Apier blog

Plain-language developer guides to the systems behind Norwegian company authority. Each guide is written from the perspective of a developer integrating against the live system.

• Why REST APIs Fail for AI Agents — autonomous agents cannot read prose docs, reason through edge cases, recover from prose errors, or prove what they did. What an agent-native API does differently, and the AVERT loop that closes the gap.
• Altinn 3 Migration for Developers — what changed on June 19, 2026 when Altinn 2 closed for new delegations. Role-to-access-package mapping, System User setup, and a live Altinn 2 code lookup.
• Maskinporten for Developers — virksomhetssertifikat, JWK upload, JWT client-credentials flow, System Users, and the ten pitfalls that cost a day each.