> For the complete documentation index, see [llms.txt](https://documentation.pushly.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://documentation.pushly.com/integration/web-push/sdk/delivery-and-security-sri.md).

# Delivery & Security (SRI)

Pushly supports loading a pinned, immutable version of the Web SDK using Subresource Integrity (SRI).

This option is intended for customers with strict security requirements, such as enforced CSP policies. Most customers should continue using the Latest SDK.

***

#### When should I use SRI?

Use SRI only if you require:

* Cryptographic verification of third-party scripts
* Enforcement of `require-sri-for script` in Content Security Policy
* Explicit control over when SDK updates occur

If you do not have these requirements, use the [Latest SDK](/integration/web-push/quick-start.md) instead.

***

#### Pinned SDK snippet example (SRI)

```html
<script
  src="https://cdn.p-n.io/sdk/web/pushly@3.1.0.min.js"
  integrity="sha384-REPLACE_WITH_HASH"
  crossorigin="anonymous"
  async
  data-domain-key="DOMAIN_KEY">
</script>
```

This loads a specific SDK version that will never change.

***

#### Get the integrity hash

The integrity hash for each SDK release is published in a release manifest.

For version 3.1.0:

```
https://cdn.p-n.io/sdk/web/releases/3.1.0/manifest.json
```

Look for the `files[].integrity` field and copy its value into the `integrity` attribute.

***

#### Upgrading a pinned SDK

Pinned SDKs do not auto-update.

To upgrade:

1. Update the SDK version in the script `src`
2. Update the corresponding `integrity` hash
3. Deploy the updated snippet

```diff
- src="https://cdn.p-n.io/sdk/web/pushly@3.1.0.min.js"
- integrity="sha384-OLD_HASH"
+ src="https://cdn.p-n.io/sdk/web/pushly@3.2.0.min.js"
+ integrity="sha384-NEW_HASH"
```

If you do not update the snippet, your site will continue running the older SDK indefinitely.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://documentation.pushly.com/integration/web-push/sdk/delivery-and-security-sri.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.