Developing for Relay

Setting up your editor for Relay

Relay workflows are written in YAML that conforms to a particular specification. It can speed up the development cycle and reduce errors if your authoring environment knows about the specification, because you can get real-time validation and data type checking as you write. Here's how to set that up.

Visual Studio Code

VS Code is the primary authoring environment Relay supports. In order to get syntax validation for Relay workflows, you'll need to follow these steps:

  • Install and enable the Red Hat maintained YAML plugin
  • Configure the plugin to associate particular YAML files with the Relay schema, and add our custom tag support. The following snippet, which goes in your settings.json, matches every YAML that's in a subdirectory named 'relay' with the schema (you may have to modify this for your own environment, see the plugin's docs for details)
   "yaml.schemas": {
        "": ["relay*/*.yaml"]
        "yaml.customTags": [
        "!Secret scalar",
        "!Parameter scalar",
        "!Connection mapping",
        "!Connection sequence",
        "!Output mapping",
        "!Output sequence",
        "!Answer mapping",            
        "!Answer sequence",            
        "!Data scalar",
        "!Fn.append sequence",
        "!Fn.concat sequence",
        "!Fn.equals sequence",            
        "!Fn.jsonUnmarshal sequence",
        "!Fn.notEquals sequence",
        "!Fn.merge sequence"
    "yaml.validate": true