Welcome to JTokkit, a Java tokenizer library designed for use with OpenAI models.

EncodingRegistry registry = Encodings.newDefaultEncodingRegistry();
Encoding enc = registry.getEncoding(EncodingType.CL100K_BASE);
assertEquals("hello world", enc.decode(enc.encode("hello world")));

// Or get the tokenizer corresponding to a specific OpenAI model
enc = registry.getEncodingForModel(ModelType.TEXT_EMBEDDING_ADA_002);

JTokkit aims to be a fast and efficient tokenizer designed for use in natural language processing tasks using the OpenAI models. It provides an easy-to-use interface for tokenizing input text, for example for counting required tokens in preparation of requests to the GPT-3.5 model. This library resulted out of the need to have similar capacities in the JVM ecosystem as the library tiktoken provides for Python.

✅ Implements encoding and decoding via r50k_base, p50k_base, p50k_edit and cl100k_base

✅ Easy-to-use API

✅ Easy extensibility for custom encoding algorithms

✅ Zero Dependencies

✅ Supports Java 8 and above

✅ Fast and efficient performance

🔨 Handling of special tokens during encoding (not started)

JTokkit is between 2-3 times faster than a comparable tokenizer.

For details on the benchmark, see the benchmark directory.

You can install JTokkit by adding the following dependency to your Maven project:

<dependency>
    <groupId>com.knuddels</groupId>
    <artifactId>jtokkit</artifactId>
    <version>0.3.0</version>
</dependency>

Or alternatively using Gradle:

dependencies {
    implementation 'com.knuddels:jtokkit:0.3.0'
}

To use JTokkit, simply create a new EncodingRegistry and use getEncoding to retrieve the encoding you want to use. You can then use the encode and decode methods to encode and decode text.

EncodingRegistry registry = Encodings.newDefaultEncodingRegistry();
Encoding enc = registry.getEncoding(EncodingType.CL100K_BASE);
List<Integer> encoded = enc.encode("This is a sample sentence.");
// encoded = [2028, 374, 264, 6205, 11914, 13]
        
String decoded = enc.decode(encoded);
// decoded = "This is a sample sentence."

// Or get the tokenizer based on the model type
Encoding secondEnc = registry.getEncodingForModel(ModelType.TEXT_EMBEDDING_ADA_002);
// enc == secondEnc

The EncodingRegistry and Encoding classes are thread-safe and can be freely shared among components.

You may want to extend JTokkit to support custom encodings. To do so, you have two options:

1. Implement the Encoding interface and register it with the EncodingRegistry

EncodingRegistry registry = Encodings.newDefaultEncodingRegistry();
Encoding customEncoding = new CustomEncoding();
registry.registerEncoding(customEncoding);

2. Add new parameters for use with the existing BPE algorithm

EncodingRegistry registry = Encodings.newDefaultEncodingRegistry();
GptBytePairEncodingParams params = new GptBytePairEncodingParams(
        "custom-name",
        Pattern.compile("some custom pattern"),
        encodingMap,
        specialTokenEncodingMap
);
registry.registerGptBytePairEncoding(params);

Afterwards you can use the custom encodings alongside the default ones and access them by using registry.getEncoding("custom-name"). See the JavaDoc for more details.

JTokkit is licensed under the MIT License. See the LICENSE file for more information.