RiveScript exposes a simple plain text scripting language that's easy to learn and begin writing in quickly. No need to mess with complicated opaque XML structures or random symbols and line noise like with some other chatbot languages!
RiveScript has a handful of simple rules that can be combined in powerful ways to build an impressive chatbot personality. Write triggers in a simplified regular expression format to match complex sets of word patterns in one go.
RiveScript takes a "Unix-like" approach to its development: the core library is small and self-contained and it does one thing very well—takes human input and gives an intelligent response. This flexibility enables RiveScript to be used how you need it to.
Released under the most liberal open source license available, MIT. Interfaces are available for Rust, Go, Java, JavaScript, Perl and Python. Learn more.
On May 19 2026 RiveScript.com was converted into a 'static website' after having been a (needlessly) dynamic website with a Python back-end since at least 2015. This move to a static website makes RiveScript.com easier to maintain going into the future (for example, making it less prone to outages after upgrading its web server's OS and breaking all of the Python virtualenvs!), and I took the opportunity to modernize its look by moving away from Twitter Bootstrap CSS and onto Bulma, which gave us free "dark mode" support as well!
As for RiveScript itself, I have some news to talk about in 2026 and some reflections on the current state of chatbot technology with the Large Language Models (LLMs) that we are all familiar with today.
In 2026, the original author of RiveScript has ported the chatbot engine to yet another new programming language: this time to Rust!
RiveScript in Rust is mildly interesting because RiveScript originally used the file extension
.rs for its chatbot source files, since the original Perl version released in 2005.
In 2013, I was contacted by a developer of the upcoming Rust language about changing my file
extension to something else to avoid confusion with Rust source files. The file extension was
changed to .rive, but anyway, the Rust port brings us full circle again with a
native implementation of rivescript.rs now being a thing that exists!
The Rust port is fully 'feature complete' on par with the other five implementations. Like the Go version, it comes with a JavaScript engine for RiveScript object macros and a Redis implementation to store user variables in that rather than the default in-memory hash maps. You can read about it on the author's blog!
RiveScript has nothing in common with the modern style of LLM chatbots such as ChatGPT, Claude or Gemini. Instead, RiveScript is in the category of "canned responses" types of chatbots, where the botmaster had to anticipate all of the possible questions that a user might ask and program the responses to those questions in advance. This puts RiveScript in the same category as AIML (which is its primary inspiration) and ChatScript.
However, in 2026 RiveScript can be paired very well with LLMs!
A big problem with LLMs is that they are "unpredictable" and maybe you want to hard-code certain responses into your chatbot. RiveScript is specifically designed to make those "canned responses" easy to write and maintain! So you could put RiveScript "in front" for your chatbot and let it have first dibs on answering a user's question, and only when RiveScript had no match for their message, would you pass the message along to your LLM to provide a good answer for whatever random query your user had. This way you could control how your bot responds to your important questions, while still providing a satisfying user experience for everything else they could possibly ask of your bot!
RiveScript itself is just the lightweight 'black box' reply engine so it can be trivially easy to check it for a reply and, if it didn't match the user's message to any triggers you programmed into it, have it fall back to your LLM to fetch a response instead.
RiveScript (as a language) has generally been considered to be "feature complete" for well over a decade at this point. Before the Rust version, the last new first-party implementation was the Go version released in 2015.
During RiveScript's lifetime, I had seen the "chatbot hype" rise and fall a couple different times. In 2005 with the original Perl version, chatbots on AOL Instant Messenger were highly popular. A second surge in hype came about around 2012 with the Facebook Bot Platform and similar products from Google and Microsoft. And then the third wave came after 2022 with the rise of ChatGPT and modern Large Language Models.
That middle wave attracted a lot of interest towards RiveScript and the Python and JavaScript ports (in particular) received tons of contributions from people on GitHub. RiveScript also was used around that time to power a whole startup company called RunDexter!
RiveScript being available in multiple different programming languages proved to be both a blessing and a curse. It broadened the reach of RiveScript to be accessible to more developers, but in turn it caused the RiveScript language itself to become slow to evolve: any significant new feature needed to be implemented five different times in five different programming languages!
If there is to be any significant new work on RiveScript, that work would be done in the Rust programming language. This is because Rust can easily be compiled into a C compatible shared library, which all other languages are able to link with, alleviating the problem of needing to keep so many different implementations in sync. The recent port of RiveScript to Rust is a big step in that direction.
As the original author of RiveScript, I have a lot of competing priorities and other projects nowadays. I make no promises that RiveScript will be extended any time soon with significant new features. However, if a new wave of interest returns to RiveScript in the future (the current LLM wave has so far passed RiveScript by), it may reignite my interest in getting back into RiveScript at a deeper level.
In the mean time, the primary six RiveScript ports are all feature complete, working and are generally stable. Apart from the Rust port which was most recently created, the others are in 'maintenance mode' where they may receive bug fixes but probably no significant new features.