OneSignal Notifications?c=push API

openapi: 3.2.0
info:
  title: api.onesignal.com Notifications?c=push API
  version: '11.6'
servers:
- url: https://api.onesignal.com
security:
- {}
tags:
- name: Notifications?c=push
paths:
  /notifications?c=push:
    post:
      summary: Push notification
      description: Send a message using the push notification channel.
      operationId: push-notification
      x-codeSamples:
      - lang: typescript
        label: Node.js SDK
        source: "import Onesignal from '@onesignal/node-onesignal';\nimport { randomUUID } from 'node:crypto';\n\nconst configuration = Onesignal.createConfiguration({\n    restApiKey: 'YOUR_REST_API_KEY',\n});\nconst apiInstance = new Onesignal.DefaultApi(configuration);\n\nconst notification = new Onesignal.Notification();\nnotification.app_id = 'YOUR_APP_ID';\nnotification.contents = { en: 'Hello from OneSignal!' };\nnotification.headings = { en: 'Push Notification' };\n// Target by External ID: alias keys must match the API (external_id, not externalId).\nnotification.include_aliases = { external_id: ['YOUR_USER_EXTERNAL_ID'] };\nnotification.target_channel = 'push';\n// Idempotency key: a client-generated UUID that lets you safely retry on network failure.\n// If two requests arrive with the same key inside the 30-day window, only the first is sent\n// and the second returns the original response. `randomUUID` is imported from `node:crypto`\n// (available on Node 14.17+) — DO NOT reuse keys across logically distinct sends.\nnotification.idempotency_key = randomUUID();\n\ntry {\n  const response = await apiInstance.createNotification(notification);\n  // `response.id` discriminates the two HTTP 200 shapes. A falsy value (empty string,\n  // null, or undefined) means no notification was created (e.g. all targets were\n  // unreachable / not subscribed). `response.errors` is polymorphic: a `string[]` in the\n  // no-subscribers case, or an object keyed by recipient-identifier type\n  // (`invalid_player_ids`, `invalid_external_user_ids`, `invalid_aliases`, …) when the\n  // notification WAS created but some recipients were skipped.\n  if (!response.id) {\n    console.warn(\"Notification was not sent:\", response.errors);\n  } else if (response.errors) {\n    console.log(\"Notification created:\", response.id, \"(partial failures:\", response.errors, \")\");\n  } else {\n    console.log(\"Notification created:\", response.id);\n  }\n} catch (e) {\n  if (e instanceof Onesignal.ApiException) {\n    // `e.errorMessages` flattens any error-envelope shape to a `string[]`;\n    // the raw parsed body remains on `e.body`.\n    console.error(\"createNotification failed: HTTP \" + e.code, e.errorMessages);\n  } else {\n    throw e;\n  }\n}"
      - lang: python
        label: Python SDK
        source: "import uuid\nimport onesignal\nfrom onesignal.api import default_api\nfrom onesignal.model.language_string_map import LanguageStringMap\nfrom onesignal.model.notification import Notification\n\n# See configuration.py for a list of all supported configuration parameters.\n# Some of the OneSignal endpoints require ORGANIZATION_API_KEY token for authorization, while others require REST_API_KEY.\n# We recommend adding both of them in the configuration page so that you will not need to figure it out yourself.\nconfiguration = onesignal.Configuration(\n    rest_api_key = \"YOUR_REST_API_KEY\", # App REST API key required for most endpoints\n    organization_api_key = \"YOUR_ORGANIZATION_API_KEY\" # Organization key is only required for creating new apps and other top-level endpoints\n)\n\n\nwith onesignal.ApiClient(configuration) as api_client:\n    api_instance = default_api.DefaultApi(api_client)\n    notification = Notification(\n        app_id='YOUR_APP_ID',\n        contents=LanguageStringMap(en='Hello from OneSignal!'),\n        headings=LanguageStringMap(en='Push Notification'),\n        include_aliases={'external_id': ['YOUR_USER_EXTERNAL_ID']},\n        target_channel='push',\n        # Idempotency key: a client-generated UUID that lets you safely retry on network\n        # failure. If two requests arrive with the same key inside the 30-day window, only\n        # the first is sent and the second returns the original response. Use uuid.uuid4()\n        # or a similar source of randomness — DO NOT reuse keys across logically distinct\n        # sends.