Edit metadata for your first CWL tool

In this tutorial, you will add publication-ready Schema.org metadata to a small CWL command-line tool without leaving VS Code.

Before you begin

You need Visual Studio Code and the CWL Metadata Editor extension installed. If you are installing a locally built package, run:

code --install-extension cwl-metadata-editor.vsix

1. Create a CWL file

Create hello.cwl and paste this document:

cwlVersion: v1.2
class: CommandLineTool
baseCommand: echo
inputs:
  message:
    type: string
    inputBinding:
      position: 1
outputs: {}

Keep hello.cwl active in the editor.

2. Open the metadata editor

Press Ctrl+K Shift+M (⌘K Shift+M on macOS) or open the Command Palette and run CWL: Edit Metadata. You can also use the command from the editor title or the .cwl file's editor context menu.

The form opens beside hello.cwl. Because the file has no supported metadata yet, its fields are initially empty.

Open the metadata editor

3. Describe the software

Enter the following values in Software:

Field Value
Name Hello CWL
Creation date today's date
Description Print a supplied message.
Software version 1.0.0

Choose an operating system if the tool is platform-specific, and list any runtime or dependency under Software requirements.

Watch hello.cwl as you edit. The metadata block appears in the document automatically; there is no Generate or Copy step.

4. Add attribution

Under Licenses, choose an SPDX identifier. Add a Software help entry with a name and URL.

Enter the publisher organization. When its name matches a Research Organization Registry (ROR) record, the editor can suggest its identifier. Then complete the first author. Use Use publisher affiliation if the author's organization is the publisher.

Optionally choose a CRediT role. Supplying role details makes the author a Schema.org Role whose s:author value is the person.

5. Add discovery terms

Add free-text keywords, select Earth Observation keywords, or add a GCMD Science keyword through the hierarchical picker. Structured GCMD entries are written as Schema.org DefinedTerm values.

6. Review the result

Return to hello.cwl. Its CWL implementation is unchanged, while the file now begins with metadata similar to:

$namespaces:
  s: https://schema.org/
'@type': s:SoftwareApplication
s:name: Hello CWL
s:description: Print a supplied message.
s:dateCreated: '2026-08-01'
s:softwareVersion: 1.0.0

cwlVersion: v1.2
class: CommandLineTool
baseCommand: echo
inputs:
  message:
    type: string
    inputBinding:
      position: 1
outputs: {}

The complete block will also contain the license, help, publisher, author, and keyword values you supplied.

Save the file and inspect its source-control diff as you would for any code change. You have now added metadata without moving generated YAML between a browser and your source tree.

Review the result

Next steps