---
layout: default
title: API
has_children: false
nav_order: 99
---

# ML Commons API 

---

#### Table of contents
- TOC
{:toc}


---

The Machine Learning (ML) commons API lets you train ML algorithms synchronously and asynchronously, make predictions with that trained model, and train and predict with the same data set.

In order to train tasks through the API, three inputs are required. 

- Algorithm name: Must be one of a [FunctionName](https://github.com/opensearch-project/ml-commons/blob/1.3/common/src/main/java/org/opensearch/ml/common/parameter/FunctionName.java). This determines what algorithm the ML Engine runs. To add a new function, see [How To Add a New Function](https://github.com/opensearch-project/ml-commons/blob/main/docs/how-to-add-new-function.md).
- Model hyper parameters: Adjust these parameters to make the model train better.  
- Input data: The data input that trains the ML model, or applies the ML models to predictions. You can input data in two ways, query against your index or use data frame.


## Train model

The train operation trains a model based on a selected algorithm. Training can occur both synchronously and asynchronously.

### Request 

The following examples use the kmeans algorithm to train index data.

**Train with kmeans synchronously** 

```json
POST /_plugins/_ml/_train/kmeans
{
    "parameters": {
        "centroids": 3,
        "iterations": 10,
        "distance_type": "COSINE"
    },
    "input_query": {
        "_source": ["petal_length_in_cm", "petal_width_in_cm"],
        "size": 10000
    },
    "input_index": [
        "iris_data"
    ]
}
```

**Train with kmeans asynchronously**

```json
POST /_plugins/_ml/_train/kmeans?async=true
{
    "parameters": {
        "centroids": 3,
        "iterations": 10,
        "distance_type": "COSINE"
    },
    "input_query": {
        "_source": ["petal_length_in_cm", "petal_width_in_cm"],
        "size": 10000
    },
    "input_index": [
        "iris_data"
    ]
}
```

### Response

**Synchronously**

For synchronous responses, the API returns the model_id, which can be used to get or delete a model.

```json
{
  "model_id" : "lblVmX8BO5w8y8RaYYvN",
  "status" : "COMPLETED"
}
```

**Asynchronously**

For asynchronous responses, the API returns the task_id, which can be used to get or delete a task.

```json
{
  "task_id" : "lrlamX8BO5w8y8Ra2otd",
  "status" : "CREATED"
}
```

## Getting model information

You can retrieve information on your model using the model_id.

```json
GET /_plugins/_ml/models/<model-id>
```

The API returns information on the model, the algorithm used, and the content found within the model.

```json
{
  "name" : "KMEANS",
  "algorithm" : "KMEANS",
  "version" : 1,
  "content" : ""
}
```

## Registering a model

Use the register operation to register a custom model to a model index. ML Commons splits the model into smaller chunks and saves those chunks in the model's index.

```json
POST /_plugins/_ml/models/_register
```

### Request fields

All request fields are required. 

Field | Data type | Description
:---  | :--- | :--- 
`name`| string | The name of the model. |
`version` | integer | The version number of the model. |
`model_format` | string | The portable format of the model file. Currently only supports `TORCH_SCRIPT`. |
`model_config`  | json object | The model's configuration, including the `model_type`, `embedding_dimension`, and `framework_type`. `all_config` is an optional JSON string which contains all model configurations. |
`url` | string | The URL which contains the model. |

### Example

The following example request registers a version `1.0.0` of an NLP sentence transformation model named `all-MiniLM-L6-v2`.

```json
POST /_plugins/_ml/models/_register
{
  "name": "all-MiniLM-L6-v2",
  "version": "1.0.0",
  "description": "test model",
  "model_format": "TORCH_SCRIPT",
  "model_config": {
    "model_type": "bert",
    "embedding_dimension": 384,
    "framework_type": "sentence_transformers",
  },
  "url": "https://github.com/opensearch-project/ml-commons/raw/2.x/ml-algorithms/src/test/resources/org/opensearch/ml/engine/algorithms/text_embedding/all-MiniLM-L6-v2_torchscript_sentence-transformer.zip?raw=true"
}
```