\n        idempotency_key=str(uuid.uuid4()),\n    )\n    try:\n        api_response = api_instance.create_notification(notification)\n        # `api_response.id` discriminates the two HTTP 200 shapes. A falsy value means no\n        # notification was created (e.g. all targets were unreachable / not subscribed).\n        # `api_response.errors` is polymorphic: a `list[str]` in the no-subscribers case, or\n        # a dict keyed by recipient-identifier type (`invalid_player_ids`,\n        # `invalid_external_user_ids`, `invalid_aliases`, ...) when the notification WAS\n        # created but some recipients were skipped. Access via `.get('errors')` rather than\n        # attribute access — the legacy Python generator's `ModelNormal.__getattr__` raises\n        # `ApiAttributeError` for optional fields that the server omitted, so plain\n        # `api_response.errors` would crash on the pure-success path.\n        response_id = api_response.get('id')\n        response_errors = api_response.get('errors')\n        if not response_id:\n            print('Notification was not sent:', response_errors)\n        elif response_errors:\n            print('Notification created:', response_id, '(partial failures:', response_errors, ')')\n        else:\n            print('Notification created:', response_id)\n    except onesignal.ApiException as e:\n        print('Exception when calling DefaultApi->create_notification: %s\\n' % e)\n        print('Status Code: %s' % e.status)\n        # `e.error_messages` flattens any error-envelope shape to a list[str];\n        # the raw body remains on `e.body`.\n        print('Error Messages: %s' % e.error_messages)\n        print('Response Body: %s' % e.body)"
      - lang: php
        label: PHP SDK
        source: "<?php\nrequire_once(__DIR__ . '/vendor/autoload.php');\n\n\n// Configure Bearer authorization: rest_api_key\n$config = onesignal\\client\\Configuration::getDefaultConfiguration()\n                                                ->setRestApiKeyToken('YOUR_REST_API_KEY')\n                                                ->setOrganizationApiKeyToken('YOUR_ORGANIZATION_API_KEY');\n\n\n\n$apiInstance = new onesignal\\client\\Api\\DefaultApi(\n    new GuzzleHttp\\Client(),\n    $config\n);\n\n$notification = new onesignal\\client\\Model\\Notification();\n$notification->setAppId('YOUR_APP_ID');\n$contents = new onesignal\\client\\Model\\LanguageStringMap();\n$contents->setEn('Hello from OneSignal!');\n$notification->setContents($contents);\n$headings = new onesignal\\client\\Model\\LanguageStringMap();\n$headings->setEn('Push Notification');\n$notification->setHeadings($headings);\n$notification->setIncludeAliases(['external_id' => ['YOUR_USER_EXTERNAL_ID']]);\n$notification->setTargetChannel('push');\n// Idempotency key: a client-generated UUID that lets you safely retry on network failure.\n// If two requests arrive with the same key inside the 30-day window, only the first is sent\n// and the second returns the original response. Use a strong source of randomness — DO NOT\n// reuse keys across logically distinct sends. We use PHP 7+'s built-in random_bytes() here\n// so the snippet works against this SDK's declared composer.json deps (Guzzle + PSR-7) with\n// no extra install; projects that already pull in ramsey/uuid can swap in\n// `\\Ramsey\\Uuid\\Uuid::uuid4()->toString()` instead.\n$idempotencyKeyBytes = random_bytes(16);\n$idempotencyKeyBytes[6] = chr(ord($idempotencyKeyBytes[6]) & 0x0f | 0x40);\n$idempotencyKeyBytes[8] = chr(ord($idempotencyKeyBytes[8]) & 0x3f | 0x80);\n$idempotencyKey = vsprintf('%s%s-%s-%s-%s-%s%s%s', str_split(bin2hex($idempotencyKeyBytes), 4));\n$notification->setIdempotencyKey($idempotencyKey);\n\ntry {\n    $result = $apiInstance->createNotification($notification);\n    // `$result->getId()` discriminates the two HTTP 200 shapes. A falsy value (empty\n    // string or null) means no notification was created (e.g. all targets were\n    // unreachable / not subscribed). `$result->getErrors()` is polymorphic: a `string[]`\n    // in the no-subscribers case, or an object keyed by recipient-identifier type\n    // (`invalid_player_ids`, `invalid_external_user_ids`, `invalid_aliases`, ...) when\n    // the notification WAS created but some recipients were skipped.