How Nelkap works
Does my code run on Nelkap’s servers?
No. Your workflows run in your own app, next to your database and your other code. Nelkap keeps each run’s state, decides when it goes on, and calls your app’s endpoint when there’s work to do. See How Nelkap works.Do I need a queue, a worker, or a database for Nelkap?
No. Nelkap keeps the runs, the schedule, and the saved steps. Your app needs the SDK and one route.Which languages and runtimes does the SDK support?
The SDK is written in TypeScript, and works in JavaScript too. It needs Node.js 22 or later. See Installation.Which frameworks and hosts work with Nelkap?
Any framework where a route can hand the SDK a standard webRequest, on any host that serves it over public HTTPS: a server, a container, or a serverless function. The framework guides cover Next.js, React Router, SvelteKit, Nuxt, Astro, Hono, and Express.
Can I run workflows on my own computer?
Nelkap calls your app over the internet, so it can’t reachlocalhost. Deploy to a staging environment, with its own project, and test there. See Staging and production.
Writing workflows
Does Nelkap retry a failed step?
Your workflow decides. A failed step is saved like a result, so every later call sees the same failure, and your code chooses what comes next: take another path, or try again with a new step after a sleep. See Handle failures.Can a step run twice?
A saved step never runs again. A step cut off before its result was saved, by a crash or a deploy, runs again from its start. See Make steps safe to run twice.How long can a run last?
As long as it needs. Nelkap puts no limit on a run or a step. A run can sleep or wait for up to a year at a time, as many times as its 100 steps allow. Your host may limit how long a single call lasts. See Time limits.Can one workflow start another?
Yes. Callnelkap.run inside a step, so the new run starts only once, even if the first one picks up again. See Split a job across runs.
Can I change a workflow while runs are in progress?
Yes. Runs in progress go on with your new code, from their last saved step. Some changes need care, like renaming a step that runs have already passed. See Change a workflow safely.Where do my logs go?
Nelkap records each run and each step, with what it returned or the error it threw. What your code writes withconsole.log goes to your host’s logs, as usual. Code outside steps runs again on every call of the run, so a line logged there can show up more than once. Log inside a step to write it once.
Running in production
What happens if my app is down?
Runs that are sleeping or waiting aren’t affected. A run due while your app is down is tried three times, over about three minutes, then fails withdeliveryFailed: replay it once your app is back. A run cut off in the middle picks up about five minutes later. See Deploy your app.
What happens to runs when I deploy?
Nothing is lost. A run cut off by the deploy picks up from its last saved step, on your new version. See Runs during a deploy.How do I stop a workflow?
Cancel one run from its page. To stop a workflow for good, remove it fromregisterWorkflows: its runs that haven’t started, and those sleeping or waiting, are canceled. See Runs.