How Hermes Agent handles this
Hermes Agent runs on a server and has cron, so it can do the check you only do when a client complains. Describe a standing job in plain words: on the first of the month, read get_score_history for each site, compare the latest mobile and desktop scores with the month before, and write up what changed, with the LCP and CLS numbers beside each score. The scheduler lives in the Hermes gateway process, so the gateway has to be running, and each run starts a fresh session. The Hub keeps no timer of its own for agent prompts.
The report is only as fresh as the history. get_score_history returns stored runs and starts nothing, and the Hub does not run PageSpeed tests on a schedule. The Hub pulls the plugin's stored PageSpeed and GTmetrix reports every day, so a month with no new stored report can look unchanged because nothing was measured. A run_speed_test that someone starts goes to the Hub's own report history, which get_score_history may not read. Ask the report to name the date of the newest run for each site, so a flat line is not mistaken for a stable one.
Add run_benchmark to the same job if you also want a response-time reading. It times the home page cached and uncached for every site in a workspace in one call and has no Lighthouse score, so keep it in its own section of the report.
Set up Hermes Agent once
Already connected? Skip to the prompts. Alternatives and troubleshooting are on the Hermes Agent guide.
1Put 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.
2Add xSpeed Hub to config.yaml
Add this entry under mcp_servers. auth: oauth tells Hermes to handle discovery, dynamic client registration, PKCE and token refresh itself. If you edit the file from inside a running session, Hermes reloads its MCP connections with a 30 second timeout, which is too short for a browser sign-in, so finish the entry and then run the login in the next step.
mcp_servers:
xspeedhub:
url: "https://app.xspeedcache.com/xspeed/mcp"
auth: oauth 3Sign in with hermes mcp login
Run this once. Hermes prints an authorization URL, opens your browser where it can, and waits for the callback on a local loopback port. Sign in to xSpeed Hub and approve. There is no token to paste; Hermes caches the credentials it receives under ~/.hermes/mcp-tokens. On a remote host, paste the redirect URL back into the terminal when Hermes asks, or forward the callback port over SSH.
hermes mcp login xspeedhub hermes mcp test xspeedhub
Full Hermes Agent setup, sign-in options and FAQ
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. A Hermes server entry has a trust setting. The default, full, adds no approval prompt for that server's tools, and the approvals setting covers dangerous shell commands, not MCP tools. Set trust: untrusted on the xspeedhub entry and Hermes asks before every call to a tool that lacks a readOnlyHint of true. The Hub does not mark its tools that way, so with untrusted every Hub call asks, reads included. To remove writes instead of prompting, set tools.include on the entry to the read tools; the filter takes globs and include wins over exclude. The Hub itself has no confirmation step.
What do I ask?
Three prompts written for Hermes Agent. More for this job are below.
On the first of each month, use xSpeed Hub to read the PageSpeed history for every site, compare it with the month before and list the sites that got worse. Include the date of the newest run for each.
Right now, ask xSpeed Hub for the stored scores on shop and blog and tell me which site has the older data.
With xSpeed Hub, time every site cached and uncached and put it in a separate section from the PageSpeed scores.
What happens, step by step
PageSpeed Insights is Google's Lighthouse audit, and its score and Core Web Vitals are the numbers most people mean by "my speed". Through xSpeed Hub an agent can read the scores a site has already stored, run a new PageSpeed test on mobile or desktop, and read or run a separate benchmark of cached against uncached response time. The three answer different questions, and the Hub tells the agent which to use for each.
01
Read before you test
get_score_history returns the stored PageSpeed Insights and GTmetrix runs for a site: the score per run, with LCP, FCP, CLS, TBT, Speed Index and TTFB, mobile and desktop. It starts nothing. The Hub tells the agent to use it whenever you ask what your score is, or whether it improved, because a new test spends a shared allowance.
02
Run a new test when you need one
run_speed_test runs a real PageSpeed Insights audit on the site from the Hub and returns the score, the Core Web Vitals and the top opportunities. strategy is mobile (the default) or desktop, and one call tests one of them. It can take up to about 2 minutes, so the agent should say it is running before it calls.
03
Test the other device
Mobile and desktop scores differ, often by a lot. For both, the agent makes two calls, one per strategy. A failure is reported with its reason: PageSpeed not configured, quota reached, a timeout, or a site the audit cannot reach.
