qdb

Thread Subject Record V1

This document defines the canonical append-only thread-subject record family: one event that sets the displayed title (subject) of an existing thread without rewriting the thread root post.

Scope and location

  • One ASCII text file represents one subject-set event.

  • Files live in records/thread-subjects/<record-id>.txt; the filename stem must match Record-ID, which keeps the thread-subject- prefix.

  • V1 supports Operation: set only. There is no clear or remove operation.

Format

Headers in Key: Value form, then one blank line, then an optional (usually empty) body.

  • Record-ID (required)

  • Created-At (required): RFC 3339 UTC, for example 2026-11-03T05:13:04Z; authoritative canonical time for ordering

  • Thread-ID (required): the root post ID of the target thread

  • Operation (required): set

  • Subject (required): the new title, one line, leading and trailing space trimmed

  • Author-Identity-ID (optional): openpgp: and 40 lowercase hex digits; present on authored records, absent on system records

  • Source-Post-ID and Source-Post-SHA256 (optional, together): the reply whose title: line produced this record and the SHA-256 of that reply's exact canonical bytes; one without the other is rejected

  • Action-At (optional): RFC 3339 UTC, milliseconds allowed

  • Intent-ID (optional): offline signed intent that produced the record

  • Reason (optional): short ASCII explanation

Two kinds of record

  • System records have no Author-Identity-ID. The media-embed title fetch writes them. They fill only an empty subject; the earliest one wins and none ever overrides a title a person gave.

  • Authored records carry Author-Identity-ID and normally reply provenance. The write path produces one only when the author had authority for that thread at write time (see the thread title concept). The latest authored record wins over the root post's own Subject header and over system records.

An authored record whose source reply is retracted or deleted is withdrawn: readers skip it and the previously effective title returns. A record whose Thread-ID is not a known root thread is counted invalid and ignored.

Example

text
Record-ID: thread-subject-20261103051500-2fa9fbd6
Created-At: 2026-11-03T05:15:00Z
Thread-ID: thread-20261103051304-2fa9fbd6
Operation: set
Subject: Retitle a thread from a reply
Author-Identity-ID: openpgp:0168ff20eb09c3ea6193bd3c92a73aa7d20a0954
Source-Post-ID: reply-20261103051500-7c1d2e3f
Source-Post-SHA256: 9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08
Reason: Title directive in reply

Signatures

A detached ASCII-armored OpenPGP signature may accompany the exact record bytes as <record-id>.txt.asc, verified against Author-Identity-ID. Unsigned records remain valid. Signing changes neither precedence nor authority.

Compatibility

Records written before this document (system records without provenance) remain valid and keep their fill-empty behavior. Readers that predate the provenance headers ignore unknown headers and still read the subject.