### Response

OpenSearch responds with the `task_id` and task `status`.

```json
{
  "task_id" : "ew8I44MBhyWuIwnfvDIH", 
  "status" : "CREATED"
}
```

To see the status of your model registration, enter the `task_id` in the [task API] ...

```json
{
  "model_id" : "WWQI44MBbzI2oUKAvNUt", 
  "task_type" : "UPLOAD_MODEL",
  "function_name" : "TEXT_EMBEDDING",
  "state" : "REGISTERED",
  "worker_node" : "KzONM8c8T4Od-NoUANQNGg",
  "create_time" : 1665961344003,
  "last_update_time" : 1665961373047,
  "is_async" : true
}
```

## Deploying a model

The deploy model operation reads the model's chunks from the model index and then creates an instance of the model to cache into memory. This operation requires the `model_id`.

```json
POST /_plugins/_ml/models/<model_id>/_deploy
```

### Example: Deploying to all available ML nodes

In this example request, OpenSearch deploys the model to any available OpenSearch ML node:

```json
POST /_plugins/_ml/models/WWQI44MBbzI2oUKAvNUt/_deploy
```

### Example: Deploying to a specific node

If you want to reserve the memory of other ML nodes within your cluster, you can deploy your model to a specific node(s) by specifying the `node_ids` in the request body:

```json
POST /_plugins/_ml/models/WWQI44MBbzI2oUKAvNUt/_deploy
{
    "node_ids": ["4PLK7KJWReyX0oWKnBA8nA"]
}
```

### Response

```json
{
  "task_id" : "hA8P44MBhyWuIwnfvTKP",
  "status" : "DEPLOYING"
}
```

## Undeploying a model

To undeploy a model from memory, use the undeploy operation:

```json
POST /_plugins/_ml/models/<model_id>/_undeploy
```

### Example: Undeploying model from all ML nodes

```json
POST /_plugins/_ml/models/MGqJhYMBbbh0ushjm8p_/_undeploy
```

### Response: Undeploying a model from all ML nodes

```json
{
    "s5JwjZRqTY6nOT0EvFwVdA": {
        "stats": {
            "MGqJhYMBbbh0ushjm8p_": "UNDEPLOYED"
        }
    }
}
```

### Example: Undeploying specific models from specific nodes

```json
POST /_plugins/_ml/models/_undeploy
{
  "node_ids": ["sv7-3CbwQW-4PiIsDOfLxQ"],
  "model_ids": ["KDo2ZYQB-v9VEDwdjkZ4"]
}
```


### Response: Undeploying specific models from specific nodes

```json
{
  "sv7-3CbwQW-4PiIsDOfLxQ" : {
    "stats" : {
      "KDo2ZYQB-v9VEDwdjkZ4" : "UNDEPLOYED"
    }
  }
}
```

### Response: Undeploying all models from specific nodes

```json
{
  "sv7-3CbwQW-4PiIsDOfLxQ" : {
    "stats" : {
      "KDo2ZYQB-v9VEDwdjkZ4" : "UNDEPLOYED",
      "-8o8ZYQBvrLMaN0vtwzN" : "UNDEPLOYED"
    }
  }
}
```

### Example: Undeploying specific models from all nodes

```json
{
  "model_ids": ["KDo2ZYQB-v9VEDwdjkZ4"]
}
```

### Response: Undeploying specific models from all nodes

```json
{
  "sv7-3CbwQW-4PiIsDOfLxQ" : {
    "stats" : {
      "KDo2ZYQB-v9VEDwdjkZ4" : "UNDEPLOYED"
    }
  }
}
```

## Searching for a model

Use this command to search models you've already created.


```json
POST /_plugins/_ml/models/_search
{query}
```

### Example: Querying all models

```json
POST /_plugins/_ml/models/_search
{
  "query": {
    "match_all": {}
  },
  "size": 1000
}
```

### Example: Querying models with algorithm "FIT_RCF"

```json
POST /_plugins/_ml/models/_search
{
  "query": {
    "term": {
      "algorithm": {
        "value": "FIT_RCF"
      }
    }
  }
}
```

