The case that your agent transcript is now a pointer into somebody else's database

Inference APIs increasingly return a mixture of text and provider-bound state that is deliberately non-portable. Opaque reasoning blobs, hosted searches whose retrieved passages the client never sees, compaction only the original provider can decrypt. The piece states: "A better term is provider-sealed state," because "this encryption does not hide the data from the inference provider; it hides it from you." Attached is a five-part test more useful than the coinage, asking of any session whether it supports Inspection, Export, Replay, Audit and Deletion. Vendor documentation shows the opacity is a choice: OpenAI's server-side compaction is "opaque and not intended to be human-interpretable," while Anthropic's returns a compaction block with a readable content field.

Why it matters: The harness primitive holds the model constant and improves two external levers, context and tools. This argues both are being withdrawn from the harness builder. The operational version: if a subagent leaks a secret or edits the wrong file, can you say what it was asked to do? On the hosted multi-agent path, the piece reports, "Codex's own InterAgentCommunication.content is empty." Weigh it knowing the author is an agent-tooling vendor arguing for portable agent tooling, and that every technical claim is his reading of vendor documentation, independently corroborated by nobody here.