FAQ
Cost, privacy, accuracy, languages and who's behind the project.
Is this made by TypeSafe?
No. Jev Events is an independent open-source project that uses TypeSafe's public API. It isn't affiliated with or endorsed by TypeSafe. Jev is TypeSafe's model; you need your own TypeSafe API key.
What does it cost?
The library is free and MIT licensed. You pay TypeSafe for Jev: $0.042 per million input tokens, with output free, at the time of writing. See TypeSafe's models page for the current price.
What one item costs depends on your questions and how much context you send. monitor.stats() reports tokens and estimated spend as you go, and budget puts a hard daily cap on it. To see what your own stream costs before writing any code, watch it with the CLI for a while and stop it with Ctrl-C: it prints the tokens used and the estimated spend.
Where does my data go?
Items go from your process to TypeSafe's API to be judged, and actions go from your process to the platform. Jev Events is a library, not a service: it has no servers and collects nothing. Tokens stay on your machine, in .jev-events/, or in your own database, encrypted with your own key.
TypeSafe's own policies cover how they handle requests. Jev sees the item's text, author name, roles and facts, plus any context you add; item.raw, the original platform payload, is never sent.
Does it scrape anything?
No. Every integration uses the platform's official API or public protocol.
How accurate is it?
It depends on the question and your threshold. The benchmarks report precision and recall at several thresholds for the chat recipes. Measure your own questions on your own data before acting on them automatically, and use a review band where a mistake is costly.
Which languages work?
English is Jev's primary language. The benchmark dataset includes messages in 12 other languages and reports them as a separate slice, so you can see what to expect.
Which runtimes are supported?
Node.js 22 and newer. The library needs a server-side runtime because your API keys must never reach a browser. Other runtimes may work but aren't tested.
Can it run in a browser or on serverless?
Not in a browser: your API key and your users' tokens have to stay on a server. Serverless functions on Node.js work for anything that's checked or pushed, such as Gmail, Google Calendar, Slack and webhooks, through the cron and webhook routes. Chat streams such as Twitch hold a connection open, so they need a worker: a process that stays up, on a small server or a container. Edge runtimes aren't tested.
Will it do something I didn't expect?
Built-in actions start in dry-run: they only log what they would do until you pass dryRun: false. They never act on protected people, such as your colleagues or your channel's moderators, and each runs at most once per item. Gmail's actions trash instead of deleting, and save replies as drafts instead of sending them. See Safety.