### Response

```json
{
    "took" : 8,
    "timed_out" : false,
    "_shards" : {
      "total" : 1,
      "successful" : 1,
      "skipped" : 0,
      "failed" : 0
    },
    "hits" : {
      "total" : {
        "value" : 2,
        "relation" : "eq"
      },
      "max_score" : 2.4159138,
      "hits" : [
        {
          "_index" : ".plugins-ml-model",
          "_id" : "-QkKJX8BvytMh9aUeuLD",
          "_version" : 1,
          "_seq_no" : 12,
          "_primary_term" : 15,
          "_score" : 2.4159138,
          "_source" : {
            "name" : "FIT_RCF",
            "version" : 1,
            "content" : "xxx",
            "algorithm" : "FIT_RCF"
          }
        },
        {
          "_index" : ".plugins-ml-model",
          "_id" : "OxkvHn8BNJ65KnIpck8x",
          "_version" : 1,
          "_seq_no" : 2,
          "_primary_term" : 8,
          "_score" : 2.4159138,
          "_source" : {
            "name" : "FIT_RCF",
            "version" : 1,
            "content" : "xxx",
            "algorithm" : "FIT_RCF"
          }
        }
      ]
    }
  }
```

## Deleting a model

Deletes a model based on the `model_id`.

```json
DELETE /_plugins/_ml/models/<model_id>
```

The API returns the following:

```json
{
  "_index" : ".plugins-ml-model",
  "_id" : "MzcIJX8BA7mbufL6DOwl",
  "_version" : 2,
  "result" : "deleted",
  "_shards" : {
    "total" : 2,
    "successful" : 2,
    "failed" : 0
  },
  "_seq_no" : 27,
  "_primary_term" : 18
}
```

## Profile

The profile operation returns runtime information on ML tasks and models. The profile operation can help debug issues with models at runtime.


```json
GET /_plugins/_ml/profile
GET /_plugins/_ml/profile/models
GET /_plugins/_ml/profile/tasks
```

### Path parameters

Parameter | Data type | Description
:--- | :--- | :---
model_id | string | Returns runtime data for a specific model. You can string together multiple `model_id`s to return multiple model profiles.
tasks | string | Returns runtime data for a specific task. You can string together multiple `task_id`s to return multiple task profiles.

### Request fields

All profile body request fields are optional.

Field | Data type | Description
:--- | :--- | :--- 
node_ids | string | Returns all tasks and profiles from a specific node. 
model_ids | string | Returns runtime data for a specific model. You can string together multiple `model_id`s to return multiple model profiles.
task_ids | string | Returns runtime data for a specific task. You can string together multiple `task_id`s to return multiple task profiles.
return_all_tasks | boolean | Determines whether or not a request returns all tasks. When set to `false` task profiles are left out of the response.
return_all_models | boolean | Determines whether or not a profile request returns all models. When set to `false` model profiles are left out of the response.

### Example: Returning all tasks and models on a specific node

```json
GET /_plugins/_ml/profile
{
  "node_ids": ["KzONM8c8T4Od-NoUANQNGg"],
  "return_all_tasks": true,
  "return_all_models": true
}
```

### Response: Returning all tasks and models on a specific node

```json
{
  "nodes" : {
    "qTduw0FJTrmGrqMrxH0dcA" : { # node id
      "models" : {
        "WWQI44MBbzI2oUKAvNUt" : { # model id
          "worker_nodes" : [ # routing table
            "KzONM8c8T4Od-NoUANQNGg"
          ]
        }
      }
    },
...
    "KzONM8c8T4Od-NoUANQNGg" : { # node id
      "models" : {
        "WWQI44MBbzI2oUKAvNUt" : { # model id
          "model_state" : "DEPLOYED", # model status
          "predictor" : "org.opensearch.ml.engine.algorithms.text_embedding.TextEmbeddingModel@592814c9",
          "worker_nodes" : [ # routing table
            "KzONM8c8T4Od-NoUANQNGg"
          ],
          "predict_request_stats" : { # predict request stats on this node
            "count" : 2, # total predict requests on this node
            "max" : 89.978681, # max latency in milliseconds
            "min" : 5.402,
            "average" : 47.6903405,
            "p50" : 47.6903405,
            "p90" : 81.5210129,
            "p99" : 89.13291418999998
          }
        }
      }
    },
...
}
```


