• If you are running API Platform on development machine which does not have valid TLS certificate, add NODE_TLS_REJECT_UNAUTHORIZED=0 before running client-generator
NODE_TLS_REJECT_UNAUTHORIZED=0 npx @api-platform/client-generator --generator typescript src/
  • The generator does not perform any authentication, so you must ensure that all referenced Hydra paths for your API are accessible anonymously. If you are using API Platform this will at least include:
api_entrypoint                             ANY      ANY      ANY    /{index}.{_format}
api_doc                                    ANY      ANY      ANY    /docs.{_format}
api_jsonld_context                         ANY      ANY      ANY    /contexts/{shortName}.{_format}
  • If you receive Error: The class doesn't exist. you may have specified the documentation URL instead of the entrypoint. For example if you are using API Platform and your documentation URL is at the entry point is likely at You can see an example of the expected response from an entrypoint in your browser by visiting
  • If you receive TypeError: Cannot read property '@type' of undefined or TypeError: Cannot read property '0' of undefined check that the URL you specified is accessible and returns jsonld. You can check from the command line you are using by running something like curl
  • If you receive a message like this:
{ Error
at done (/usr/local/share/.config/yarn/global/node_modules/jsonld/js/jsonld.js:6851:19)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)
name: 'jsonld.InvalidUrl',
message: 'Dereferencing a URL did not result in a JSON object. The response was valid JSON, but it was not a JSON object.',
{ code: 'invalid remote context',
 url: '',
 cause: null } }

Check access to the specified URL, in this case, use curl to check access and the response curl In the above case an "Access Denied" message in JSON format was being returned.