/models/MODEL-ID-HERE?rev=MODEL-REVISION-NUMBER-HERE&version=2021-12-01&space_id=SPACE-ID-HERE" \
     -H "Authorization: bearer TOKEN-HERE" \
     -H "Content-Type: application/json" \
     -d @update_model.json

   The update_model.json file, with the default Python version stated explicitly, contains the following code:

   [
    {
    "op": "add",
    "path": "/custom",
    "value": {
      "decision_optimization":{
         "oaas.docplex.python": "3.11"
        }
      }
    }
   ]

   Alternatively, to remove any explicit mention of a Python version so that the default version will always be used:

   [
    {
    "op": "remove",
    "path": "/custom/decision_optimization"
    }
   ]

4. Patch the deployment to use the model that was created for Python to use version 3.11

   curl --location --request PATCH \
     "https://us-south.ml.cloud.ibm.com/ml/v4/deployments/DEPLOYMENT-ID-HERE?version=2021-12-01&space_id=SPACE-ID-HERE" \
     -H "Authorization: bearer TOKEN-HERE" \
     -H "Content-Type: application/json" \
     -d @update_deploy.json

   The update_deploy.json file contains the following code:

   [
    {
      "op": "add",
      "path": "/asset",
      "value": { "id":"MODEL-ID-HERE"}
    }
   ]