01 / The repeated work
Long shared prefixes should not be processed from zero every time.
Tool definitions, system instructions, repository context, and conversation history often repeat between requests. Astronomical records exact decoder state at fixed 2,048-token boundaries in a bounded persistent store. A matching future prefix can resume from that state instead of replaying every earlier token.
02 / Measured
Miss once. Publish state. Hit on the identical request.
Lookup misses. The model processes the prompt and publishes one complete state block.
MISSThe identical prefix matches. One block returns directly to live decoder state.
2,048 SAVEDThe acceptance compares cold and restored output token IDs, not only a hit counter. This guards against a fast restore that resumes from the wrong model state.
03 / The MTP boundary
Persistent target state and speculative state are not interchangeable.
The current persistent format stores target decoder state. It does not store the shifted request history used by multi-token prediction. Restoring target state into an active speculative request would therefore combine incompatible histories.
Astronomical resolves this without disabling reuse: when persistent prompt storage is available, the request uses target-only execution. When it is unavailable, an eligible highest-logit request can use multi-token prediction normally.
Never trade correct model state for speculative speed. Reuse the compatible target path instead.
04 / What it means
The cache behavior is proven. Universal speedup is not.
The result proves persistent publication, lookup, state restoration, and output parity through the real supervisor and worker path. The amount of wall-clock acceleration depends on prompt length, model, memory ceiling, existing operating-system file pages, and storage.
A representative public performance claim still requires approximately 1,000 generated tokens and explicit cold/warm methodology. This report therefore publishes tokens avoided, not a universal percentage speedup.