\n    if (!$result->getId()) {\n        echo 'Notification was not sent: ', print_r($result->getErrors(), true), PHP_EOL;\n    } elseif ($result->getErrors()) {\n        echo 'Notification created: ', $result->getId(), ' (partial failures: ', print_r($result->getErrors(), true), ')', PHP_EOL;\n    } else {\n        echo 'Notification created: ', $result->getId(), PHP_EOL;\n    }\n} catch (\\onesignal\\client\\ApiException $e) {\n    echo 'Exception when calling DefaultApi->createNotification: ', $e->getMessage(), PHP_EOL;\n    echo 'Status Code: ', $e->getCode(), PHP_EOL;\n    echo 'Response Body: ', $e->getResponseBody(), PHP_EOL;\n} catch (\\Exception $e) {\n    echo 'Exception when calling DefaultApi->createNotification: ', $e->getMessage(), PHP_EOL;\n}"
      - lang: go
        label: Go SDK
        source: "package main\n\nimport (\n    \"context\"\n    \"fmt\"\n    \"os\"\n\n    \"github.com/google/uuid\"\n    \"github.com/OneSignal/onesignal-go-api/v5\"\n)\n\nfunc main() {\n    configuration := onesignal.NewConfiguration()\n    apiClient := onesignal.NewAPIClient(configuration)\n\n    restAuth := context.WithValue(context.Background(), onesignal.RestApiKey, \"YOUR_REST_API_KEY\")\n\n    notification := onesignal.NewNotification(\"YOUR_APP_ID\")\n    contents := onesignal.NewLanguageStringMap()\n    contents.SetEn(\"Hello from OneSignal!\")\n    notification.SetContents(*contents)\n    headings := onesignal.NewLanguageStringMap()\n    headings.SetEn(\"Push Notification\")\n    notification.SetHeadings(*headings)\n    notification.SetIncludeAliases(map[string][]string{\"external_id\": {\"YOUR_USER_EXTERNAL_ID\"}})\n    notification.SetTargetChannel(\"push\")\n    // Idempotency key: a client-generated UUID that lets you safely retry on network failure.\n    // If two requests arrive with the same key inside the 30-day window, only the first is\n    // sent and the second returns the original response. The `github.com/google/uuid` module\n    // is not a declared dep of this SDK; run `go get github.com/google/uuid` (or `go mod tidy`\n    // after importing it) before building. DO NOT reuse keys across logically distinct sends.\n    notification.SetIdempotencyKey(uuid.NewString())\n\n    resp, r, err := apiClient.DefaultApi.CreateNotification(restAuth).Notification(*notification).Execute()\n    if err != nil {\n        fmt.Fprintf(os.Stderr, \"Error when calling `DefaultApi.CreateNotification``: %v\\n\", err)\n        fmt.Fprintf(os.Stderr, \"Full HTTP response: %v\\n\", r)\n        if apiErr, ok := err.(*onesignal.GenericOpenAPIError); ok {\n            fmt.Fprintf(os.Stderr, \"Response Body: %s\\n\", apiErr.Body())\n        }\n        return\n    }\n    // `resp.GetId()` discriminates the two HTTP 200 shapes. An empty string means no\n    // notification was created (e.g. all targets were unreachable / not subscribed).\n    // `resp.GetErrors()` is `interface{}` because the field is polymorphic: a `[]string` in\n    // the no-subscribers case, or a map keyed by recipient-identifier type\n    // (`invalid_player_ids`, `invalid_external_user_ids`, `invalid_aliases`, ...) when\n    // the notification WAS created but some recipients were skipped.\n    if resp.GetId() == \"\" {\n        fmt.Fprintf(os.Stderr, \"Notification was not sent: %v\\n\", resp.GetErrors())\n    } else if errors := resp.GetErrors(); errors != nil {\n        fmt.Fprintf(os.Stdout, \"Notification created: %s (partial failures: %v)\\n\", resp.GetId(), errors)\n    } else {\n        fmt.Fprintf(os.Stdout, \"Notification created: %s\\n\", resp.GetId())\n    }\n}"
      - lang: ruby
        label: Ruby SDK
