Skip to main content

Quick Start

What you'll need

  • Node.js version 16.14 or above:
    • When installing Node.js, you are recommended to check all checkboxes related to dependencies.

Install the Concerto Command Line Interface (CLI)

Open a shell and run the command:

npm install -g @accordproject/concerto-cli

You can type this command into Command Prompt, Powershell, Terminal, or any other integrated terminal of your code editor.

The command also installs all necessary dependencies you need to run the Concerto CLI.

Test your install

Run the CLI help command:

concerto --help

If Concerto has been successfully installed you will see output like this:

concerto <cmd> [args]

concerto validate validate JSON against model files
concerto compile generate code for a target platform
concerto get save local copies of external model dependencies
concerto parse parse a cto string to a JSON syntax tree
concerto print print a JSON syntax tree to a cto string
concerto version <release> modify the version of one or more model files
concerto compare compare two Concerto model files
concerto infer generate a concerto model from a source schema
concerto generate <mode> generate a sample JSON object for a concept

--version Show version number [boolean]
-v, --verbose [default: false]
--help Show help [boolean]

Create your first Concerto model

Note, if you use the VSCode IDE you can install the Accord Project (Concerto) extension to benefit from syntax highlighting, compilation, and more.

Open a code or text editor and create a plain text file, with the contents:

namespace test@1.0.0

concept Person identified by email {
o String email
o DateTime dob

Save the file as test.cto.

Generate a sample instance of the model

Run the Concerto CLI generate sample command to generate an instance of the test@1.0.0.Person concept:

concerto generate sample --model test.cto --concept test@1.0.0.Person

The output should be similar to:

"$class": "test@1.0.0.Person",
"email": "resource1",
"dob": "2022-12-13T10:46:46.109Z"

Save this output as person.json.

Validate data using your data model

Modify person.json to remove the dob property and save the file:

"$class": "test@1.0.0.Person",
"email": "resource1",

Run the CLI command:

concerto validate --input person.json --model test.cto 

The output should be:

10:50:57 - INFO: Input is invalid
10:50:57 - ERROR: The instance "test@1.0.0.Person#resource1" is missing the required field "dob".

Indicating that the person.json instance of test@1.0.0.Person is invalid with respect to the model.

Now modify test.cto to declare that the dob property is optional:

namespace test@1.0.0

concept Person identified by email {
o String email
o DateTime dob optional

Rerun the validate command:

concerto validate --input person.json --model test.cto 

The output should now be:

10:53:43 - INFO: Input is valid


Well done, you've created your first Concerto model and used the CLI to validate data against the model! This is just the start...

You may want to continue to read about static code generation, or using the JavaScript runtime API to introspect models at runtime.