# Raise a WordPress site's PageSpeed score with Windsurf

> Raising a WordPress PageSpeed score with Windsurf means asking its agent to preview and then apply an xSpeed optimization pass through xSpeed Hub, and checking the pages it reports.

Page: https://xspeedcache.com/agent/windsurf/optimize-site/
Last updated: October 2026

Windsurf now ships as Devin Desktop, so the first thing to know is which agent you are talking to. The newer Devin Local agent and the older Cascade agent can both call xSpeed Hub once it is added. Either way, you name a site and a goal in the editor, and the agent calls list_sites and then optimize_site with dry_run on. The plan comes back and nothing on the site has changed. Ask for the level you want, safe, standard or aggressive, and for the reason behind each step.

When you approve, the real pass runs. xSpeed measures the site, applies each setting one at a time, checks the page after every change, and undoes anything that breaks it, which takes up to two minutes per site. If you want a number reached rather than a single pass, say the number and a round limit. The agent can pass target_score and max_rounds, up to three, but that needs the Pro plugin on the site, and each round is a real PageSpeed measurement. xSpeed may also stop early when rounds stop helping and say why.

Read the result in three parts: what was applied, what was undone and why, and what is unfixable. A site that stopped short of your target has not failed if the unfixable list explains what is left. Then take the verify step seriously. The Hub gives the agent verify_urls and tells it to check the pages before it claims success, because the plugin checks HTML in PHP and cannot see JavaScript errors. Open the pages yourself with the console visible.

## Set up Windsurf once

### 1. Put your sites in xSpeed Hub

Sign in at app.xspeedcache.com with Google or email; the Hub is free and has no site cap. Then connect each WordPress site from its own dashboard: click Connect Hub in the xSpeed Cache top bar, then Connect via xSpeed Hub. Each site needs the free xSpeed Cache plugin.

### 2. Add xSpeed Hub for the Devin Local agent

Run this in a terminal. Devin Local shares its MCP configuration with Devin CLI, and -s user saves the server to ~/.config/devin/mcp_config.json (%APPDATA%\devin\mcp_config.json on Windows) so it applies to every project. Without -s, the command saves to local scope, which is the current project only.

```bash
devin mcp add -s user xspeedhub https://app.xspeedcache.com/xspeed/mcp
```

### 3. Sign in

Run the login command and approve access on the xSpeed Hub page that opens in your browser. There is no token to paste, and the client keeps the credentials it receives. If the server later shows Needs auth in the Devin Local MCP list, click Authenticate, or run devin mcp logout and then login again.

```bash
devin mcp login xspeedhub
```

Full setup: https://xspeedcache.com/agent/windsurf/

### Before you send a prompt that changes something

Reads change nothing on your sites, though contact_support emails xSpeed support. Writes run once your connection allows them, so your client's approval prompt and a read-only connection (the token's Read-only everywhere switch, or a Viewer sign-in) are the gates that matter. The Devin Local agent prompts for approval before it calls any MCP tool. In the prompt you can allow that one tool or every tool on the xspeedhub server, for this session or permanently, and permission rules such as mcp__xspeedhub__get_cache_status allow, deny or always ask for a named tool. Smart mode lets a fast model run what it judges safe without a prompt, and Bypass mode approves everything, so with either of those a write reaches the Hub as soon as your connection allows writes. xSpeed Hub has no confirmation step of its own.

## Prompts

- Using xSpeed Hub, preview an optimization for the restaurant site at the standard level. Do not apply it yet.
- With xSpeed Hub, apply the plan, aiming for a score of 85, with at most two rounds. Tell me first if that needs Pro.
- Explain why the xSpeed Hub run stopped, in plain words, and list what is left on the unfixable list.

## Example session

```
You: Raise the PageSpeed score on the restaurant site through xSpeed Hub. Preview first.
  → list_sites [read-only]: 4 sites; restaurant is restaurant.example.com
  → optimize_site(site: restaurant, aggressiveness: standard, dry_run: true) [dry run]: plan: 4 settings to apply (CSS minify, defer JS, lazy-load images, compression), nothing changed
Agent: The plan is CSS minify, script deferral, lazy-loading and compression. It changes nothing until you say so. Apply it to restaurant?
You: Yes, apply it.
  → optimize_site(site: restaurant, aggressiveness: standard) [changes site]: applied 4, undone 0, unfixable: autoplay hero video, large menu PDF embeds
Agent: All four settings are on. The hero video and the embedded menu files are what remain, and caching cannot reduce them. Open the home page and the menu page in a browser and check the console is clean.
```