        source: "require 'onesignal'\n# setup authorization\nOneSignal.configure do |config|\n  # Configure Bearer authorization: rest_api_key\n  config.rest_api_key = 'YOUR_REST_API_KEY'\n\nend\n\napi_instance = OneSignal::DefaultApi.new\nrequire 'securerandom'\n\nnotification = OneSignal::Notification.new\nnotification.app_id = 'YOUR_APP_ID'\nnotification.contents = OneSignal::LanguageStringMap.new({ en: 'Hello from OneSignal!' })\nnotification.headings = OneSignal::LanguageStringMap.new({ en: 'Push Notification' })\nnotification.include_aliases = { 'external_id' => ['YOUR_USER_EXTERNAL_ID'] }\nnotification.target_channel = 'push'\n# Idempotency key: a client-generated UUID that lets you safely retry on network failure.\n# If two requests arrive with the same key inside the 30-day window, only the first is sent\n# and the second returns the original response. Use SecureRandom.uuid — DO NOT reuse keys\n# across logically distinct sends.\nnotification.idempotency_key = SecureRandom.uuid\n\nbegin\n  # Create notification\n  result = api_instance.create_notification(notification)\n  # `result.id` discriminates the two HTTP 200 shapes. An empty string means no\n  # notification was created (e.g. all targets were unreachable / not subscribed).\n  # `result.errors` is polymorphic: an `Array<String>` in the no-subscribers case, or\n  # a Hash keyed by recipient-identifier type (`invalid_player_ids`,\n  # `invalid_external_user_ids`, `invalid_aliases`, ...) when the notification WAS\n  # created but some recipients were skipped.\n  if result.id.to_s.empty?\n    puts \"Notification was not sent: #{result.errors}\"\n  elsif result.errors\n    puts \"Notification created: #{result.id} (partial failures: #{result.errors})\"\n  else\n    puts \"Notification created: #{result.id}\"\n  end\nrescue OneSignal::ApiError => e\n  puts \"Error when calling DefaultApi->create_notification: #{e}\"\n  puts \"Status Code: #{e.code}\"\n  # `e.error_messages` flattens any error-envelope shape to an Array<String>;\n  # the raw body remains on `e.response_body`.\n  puts \"Error Messages: #{e.error_messages}\"\n  puts \"Response Body: #{e.response_body}\"\nend"
      - lang: java
        label: Java SDK
        source: "// Import classes:\nimport java.util.Arrays;\nimport java.util.HashMap;\nimport java.util.List;\nimport java.util.Map;\nimport java.util.UUID;\n\nimport com.onesignal.client.ApiClient;\nimport com.onesignal.client.ApiException;\nimport com.onesignal.client.Configuration;\nimport com.onesignal.client.auth.*;\nimport com.onesignal.client.model.*;\nimport com.onesignal.client.api.DefaultApi;\n\npublic class Example {\n  public static void main(String[] args) {\n    ApiClient defaultClient = Configuration.getDefaultApiClient();\n    defaultClient.setBasePath(\"https://api.onesignal.com\");\n\n    HttpBearerAuth rest_api_key = (HttpBearerAuth) defaultClient.getAuthentication(\"rest_api_key\");\n    rest_api_key.setBearerToken(\"YOUR_REST_API_KEY\");\n\n    DefaultApi apiInstance = new DefaultApi(defaultClient);\n    Notification notification = new Notification();\n    notification.setAppId(\"YOUR_APP_ID\");\n    LanguageStringMap contents = new LanguageStringMap();\n    contents.setEn(\"Hello from OneSignal!\");\n    notification.setContents(contents);\n    LanguageStringMap headings = new LanguageStringMap();\n    headings.setEn(\"Push Notification\");\n    notification.setHeadings(headings);\n    Map<String, List<String>> aliases = new HashMap<>();\n    aliases.put(\"external_id\", Arrays.asList(\"YOUR_USER_EXTERNAL_ID\"));\n    notification.setIncludeAliases(aliases);\n    notification.setTargetChannel(Notification.TargetChannelEnum.PUSH);\n    // Idempotency key: a client-generated UUID that lets you safely retry on network failure.\n    // If two requests arrive with the same key inside the 30-day window, only the first is\n    // sent and the second returns the original response. Use UUID.randomUUID() — DO NOT\n    // reuse keys across logically distinct sends.\n    notification.setIdempotencyKey(UUID.randomUUID().toString());\n\n    try {\n      CreateNotificationSuccessResponse result = apiInstance.createNotification(notification);\n      // `result.getId()` discriminates the two HTTP 200 shapes. An empty string means no\n      // notification was created (e.g. all targets were unreachable / not subscribed).\n      // `result.getErrors()` is polymorphic (declared as `Object`): a `List<String>` in the\n      // no-subscribers case, or a Map keyed by recipient-identifier type\n      // (`invalid_player_ids`, `invalid_external_user_ids`, `invalid_aliases`, ...) when\n      // the notification WAS created but some recipients were skipped.\n      if (result.getId() == null || result.getId().isEmpty()) {\n        System.out.println(\"Notification was not sent: \" + result.getErrors());\n      } else if (result.getErrors() != null) {\n        System.out.println(\"Notification created: \" + result.getId() + \" (partial failures: \" + result.getErrors() + \")\");\n      } else {\n        System.out.println(\"Notification created: \" + result.getId());\n      }\n    } catch (ApiException e) {\n      System.err.println(\"Exception when calling DefaultApi#createNotification\");\n      System.err.println(\"Status code: \" + e.getCode());\n      System.err.println(\"Reason: \" + e.getResponseBody());\n      System.err.println(\"Response headers: \" + e.getResponseHeaders());\n      e.printStackTrace();\n    }\n  }\n}"