## Predict

ML Commons can predict new data with your trained model either from indexed data or a data frame. To use the Predict API, the `model_id` is required.

```json
POST /_plugins/_ml/_predict/<algorithm_name>/<model_id>
```

### Request

```json
POST /_plugins/_ml/_predict/kmeans/<model-id>
{
    "input_query": {
        "_source": ["petal_length_in_cm", "petal_width_in_cm"],
        "size": 10000
    },
    "input_index": [
        "iris_data"
    ]
}
```

### Response

```json
{
  "status" : "COMPLETED",
  "prediction_result" : {
    "column_metas" : [
      {
        "name" : "ClusterID",
        "column_type" : "INTEGER"
      }
    ],
    "rows" : [
      {
        "values" : [
          {
            "column_type" : "INTEGER",
            "value" : 1
          }
        ]
      },
      {
        "values" : [
          {
            "column_type" : "INTEGER",
            "value" : 1
          }
        ]
      },
      {
        "values" : [
          {
            "column_type" : "INTEGER",
            "value" : 0
          }
        ]
      },
      {
        "values" : [
          {
            "column_type" : "INTEGER",
            "value" : 0
          }
        ]
      },
      {
        "values" : [
          {
            "column_type" : "INTEGER",
            "value" : 0
          }
        ]
      },
      {
        "values" : [
          {
            "column_type" : "INTEGER",
            "value" : 0
          }
        ]
      }
    ]
  }
```


## Train and predict

Use to train and then immediately predict against the same training data set. Can only be used with unsupervised learning models and the following algorithms:

- BATCH_RCF
- FIT_RCF
- kmeans

### Example: Train and predict with indexed data


```json
POST /_plugins/_ml/_train_predict/kmeans
{
    "parameters": {
        "centroids": 2,
        "iterations": 10,
        "distance_type": "COSINE"
    },
    "input_query": {
        "query": {
            "bool": {
                "filter": [
                    {
                        "range": {
                            "k1": {
                                "gte": 0
                            }
                        }
                    }
                ]
            }
        },
        "size": 10
    },
    "input_index": [
        "test_data"
    ]
}
```

### Example: Train and predict with data directly

```json
POST /_plugins/_ml/_train_predict/kmeans
{
    "parameters": {
        "centroids": 2,
        "iterations": 1,
        "distance_type": "EUCLIDEAN"
    },
    "input_data": {
        "column_metas": [
            {
                "name": "k1",
                "column_type": "DOUBLE"
            },
            {
                "name": "k2",
                "column_type": "DOUBLE"
            }
        ],
        "rows": [
            {
                "values": [
                    {
                        "column_type": "DOUBLE",
                        "value": 1.00
                    },
                    {
                        "column_type": "DOUBLE",
                        "value": 2.00
                    }
                ]
            },
            {
                "values": [
                    {
                        "column_type": "DOUBLE",
                        "value": 1.00
                    },
                    {
                        "column_type": "DOUBLE",
                        "value": 4.00
                    }
                ]
            },
            {
                "values": [
                    {
                        "column_type": "DOUBLE",
                        "value": 1.00
                    },
                    {
                        "column_type": "DOUBLE",
                        "value": 0.00
                    }
                ]
            },
            {
                "values": [
                    {
                        "column_type": "DOUBLE",
                        "value": 10.00
                    },
                    {
                        "column_type": "DOUBLE",
                        "value": 2.00
                    }
                ]
            },
            {
                "values": [
                    {
                        "column_type": "DOUBLE",
                        "value": 10.00
                    },
                    {
                        "column_type": "DOUBLE",
                        "value": 4.00
                    }
                ]
            },
            {
                "values": [
                    {
                        "column_type": "DOUBLE",
                        "value": 10.00
                    },
                    {
                        "column_type": "DOUBLE",
                        "value": 0.00
                    }
                ]
            }
        ]
    }
}
```

