# 🧠 Review Sentiment Analyzer — Themes, Trends & Complaints (`nexgenwatch/review-sentiment-analyzer`) Actor

Turn any review set into themes, complaints, sentiment % and trends.

- **URL**: https://apify.com/nexgenwatch/review-sentiment-analyzer.md
- **Developed by:** [NexGen Watch](https://apify.com/nexgenwatch) (community)
- **Categories:** Business, Agents
- **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

from $335.00 / 1,000 100 reviews analyzeds

This Actor is paid per event. You are not charged for the Apify platform usage, but only a fixed price for specific events.
Since this Actor supports Apify Store discounts, the price gets lower the higher subscription plan you have.

Learn more: https://docs.apify.com/platform/actors/running/actors-in-store#pay-per-event

## What's an Apify Actor?

Actors are a software tools running on the Apify platform, for all kinds of web data extraction and automation use cases.
In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours,
and optionally produces a well-defined JSON output, datasets with results, or files in key-value store.
In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server.
Actors are written with capital "A".

## How to integrate an Actor?

If asked about integration, you help developers integrate Actors into their projects.
You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready.
The best way to integrate Actors is as follows.

In JavaScript/TypeScript projects, use official [JavaScript/TypeScript client](https://docs.apify.com/api/client/js/docs.md):

```bash
npm install apify-client
```

In Python projects, use official [Python client library](https://docs.apify.com/api/client/python/docs.md):

```bash
pip install apify-client
```

In shell scripts, use [Apify CLI](https://docs.apify.com/cli/docs.md):

````bash
# MacOS / Linux
curl -fsSL https://apify.com/install-cli.sh | bash
# Windows
irm https://apify.com/install-cli.ps1 | iex
```bash

In AI frameworks, you might use the [Apify MCP server](https://docs.apify.com/integrations/mcp.md).

If your project is in a different language, use the [REST API](https://docs.apify.com/api/v2.md).

For usage examples, see the [API](#api) section below.

For more details, see Apify documentation as [Markdown index](https://docs.apify.com/llms.txt) and [Markdown full-text](https://docs.apify.com/llms-full.txt).


# README

## 🧠 Review Sentiment Analyzer — Themes, Trends & Complaints

Extractors stop at raw reviews. Product, CX, and reputation teams pay for the *analysis* — themes, complaint clusters, sentiment percentages, and trends they can act on this week.

### What you get

- Themes and bigram topics ranked by mention count
- Complaint clusters that group the recurring pain points
- Sentiment split (positive / neutral / negative %) plus counts and an average sentiment score
- Time-bucketed trend data and a stable analysis ID for like-for-like delta comparisons later
- Developer-response coverage %, representative example reviews, and run metadata

### Use cases by team

- **Product:** See which features drive praise vs. churn without reading thousands of reviews by hand.
- **Customer experience:** Surface the top complaint clusters for this release and track whether they shrink next release.
- **Reputation / brand:** Quantify sentiment movement over time with reproducible numbers you can put in a report.
- **Analysts:** Get auditable, deterministic scores that don't drift run-to-run — safe for regulated or repeatable reporting.

### Example inputs

*Analyze inline reviews*

```json
{
  "reviews": [
    {
      "review_text": "Great and fast",
      "rating": 5
    },
    {
      "review_text": "Crashes after login",
      "rating": 1
    }
  ]
}
````

*Analyze an Apify dataset you already collected*

```json
{
  "dataset_id": "YOUR_DATASET_ID",
  "max_items": 5000
}
```

*Tune theme extraction*

```json
{
  "reviews": [
    {
      "review_text": "Battery drains overnight",
      "rating": 2
    }
  ],
  "max_themes": 20
}
```

### 📊 Sample Output

```json
{
  "review_count": 2,
  "sentiment_positive_pct": 50.0,
  "sentiment_negative_pct": 50.0,
  "sentiment_counts": {
    "positive": 1,
    "neutral": 0,
    "negative": 1
  },
  "average_rating": 3.0,
  "themes": [
    {
      "theme": "crashes login",
      "mentions": 1
    }
  ],
  "complaint_clusters": [
    {
      "cluster": "stability",
      "mentions": 1
    }
  ],
  "method": "ngd-lexicon-v1",
  "partial": false
}
```

### How it works

Feed it inline reviews or a user-authorized Apify dataset ID. It scores every review with a transparent deterministic lexicon-plus-rating-prior model (`ngd-lexicon-v1`) — **not an LLM**. The same reviews in produce the same analysis out, every time: no model drift, no API key, no per-token fees. Every score is reproducible and auditable. No external review source is fetched — you bring the data, it does the analysis.