      - lang: csharp
        label: C# SDK
        source: "using System;\nusing System.Collections.Generic;\nusing System.Diagnostics;\nusing OneSignalApi.Api;\nusing OneSignalApi.Client;\nusing OneSignalApi.Model;\n\nnamespace Example\n{\n    public class CreateNotificationExample\n    {\n        public static void Main()\n        {\n            Configuration config = new Configuration();\n            config.BasePath = \"https://api.onesignal.com\";\n            config.AccessToken = \"YOUR_REST_API_KEY\";\n\n            var apiInstance = new DefaultApi(config);\n\n            var notification = new Notification\n            {\n                AppId = \"YOUR_APP_ID\",\n                Contents = new LanguageStringMap(en: \"Hello from OneSignal!\"),\n                Headings = new LanguageStringMap(en: \"Push Notification\"),\n                IncludeAliases = new Dictionary<string, List<string>>\n                {\n                    { \"external_id\", new List<string> { \"YOUR_USER_EXTERNAL_ID\" } }\n                },\n                TargetChannel = Notification.TargetChannelEnum.Push,\n                // Idempotency key: a client-generated UUID that lets you safely retry on\n                // network failure. If two requests arrive with the same key inside the\n                // 30-day window, only the first is sent and the second returns the original\n                // response. Use Guid.NewGuid() — DO NOT reuse keys across logically distinct\n                // sends.\n                IdempotencyKey = Guid.NewGuid().ToString()\n            };\n\n            try\n            {\n                CreateNotificationSuccessResponse result = apiInstance.CreateNotification(notification);\n                // `result.Id` discriminates the two HTTP 200 shapes. An empty string means\n                // no notification was created (e.g. all targets were unreachable / not\n                // subscribed). `result.Errors` is polymorphic: a `List<string>` in the\n                // no-subscribers case, or an object keyed by recipient-identifier type\n                // (`invalid_player_ids`, `invalid_external_user_ids`, `invalid_aliases`, ...)\n                // when the notification WAS created but some recipients were skipped.\n                if (string.IsNullOrEmpty(result.Id))\n                {\n                    Debug.WriteLine(\"Notification was not sent: \" + result.Errors);\n                }\n                else if (result.Errors != null)\n                {\n                    Debug.WriteLine(\"Notification created: \" + result.Id + \" (partial failures: \" + result.Errors + \")\");\n                }\n                else\n                {\n                    Debug.WriteLine(\"Notification created: \" + result.Id);\n                }\n            }\n            catch (ApiException e)\n            {\n                Debug.Print(\"Exception when calling DefaultApi.CreateNotification: \" + e.Message);\n                Debug.Print(\"Status Code: \" + e.ErrorCode);\n                Debug.Print(\"Response Body: \" + e.ErrorContent);\n                Debug.Print(e.StackTrace);\n            }\n        }\n    }\n}"
      - lang: rust
        label: Rust SDK
