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Uptime monitors

HTTP and HTTPS monitors

An HTTP or HTTPS monitor sends a request to a URL and checks the response. The check passes when the status code is one you expect and, if you set one, the body contains a keyword. An HTTPS monitor also checks the TLS certificate of the server.

Add an HTTP or HTTPS monitor

1. In the sidebar, select Monitors.
2. Select Create monitor.
3. Under Type, select HTTPS or HTTP.
4. In Target, enter the URL without the scheme, for example example.com/health.
5. In Max redirects, enter how many redirects Spectate follows, 0 to 10.
6. Select Create and start.

The other settings are on the Settings tab of the monitor. Select Save changes after you change them.

Target format

The type of the monitor sets the scheme. An HTTPS monitor requests https:// and the target, and an HTTP monitor requests http:// and the target. Spectate stores the target without the scheme, for example example.com/health.

If you paste a URL with a scheme into Target, the dashboard removes the scheme. To change the scheme, change Type.

In the public API and the MCP server, the scheme in uri is optional:

The response has the stored target in uri, and the full URL in url.

What a check does

1. The Spectate checker looks up the host name and opens a new connection. It never reuses a connection, so each check measures DNS, connect and TLS time.
2. It sends the request with the method, headers and authentication of the monitor. The request has no body.
3. It follows redirects, up to Max redirects.
4. It compares the status code with Expected status.
5. If the status code is expected and the monitor has a Keyword, it looks for the keyword in the body.

The check fails if any of these is true:

• The host name does not resolve, or resolves to a private or reserved address.
• The connection fails or the TLS handshake fails.
• The certificate is not valid, and Allow insecure requests is off. This applies to HTTPS only.
• The check takes longer than Timeout.
• The status code is not expected.
• The keyword check fails.

One failed check does not make the monitor down. Spectate checks again about 5 seconds later, and only a second failure makes the monitor down. See Locations and checks.

Expected status codes

Expected status (expected_http_status_code in the API) lists the status codes that count as up. Separate codes with commas. A * matches any digit.

2* is the same as 2**. The value can have up to 200 characters.

Keyword

Keyword is text that must be in the response body. The match is case-sensitive. Spectate reads up to 1 MiB of the body. Text after the first 1 MiB is not checked.

Select Invert keyword check to fail the check when the body contains the keyword. Use this for text such as Maintenance mode or Fatal error.

Spectate checks the keyword only when the status code is expected. The keyword can have up to 255 characters.

Method, headers and user agent

To add a header, go to the Headers section and select Add header. A Host header sets the host name that the request asks for. If you set both User agent and a User-Agent header, User agent wins.

Some firewalls block unknown bots. To allow Spectate, see The uptime monitor bot and IP addresses.

Authentication

Set Authentication under HTTP request → Advanced.

Spectate encrypts the password or token. The dashboard and the API never show it again. The field shows Saved when Spectate has a stored value. To keep the stored value, leave the field empty when you save.

Redirects

Spectate follows up to Max redirects redirects, 0 to 10. The dashboard sets 3 for a new monitor. In the API, max_redirects: null follows up to 10.

If the server asks for more redirects than the limit, Spectate checks the last redirect response itself. With the default Expected status, a 3xx response counts as up.

If a redirect goes to another host, scheme or port, Spectate removes credentials before it follows the redirect. It removes Authorization, Cookie and your custom headers. It keeps Accept, Accept-Encoding, Accept-Language, Cache-Control, Pragma and User-Agent. A redirect from http on port 80 to https on port 443 of the same host keeps all headers.

Timeouts

Connection timeout is under HTTP request → Advanced. If it is longer than Timeout, Timeout applies.

TLS

An HTTPS monitor verifies the certificate of the server against the trust store of the checker and the host name of the URL. If the verification fails, the check fails.

Select Allow insecure requests in the TLS section to skip this verification for the uptime check. Use it for self-signed certificates or an internal certificate authority. The separate certificate checks still report and alert on certificate problems.

Failure snapshots and screenshots

When an HTTP or HTTPS monitor goes down, Spectate keeps a snapshot of what the checker saw. It records one snapshot per outage, from the check that confirmed the failure.

A snapshot has:

• The error, the status code and the response time.
• The final URL after redirects, and the IP address that answered.
• The response headers. Spectate replaces the values of Set-Cookie, Cookie, Authorization and Proxy-Authorization with [redacted].
• The first 128 KiB of the body, and the page title.
• A screenshot of the page, 1440 by 900 pixels, from the same region.

Spectate takes the response and the screenshot only when the server sent an HTTP response. A refused connection, a DNS error or a TLS error has no snapshot body and no screenshot.

The screenshot uses the user agent, headers and Basic or Bearer authentication of the monitor. It sends them only to the monitor's own host. Digest authentication does not work for screenshots.

Screenshots are part of every paid plan and the trial. The snapshot shows on the alert page under What we saw, and on the monitor Overview under Recent failures. Spectate deletes snapshots and screenshots after 90 days.

Settings reference

The names in the public API. Settings in advanced_settings are marked with advanced_settings..