Command Line Interface


Basic syntax is:

concordia [dir] [options]


  • A parameter between[ and ] means that it is optional.

  • [dir] is the directory that contains your .feature files. Whether it is not informed, the tool searches all the subdirectories from the current path.

  • [options] changes how the tool behaves.

You can run concordia --help to see all the command line interface (CLI) options.

You need to use npx before the commands if you opted for a local installation.



Indicates a configuration file

Alias: -c

concordia --config /path/to/.concordiarc

By default the configuration file is loaded from the current directory.


Creates a configuration file and optionally installs plug-ins and databases.

concordia --init

This command asks about your preferences. By hitting Enter without giving an answer, it will select the suggested (default) value. You can use Up and Down to navigate the answers and hit Enter to select it. For multiple selection (when available), hitSpace.

By using a configuration file (e.g. .concordiarc) you avoid informing the configured parameters in the console/terminal. For instance, whether plugin is defined in the configuration file, you don't need to inform --plugin anymore.

CLI options take precedence over values from configuration files.


Add CLI parameters to the configuration file

The following example will consider the given directory and add it to the configuration file:

concordia --save-config --directory ./features

Directories and files


Indicates the directory that has .feature and .testcase files.

Alias: -d

When not given, it will search the current directory and all subdirectories recursively.

We strongly recommend to use it or set it in the configuration file.


concordia --directory ./features

This is equivalent to:

concordia ./features

You can use it with --no-recursive to disable recursive search.


Specifies .feature files to consider

Aliases: -f, --files

Files must be separated by comma.

concordia --file "file1.feature,/path/to/file2.feature"

Whether the command also informs a directory (e.g. --directory), it searches the files inside the directory. Example:

concordia ./feature --file "f1.feature,f2.feature"

The example above will search for ./feature/f1.feature and ./feature/f1.feature.


Specify .feature files to ignore when a directory is informed

Alias: -i

Files must be separated by comma.

concordia ./feature --ignore "f3.feature,f4.feature"


Disables recursive search when a directory is informed

concordia ./features --no-recursive

Output directories

The directories will be used by a plug-in. We strongly recommend that you specify them in a configuration file.


Specifies the directory for test reports and screenshots.

Alias: -O

concordia --dir-result output


Specifies the directory for test script files.

Alias: -o

concordia --dir-script test

Language and locale


Sets the default language to consider.

Alias: -l

The language code must have only 2 characters and needs to be one of the available languages.

concordia --language pt


Lists the available language codes.

concordia --language-list


Lists the available locales.

concordia --locale-list

Processing and output


Just generates test scripts

concordia --just-script


Just verifies specification files

concordia --just-spec


Just generates test cases

concordia --just-script


Just execute test script files

concordia --just-run


Avoids generating test scripts

concordia --no-script


Avoids processing specification files

concordia --no-spec


Avoids generating test cases

concordia --no-test-case


Avoids reading test scripts' results

concordia --no-result


Avoids running test scripts

concordia --no-run

Use -x to combine --no-run and --no-result

concordia -x


Uses a verbose output

concordia --verbose

Test script execution

These parameters require a plugin (--plugin) and some plug-ins may not support them.


Number of parallel instances to execute.

Alias: -I

concordia --instances 2


Executes browsers in headless mode.

Alias: -H

concordia --headless


Sets one or more test script files to execute

Aliases: -F, --script-files

Files must be separated by comma.

concordia --script-file "test1.js,test2.js"


Sets a text or regular expression to filter the files to execute

Alias: -G

concordia --script-grep "Sales"


Sets target browsers or platforms to execute

Alias: -T

Browser or platforms must be separated by comma.

concordia --target "chrome,firefox,edge"


You can omit the prefix concordialang- from plug-in names. For instance, concordialang-codeceptjs-playwright becomescodeceptjs-playwright.


Uses the given plug-in (if installed)

Alias: -p

concordia --plugin <plugin>

You can use it with -x to avoid running test scripts and reading their output:

concordia -p <plugin> -x


Shows information about an installed plug-in

Alias: --plugin-info

concordia --plugin-info <plugin>


Installs a plug-in

concordia --plugin-install <plugin>


Lists installed plug-ins

concordia --plugin-list


Starts a testing server for a plug-in

Alias: -S

concordia --plugin-serve <plugin>

The testing server will keep running. Thus, it's a good idea to open a separate terminal/console for it. To stop it later, type Ctrl + C.


Uninstalls a plug-in

concordia --plugin-uninstall <plugin>


See Using Databases for the list of available databases.


Installs a database driver

concordia --db-install <database>


Lists installed databases

concordia --db-list


Uninstalls a database driver

concordia --db-uninstall <database>

Random generation


Maximum random string size to generate, when free values are allowed.

The default value is 500 .

concordia --random-max-string-size 100


Minimum random string size to generate, when free values are allowed.

The default value is 0 .

concordia --random-min-string-size 1


Random tries to generate invalid values.

When there is a set of valid values and any value different from those in the set is considered an invalid, random generation is used to produce an invalid value. This parameter defines how many tries to take. Usually it gets on the first try.

The default value is 5 .

concordia --random-tries 10


Sets a random seed

concordia --seed="example"

Concordia Compiler can use random selection in its algorithms. By default, it generates the seed using the current date and time. Using the same seed makes the algorithms produce the same output (e.g., same values and paths). While that's interesting for reproducing a past behavior, we don't recommend it for finding new defects. Using new seeds, Concordia Compiler will select different test data, test oracles, and test paths over time.

You can also set the algorithms to use, in order to avoid random selection. Full combination (therefore full coverage of the requirements) can be achieved and it is recommend for complete checking before a new release. However, it may take some time to execute.

Combination strategies





File formats and extensions

You probably don't need to use them, unless you're facing problems to read files.


Sets the character(s) used for breaking lines.

Since by default the line breaker is detected automatically, this command may not be useful for you in most cases.

concordia --line-breaker "\n"

Note on line breakers:

  • Linux uses "\n"

  • MacOS uses "\r"

  • Windows uses "\r\n"


Sets the expected file encoding

Alias: -e

The default is utf8. Possible values are:

  • ascii

  • latin1

  • ucs2 or ucs-2

  • utf16le or utf-16le

  • utf8 or utf-8

concordia --encoding latin1



Shows information about the compiler.

concordia --about


Shows the available commands

concordia --help


Verify if there is a newer version.

concordia --newer


Shows the current version.

concordia --version

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