        source: "use onesignal_rust_api::apis::configuration::Configuration;\nuse onesignal_rust_api::apis::default_api;\nuse onesignal_rust_api::models::notification::TargetChannelType;\nuse onesignal_rust_api::models::{LanguageStringMap, Notification};\nuse uuid::Uuid;\n\n#[tokio::main]\nasync fn main() {\n    let mut configuration = Configuration::new();\n    configuration.rest_api_key_token = Some(\"YOUR_REST_API_KEY\".to_string());\n\n    let mut notification = Notification::new(\"YOUR_APP_ID\".to_string());\n    notification.contents = Some(Box::new(LanguageStringMap {\n        en: Some(\"Hello from OneSignal!\".to_string()),\n        ..Default::default()\n    }));\n    notification.headings = Some(Box::new(LanguageStringMap {\n        en: Some(\"Push Notification\".to_string()),\n        ..Default::default()\n    }));\n    let mut aliases = std::collections::HashMap::new();\n    aliases.insert(\n        \"external_id\".to_string(),\n        vec![\"YOUR_USER_EXTERNAL_ID\".to_string()],\n    );\n    notification.include_aliases = Some(aliases);\n    notification.target_channel = Some(TargetChannelType::Push);\n    // Idempotency key: a client-generated UUID that lets you safely retry on network failure.\n    // If two requests arrive with the same key inside the 30-day window, only the first is\n    // sent and the second returns the original response. The `uuid` crate must be declared\n    // in your own Cargo.toml (Cargo doesn't expose transitive crates by name to downstream\n    // code) — add `uuid = { version = \"1\", features = [\"v4\"] }` to your `[dependencies]`.\n    // DO NOT reuse keys across logically distinct sends.\n    notification.idempotency_key = Some(Uuid::new_v4().to_string());\n\n    match default_api::create_notification(&configuration, notification).await {\n        Ok(resp) => {\n            // `resp.id` discriminates the two HTTP 200 shapes. An empty string or `None`\n            // means no notification was created (e.g. all targets were unreachable / not\n            // subscribed). `resp.errors` is polymorphic (typed as `Option<serde_json::Value>`):\n            // a `Vec<String>` in the no-subscribers case, or an object keyed by\n            // recipient-identifier type (`invalid_player_ids`, `invalid_external_user_ids`,\n            // `invalid_aliases`, ...) when the notification WAS created but some recipients\n            // were skipped.\n            match resp.id.as_deref() {\n                Some(\"\") | None => eprintln!(\"Notification was not sent: {:?}\", resp.errors),\n                Some(id) if resp.errors.is_some() => {\n                    println!(\"Notification created: {} (partial failures: {:?})\", id, resp.errors)\n                }\n                Some(id) => println!(\"Notification created: {}\", id),\n            }\n        }\n        Err(onesignal_rust_api::apis::Error::ResponseError(content)) => {\n            eprintln!(\"create_notification failed: HTTP {}\", content.status);\n            eprintln!(\"Response Body: {}\", content.content);\n        }\n        Err(e) => eprintln!(\"create_notification failed: {:?}\", e),\n    }\n}"
      parameters:
      - name: Authorization
        in: header
        description: Your App API key with prefix `Key `. See [Keys & IDs](/docs/en/keys-and-ids).
        required: true
        schema:
          type: string
          default: Key YOUR_APP_API_KEY
      requestBody:
        content:
          application/json:
            schema:
              type: object
              required:
              - app_id
              - contents
              properties:
                app_id:
                  type: string
                  description: Your OneSignal App ID in UUID v4 format. See [Keys & IDs](/docs/en/keys-and-ids).
                  default: YOUR_APP_ID
                include_aliases:
                  type: object
                  description: Target up to 20,000 users by their `external_id`, `onesignal_id`, or your own custom alias. Use with `target_channel` to control the delivery channel. Not compatible with any other targeting parameters like `filters`, `include_subscription_ids`, `included_segments`, or `excluded_segments`. See [Sending messages with the OneSignal API](/reference/create-message#include-aliases).
                  format: json
                  properties:
                    external_id:
                      description: An array of external IDs which should be the same as the user ID in your app. This is the recommended method for targeting users. See [Users](/docs/users).
                      type: array
                      items:
                        type: string
                target_channel:
                  type: string
                  description: The targeted delivery channel. Required when using `include_aliases`. Accepts `push`, `email`, or `sms`.
