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

# Workflows

> Train Nexus on a task once, then re-run it with one click — no re-prompting, just new inputs.

## Overview

Some tasks you do exactly the same way, over and over: the same drawing template applied to a new part, the same defeaturing rule on a new supplier file, the same review checklist before every release. Prompting Nexus from scratch each time works, but it's wasted effort when the procedure never actually changes — only the file or a value or two does.

**Workflows** let you do the task once, save it, and reuse it as a button. Build the procedure in chat, validate it on a real file, and it's saved to your Workflows library. From then on, running it is: open it, confirm or swap the inputs, hit **Run** — no re-describing the steps.

## How it works

<Steps>
  <Step title="Build it">
    Open **Workflows** in the sidebar and select **Create workflow**. This starts a normal chat — describe the task like you always would. As you go, Nexus proposes a step-by-step plan alongside the conversation, with editable chips for the parts that should change on future runs: a file path, a dimension, a material, a template.

    ```text theme={null}
    "Generate an assembly drawing of the current assembly from our A3 template — Front + Right view, third-angle, fully dimensioned from DimXpert data."
    ```

    Click any chip or step to edit it directly, or just say what to change in chat — the plan updates either way.
  </Step>

  <Step title="Test run to validate">
    A workflow can't be run until it's proven to actually work. Click **Test run** to have Nexus execute the full plan end to end on a real file. If it succeeds, the workflow is marked **Validated** and saved to your library. If a step fails, fix it and test again.

    This single validated run is what "trains" the workflow — you don't re-teach it after this.
  </Step>

  <Step title="Run it, anytime">
    From the Workflows library, click **Run** on a validated workflow. A dialog shows the parameters from your original run — swap in a new file or new values, add optional custom instructions for anything specific to this run, and confirm. Nexus executes the entire procedure without you re-typing a single instruction.

    Every run is logged under the workflow's **Runs** tab, so you can check history or confirm what happened on a past run.
  </Step>
</Steps>

<Note>Only validated workflows can be run. If you edit a workflow's steps significantly after validation, test it again before trusting the Run button on the new version.</Note>

## Where workflows are useful

* **Recurring drawing templates** — the same view set, dimensioning scheme, and title block, applied to a new part every time. See [Drawing Creation](/cad/drawing-creation#doing-the-same-drawing-over-and-over-train-a-workflow).
* **Standard review checklists** — the same compliance or house-rules pass run before every release.
* **Repeated defeaturing or export rules** — a simplification or format-conversion rule your team runs on every incoming supplier file.
* **Routine simulation setup** — the same preprocessing or postprocessing steps rebuilt for every new geometry or load case.
* **Any multi-step task where only the inputs change** — the procedure itself is stable; only a file, a value, or a target varies between runs.

If a task is genuinely one-off, just prompt Nexus directly — Workflows pay off once you're repeating the same procedure.

## Workflows vs. skills

Both let you avoid re-explaining a task, but they're triggered differently:

* **A skill** is invoked by name in a prompt — you type something like *"run apply-tolerances-mystandard on this part."*
* **A workflow** is triggered from the UI — no prompt required. Open it in the library and click **Run**.

Under the hood, validating a workflow also saves a reusable skill — so a workflow is effectively a skill wrapped in a parameter form and a run history, with a button in place of a prompt. Use a skill when you want to reference a procedure by name mid-conversation; use a workflow when the task deserves its own place in your library with tracked runs and an explicit input form.

## Tips for building workflows

* **Validate on a real, representative file** — the test run is what proves the workflow works. Don't validate on a trivial or unusual case if most future runs won't look like it.
* **Turn the varying parts into parameters, not hard-coded values** — a file path, a dimension, a target — so future runs only need new inputs, not an edited plan.
* **Use custom instructions for one-off tweaks** — if a single run needs a small deviation, add it in the run dialog rather than editing the saved workflow.
* **Check the Runs tab before re-running blind** — confirm what actually happened on the last run, especially if the result looked unexpected.
* **Re-test after a meaningful edit** — if you change the steps significantly after validation, run it again before relying on it.