# LeaderSSL Partner API > HTTPS API for LeaderSSL partners (resellers): list the SSL certificate products and your prices, order certificates, run domain control validation (DCV), download, reissue and cancel certificates, and read the account balance. Base URL: https://api.leaderssl.com - Sign in with POST /api/v1/users/signin (login and password) and send the returned auth_token in the X-AUTH-TOKEN header of every other call. Store the token and sign in again only when a call answers HTTP 401. - Every POST /api/v1/order is a new certificate order and is billed. To get a new certificate for an existing order (a new private key, or coverage until the end of a multi-year subscription), call POST /api/v1/ssl_certificates/{certificate_id}/reissue instead. A reissue is not charged. - A reissue is finished when the downloaded certificate has a new serial number. Meanwhile the status call can keep showing "issued" for the previous certificate. - Change DCV, resend DCV and cancel answer HTTP 200 also when the action is refused: check the success field. - The prolongation_token of a certificate (POST /api/v1/ssl_certificates/{certificate_id}/prolong, also listed by GET /api/v1/ssl_certificates) is a credential: its continue_order link signs the visitor in as your account. Never pass it to customers or third parties. ## Docs - [API reference (Markdown)](https://api.leaderssl.com/doc.md): every call with its parameters, responses, errors and curl examples - [API reference (web page)](https://api.leaderssl.com/): the same reference as HTML - [OpenAPI 3.1 description](https://api.leaderssl.com/openapi.json): the same calls in machine-readable form