---
title: "Recommend Users to Item"
method: POST
path: "/{databaseId}/recomms/items/{itemId}/users/"
tags: ["Recommendations"]
---

# Recommend Users to Item

`POST /{databaseId}/recomms/items/{itemId}/users/`

Recommends users that are likely to be interested in the given item.

It is also possible to use POST HTTP method (for example in the case of a very long ReQL filter) - query parameters then become body parameters.

The returned users are sorted by predicted interest in the item (the first user being the most interested).

## Path parameters

- `databaseId` string, required
- `itemId` string, required

## Request body

- RecommendUsersToItemParameters
  - `count` integer, required — Number of users to be recommended (N for the top-N recommendation).
  - `scenario` string — Scenario defines a particular application of recommendations. It can be, for example, "homepage", "cart", or "emailing". You can set various settings to the [scenario](https://docs.recombee.com/scenarios) in the [Admin UI](https://admin.recombee.com). You can also see the performance of each scenario in the Admin UI separately, so you can check how well each application performs. The AI that optimizes models to get the best results may optimize different scenarios separately or even use different models in each of the scenarios.
  - `cascadeCreate` boolean — If an item of the given *itemId* doesn't exist in the database, it creates the missing item.
  - `returnProperties` boolean — With `returnProperties=true`, property values of the recommended users are returned along with their IDs in a JSON dictionary. The acquired property values can be used to easily display the recommended users. Example response: ```json { "recommId": "039b71dc-b9cc-4645-a84f-62b841eecfce", "recomms": [ { "id": "user-17", "values": { "country": "US", "sex": "F" } }, { "id": "user-2", "values": { "country": "CAN", "sex": "M" } } ], "numberNextRecommsCalls": 0 } ```
  - `includedProperties` string[] — Allows specifying which properties should be returned when `returnProperties=true` is set. The properties are given as a comma-separated list. Example response for `includedProperties=country`: ```json { "recommId": "b2b355dd-972a-4728-9c6b-2dc229db0678", "recomms": [ { "id": "user-17", "values": { "country": "US" } }, { "id": "user-2", "values": { "country": "CAN" } } ], "numberNextRecommsCalls": 0 } ```
  - `filter` string — Boolean-returning [ReQL](https://docs.recombee.com/reql) expression, which allows you to filter recommended users based on the values of their attributes. Filters can also be assigned to a [scenario](https://docs.recombee.com/scenarios) in the [Admin UI](https://admin.recombee.com).
  - `booster` string — Number-returning [ReQL](https://docs.recombee.com/reql) expression, which allows you to boost the recommendation rate of some users based on the values of their attributes. Boosters can also be assigned to a [scenario](https://docs.recombee.com/scenarios) in the [Admin UI](https://admin.recombee.com).
  - `logic` union
    - string
    - object
      - `name` string — Name of the logic that should be used
      - `settings` object — Parameters passed to the logic
  - `reqlExpressions` object — A dictionary of [ReQL](https://docs.recombee.com/reql) expressions that will be executed for each recommended user. This can be used to compute additional properties of the recommended users that are not stored in the database. The keys are the names of the expressions, and the values are the actual ReQL expressions. Example request: ```json { "reqlExpressions": { "isInUsersCity": "context_user[\"city\"] in 'cities'", "distanceToUser": "earth_distance('location', context_user[\"location\"])", "isFromSameCompany": "'company' == context_item[\"company\"]" } } ``` Example response: ```json { "recommId": "ce52ada4-e4d9-4885-943c-407db2dee837", "recomms": [ { "id": "restaurant-178", "reqlEvaluations": { "isInUsersCity": true, "distanceToUser": 5200.2, "isFromSameCompany": false } }, { "id": "bar-42", "reqlEvaluations": { "isInUsersCity": false, "distanceToUser": 2516.0, "isFromSameCompany": true } } ], "numberNextRecommsCalls": 0 } ```
  - `diversity` number, double — **Expert option:** Real number from [0.0, 1.0], which determines how mutually dissimilar the recommended users should be. The default value is 0.0, i.e., no diversification. Value 1.0 means maximal diversification.
  - `expertSettings` object — Dictionary of custom options.
  - `returnAbGroup` boolean — If there is a custom AB-testing running, return the name of the group to which the request belongs.

## Response `200`

Successful operation.

- RecommendationResponse
  - `recommId` string, required — Id of the recommendation request
  - `recomms` Recommendation[], required — Obtained recommendations
    - `id` string, required — Id of the recommended item
    - `values` object — Property values of the recommended item
    - `reqlEvaluations` object — Dictionary of evaluated ReQL expressions specified in the request and calculated for the recommended item. The keys are the names of the ReQL expressions, and the values are the results of the evaluations.
  - `numberNextRecommsCalls` integer — How many times *Recommend Next Items* have been called for this `recommId`
  - `abGroup` string — Name of AB-testing group to which the request belongs if there is a custom AB-testing running.

## Other responses

- `400` — itemId does not match ^[a-zA-Z0-9_\-:@\.]+$, count is not a positive integer, filter or booster is not valid [ReQL](https://docs.recombee.com/reql) expressions, filter expression does not return boolean, booster does not return double or integer.
- `404` — itemId not found in the database and cascadeCreate is false. If there is no additional info in the JSON response, you probably have an error in your URL.

---

[API](https://skmtc.dev/recombee/apis/recombee-api.md) · [All operations](https://skmtc.dev/recombee/apis/recombee-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/recombee/recombee-api/revisions/a9c9c33eb2e8/schema)