### Response

```json
{
  "status" : "COMPLETED",
  "prediction_result" : {
    "column_metas" : [
      {
        "name" : "ClusterID",
        "column_type" : "INTEGER"
      }
    ],
    "rows" : [
      {
        "values" : [
          {
            "column_type" : "INTEGER",
            "value" : 1
          }
        ]
      },
      {
        "values" : [
          {
            "column_type" : "INTEGER",
            "value" : 1
          }
        ]
      },
      {
        "values" : [
          {
            "column_type" : "INTEGER",
            "value" : 1
          }
        ]
      },
      {
        "values" : [
          {
            "column_type" : "INTEGER",
            "value" : 0
          }
        ]
      },
      {
        "values" : [
          {
            "column_type" : "INTEGER",
            "value" : 0
          }
        ]
      },
      {
        "values" : [
          {
            "column_type" : "INTEGER",
            "value" : 0
          }
        ]
      }
    ]
  }
}
```

## Getting task information

You can retrieve information about a task using the task_id.

```json
GET /_plugins/_ml/tasks/<task_id>
```

The response includes information about the task.

```json
{
  "model_id" : "l7lamX8BO5w8y8Ra2oty",
  "task_type" : "TRAINING",
  "function_name" : "KMEANS",
  "state" : "COMPLETED",
  "input_type" : "SEARCH_QUERY",
  "worker_node" : "54xOe0w8Qjyze00UuLDfdA",
  "create_time" : 1647545342556,
  "last_update_time" : 1647545342587,
  "is_async" : true
}
```

## Searching for a task

Search tasks based on parameters indicated in the request body.

```json
GET /_plugins/_ml/tasks/_search
{query body}
```


### Example: Search task which "function_name" is "KMEANS"

```json
GET /_plugins/_ml/tasks/_search
{
  "query": {
    "bool": {
      "filter": [
        {
          "term": {
            "function_name": "KMEANS"
          }
        }
      ]
    }
  }
}
```

### Response

```json
{
  "took" : 12,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 2,
      "relation" : "eq"
    },
    "max_score" : 0.0,
    "hits" : [
      {
        "_index" : ".plugins-ml-task",
        "_id" : "_wnLJ38BvytMh9aUi-Ia",
        "_version" : 4,
        "_seq_no" : 29,
        "_primary_term" : 4,
        "_score" : 0.0,
        "_source" : {
          "last_update_time" : 1645640125267,
          "create_time" : 1645640125209,
          "is_async" : true,
          "function_name" : "KMEANS",
          "input_type" : "SEARCH_QUERY",
          "worker_node" : "jjqFrlW7QWmni1tRnb_7Dg",
          "state" : "COMPLETED",
          "model_id" : "AAnLJ38BvytMh9aUi-M2",
          "task_type" : "TRAINING"
        }
      },
      {
        "_index" : ".plugins-ml-task",
        "_id" : "wwRRLX8BydmmU1x6I-AI",
        "_version" : 3,
        "_seq_no" : 38,
        "_primary_term" : 7,
        "_score" : 0.0,
        "_source" : {
          "last_update_time" : 1645732766656,
          "create_time" : 1645732766472,
          "is_async" : true,
          "function_name" : "KMEANS",
          "input_type" : "SEARCH_QUERY",
          "worker_node" : "A_IiqoloTDK01uZvCjREaA",
          "state" : "COMPLETED",
          "model_id" : "xARRLX8BydmmU1x6I-CG",
          "task_type" : "TRAINING"
        }
      }
    ]
  }
}
```

## Deleting a task

Delete a task based on the task_id.

ML Commons does not check the task status when running the `Delete` request. There is a risk that a currently running task could be deleted before the task completes. To check the status of a task, run `GET /_plugins/_ml/tasks/<task_id>` before task deletion.
{: .note}

```json
DELETE /_plugins/_ml/tasks/{task_id}
```

The API returns the following:

```json
{
  "_index" : ".plugins-ml-task",
  "_id" : "xQRYLX8BydmmU1x6nuD3",
  "_version" : 4,
  "result" : "deleted",
  "_shards" : {
    "total" : 2,
    "successful" : 2,
    "failed" : 0
  },
  "_seq_no" : 42,
  "_primary_term" : 7
}
```

## Stats

Get statistics related to the number of tasks. 

