You can find your partner API key here.
You can find your affiliate API key by clicking the "API Access" link on the affiliate menu.
Your partner or affiliate API keys should be sent in the api_key and api_secret fields in API calls.
If you have a RunSignup account, you can register your application to take advantage of our OAuth 1.0 authentication. This allows you to securely access user information via the API. To make API calls, you should use the standard OAuth authentication methods and leave the api_key, api_secret, tmp_key, and tmp_secret fields empty in API calls. To get started, Sign In or Create a New Account.