# Add CLItrail to Gatsby

Where the CLItrail tag goes in Gatsby, in its own idiom, with the consent, CSP and client-side routing details and how to check it works.

Written for Gatsby 5

## Where the tag goes

Edit `gatsby-ssr.js (or gatsby-ssr.tsx)`. Put the tag on every page that shows your install command; site-wide is best, after your existing analytics tags.

```js
export const onRenderBody = ({ setHeadComponents }) => {
  setHeadComponents([
    <script key="clitrail" defer src="https://YOUR_SERVICE/browser.js" data-website="YOUR_WEBSITE_ID" />,
  ]);
};
```

## Only after consent

Use the loader in place of the tag: nothing from CLItrail loads until `startClitrail()` runs. Load the loader before your consent manager's script and call `startClitrail()` from the manager's accept callback (most managers also run it on later visits once a choice is stored; check yours). Use the marketing category when installs go to Google Ads, Meta, TikTok or X Ads, and the analytics category when they only reach GA4 or your webhooks.

Consent loader

```js
// Loads CLItrail only after the visitor agrees. Call startClitrail() from your
// consent manager's "accepted" callback; nothing is fetched or stored before that.
window.startClitrail = () => {
  if (document.getElementById('clitrail')) return;
  const tag = document.createElement('script');
  tag.id = 'clitrail';
  tag.src = 'https://YOUR_SERVICE/browser.js';
  tag.dataset.website = 'YOUR_WEBSITE_ID';
  document.head.append(tag);
};
```

```js
export const onRenderBody = ({ setHeadComponents }) => {
  setHeadComponents([<script key="clitrail-consent" defer src="/clitrail-consent.js" />]);
};
```

## Client-side routing

Gatsby changes pages without a reload and calls `onRouteUpdate` after each change (and on the first load, which the tag already recorded).

Route helper

```js
// Records a visit when client-side navigation opens a new page path. The tag records
// the page the browser loaded, so that page is never recorded twice; before the SDK has
// started (for example, before consent) it records nothing.
let recorded;

export function recordVisit() {
  if (typeof window === 'undefined') return;
  recorded ??= new URL(performance.getEntriesByType('navigation')[0]?.name ?? location.href).pathname;
  const sdk = window.InstallAttribution;
  if (!sdk?.ready || location.pathname === recorded) return;
  recorded = location.pathname;
  sdk.ready = sdk.init({ service: 'https://YOUR_SERVICE', project: 'YOUR_WEBSITE_ID' });
}
```

```js
import { recordVisit } from './src/clitrail';

export const onRouteUpdate = () => recordVisit();
```

## Content Security Policy

The build is static files, so the policy lives in your host's header settings (for example `_headers` on Cloudflare Pages or Netlify, or `vercel.json`): add `https://YOUR_SERVICE` to `script-src` and `connect-src`, and `blob:` to `worker-src` (only Safari before 26 needs that one).

```
script-src 'self' https://YOUR_SERVICE;
connect-src 'self' https://YOUR_SERVICE;
worker-src 'self' blob:;
```

## Verify it works

1. Run `npm run develop` (http://localhost:8000) or deploy.
2. Open a page with the tag in Chrome or Firefox (accept analytics first if you gate CLItrail on consent), open the developer console and run `await InstallAttribution.ready`. It resolves to `{ ok: true, urlId, hasAnalyticsContext, expiresAt }`.
3. In the CLItrail dashboard, open Visits & identities: the visit is listed.
4. Anything else names the cause: `disabled` (no consent yet, or `data-enabled="false"`), `opfs_unavailable` (the page is not served over https or from localhost), `Error` (the service refused the visit: add the page's origin, including a development origin such as `http://localhost:3000`, under Settings → Additional domains). If `InstallAttribution` is undefined, the tag did not load: check the Network tab and your Content-Security-Policy.

Then run your installer on the same computer and check **Install events**, or run the hook with [`--doctor`](https://clitrail.com/docs/doctor).

## Notes

`setHeadComponents` writes a real `<script>` element into every page's `<head>`, with its attributes.

Gatsby documentation: [www.gatsbyjs.com/docs/reference/config-files/gatsby-ssr](https://www.gatsbyjs.com/docs/reference/config-files/gatsby-ssr/)

Using other install paths or destinations? The [setup generator](https://clitrail.com/docs/setup-generator) puts this snippet together with your hooks and destination checklist.