tl;dr: Inference APIs are increasingly returning provider-sealed state—encrypted reasoning tokens, opaque compaction blobs, hidden web search context, and encrypted subagent messages—that locks sessions to a single provider and prevents users from exporting a self-contained transcript to another model. The author argues providers should make local logs canonical, keep hosted tools observable, ensure compaction and agent communication are readable/auditable, and treat distillation as legitimate rather than an "attack," so users retain the freedom to migrate sessions across models.