## How it works

1. **See where the site stands**: The agent reads get_score_history for the last stored scores and list_modules for which modules exist on that site and what state they are in. Neither changes anything.
2. **Preview with dry_run**: optimize_site with dry_run: true returns the plan: each change and its tier, what would be skipped (already on, or needing a higher aggressiveness) and what it cannot fix. Nothing is applied. The tool description tells the agent to prefer this before the first real run on a site you have not optimized before.
3. **Apply it**: optimize_site without dry_run applies the plan. aggressiveness is safe (removals and server-side changes only), standard (the default) or aggressive, which includes settings known to break some themes and should be opted into deliberately. A run can take up to about 2 minutes per site.
4. **Look at the site afterwards**: When changes were applied, the result carries verify_urls and a note. The site checks its own HTML and reverts anything that breaks it, but it cannot run JavaScript, so verified: true does not prove the page works in a browser. The Hub tells the agent to open those URLs and check the page renders and the console is clean, or to tell you which URLs to check.
5. **Reach for a number only if you named one**: target_score (1 to 100, Pro sites only) turns one pass into repeated rounds toward that score, up to max_rounds, with 3 as the most per site. Each round is a real PageSpeed measurement and up to about 2 minutes. The result says why it stopped, and diminishing returns means what is left is outside what caching can reach.
6. **Critical CSS on Pro sites**: generate_critical_css generates above-the-fold CSS so the first screen can paint without waiting for the full stylesheets. It needs the Pro Critical CSS module on that site, and the site answers with an unknown-tool error without it. Pages are rebuilt with it on their next build, so the agent purges the cache afterwards.

## Reference

| | |
| --- | --- |
| Main tool | optimize_site (write): measure, apply one setting at a time, verify, undo what breaks, re-measure |
| Preview | dry_run: true returns the plan and changes nothing |
| aggressiveness | safe, standard (default) or aggressive |
| Every site at once | site: "all" or a list of handles, one result per site, sites run one after another; the Hub's confirm-once instruction does not name optimize_site, so your client's prompt is the gate |
| Time | Up to about 2 minutes per site |
| target_score | 1 to 100; needs Pro on the site; without it the site runs one pass and says so |
| max_rounds | Up to 3 per site; only sent along with target_score; 12 rounds in total per call |
| Wide fan-out with a target | Each site gets fewer rounds, and the result carries a note saying so |
| Result fields | applied, skipped, reverted, unfixable, score, verified, rounds; verify_urls after a run that changed something |
| Already tuned site | Returns "everything is already on" plus what it cannot fix; that is an answer, not a failure |
| Critical CSS | generate_critical_css (write), Pro Critical CSS module required; purge_cache afterwards |
| Read-only connection | optimize_site and generate_critical_css are refused; dry_run is still a write call, so it is refused too. Applies to the connection token with Read-only everywhere on and to a Viewer sign-in, not to other OAuth sign-ins |

## Rules

- Run dry_run first. optimize_site changes live site settings as soon as your connection allows writes. The tool description tells the agent to preview first on a site that has not been optimized, but that is guidance, so your client's approval prompt and a read-only connection (the connection token with Read-only everywhere on, or a Viewer sign-in) are the real gates.
- Keep aggressive for a deliberate choice. It includes settings known to break some themes, and the agent should say so before using it.
- After a run that changed something, open the pages in verify_urls. The HTML checks cannot run JavaScript, so a page can pass them and still be broken in a browser. Do not call a run safe because verified is true.
- Relay the unfixable list. When a site is already tuned, the honest answer is that caching is done and the rest is page weight, hotlinked images or DOM size. The agent should not retry the tool or claim a gain it did not make.
- Only ask for target_score when you want the site driven to a number. Each round costs a real PageSpeed measurement, and a plain "make it faster" is one pass.

## Good to know with Windsurf

The Devin Local agent prompts before it calls any MCP tool. In the prompt you can allow that one tool or every tool on the xspeedhub server, for this session or permanently. Because the dry run and the real pass are the same tool, allowing optimize_site on the first prompt covers the real pass too, and Smart mode and Bypass mode send it with no prompt at all. Allow only once, or set a rule that keeps optimize_site on ask. The rename to Devin Desktop also means older guides describe Cascade settings that may not match what you see, so check which agent you are in. Cascade caps the tools across all your servers at 100, and the 29 Hub tools count toward that cap.

## More prompts for this job

They work in any client connected to xSpeed Hub.

- Ask xSpeed Hub to preview what optimize_site would change on shop with a safe pass. Do not apply anything.
- Use xSpeed Hub to optimize the blog site with the standard pass, then give me the pages to check by hand.
- With xSpeed Hub, get docs to a mobile PageSpeed score of 90 if you can, and tell me why it stopped if it does not get there.
- Use xSpeed Hub to show me what optimize_site would do on every site, as a dry run, and list which sites have the most left to change.
- Use xSpeed Hub to generate critical CSS for shop, then purge the cache so the pages are rebuilt with it.
- With xSpeed Hub, optimize shop, then compare the new PageSpeed score with the last stored one.
- Using xSpeed Hub, what could optimize_site not fix on the shop site?

## Frequently asked questions

### Does xSpeed work with Windsurf now that it is Devin Desktop?

The Devin Local agent and the legacy Cascade agent can both connect to xSpeed Hub as a remote MCP server. Which agent you use changes how you add the server, not what optimize_site does. The approval behaviour on this page is Devin Local's: it prompts before any MCP tool call by default.

### Why is optimize_site missing from my Windsurf tool list?

On the legacy Cascade agent, check the tool cap first. Cascade allows 100 tools at a time across all servers, and xSpeed Hub adds 29, so a crowded setup can hit it. Switch off tools you do not use with disabledTools on the server entry, then reload the server.

