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

# NestJS

export const VersionRequirements = ({versions = []}) => {
  if (!Array.isArray(versions) || versions.length === 0) {
    return null;
  }
  const boundaries = {
    upper: " or lower",
    exact: "",
    lower: " or higher"
  };
  const containerStyle = {
    marginTop: "0.5rem",
    marginBottom: "1.5rem"
  };
  const lineStyle = {
    display: "block",
    margin: "0 0 0.35rem 0",
    fontSize: "0.875rem",
    lineHeight: "1.4"
  };
  const pillBaseStyle = {
    display: "inline-block",
    padding: "0.1em 0.4em",
    borderRadius: "0.25rem",
    border: "1px solid",
    fontFamily: "ui-monospace, SFMono-Regular, Menlo, monospace",
    fontSize: "0.85em",
    fontWeight: 500
  };
  const pillColors = {
    "AppSignal for Elixir": {
      background: "#f3e8ff",
      borderColor: "#e9d5ff",
      color: "#9333ea"
    },
    "AppSignal for Front-end": {
      background: "#fef9c3",
      borderColor: "#fde68a",
      color: "#ca8a04"
    },
    "AppSignal for Go": {
      background: "#ccfbf1",
      borderColor: "#99f6e4",
      color: "#0d9488"
    },
    "AppSignal for JavaScript": {
      background: "#fef9c3",
      borderColor: "#fde68a",
      color: "#ca8a04"
    },
    "AppSignal for Node.js": {
      background: "#dcfce7",
      borderColor: "#bbf7d0",
      color: "#16a34a"
    },
    "AppSignal for Python": {
      background: "#dbeafe",
      borderColor: "#bfdbfe",
      color: "#2563eb"
    },
    "AppSignal for Ruby": {
      background: "#fee2e2",
      borderColor: "#fecaca",
      color: "#dc2626"
    },
    "AppSignal for Rust": {
      background: "#ffedd5",
      borderColor: "#fed7aa",
      color: "#ea580c"
    }
  };
  const defaultPillColor = {
    background: "#f4f4f5",
    borderColor: "#e4e4e7",
    color: "#52525b"
  };
  const getPillStyle = name => ({
    ...pillBaseStyle,
    ...pillColors[name] || defaultPillColor
  });
  const getBoundText = bound => {
    return boundaries[bound] || boundaries.lower;
  };
  return <div style={containerStyle}>
      {versions.map((v, i) => <p key={`${v.name}-${v.version}-${v.bound || "lower"}-${i}`} style={lineStyle}>
          This feature requires{" "}
          <code style={getPillStyle(v.name)}>{v.name}</code> version {v.version}
          {getBoundText(v.bound)}.
        </p>)}
    </div>;
};

<VersionRequirements
  versions={[
{ name: "AppSignal for Node.js", version: "3.0.0" },
{ name: "NestJS", version: "4.0.0" }
]}
/>

<Note>
  Default instrumentations can be disabled via the `disableDefaultInstrumentations` config option. You can read more about how to configure this in our [Configuration Options documentation](/nodejs/3.x/configuration/options#option-disabledefaultinstrumentations).
</Note>

The AppSignal for Node.js integration for [NestJS](https://nestjs.com/).

## Installation

NestJS is instrumented automatically by the AppSignal for Node.js package.

When calling `nest start` directly, you can use the `NODE_OPTIONS` environment variable to require it:

<CodeGroup>
  ```bash Bash theme={null}
  NODE_OPTIONS='--require ./appsignal.cjs' nest start
  ```
</CodeGroup>

The start script references the `appsignal.cjs` file that was created [when configuring AppSignal](/nodejs/3.x/configuration#minimal-required-configuration).

To use AppSignal from the `npm` commands generated when creating an application with the `nest new` command, modify the following scripts from the `scripts` section of your `package.json` file as follows:

<CodeGroup>
  ```json JSON theme={null}
  {
    "scripts": {
      "start": "NODE_OPTIONS='--require ./appsignal.cjs' nest start",
      "start:dev": "NODE_OPTIONS='--require ./appsignal.cjs' nest start --watch",
      "start:debug": "NODE_OPTIONS='--require ./appsignal.cjs' nest start --debug --watch",
      "start:prod": "node --require ./appsignal.cjs dist/main"
    }
  }
  ```
</CodeGroup>

## Features

The NestJS integration will send AppSignal a child span representing the execution time of each middleware, as well as a child span for the request handler.

The name of the controller class and method that handled the request will be used as the name of the action.

Any errors raised by your NestJS application will be reported to AppSignal.