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Flags are chainable properties that are applied at the beginning of a phrase. They allow you to customize how Fossabot should parse, and match a given phrase.

For example, given the phrase foobar, in order to make this phrase use regex, it would become regex:foobar. If the phrase should also be case-sensitive, and use regex, then the phrase should be regex:sensitive:foobar. The order in which you chain flags is irrelevant to how Fossabot parses the phrase, as long as they all exist before the phrase content.

The only flag which does not support functionality from other flags, is var.


Your regex must be compatible with the RE2 regex engine!

Fossabot executes regular expressions using RE2, a regex engine created by Google. Not all features are supported by this engine, and you are responsible for ensuring that your regex is compatible with this engine, else Fossabot will silently ignore it.

You can validate your regular expression by using sites such as Make sure you select Golang as the regex flavor on the left sidebar.

The use of regex: in a phrase tells Fossabot to treat the following phrase as a Regular Expression, and will test the given keyword target against the phrase.




Instructs Fossabot to match your phrase with case sensitivity. By default, all phrases in keywords are case insensitive.




Instructs Fossabot to count this phrase as a match if the phrase is not able to be matched against the keyword target. This is particularly useful if you create a regular expression, then want to ensure that it doesn't match particular edge cases.

For example, if you had a phrase group with the phrase test, and a message with foobar was sent, this would count as a match - because test is not present in foobar.




All other flags are ignored when using var:.

If you define other flags on the phrase, they will be ignored.

Instructs Fossabot to reference your keyword variable for defining the properties of a given phrase. The content of a keyword must be the variable key.

For more information on variables, check out our variables documentation.


For a variable, that has a key of myKey: