---
title: "Advanced Monitoring Fields — Lemwatch Help"
description: "The four advanced site fields — response-time threshold, HTTP method, custom headers, and expected body — explained with examples."
canonical: "https://lemwatch.com/help/advanced-monitoring-fields"
source: "https://lemwatch.com"
---

# Advanced Monitoring Fields

> The four advanced site fields — response-time threshold, HTTP method, custom headers, and expected body — explained with examples.

## Advanced Monitoring Fields

 The **Advanced Monitoring** section on Add Site / Edit Site exposes four fields that let you tune exactly how LemWatch probes your endpoint. All four persist correctly — earlier versions silently dropped them because they were missing from the validation schema. That's fixed.

### 1. Response time threshold (ms)

- Whole number, 0 – 60,000

- Triggers a "slow response" alert when a check exceeds it

- Leave blank for the platform default — see Response-time thresholds

### 2. HTTP method

- One of: HEAD , GET , POST , PUT

- Default HEAD is cheapest; switch to GET if your origin returns 405 on HEAD

- See Custom HTTP methods

### 3. Custom headers

- JSON object string, max 4,000 characters

- Validated as a real JSON object on save — pasted strings are parsed before write

- Use for bearer tokens, custom User-Agents, host overrides

- Full guide: Custom request headers

### 4. Expected body contains

- Up to 500 characters of plain text

- Treated as a substring match against the response body

- Fires a "content missing" alert when the substring is absent

- Full guide: Expected body content

### Where these live

 Together with the [health alert threshold](https://lemwatch.com/help/health-alert-threshold) they form the per-site **alerting contract**. Save the site to apply — changes take effect on the next scheduled check.

### Troubleshooting

- Field reverts to blank after save? Older builds had this bug; pull the latest and retry.

- Headers rejected? The JSON must parse as an object (e.g. {"X-Token":"abc"} ), not an array or string.


## Related

- [Help centre](https://lemwatch.com/help)
- [Response Time Threshold Alerts](https://lemwatch.com/help/response-time-thresholds)
- [Custom HTTP Methods & Headers](https://lemwatch.com/help/custom-http-methods)
- [Custom Request Headers](https://lemwatch.com/help/custom-request-headers)
- [Expected Body Content](https://lemwatch.com/help/expected-body-content)
- [Lemwatch pricing](https://lemwatch.com/pricing)
- [Is there a Lemwatch affiliate program?](https://lemwatch.com/help/affiliate-program-details)
- [Adding Your First Site](https://lemwatch.com/help/adding-your-first-site)