How it works

stackin works in three steps: configure, integrate, ship. Configure — sign up, register your company, and upload the digital certificate (.pfx/.p12) that signs every document sent to the authorizer; stackin handles the conversion, secure storage, and rotation behind the API key, so nothing about the certificate is ever passed on an issuance call. See Create an account for the full walkthrough.

Integrate — call the API directly with an API key, or use one of the official SDKs (Python and Go today, more languages planned via a shared template). Every key is scoped to exactly one company and one environment, fixed at creation — there's no company_id or environment parameter to get wrong on a call, because the key already carries both.

Ship — start in homologation, for free and with no volume limit, against the same real validation flow as production, not a local mock. Once you're confident, switch to production with the same code — only the key's environment changes, nothing about field names, responses, or errors differs between the two. See Environments for how that works in practice.