# Chat retrieval: authority map and cut

Serves `gamecult-chat:follow_up:chat-s732-733` (Meta, #swarm, 2026-11-01).
Extends `prose-knowledge-target.md` §4. Written by Imagination (Self, run
`mind-20261101T073859496Z`) against Huginn `55484c0`. Nothing here is built. See Status for what changed after writing.

## What changed since §4

§4 rejected "a second prose index in Huginn" because VoidBot owned prose
retrieval. Ruling `eureka-body:ruling:huginn-owns-prose-retrieval` moved it, and
Huginn now has the index: `huginn-daemon/src/sources` (collection
`huginn_sources`, one writer `refresh` run by the `huginn-sources` oneshot, the
daemon only reads through `sources::search`). The rejection stands in a new
form: **chat joins that organ; there is no second collection, embedder, writer
or search path.**

## Current mechanism (read, not guessed)

- `sources::search` (sources/mod.rs:439) embeds ONE text, `Instruct:`-prefixed,
  and asks `SourceIndex::search_sources` for the nearest chunks. `SourceQuery`
  (huginn-mind wire.rs:187) is `{text: Line, top_k, repo}`; `Line` is 1,000
  bytes, so a long brief cannot even be sent whole, and a clipped brief is one
  vector that averages its topics. That is the "long briefs retrieve poorly".
- `Embedder::embed(&[String])` already takes a batch (index/mod.rs:209).
- `SourcesMeta.corpus` is the constant `forge:GameCult`; cursors are
  `BTreeMap<repo, commit>` written whole by the job alone, advanced only after
  acknowledged upserts, dropped before a repo's first delete (sources/mod.rs:9-18).
- A Persona turn's recall (`mind-body/src/recall.rs`) reads only her own mind
  and "reads no chat"; ruling `persona-memory-written-not-transcript` says what
  she must keep is written as memory, not recovered from a transcript. The
  Persona call was tool-less when this was written and retrieval had to arrive
  in her input; that premise no longer holds: Personas have a shell and run
  `huginn sources` (see Ruling below).
- Matrix: Synapse is the truth of events. Only the Bifrost mouth holds Matrix
  tokens; no Persona unit holds a credential. Rooms are plain (F2 recommends
  encrypted DMs only), DMs exist, and the Discord bridge is a later campaign.
  Rulings `no-discord-ingestion` and `discord-taints-training` are in force.

## Authority map

| Decision | Owner | Forbidden writers |
| --- | --- | --- |
| Which events exist, who sent them, redactions | Synapse | Huginn, Bifrost mouth |
| Which rooms are in the corpus | Huginn `sources` config: the rooms the reader user is joined to, minus an in-code exclusion (DM flag; `#users`, `#members`, `#patrons` by id and alias) as a second lock (`gamecult-chat:ruling:chat-index-minds-rooms`) | any Persona, any query |
| Chunks, vectors, cursors for rooms | `sources::refresh`, the one writer | the daemon's `search`, Persona units |
| Query embedding and rank fusion | `sources::search` | the caller (Persona, CLI) |
| What a Persona sees from chat | her own lookup: she runs `huginn sources`; no recall lane, nothing is pushed into her input | the index writer, any per-turn injection |
| Reader roster (which rooms the reader joins) | one owner per thing: mechanism `gamecult-chat:follow_up:chat-reader-roster-script-r3`, data `gamecult-chat:follow_up:chat-reader-roster-rooms-r4` | the ingest job, any Persona |
| Discord exclusion | the room scope plus an ingest refusal (below), both in `refresh` | nothing downstream may be relied on to filter |

One cursor map, keyed by source id (`repo name` or `room id`); a room cursor is
the last event the collection holds, advanced only after acknowledged upserts,
exactly as a repo's commit is. Two further key kinds live in the same map:
`chat:` room cursors carry the chat version, which includes the credential
scrub version (`huginn_mind::redact`, applied to every body before chunking),
and `chat-purge:<room id>` tombstones record steward purge windows, applied by
the next run. The `chat-purge` subcommand needs only host-level run rights;
host admin is the trust root (`gamecult-chat:follow_up:chat-reader-roster-script-r3`).
Chat search indexes text and links only, never audio or other media. Payload gains `corpus` (`forge` or `chat`) so a
query can filter; `SourcesMeta.corpus` becomes the set both write under, which
is a collection rebuild once (the meta already forces rebuild on mismatch).

## Citations

A chat chunk is a window of consecutive messages in one room (bounded by bytes
and a time gap), so a hit cites: room id and alias, the first and last event id
in the window, each message's sender mxid and timestamp inside the chunk text.
Hits are `huginn sources` output, cited by room alias or id, event id and
timestamp; the caller reads them as lookup results, and nothing renders them
into a Persona turn. Edits replace by event id; a redaction
deletes the chunk window's points and re-chunks the window without it.

