# Warm the WordPress cache with Antigravity

> Warming the WordPress cache with Antigravity means asking its agent, in the editor where you work on the site, to start the xSpeed preloader through xSpeed Hub and to say how far the crawl has got.

Page: https://xspeedcache.com/agent/antigravity/preload-cache/
Last updated: October 2026

You are in Antigravity with a WordPress project open, and you have just released a change. You ask the agent to warm the live site. It calls list_sites to find the handle, then start_preloader. The plugin on the site starts crawling the sitemap in the background, a small batch of pages at a time, so visitors do not have to be the ones who trigger each page build.

You can ask for the status at any point. The agent calls get_preloader_status, which says whether a run is active and how far through the URL list it has got. It is a read and changes nothing, so it is a good call to keep repeating while the crawl is going. If the crawl has to stop, the agent calls stop_preloader, and the pages already warmed stay in the cache.

Antigravity runs unconfigured MCP tools in Ask mode, so each call waits for your approval in a card before it executes. The card carries a target string you can read and edit before you approve. Allow rules name the server and the tool, as in mcp(xspeedhub/get_preloader_status), and Ask and Deny rules take precedence over Allow. The Turbo permission preset allows MCP actions without asking, and then a start runs as soon as your connection allows writes, because xSpeed Hub has no confirmation step of its own. Sign-in to the Hub happens once, in the browser, and you paste the authorization code it shows back into the settings panel. The client then keeps the credentials it receives and refreshes them.

## Set up Antigravity 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 to mcp_config.json

Antigravity reads ~/.gemini/config/mcp_config.json for every project, or .agents/mcp_config.json inside one workspace. In the IDE, open the ... menu at the top of the agent side panel, choose MCP Servers, then Manage MCP Servers and View raw config. Remote servers must use the serverUrl field; the older url and httpUrl fields are not supported.

File: `~/.gemini/config/mcp_config.json`

```json
{
  "mcpServers": {
    "xspeedhub": {
      "serverUrl": "https://app.xspeedcache.com/xspeed/mcp"
    }
  }
}
```

### 3. Authenticate

Open Agent settings with Cmd+, on macOS or Ctrl+, on Windows and Linux, go to the Customizations tab and click Authenticate next to xspeedhub. Sign in to xSpeed Hub in the browser and approve access, copy the authorization code the page shows, paste it into the settings panel and click Submit. Antigravity keeps the credentials it receives and refreshes them. In the CLI, type /mcp to open the MCP manager and check the server status.

```
Settings → Customizations → Authenticate
```

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

### 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. Antigravity runs unconfigured MCP tools in Ask mode, so each call waits for your approval in a card before it executes. Allow rules such as mcp(xspeedhub/get_cache_status) or mcp(xspeedhub/*) let calls through without a prompt, Ask and Deny rules take precedence over Allow, and the Turbo permission preset allows MCP and web actions without asking. When you approve a card you can also edit its target to widen the grant. With Turbo or a broad allow rule, a write reaches the Hub as soon as your connection allows writes. xSpeed Hub has no confirmation step of its own.

## Prompts

- Use xSpeed Hub to warm the shop site and tell me what the preloader status says afterwards.
- Ask xSpeed Hub for the preloader status on blog. Do not start or stop anything, only read.
- With xSpeed Hub, stop the preloader on docs and confirm that the pages already warmed are still cached.

## Example session

```
You: Use xSpeed Hub to warm the cache on docs, I just updated the guides.
  → start_preloader(site: docs) [changes site]: Queued 140 URLs from the sitemap; pages are fetched in the background
Agent: Started on docs. I can check progress whenever you ask.
You: Check progress.
  → get_preloader_status(site: docs) [read-only]: Running, 50 of 140 URLs warmed
Agent: 50 of 140 pages are warm and the crawl is still going.
```

## How it works

1. **Check the cache and the preloader**: get_cache_status tells the agent whether page caching is on, because there is nothing to fill when it is off. get_preloader_status shows whether a crawl is already running, so the agent does not start a second one.
2. **Make sure the preloader is switched on**: The preloader module is off on a fresh install, and the site refuses start_preloader until it is on. The agent can read the module with get_settings and, if you agree, switch it on with update_settings on the preloader module. The Hub tells the agent to briefly confirm intent before an update_settings call, but that is guidance to the agent, not a lock.
3. **Start the crawl**: start_preloader makes the site read its sitemap, follow any nested sitemap indexes, drop URLs that your cache exclusion rules skip, and queue the rest. The call returns once the queue is built; the pages are then fetched in the background, a few per run. For every site at once the agent passes site: "all", and the Hub starts the sites one after another with a one-second pause.
4. **Watch the progress**: get_preloader_status reports whether a crawl is running, how many URLs it has processed out of the total, the last URL it visited and the most recent errors. It works on one site at a time, so for several sites the agent calls it once per site.
5. **Read what failed**: A page that answers 403 or 406 usually means a server firewall is blocking the warmer by its user-agent, not that the page is broken. The status message names the user-agent to allow. A crawl that queues no URLs is reported as an error with the reason, not as a success.
6. **Stop it if the server struggles**: stop_preloader ends a running crawl. It is safe mid-run: pages already warmed stay cached. The agent can stop one site or every site in the workspace.