### Pricing

| Event | Price (FREE tier) |
|---|---|
| Actor start (`apify-actor-start`) | $0.05 flat |
| Reviews analyzed (`reviews-analyzed-100`) | $0.50 per 100 reviews, block-rounded |

Pay-per-event with a four-tier ladder (FREE → Gold): $0.50 / $0.45 / $0.40 / $0.335 per 100 reviews. Apify applies its automatic plan discount on top. Worked example: 250 reviews on FREE = $0.05 start + 3 × $0.50 = **$1.55**. Blocked or zero-result runs do not intentionally charge. New to Apify? [Start free](https://apify.com/fpr=2ayu9b).

### Run it — API, CLI, MCP

API:

```bash
curl -X POST "https://api.apify.com/v2/acts/nexgenwatch~review-sentiment-analyzer/runs?token=$APIFY_TOKEN" \
  -H "Content-Type: application/json" -d @input.json
```

CLI:

```bash
apify call nexgenwatch/review-sentiment-analyzer -i @input.json
```

MCP: expose `nexgenwatch/review-sentiment-analyzer` through Apify's MCP server, select it as a tool, and pass the same input object.

### Related actors — App Intelligence cluster

| Actor | What it does |
|---|---|
| [Apple App Store Reviews](https://apify.com/nexgenwatch/ios-app-reviews?fpr=2ayu9b) | Scrape public Apple App Store reviews for any app. |
| [Google Play Reviews](https://apify.com/nexgenwatch/google-play-reviews?fpr=2ayu9b) | Scrape public Google Play reviews for any app. |
| [App Rankings Tracker](https://apify.com/nexgenwatch/app-rankings-tracker?fpr=2ayu9b) | Track Apple App Store top-chart rankings by country. |
| [ASO Keyword Tracker](https://apify.com/nexgenwatch/aso-keyword-tracker?fpr=2ayu9b) | Track keyword rankings across App Store & Google Play. |

### Compliance & honest limits

- You supply the review data (inline or an Apify dataset you authorize); this actor does not scrape a review source itself.
- Deterministic lexicon model — powerful for reproducibility, but it is not a generative summarizer and will not write freeform narratives.
- A source-confirmed empty input returns `SUCCEEDED-0: GENUINE_EMPTY`; truncated runs are labeled `PARTIAL`.

### FAQ

**Is this AI or an LLM?**

No — deliberately. It is a deterministic lexicon-and-rating-prior model (`ngd-lexicon-v1`): same reviews in, same analysis out, with no model drift and no API key. That reproducibility is the point — it suits regulated, comparable, or repeatable reporting where an LLM's run-to-run variation is a liability.

**Where do the reviews come from?**

You provide them — paste them inline or pass a `dataset_id` from a review scraper (for example our Apple App Store or Google Play reviews actors). Nothing external is fetched.

**How does pricing work?**

Pay-per-event: a $0.05 start plus $0.50 per 100 reviews analyzed on FREE (lower at Bronze / Silver / Gold). All-in — no separate LLM or API-key cost.

**Does zero mean blocked?**

No. A confirmed-empty input is `SUCCEEDED-0: GENUINE_EMPTY`; only exhausted retries fail, and truncated runs are labeled `PARTIAL`.

**Can I compare two batches over time?**

Yes. Each run returns a stable analysis ID and deterministic period buckets so a later delta layer can compare like-for-like batches.

**What languages does it handle?**

The lexicon is tuned for English review text; other languages score but with reduced theme quality.

