# Developers

- [HTML Widget](/developers/html-widget.md): Your campaign widget exposes various functionality to your site in order to create seamless onboarding experiences.
- [JS SDK](/developers/js-sdk.md): Created Identities and register Events in your application using \`THXAPIClient\` or rebuild the campaign widget in your own environment using \`THXBrowserClient\`.
- [Identity](/developers/js-sdk/identity.md): Use an Identity to assign Events in your system to THX users and build quests around it.  Learn how to connect an Identity to a THX account using your campaign widget.
- [Events](/developers/js-sdk/events.md): Create event data and configure custom quests for these events. Your users will be able to earn points for for example levelling up in your game.
- [API](/developers/api.md): Using the API keys and an OAuth2 grant you will be able to access API resources for your campaign.
- [API Specification](/developers/api/api-specification.md): Below we have listed the resources and their API specification that you should implement as part of the Identity & Event framework.
- [Example](/developers/api/example.md): Using the new and improved authentication method one can build their own campaign UI.
- [Webhooks](/developers/webhooks.md): Implement a public endpoint in your app and receive campaign events. Verify requests using the signing secret as in the given example. This is what protects the endpoint!
- [QR codes](/developers/qr-codes.md): Use QR codes to distribute rewards in offline environments.
- [Audits](/developers/audits.md): In June 2021 the team of security audit firm Pessimistic.io conducted an extensive on the state of our smart contracts as of commit b5587b48112e3b319212aef06264c1d38fbe1cad.