History Is The Append-Only Log: The Objects Are Immutable And The Reference Is Not
Summary
The brief that dissolves a tension between two of this site's own published rules. Revocation-as-a-signed-append and size-bounded records pull against each other only while the entry is treated as a record that accumulates; seen as a file inside a commit graph, the two rules govern different structures and the conflict disappears. It also corrects a comfortable assumption: blobs, trees and commits are content-addressed and immutable, but branch references are mutable and a history reset is a shipped command — so append-only history is a policy about one pointer, not a property of the store. The fix is the site's own standard: publish the head, signed and dated, so a rewrite becomes falsifiable by any reader who kept the last one. And it names the register's central query — what did this identity look like on this date — as the one piece with no command behind it.
Key concepts
- Two append-only structures — the commit graph gated by the write key, the lane open to token holders — rule 1 as topology, not policy
- The reference is mutable — objects cannot be altered undetectably; the pointer that selects them can be moved
- Publish the head — turning an append-only promise into something a reader can falsify
- The missing traversal — path-scoped history is the register's product and has no command
Key ideas
- A third party has nowhere to write into the owner's record — that is a stronger form of rule 1 than a rule can be.
- The entry file carries current state and no history array; a consumer wanting the answer fetches one object, one wanting the story clones.
- Content addressing makes the traversal a hash comparison per commit rather than a diff, so it is cheaper than it looks.
- A mandate's trust ceiling is its issuer's, not its subject's — and it will read as a defect the first time a familiar agent resolves to an unrecognised mandate.
On this site
Folded into the MVP pack as change-control entries C7 and C8, and into the rules page as the proposed fifth rule about the reference.