> ## Documentation Index
> Fetch the complete documentation index at: https://docs.nelkap.com/llms.txt
> Use this file to discover all available pages before exploring further.

# FAQ

> Short answers to the questions teams ask most about Nelkap.

## 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](https://docs.nelkap.com/concepts/how-it-works.md).

> **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](https://docs.nelkap.com/installation.md#requirements).

> **Which frameworks and hosts work with Nelkap?**
>
> Any framework where a route can hand the SDK a standard web `Request`, on any host that serves it over public HTTPS: a server, a container, or a serverless function. The [framework guides](https://docs.nelkap.com/frameworks/overview.md) 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 reach `localhost`. Deploy to a staging environment, with its own project, and test there. See [Staging and production](https://docs.nelkap.com/deploy/environments.md).

## 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](https://docs.nelkap.com/guides/failures.md#try-a-step-again).

> **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](https://docs.nelkap.com/guides/idempotency.md).

> **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](https://docs.nelkap.com/deploy/overview.md#time-limits).

> **Can one workflow start another?**
>
> Yes. Call `nelkap.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](https://docs.nelkap.com/guides/loops.md#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](https://docs.nelkap.com/guides/versioning.md).

> **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 with `console.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 with `deliveryFailed`: replay it once your app is back. A run cut off in the middle picks up about five minutes later. See [Deploy your app](https://docs.nelkap.com/deploy/overview.md#how-nelkap-calls-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](https://docs.nelkap.com/deploy/overview.md#runs-during-a-deploy).

> **How do I stop a workflow?**
>
> Cancel one run from its page. To stop a workflow for good, remove it from `registerWorkflows`: its runs that haven't started, and those sleeping or waiting, are canceled. See [Runs](https://docs.nelkap.com/monitor/runs.md#cancel-a-run).

> **How many runs can go at once?**
>
> Up to your plan's limit for the workspace: 50, 100, or 500 runs. Sleeping and waiting runs don't count. Runs over the limit wait their turn, and none is lost. See [Limits](https://docs.nelkap.com/limits.md#by-plan).

> **How long does Nelkap keep my runs?**
>
> 1, 7, or 15 days after a run ends, depending on your plan. Runs still going are kept for as long as they last. To keep them longer, [export them](https://docs.nelkap.com/manage/exports.md).


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.