HORIZON SHIELD / mould
An open ledger · free · rates nobody

Record the mould,
not the letter.

A compositor finds a flaw in one cast letter and files it smooth. The matrix that cast it goes back in the drawer, ready to cast the same flaw into the next hundred. A fix repairs one casting. The mould that cast it sits untouched unless somebody goes looking.

This ledger records four things about a fix and freezes them: the class of assumption behind it, where the author searched for that same assumption, what they found at each place, and at what volume each casting failed. Append only. Every record carries a SHA-256 you can recompute yourself.

The category was named by Federico Blanco Sanchez-Llanos in "The Mould, Not the Letter", 2026-08-20. He wrote that it was category formation rather than commentary. We took that literally and built the place to keep it.

What a record holds

Four fields, and nothing that resembles a score. A record is a description of a search, written by the person who did or did not do it.

classThe assumption, written so someone could search a codebase for it. Not a description of the symptom. "A model response is always a string" is a class. "The endpoint returned 500" is not.
searchedThe space the author says they searched. Naming it is the whole point. This ledger does not verify that the search happened.
foundPer location: already_correct, fixed, absent, or live. A location where the correct handling already existed is the sharpest kind of finding: the mould had been recut once, in one file, and nobody carried it to the others.
volumeloud if it threw or returned an error. quiet if it degraded without complaining.

The same mould does not cast identical failures

It casts the same flaw at different volumes. One casting throws a 500 and gets fixed within the hour of being noticed. Another one, from the same mould, never throws: a helper quietly turns an object into [object Object], a classifier finds no match, and a record silently loses fifteen points. Nothing errors. Nothing logs.

The instance you notice is the loudest one, not the worst one. A quiet casting survives precisely because it never complains, which means a bug-driven search always finds the wrong member of the family first. That is why the volume column exists, and why a record is worth writing even when nothing broke.

A record with an empty search list is published as such

This is the rule the ledger exists for.

If you fixed the instance and never went looking for the class, say so and submit it. The record is accepted, published with an empty search list, and marked on this page in amber. It is not rejected. It is not hidden. It is not ranked below a thorough one, because there is no ranking here at all.

A ledger that only accepted diligent entries would record nothing but diligence, and would therefore be worth nothing. The honest shape of this problem is that almost nobody searches for the class. A place that cannot say so is not a record of the problem, it is an advertisement.

Records

Drawn live from the ledger every time this page opens. Nothing on this page is baked in, because a page with the numbers frozen into it goes stale while the ledger moves and nobody notices.

Reading the ledger.

Record one

Open an issue. That is the whole procedure. A workflow sends the ledger one thing — the issue number — and the gate then fetches your issue from GitHub itself and records what GitHub shows. It replies in the issue with the record id and its hash. No account here, no fee, no review queue, and no way to pay for anything.

Record a mould

What that establishes: GitHub authenticated your account, and the gate read your words from GitHub directly rather than being handed them. What it does not establish: that the search you describe actually happened. Nobody checked. The record says so in its own body, in the field submission.what_this_establishes.

There is no write key anywhere in this path. POST /mould/from-issue takes an issue number and nothing else — you cannot supply the content, so there is nothing to forge, and there is no shared token that can leak or be handed to the wrong person. We considered issuing one, and then removed the need for it. A credential that does not exist cannot be stolen and does not have to be rotated.

Records are append only. Once written, a record is never edited or deleted, including by its author, including if the issue is closed. Write it as something you are willing to leave standing.

What this is not

Read it as a machine

An agent should not have to read this page. Two routes, no key, no account, CORS open.

curl -s https://gate.horizonshield.dev/mould
curl -s https://gate.horizonshield.dev/mould/mould-0001

Every record carries record_sha256 and the instructions to reproduce it. Remove the record_sha256 and recompute_note fields, serialise the remainder in the order returned, take the SHA-256, and it must match. If it does not, the record has been altered and we would want to know before you do.