## Reference

| | |
| --- | --- |
| Start and stop | start_preloader and stop_preloader (write) |
| Progress | get_preloader_status (read): running or not, processed out of total, last URL, recent errors |
| What gets crawled | The sitemap (the WordPress one at /wp-sitemap.xml unless you set another), nested indexes followed, excluded URLs skipped |
| Needs | The preloader module switched on (it is off by default) and page caching on |
| Pages per run | 5 by default, 1 to 50, set in the preloader module |
| Schedule setting | manual, hourly, daily or weekly, set in the preloader module |
| Every site at once | start_preloader and stop_preloader accept site: "all"; get_preloader_status does not |
| Fan-out pacing | Sites start one after another with a 1 second pause, one result per site |
| Warmer user-agent | xSpeed-Warmer/1.0, the string a firewall rule would need to allow |
| Stopping | Safe mid-run; warmed pages stay cached |
| Read-only access | A Viewer member's sign-in, or the connection token with Read-only everywhere on: start_preloader and stop_preloader are refused; get_preloader_status works. An OAuth sign-in by anyone else gets the scopes the client asks for. |
| Confirmation | None on the Hub; your client's prompt is the gate |

## Rules

- Warm after a purge, not instead of one. The Hub tells the agent that starting the preloader after a purge saves the next visitor from paying for the rebuild.
- A crawl requests every page in the sitemap, so it adds load to the origin. Start with one site, and on a small host keep Pages per run low or stop the crawl if the site slows.
- start_preloader and stop_preloader are write tools. The Hub calls the preloader low-risk and only asks the agent to confirm when the target site is unclear or the call covers every site, so your client's approval prompt and read-only access (a Viewer sign-in, or the connection token with Read-only everywhere on) are the gates that matter.
- A fan-out only starts the crawls. Check each site with get_preloader_status afterwards, and treat some sites failing to start as a partial result, not a failure of the whole call.

## Good to know with Antigravity

If you use the Turbo preset, add an Ask rule for start_preloader and stop_preloader, because Ask takes precedence over Allow and the writes then still wait for you. For sessions where you only want to look at progress, sign in to xSpeed Hub as a Viewer member, or put the connection token with Read-only everywhere on in a header. Either makes the Hub refuse every write tool and leaves get_preloader_status working. When you approve a card, check the target before you widen it: editing it to cover the whole xspeedhub server lets every Hub tool through.

## More prompts for this job

They work in any client connected to xSpeed Hub.

- Use xSpeed Hub to start the preloader on shop and tell me how many URLs it queued.
- Using xSpeed Hub, how far through its crawl is blog? Show processed against total and any errors.
- With xSpeed Hub, purge the cache on docs, then warm it again.
- Use xSpeed Hub to start the preloader on every site in my workspace and tell me which ones refused.
- Use xSpeed Hub to stop the preloader on shop. It is slowing the server down.
- The preloader on shop says it is disabled. Use xSpeed Hub to turn the module on, then start the crawl.
- Using xSpeed Hub, which of my sites has no running crawl and a low hit ratio?

## Frequently asked questions

### Can I make Antigravity check the preloader without starting one?

Yes. Ask it to call get_preloader_status only, which is a read. For a hard limit, list start_preloader and stop_preloader in disabledTools on the server entry so the model never sees them, or sign in as a Viewer member (or use the connection token with Read-only everywhere on), and the Hub then refuses both whatever the agent tries.

### Do I paste a token into Antigravity?

Not a connection token. Antigravity registers itself with the Hub through dynamic client registration, you approve access in the browser, and you paste the authorization code the page shows into the settings panel. The client then keeps the credentials it receives. A connection token from the Hub is the alternative where you want a header.

### Why does start_preloader say the preloader is disabled?

The preloader module is off by default on a new install, and the site refuses to start a crawl until it is on. The agent can switch it on with update_settings on the preloader module, or you can turn it on in the xSpeed Cache panel in wp-admin. Page caching also has to be on, because the crawl exists to fill that cache.

### What does the preloader actually warm?

It reads the site's sitemap, which is the WordPress one at /wp-sitemap.xml unless you set a different sitemap URL, follows nested sitemap indexes and skips any URL your cache exclusion rules leave out. If the sitemap cannot be read, the site falls back to a list built from its own content and says so. If nothing at all is queued, the call reports an error with the reason.

### Can I warm every site with one prompt?

Yes. The agent passes site: "all" to start_preloader and the Hub starts the crawl on every site in the workspace one after another, returning a result per site. The Hub tells the agent to confirm that with you once first. The call only starts the crawls, so progress is read afterwards with get_preloader_status, one site at a time.

### Will warming slow my site down?

A crawl fetches your own pages, a few per run, so it adds load while it runs. The Pages per run setting controls how many, from 1 to 50 with a default of 5. If a site struggles, stop_preloader ends the crawl and the pages already warmed stay cached.

### Why do some pages fail with HTTP 403 or 406?

Those codes are what bad-bot firewall rules usually answer with, and they mean the warmer was judged by its user-agent, not that the page is missing. The warmer identifies itself as xSpeed-Warmer/1.0. Allow that user-agent in the server rule, or change it with the xspeed_preloader_user_agent filter, and run the crawl again.

### Can the agent keep my cache warm on a schedule?

The preloader has its own Schedule setting in WordPress: manual, hourly, daily or weekly. An agent can change it with update_settings. The Hub itself has no scheduler for agent prompts, so a prompt only runs when you send it or when your AI client runs it on a timer.

## Warm the cache with other agents

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

## More with Antigravity

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

## Documentation

- How to warm your cache ahead of visitors: https://xspeedcache.com/docs/preloader/
- How to crawl your sitemap: https://xspeedcache.com/docs/crawl-now/
- How to enable Page Cache: https://xspeedcache.com/docs/page-cache/
- Managing your fleet with xSpeed Hub: https://xspeedcache.com/docs/managing-your-fleet-with-xspeed-hub/