### What does optimize_site actually do?

It measures the site, applies the recommended xSpeed settings one at a time, checks that the page still renders after each change, and undoes any change that breaks it. It then reports what was applied, skipped and reverted, and what it could not fix. It reaches caching and asset delivery only.

### Should I run a dry run first?

Yes, especially on a site you have not optimized before. dry_run: true returns the plan, what would be skipped and what cannot be fixed, and changes nothing. The tool description tells the agent to prefer it, but nothing forces it, so say so in your prompt if you want a preview.

### Can I tell it to get my site to a score of 90?

Yes, with target_score, on a site that has xSpeed Pro. It repeats measure, apply and re-measure for up to 3 rounds per site and stops early when rounds stop helping, saying why. On a Free site the score target is ignored and you get a single pass with a note that no iterative tuner is installed.

### Why did it say everything is already on?

That is a real answer. The settings it can apply were already enabled, so there was nothing to change. The result also lists what it could not fix, such as page weight, images hosted on another domain or DOM size, and those need changes outside a caching plugin.

### Does the agent check that my pages still work?

The site checks its own HTML after each change and reverts anything that breaks it, but it cannot run JavaScript. After a run that changed something, the Hub tells the agent to open the returned verify_urls and check the page renders and the console is clean, or to give you the URLs to check yourself.

### Does generate_critical_css work on a Free site?

No. It needs the Pro Critical CSS module on that site, and without it the site answers with an unknown-tool error. On a Pro site, purge the cache afterwards, because pages already cached were built without the critical CSS.

## Raise the PageSpeed score with other agents

[Claude Code](https://xspeedcache.com/agent/claude-code/optimize-site/) · [Claude](https://xspeedcache.com/agent/claude/optimize-site/) · [Claude Cowork](https://xspeedcache.com/agent/claude-cowork/optimize-site/) · [ChatGPT](https://xspeedcache.com/agent/chatgpt/optimize-site/) · [Codex](https://xspeedcache.com/agent/codex/optimize-site/) · [Cursor](https://xspeedcache.com/agent/cursor/optimize-site/) · [GitHub Copilot in VS Code](https://xspeedcache.com/agent/github-copilot/optimize-site/) · [Gemini CLI](https://xspeedcache.com/agent/gemini-cli/optimize-site/) · [Antigravity](https://xspeedcache.com/agent/antigravity/optimize-site/) · [Zed](https://xspeedcache.com/agent/zed/optimize-site/) · [Kiro](https://xspeedcache.com/agent/kiro/optimize-site/) · [OpenCode](https://xspeedcache.com/agent/opencode/optimize-site/) · [OpenClaw](https://xspeedcache.com/agent/openclaw/optimize-site/) · [Hermes Agent](https://xspeedcache.com/agent/hermes-agent/optimize-site/) · [Grok Build](https://xspeedcache.com/agent/grok-build/optimize-site/) · [ChatGPT dots](https://xspeedcache.com/agent/chatgpt-dots/optimize-site/) · [Grok](https://xspeedcache.com/agent/grok/optimize-site/) · [Grok Bot](https://xspeedcache.com/agent/grok-bot/optimize-site/) · [Muse](https://xspeedcache.com/agent/muse/optimize-site/) · [Manus](https://xspeedcache.com/agent/manus/optimize-site/) · [Kimi Code](https://xspeedcache.com/agent/kimi/optimize-site/) · [Paperclip](https://xspeedcache.com/agent/paperclip/optimize-site/) · [NanoClaw](https://xspeedcache.com/agent/nanoclaw/optimize-site/)

## More with Windsurf

- [Purge the WordPress cache with Windsurf](https://xspeedcache.com/agent/windsurf/purge-cache/)
- [Find out why WordPress pages are not cached with Windsurf](https://xspeedcache.com/agent/windsurf/troubleshoot-cache/)
- [Scan a website for speed problems with Windsurf](https://xspeedcache.com/agent/windsurf/speed-scan/)
- [Run and track PageSpeed tests with Windsurf](https://xspeedcache.com/agent/windsurf/pagespeed-tests/)
- [Tune WordPress cache settings with Windsurf](https://xspeedcache.com/agent/windsurf/cache-settings/)
- [Warm the WordPress cache with Windsurf](https://xspeedcache.com/agent/windsurf/preload-cache/)
- [Set up the Redis object cache with Windsurf](https://xspeedcache.com/agent/windsurf/object-cache/)
- [Manage Cloudflare caching with Windsurf](https://xspeedcache.com/agent/windsurf/cloudflare/)
- [Manage every WordPress site at once with Windsurf](https://xspeedcache.com/agent/windsurf/fleet/)

## Documentation

- How to generate Critical CSS: https://xspeedcache.com/docs/critical-css/
- Performance recommendations: https://xspeedcache.com/docs/performance-recommendations/
- How to run a speed test: https://xspeedcache.com/docs/external-score/
- Free vs Pro: what is included: https://xspeedcache.com/docs/free-vs-pro/