To receive all stats, use:

```json
GET /_plugins/_ml/stats
```

To receive stats for a specific node, use:

```json
GET /_plugins/_ml/<nodeId>/stats/
```

To receive stats for a specific node and  return a specified stat, use:

```json
GET /_plugins/_ml/<nodeId>/stats/<stat>
```

To receive information on a specific stat from all nodes, use:

```json
GET /_plugins/_ml/stats/<stat>
```


### Example: Get all stats

```json
GET /_plugins/_ml/stats
```

### Response

```json
{
  "zbduvgCCSOeu6cfbQhTpnQ" : {
    "ml_executing_task_count" : 0
  },
  "54xOe0w8Qjyze00UuLDfdA" : {
    "ml_executing_task_count" : 0
  },
  "UJiykI7bTKiCpR-rqLYHyw" : {
    "ml_executing_task_count" : 0
  },
  "zj2_NgIbTP-StNlGZJlxdg" : {
    "ml_executing_task_count" : 0
  },
  "jjqFrlW7QWmni1tRnb_7Dg" : {
    "ml_executing_task_count" : 0
  },
  "3pSSjl5PSVqzv5-hBdFqyA" : {
    "ml_executing_task_count" : 0
  },
  "A_IiqoloTDK01uZvCjREaA" : {
    "ml_executing_task_count" : 0
  }
}
```

## Execute

Some algorithms, such as [Localization]({{site.url}}{{site.baseurl}}/ml-commons-plugin/algorithms#localization), don't require trained models. You can run no-model-based algorithms using the `execute` API.

```json
POST _plugins/_ml/_execute/<algorithm_name>
```

### Example: Execute localization 

The following example uses the Localization algorithm to find subset-level information for aggregate data (for example, aggregated over time) that demonstrates the activity of interest, such as spikes, drops, changes, or anomalies.

```json
POST /_plugins/_ml/_execute/anomaly_localization
{
  "index_name": "rca-index",
  "attribute_field_names": [
    "attribute"
  ],
  "aggregations": [
    {
      "sum": {
        "sum": {
          "field": "value"
        }
      }
    }
  ],
  "time_field_name": "timestamp",
  "start_time": 1620630000000,
  "end_time": 1621234800000,
  "min_time_interval": 86400000,
  "num_outputs": 10
}
```

Upon execution, the API returns the following:

```json
  "results" : [
    {
      "name" : "sum",
      "result" : {
        "buckets" : [
          {
            "start_time" : 1620630000000,
            "end_time" : 1620716400000,
            "overall_aggregate_value" : 65.0
          },
          {
            "start_time" : 1620716400000,
            "end_time" : 1620802800000,
            "overall_aggregate_value" : 75.0,
            "entities" : [
              {
                "key" : [
                  "attr0"
                ],
                "contribution_value" : 1.0,
                "base_value" : 2.0,
                "new_value" : 3.0
              },
              {
                "key" : [
                  "attr1"
                ],
                "contribution_value" : 1.0,
                "base_value" : 3.0,
                "new_value" : 4.0
              },
              {
                "key" : [
                  "attr2"
                ],
                "contribution_value" : 1.0,
                "base_value" : 4.0,
                "new_value" : 5.0
              },
              {
                "key" : [
                  "attr3"
                ],
                "contribution_value" : 1.0,
                "base_value" : 5.0,
                "new_value" : 6.0
              },
              {
                "key" : [
                  "attr4"
                ],
                "contribution_value" : 1.0,
                "base_value" : 6.0,
                "new_value" : 7.0
              },
              {
                "key" : [
                  "attr5"
                ],
                "contribution_value" : 1.0,
                "base_value" : 7.0,
                "new_value" : 8.0
              },
              {
                "key" : [
                  "attr6"
                ],
                "contribution_value" : 1.0,
                "base_value" : 8.0,
                "new_value" : 9.0
              },
              {
                "key" : [
                  "attr7"
                ],
                "contribution_value" : 1.0,
                "base_value" : 9.0,
                "new_value" : 10.0
              },
              {
                "key" : [
                  "attr8"
                ],
                "contribution_value" : 1.0,
                "base_value" : 10.0,
                "new_value" : 11.0
              },
              {
                "key" : [
                  "attr9"
                ],
                "contribution_value" : 1.0,
                "base_value" : 11.0,
                "new_value" : 12.0
              }
            ]
          },
          ...
        ]
      }
    }
  ]
}
```