Projects YAML reference


This document is the YAML grammar reference used for adding and editing Semaphore 2.0 projects using the sem command line utility.

Projects can also be added to Semaphore 2.0 with the sem init command. In that case, you will not need to create a YAML file on your own. However, sem init requires a local copy of the GitHub repository, even if that repository is not up to date, that does not contain a .semaphore/semaphore.yml file. Put simply, sem init is simpler but less flexible than the sem create command.

To learn more about the sem commands for project manipulation, you can visit the sem command line tool Reference.



The apiVersion property defines the version of the YAML grammar that will be used for the definition of the YAML file. Different YAML versions might have different features.

List of value for apiVersion: v1alpha.


The value of the kind property is a string that specifies the type of the YAML file, that is whether it is for creating new projects or new secrets. For projects the value of the kind property should be Project.

The list of values for kind: Project.


The metadata property is for grouping other properties. Currently, the only supported property is name.


The name property defines the name of the Semaphore 2.0 project as it will be displayed in the Semaphore 2.0 user interface and the output of the sem get project command.

The value of the name property should be unique among all Semaphore 2.0 projects of the same organization and must only contain [a-z], [A-Z] or [0-9] characters, dashes and underscores – space characters are not allowed.

Using the same YAML file with different name values, will create multiple Semaphore 2.0 projects connected to the same GitHub repository.


The spec property is currently used for holding the required repository and optional schedulers properties.


The repository property is used for holding the url property.


The url property is a string that specifies the URL of the GitHub repository you want to add in Semaphore 2.0. The format of the url value should be as follows:

If the value of url is erroneous, you will get various types of error messages.

First, if the GitHub repository cannot be found, sem create will reply with the next error message:

$ sem create -f goDemo.yaml

error: http status 422 with message "{"message":"repository \"text/goDemo\" not found"}" received from upstream

Next, if the Semaphore 2.0 project name is already taken, sem will reply with the following error message:

$ sem create -f goDemo.yaml

error: http status 422 with message "{"message":"project name \"goDemo2.1\" is already taken"}" received from upstream

Last, if the url value does not have the correct format, sem will print the next kind of error message:

$ sem create -f goDemo.yaml

error: http status 422 with message "{"message":"repository url must be an SSH url"}" received from upstream


The schedulers property can contain a list of schedulers defined on the project.

A scheduler in Semaphore 2.0 is a way to run a pre-defined pipeline on a project at the pre-defined time.

A scheduler has a few properties: name, branch, at and pipeline_file.


The name property uniquely identifies the scheduler inside an organization.


The branch property specifies which currently existing branch will be used in running the pipeline.

The chosen branch must have at least one workflow initiated by a push in order for the scheduler to be valid.


The at property defines the schedule at which the pipeline will be ran.

Semaphore expects this property to be the standard cron syntax. For a simple way to define your cron syntax, visit


The pipeline_file property contains the relative path to the pipeline definition file from the root of the project.

For more information on defining a valid pipeline file, visit the Pipeline YAML Reference.


A simple project:

apiVersion: v1alpha
kind: Project
  name: goDemo
    url: ""

A project with schedulers:

apiVersion: v1alpha
kind: Project
  name: goDemo
    url: ""
    - name: first-scheduler
      branch: master
      at: "5 4 * * *"
      pipeline_file: ".semaphore/cron.yml"
    - name: second-scheduler
      branch: master
      at: "5 3 * * *"
      pipeline_file: ".semaphore/semaphore.yml"

See Also

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