> ## Documentation Index
> Fetch the complete documentation index at: https://bruno-a6972042-docs-api-docs-split-more-menu-ryan.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Scripting

Bruno allows you to write JavaScript code before sending a request
(Pre-request) and after receiving a response (Post-response). Use scripts to
generate dynamic data, manipulate requests, parse responses, and set
variables.

<img src="https://mintcdn.com/bruno-a6972042-docs-api-docs-split-more-menu-ryan/yaMqC_x58RstnVUl/images/screenshots/script/scripting.webp?fit=max&auto=format&n=yaMqC_x58RstnVUl&q=85&s=d22dbbc5ebe3ac400a476438fa7ae6e9" alt="bru lang sample" width="2472" height="924" data-path="images/screenshots/script/scripting.webp" />

<CardGroup cols={2}>
  <Card title="JavaScript API Reference" icon="book" href="/testing/script/javascript-reference">
    The complete `bru` API — request and response methods, environments, and
    utilities.
  </Card>

  <Card title="Script Flow" icon="diagram-project" href="/testing/script/script-flow">
    When pre-request and post-response scripts run, and in what order across
    collection, folder, and request levels.
  </Card>

  <Card title="Inbuilt Libraries" icon="cubes" href="/testing/script/inbuilt-libraries">
    Libraries bundled with Bruno, ready to require in your scripts.
  </Card>

  <Card title="External Libraries" icon="box-open" href="/testing/script/external-libraries">
    Use npm packages in your scripts with Developer Mode.
  </Card>

  <Card title="JavaScript File" icon="file-code" href="/testing/script/js-file">
    Keep shared script code in standalone `.js` files inside your collection.
  </Card>

  <Card title="Dynamic Variables" icon="shuffle" href="/testing/script/dynamic-variables">
    Generate random data like names, emails, and UUIDs on every run.
  </Card>

  <Card title="Request Chaining" icon="link" href="/testing/script/request-chaining">
    Pass data from one request to the next and control execution flow.
  </Card>

  <Card title="Request" icon="arrow-up" href="/testing/script/request/request-object">
    The `req` object — inspect and modify outgoing requests, and send
    synchronous requests from scripts.
  </Card>

  <Card title="Response" icon="arrow-down" href="/testing/script/response/response-object">
    The `res` object — read status, headers, and body, and query response data.
  </Card>

  <Card title="Variables" icon="brackets-curly" href="/testing/script/vars">
    Get and set variables from scripts with the Vars tab.
  </Card>
</CardGroup>