**Can I control how many themes come back?**

Yes — set `max_themes` (default 12, up to 50).

### Troubleshooting

- **Empty output?** Confirm your `reviews` array is non-empty or that `dataset_id` points to a dataset you own; a genuinely empty source returns GENUINE\_EMPTY by design.
- **Dataset not read?** The dataset ID must belong to your account and contain review-shaped objects; check `max_items` isn't set below your row count.
- **Themes look thin?** Raise `max_themes`, and make sure `review_text` (not just `rating`) is populated.
- **Numbers differ from last run?** They shouldn't — identical input yields identical output. If they differ, your input changed.
- **Need sentiment-shift alerts?** That delta layer is Phase 2; today's buckets + analysis ID are the foundation for it.

### About

Part of the NexGenData App Intelligence cluster — a closed web of review, metadata, ranking, and keyword actors that share one honest, deterministic contract. Built by NexGenData. Questions or need a custom feed? Open an issue on the Actor page.

# Actor input Schema

## `dataset_id` (type: `string`):

Optional user-authorized Apify dataset ID containing reviews.

## `reviews` (type: `array`):

Buyer-supplied review objects; used when dataset\_id is empty.

## `max_items` (type: `integer`):

Hard cap on records delivered by this run.

## `max_themes` (type: `integer`):

Maximum theme terms or bigrams returned.

## `proxy_configuration` (type: `object`):

Optional Apify proxy settings; a fresh session is requested for every retry.

## Actor input object example

```json
{
  "dataset_id": "",
  "reviews": [
    {
      "review_text": "Great and fast",
      "rating": 5
    },
    {
      "review_text": "Crashes after login",
      "rating": 1
    }
  ],
  "max_items": 5000,
  "max_themes": 12,
  "proxy_configuration": {
    "useApifyProxy": true
  }
}
```

# Actor output Schema

## `results` (type: `string`):

No description

# API

You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup.

## JavaScript example

```javascript
import { ApifyClient } from 'apify-client';

// Initialize the ApifyClient with your Apify API token
// Replace the '<YOUR_API_TOKEN>' with your token
const client = new ApifyClient({
    token: '<YOUR_API_TOKEN>',
});

// Prepare Actor input
const input = {};

// Run the Actor and wait for it to finish
const run = await client.actor("nexgenwatch/review-sentiment-analyzer").call(input);

// Fetch and print Actor results from the run's dataset (if any)
console.log('Results from dataset');
console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`);
const { items } = await client.dataset(run.defaultDatasetId).listItems();
items.forEach((item) => {
    console.dir(item);
});

// 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs

```

## Python example

```python
from apify_client import ApifyClient

# Initialize the ApifyClient with your Apify API token
# Replace '<YOUR_API_TOKEN>' with your token.
client = ApifyClient("<YOUR_API_TOKEN>")

# Prepare the Actor input
run_input = {}

# Run the Actor and wait for it to finish
run = client.actor("nexgenwatch/review-sentiment-analyzer").call(run_input=run_input)

# Fetch and print Actor results from the run's dataset (if there are any)
print("💾 Check your data here: https://console.apify.com/storage/datasets/" + run["defaultDatasetId"])
for item in client.dataset(run["defaultDatasetId"]).iterate_items():
    print(item)

# 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start

```

## CLI example

```bash
echo '{}' |
apify call nexgenwatch/review-sentiment-analyzer --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "command": "npx",
            "args": [
                "mcp-remote",
                "https://mcp.apify.com/?tools=nexgenwatch/review-sentiment-analyzer",
                "--header",
                "Authorization: Bearer <YOUR_API_TOKEN>"
            ]
        }
    }
}