04
Measure the cache on its own
run_benchmark times the home page with the cache bypassed and again served from cache, and returns the response times. It is a read tool, and it accepts site: "all" for every site. It does not return a Lighthouse score, so the agent must not use it to answer a PageSpeed question.
05
Compare over time
get_benchmark_history returns past benchmark runs, uncached against cached, together with the settings changes on the same timeline, which is how you answer "did that change help?". For PageSpeed scores over time, use get_score_history.
Reference
| Read stored scores | get_score_history (read): PageSpeed Insights and GTmetrix runs, starts nothing |
|---|---|
| Metrics per run | Score, LCP, FCP, CLS, TBT, Speed Index, TTFB, for mobile and desktop |
| Run a new test | run_speed_test (write, uses the shared allowance): one PageSpeed Insights run per call |
| strategy | mobile (default) or desktop |
| Duration | Up to about 2 minutes per run |
| Why a test is a write | It spends a shared PageSpeed allowance and stores a report; it changes nothing on the site |
| Read-only access | A connection token with Read-only everywhere on, or a Viewer member's sign-in: run_speed_test is refused; get_score_history, run_benchmark and get_benchmark_history still work. An OAuth sign-in gets the scopes the client asks for |
| Benchmark | run_benchmark (read): cached against uncached response time for the home page, no Lighthouse score |
| Benchmark history | get_benchmark_history (read): past runs plus settings changes on the same timeline |
| Scheduling | The Hub does not schedule PageSpeed tests itself; its daily pass only reads reports the plugin already stored |
| Where a new test is stored | In the Hub's own report history, the one the Hub dashboard shows |
Rules worth keeping
- Check the history first. Ask for stored scores before starting a test, and run a new one only when you want a fresh measurement or something changed.
- Never answer a PageSpeed or Lighthouse question with run_benchmark. It times your own cache and carries no score.
- run_speed_test changes nothing on your site, but the Hub classes it a write because it spends a shared allowance. A connection token with Read-only everywhere on, or a Viewer sign-in, refuses it. An OAuth sign-in gets the scopes the client asks for, so there your client's approval prompt is the gate.
- Lab scores move a few points between runs of the same page. The agent should compare like with like, same site, same strategy, and not report one run's difference as a trend.
- A new test does not run on a timer. If you want a regular test, the agent has to be started by something else, such as a scheduled job in your client, and a scheduled run that spends the allowance should be one you are comfortable leaving unattended.
Good to know with Hermes Agent
A cron job has nobody to say no, so make it incapable of starting a test rather than hoping it will not. Hermes adds no prompt for a server by default, and its approvals setting covers shell commands, not MCP tools. Setting trust to untrusted makes Hermes ask before every Hub call, reads included, because the Hub marks no tool read-only, and a scheduled run cannot answer. So connect the agent to the Hub read-only for scheduled work (the connection token with Read-only everywhere on, or a Viewer sign-in), or set tools.include on the entry to the read tools, and the job cannot start a test whatever the prompt says. If you want fresh data, run that test in a normal session with you present, since each test spends the shared speed-test allowance.
More prompts for this job
They work in any client connected to xSpeed Hub.
Using xSpeed Hub, what is the mobile PageSpeed score for shop? Check the stored history before you run anything.
Use xSpeed Hub to run a new mobile PageSpeed test on blog and tell me the score, LCP and the top opportunities.
With xSpeed Hub, test shop on desktop and mobile and tell me which one is worse.
Using xSpeed Hub, has the PageSpeed score on docs improved over the last few runs?
Use xSpeed Hub to benchmark the cache on every site and tell me which one saves the least time.
Did turning on minification on shop help? Use xSpeed Hub to compare the benchmark history around that change.
My PageSpeed test failed on staging. Use xSpeed Hub to tell me why.
Frequently asked questions
Keep going
Track PageSpeed scores with other agents
More with Hermes Agent
Documentation
- How to run a speed test
- PageSpeed Insights integration
- Running speed tests in xSpeed Hub
- How to run a PageSpeed audit
- How to write prompts for xSpeed Hub
- Hermes Agent + xSpeed
- Every AI agent that works with xSpeed
From the blog
- Reading a PageSpeed Report in 2026: 30% of the Score Is a Metric Google Does Not Rank You On
- 45% of the WordPress Sites Our Scan Calls Clean Are Failing Google in 2026: Lab Scores Against Field Data
- The Same Page Scored 61 and 73 Twelve Minutes Apart: How to Benchmark WordPress Caching Plugins in 2026