Pretrained text classifier

Identify text sentiment with one API call.

A pretrained text sentiment classifier that sorts text into one of 3 categories. Use the text sentiment API immediately, no training required, then adapt it to your own data when you need more.

Pretrained · Nyckel-trained 3 labels out of the box Text input

Try the text sentiment classifier

Drop in some text and get the prediction back. No signup, no setup.

What this text sentiment classifier recognizes

A sample of the 3 labels this pretrained classifier chooses between.

Negative
Neutral
& Positive

Need a label that isn't here? Clone the classifier into your Nyckel console and edit the label set to fit your data.

Call the text sentiment API

Once you've added this classifier to your console, you get your own copy of it behind your own endpoint. Invoke it with any HTTP client:

curl

curl -X POST "https://www.nyckel.com/v1/functions/YOUR_FUNCTION_ID/invoke" \
  -H "Authorization: Bearer $NYCKEL_ACCESS_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"data": "The text you want to classify"}'

Python

import requests

# Get an access token: https://www.nyckel.com/docs/api/overview/authentication/
token = "YOUR_ACCESS_TOKEN"

response = requests.post(
    "https://www.nyckel.com/v1/functions/YOUR_FUNCTION_ID/invoke",
    headers={"Authorization": "Bearer " + token},
    json={"data": "The text you want to classify"},
)
print(response.json())

Example response

{
  "labelName": "Negative",
  "labelId": "label_...",
  "confidence": 0.92
}

Under the hood

Model type
Nyckel-trained

Trained on the tweet_eval dataset and served on Nyckel's own classification infrastructure — your text snippet stays on Nyckel.

Input
Text

Send raw text to the invoke endpoint; the response is a label with a confidence score.

Make it yours
Adaptable

Clone it, then correct predictions and add your own samples in the console — Nyckel retrains automatically, turning this into a custom model tuned to your data.

More than a demo: this page is one of thousands of pretrained functions on Nyckel, an ML classification platform. You can invoke classifiers by API, review predictions, correct labels, collect samples from production traffic, and promote any pretrained function to a private custom model — without changing your integration.

Where teams use text sentiment classification

Customer Support

Automatically categorize customer feedback from support tickets to prioritize urgent issues.

Marketing Teams

Analyze social media comments to gauge public sentiment about new product launches.

Media and Entertainment

Track audience reactions to content across platforms to adjust marketing strategies.

Healthcare

Assess patient feedback on services for quality control and improvement measures.

Finance

Screen investor communications for sentiment to better understand market trends

Customer Service Departments

Improve customer engagement by responding to tweets with negative sentiments more proactively.

eCommerce

Classify user reviews to identify product strengths and weaknesses.

Common questions

What's the difference between a zero-shot and a Nyckel-trained classifier?

A zero-shot classifier uses a large foundation model's general knowledge to pick between your labels — no task-specific training, so new or edited labels work immediately. A Nyckel-trained classifier has been trained on labeled examples and runs on Nyckel's own infrastructure, which typically makes it faster, cheaper per call, and more accurate on data that resembles its training set. The "Under the hood" section on this page shows which kind this classifier is, and any classifier can be adapted into a trained one by adding your own examples.

How do I know whether this will work for my application?

Honestly: we can't know in advance — it depends on your data stream and how closely it resembles what this classifier has seen. The reliable way to find out is to measure it on your own data: start invoking the classifier with real traffic, or upload and annotate a set of text samples in the console — make sure they look like your production data, not idealized examples. Nyckel's evaluation metrics then show you exactly how it performs on that data before you rely on it.

What happens when it makes a mistake?

No classifier is perfect, so Nyckel is built around the correction loop: invokes can be captured for review, you confirm or correct predictions in the console, and corrections become training data. Over time the model adapts to your data distribution — accuracy on your traffic improves with use rather than staying fixed.

Do I need training data to get started?

No. This text sentiment classifier works out of the box — clone it into your console and you'll have your own API endpoint in under a minute. Training data only enters the picture when you want to adapt it: your corrected predictions and uploaded samples improve the model, and you can also edit the label set to match your needs.

What does it cost to try?

Trying the classifier on this page is free with no signup. Cloning it requires a free account, and the free tier covers your first API calls each month — see nyckel.com/pricing for current limits and paid tiers.

Ready to classify text sentiment at scale?

Add this pretrained classifier to your Nyckel console — you'll get a live API endpoint in under a minute, and a path to a custom model when you need one.