```

## OpenAPI specification

```json
{
    "openapi": "3.0.1",
    "info": {
        "title": "🧠 Review Sentiment Analyzer — Themes, Trends & Complaints",
        "description": "Turn any review set into themes, complaints, sentiment % and trends.",
        "version": "0.1",
        "x-build-id": "0RSG0guf5QqIkkLha"
    },
    "servers": [
        {
            "url": "https://api.apify.com/v2"
        }
    ],
    "paths": {
        "/acts/nexgenwatch~review-sentiment-analyzer/run-sync-get-dataset-items": {
            "post": {
                "operationId": "run-sync-get-dataset-items-nexgenwatch-review-sentiment-analyzer",
                "x-openai-isConsequential": false,
                "summary": "Executes an Actor, waits for its completion, and returns Actor's dataset items in response.",
                "tags": [
                    "Run Actor"
                ],
                "requestBody": {
                    "required": true,
                    "content": {
                        "application/json": {
                            "schema": {
                                "$ref": "#/components/schemas/inputSchema"
                            }
                        }
                    }
                },
                "parameters": [
                    {
                        "name": "token",
                        "in": "query",
                        "required": true,
                        "schema": {
                            "type": "string"
                        },
                        "description": "Enter your Apify token here"
                    }
                ],
                "responses": {
                    "200": {
                        "description": "OK"
                    }
                }
            }
        },
        "/acts/nexgenwatch~review-sentiment-analyzer/runs": {
            "post": {
                "operationId": "runs-sync-nexgenwatch-review-sentiment-analyzer",
                "x-openai-isConsequential": false,
                "summary": "Executes an Actor and returns information about the initiated run in response.",
                "tags": [
                    "Run Actor"
                ],
                "requestBody": {
                    "required": true,
                    "content": {
                        "application/json": {
                            "schema": {
                                "$ref": "#/components/schemas/inputSchema"
                            }
                        }
                    }
                },
                "parameters": [
                    {
                        "name": "token",
                        "in": "query",
                        "required": true,
                        "schema": {
                            "type": "string"
                        },
                        "description": "Enter your Apify token here"
                    }
                ],
                "responses": {
                    "200": {
                        "description": "OK",
                        "content": {
                            "application/json": {
                                "schema": {
                                    "$ref": "#/components/schemas/runsResponseSchema"
                                }
                            }
                        }
                    }
                }
            }
        },
        "/acts/nexgenwatch~review-sentiment-analyzer/run-sync": {
            "post": {
                "operationId": "run-sync-nexgenwatch-review-sentiment-analyzer",
                "x-openai-isConsequential": false,
                "summary": "Executes an Actor, waits for completion, and returns the OUTPUT from Key-value store in response.",
                "tags": [
                    "Run Actor"
                ],
                "requestBody": {
                    "required": true,
                    "content": {
                        "application/json": {
                            "schema": {
                                "$ref": "#/components/schemas/inputSchema"
                            }
                        }
                    }
                },
                "parameters": [
                    {
                        "name": "token",
                        "in": "query",
                        "required": true,
                        "schema": {
                            "type": "string"
                        },
                        "description": "Enter your Apify token here"
                    }
                ],
                "responses": {
                    "200": {
                        "description": "OK"
                    }
                }
            }
        }
    },
    "components": {
        "schemas": {
            "inputSchema": {
                "type": "object",
                "required": [
                    "reviews"
                ],
                "properties": {
                    "dataset_id": {
                        "title": "Dataset ID",
                        "type": "string",
                        "description": "Optional user-authorized Apify dataset ID containing reviews.",
                        "default": ""
                    },
                    "reviews": {
                        "title": "Inline reviews",
                        "type": "array",
                        "description": "Buyer-supplied review objects; used when dataset_id is empty.",
                        "items": {
                            "type": "object"
                        },
                        "default": [
                            {
                                "review_text": "Great and fast",
                                "rating": 5
                            },
                            {
                                "review_text": "Crashes after login",
                                "rating": 1
                            }
                        ]
                    },
                    "max_items": {
                        "title": "Maximum records",
                        "minimum": 1,
                        "maximum": 50000,
                        "type": "integer",
                        "description": "Hard cap on records delivered by this run.",
                        "default": 5000
                    },
                    "max_themes": {
                        "title": "Maximum themes",
                        "minimum": 1,
                        "maximum": 50,
                        "type": "integer",
                        "description": "Maximum theme terms or bigrams returned.",
                        "default": 12
                    },
                    "proxy_configuration": {
                        "title": "Proxy configuration",
                        "type": "object",
                        "description": "Optional Apify proxy settings; a fresh session is requested for every retry.",
                        "default": {
                            "useApifyProxy": true
                        }
                    }
                }
            },
            "runsResponseSchema": {
                "type": "object",