                  enum:
                  - push
                  - email
                  - sms
                  default: push
                include_subscription_ids:
                  type: array
                  description: Target users' specific [subscriptions](/docs/subscriptions) by ID. Include up to 20,000 `subscription_id` per API call. Not compatible with any other targeting parameters like `filters`, `include_aliases`, `included_segments`, or `excluded_segments`. See [Sending messages with the OneSignal API](/reference/create-message).
                  items:
                    type: string
                included_segments:
                  type: array
                  description: Target predefined [Segments](/docs/segmentation). Users that are in multiple segments will only be sent the message once. Can be combined with `excluded_segments`. Not compatible with any other targeting parameters like `filters`, `include_aliases`, or `include_subscription_ids`. See [Sending messages with the OneSignal API](/reference/create-message).
                  items:
                    type: string
                excluded_segments:
                  type: array
                  description: Exclude users in predefined [Segments](/docs/segmentation). Overrides membership in any segment specified in the `included_segments`. Not compatible with any other targeting parameters like `filters`, `include_aliases`, or `include_subscription_ids`. See [Sending messages with the OneSignal API](/reference/create-message).
                  items:
                    type: string
                filters:
                  type: array
                  description: Filters define the segment based on user properties like tags, activity, or location using flexible AND/OR logic. Limited to 200 total entries, including fields and `OR` operators. See [Sending messages with the OneSignal API](/reference/create-message#filters).
                  items:
                    oneOf:
                    - title: Filter
                      description: Required. The fitler object.
                      required:
                      - field
                      - relation
                      type: object
                      properties:
                        field:
                          type: string
                          description: The name of the filter to use.
                          enum:
                          - tag
                          - last_session
                          - first_session
                          - session_count
                          - session_time
                          - language
                          - app_version
                          - location
                          - country
                        relation:
                          type: string
                          description: Used with most filters. See details on the specific filter.
                          enum:
                          - '='
                          - '!='
                          - '>'
                          - <
                          - exists
                          - not_exists
                          - in_array
                          - not_in_array
                          - time_elapsed_gt
                          - time_elapsed_lt
                        key:
                          type: string
                          description: Used with the `tag` filter. This is the tag `key`.
                        value:
                          type: string
                          description: The value of the `field` or tag `key` in which you want to filter with.
                    - title: Operator
                      type: object
                      properties:
                        operator:
                          type: string
                          description: Chain filter conditions with implicit `AND` and `OR` logic. Never end your `filters` object with an `operator`. See [filters](/reference/create-message#filters) for more.
                          enum:
                          - AND
                          - OR
                          default: AND
                  minItems: 1
                  maxItems: 200
                contents:
                  type: object
                  description: The main message body with [language-specific values](/docs/en/multi-language-messaging#supported-languages). Supports [Message Personalization](/docs/message-personalization).
                  required:
                  - en
                  properties:
                    en:
                      type: string
                      description: The required message language type. See [Supported Languages](/docs/en/multi-language-messaging#supported-languages).
                      default: Default message.
                headings:
                  type: object
                  description: The message title with [language-specific values](/docs/en/multi-language-messaging#supported-languages). Required for Huawei and Web Push. If not set for Web Push, it defaults to your 'Site Name'. Not required if using `template_id` or `content_available`. Supports [Message Personalization](/docs/message-personalization) and must include the same languages as `contents` to ensure localization consistency.
                  properties:
                    en:
                      type: string
                      description: The title in English. If used, must include the same languages as `contents`.
                subtitle:
                  type: object
                  description: iOS only. The subtitle with [language-specific values](/docs/en/multi-language-messaging#supported-languages). Supports [Message Personalization](/docs/message-personalization) and must include the same languages as `contents` to ensure localization consistency.
                  properties:
                    en:
                      type: string
                      description: The subtitle for iOS push only. If used, must include the same languages as `contents`.
                name:
                  type: string
                  description: An internal name you set to help organize and track messages. Not shown to recipients. Maximum 128 characters.
                template_id:
                  type: string
                  description: The template ID in UUID v4 format set for the message if applicable. See [Templates](/docs/en/templates).
                custom_data:
                  type: object
                  description: 'Include user or context-specific data (e.g., cart items, OTPs, links) in a message. Use with `template_id`. See [Message Personalization](/docs/message-personalization). Max size: 2KB (Push/SMS), 10KB (Email).'

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# Full source: https://raw.githubusercontent.com/api-evangelist/onesignal/refs/heads/main/openapi/onesignal-notifications-c-push-api-openapi.yml