InPost REST APIs

For API access, obtain an InPost client_id and client_secret by contacting the Integration Team with the scopes you need, as described in Authentication. InPost is also rolling out self-service app setup in the Merchant Portal. Use those app credentials to mint OAuth 2.1 access tokens via the token endpoint, using either the client credentials flow for server-to-server integrations or the authorization code flow with PKCE for broker apps acting on behalf of users.