                "properties": {
                    "data": {
                        "type": "object",
                        "properties": {
                            "id": {
                                "type": "string"
                            },
                            "actId": {
                                "type": "string"
                            },
                            "userId": {
                                "type": "string"
                            },
                            "startedAt": {
                                "type": "string",
                                "format": "date-time",
                                "example": "2025-01-08T00:00:00.000Z"
                            },
                            "finishedAt": {
                                "type": "string",
                                "format": "date-time",
                                "example": "2025-01-08T00:00:00.000Z"
                            },
                            "status": {
                                "type": "string",
                                "example": "READY"
                            },
                            "meta": {
                                "type": "object",
                                "properties": {
                                    "origin": {
                                        "type": "string",
                                        "example": "API"
                                    },
                                    "userAgent": {
                                        "type": "string"
                                    }
                                }
                            },
                            "stats": {
                                "type": "object",
                                "properties": {
                                    "inputBodyLen": {
                                        "type": "integer",
                                        "example": 2000
                                    },
                                    "rebootCount": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "restartCount": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "resurrectCount": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "computeUnits": {
                                        "type": "integer",
                                        "example": 0
                                    }
                                }
                            },
                            "options": {
                                "type": "object",
                                "properties": {
                                    "build": {
                                        "type": "string",
                                        "example": "latest"
                                    },
                                    "timeoutSecs": {
                                        "type": "integer",
                                        "example": 300
                                    },
                                    "memoryMbytes": {
                                        "type": "integer",
                                        "example": 1024
                                    },
                                    "diskMbytes": {
                                        "type": "integer",
                                        "example": 2048
                                    }
                                }
                            },
                            "buildId": {
                                "type": "string"
                            },
                            "defaultKeyValueStoreId": {
                                "type": "string"
                            },
                            "defaultDatasetId": {
                                "type": "string"
                            },
                            "defaultRequestQueueId": {
                                "type": "string"
                            },
                            "buildNumber": {
                                "type": "string",
                                "example": "1.0.0"
                            },
                            "containerUrl": {
                                "type": "string"
                            },
                            "usage": {
                                "type": "object",
                                "properties": {
                                    "ACTOR_COMPUTE_UNITS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATASET_READS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATASET_WRITES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "KEY_VALUE_STORE_READS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "KEY_VALUE_STORE_WRITES": {
                                        "type": "integer",
                                        "example": 1
                                    },
                                    "KEY_VALUE_STORE_LISTS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "REQUEST_QUEUE_READS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "REQUEST_QUEUE_WRITES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATA_TRANSFER_INTERNAL_GBYTES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATA_TRANSFER_EXTERNAL_GBYTES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "PROXY_RESIDENTIAL_TRANSFER_GBYTES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "PROXY_SERPS": {
                                        "type": "integer",
                                        "example": 0
                                    }
                                }
                            },
                            "usageTotalUsd": {
                                "type": "number",
                                "example": 0.00005
                            },
                            "usageUsd": {
                                "type": "object",
                                "properties": {
                                    "ACTOR_COMPUTE_UNITS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATASET_READS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATASET_WRITES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "KEY_VALUE_STORE_READS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "KEY_VALUE_STORE_WRITES": {
                                        "type": "number",
                                        "example": 0.00005
                                    },
                                    "KEY_VALUE_STORE_LISTS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "REQUEST_QUEUE_READS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "REQUEST_QUEUE_WRITES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATA_TRANSFER_INTERNAL_GBYTES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATA_TRANSFER_EXTERNAL_GBYTES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "PROXY_RESIDENTIAL_TRANSFER_GBYTES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "PROXY_SERPS": {
                                        "type": "integer",
                                        "example": 0
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
    }
}
```