## Cuts, smallest first

1. **multi-text-query** (no chat needed). `SourceQuery` gains `texts` (1..8
   Lines) beside, then replacing, `text`; `search` embeds all in one
   `embed` batch, asks `search_sources` per vector, fuses by reciprocal rank
   `score = Σ 1/(k + rank_i)`, k=60 (Cormack, Clarke, Büttcher, SIGIR 2009; k=60
   is their value, and the one place to calibrate), de-duplicates by chunk id,
   returns `top_k`. Negative checks: one text gives exactly today's order and
   hits; a chunk first in two lists outranks one first in a single list;
   duplicated text does not double-count; more than 8 texts or an empty one is
   refused naming the field.
2. **chat-ingest**. Port `RoomHistory` (rooms, events after a token); chunker
   for message windows; room cursors; redaction; joined-room scope. Negative checks,
   each a test that fails when the rule breaks: a room the reader has not joined,
   or an excluded room, is never read; a room carrying a bridge state event (`m.bridge` /
   `uk.half-shot.bridge`) or a sender in a bridge's puppet namespace is refused
   whole and named in the journal; an encrypted event is skipped, never stored
   as ciphertext; a DM room is refused even if listed; a redacted event's text
   is absent from every point after the next refresh; a failed upsert leaves
   the cursor where it was. A grep over the collection payload for the Discord
   puppet pattern returns nothing.
3. **persona-chat-recall: dropped.** No recall lane; a Persona has a shell
   and runs `huginn sources` (`gamecult-chat:ruling:chat-recall-lookup-not-memory-dms-out`).
   The recall lane's DM check went with it; cut 2's DM refusal above stands, and the index covers joined rooms minus DMs and
   `#users`/`#members`/`#patrons`, Discord never.

Cut 1 ships alone and improves every `huginn sources` caller. Cut 2 waits on
questions 1 and 2 (both answered, see Status).

## Questions (put to the operator; admitted as questions)

1. Credential: who reads Synapse? Answered
   (`gamecult-chat:ruling:chat-index-synapse-credential`, "I take both recs."):
   the recommendation below stands. Recommend a read-only service user, joined
   only to the rooms that qualify under question 2's ruling, its token a systemd credential on the
   refresh job only. Alternatives: Bifrost exports history over typed CultNet
   (one more server in the path), or Synapse admin API (broader than needed).
2. Scope: public community rooms only (recommended) or also Persona-visible
   private rooms. DMs stay out either way. Answered public-only
   (`gamecult-chat:ruling:chat-index-room-scope`); superseded for rooms by
   `gamecult-chat:ruling:chat-index-minds-rooms`: every room the reader is
   joined to, minus DMs, `#users`, `#members` and `#patrons`; Discord never.
3. Recall tension: answered. Lookup, not memory, no recall lane
   (`gamecult-chat:ruling:chat-recall-lookup-not-memory-dms-out`).

Confidence: cut 1 and the owner decision, high. The window chunker size and
k=60 are calibration, not design; RRF over a handful of lists is the
established baseline and I did not survey learned fusion (it needs training
data we lack).

## Status (head-maintainer pass, 2026-11-05, Huginn `25199c9`)

Checked against main on merge. Nothing in this map is built: no `texts` on
`SourceQuery`, no chat code under `sources/`. The anchors above were corrected.
What changed since the map was written:

- Questions 1 and 2 are answered with the recommendations
  (`gamecult-chat:ruling:chat-index-synapse-credential`, operator 2026-11-03,
  "I take both recs."; `gamecult-chat:ruling:chat-index-room-scope`,
  public-only, since superseded by `gamecult-chat:ruling:chat-index-minds-rooms`). Question 3 is ruled (see Ruling below).
- Cut 3 is dropped (see Ruling below).

## Ruling (2026-11-11)

`gamecult-chat:ruling:chat-recall-lookup-not-memory-dms-out`:

- Chat retrieval is conversation lookup, not memory. There is no Persona recall
  lane; Personas have a shell and run `huginn sources`. What a Mind keeps is
  written memory (`persona-memory-written-not-transcript`).
- DMs never enter the index; the index covers the rooms the reader is joined to,
  minus DMs and `#users`/`#members`/`#patrons`
  (`gamecult-chat:ruling:chat-index-minds-rooms`), Discord never.
- A Mind that must remember DM content writes a memory citing the chat or room
  id as its source; the index is not where DM content is kept.

## Status: read side (cut chat-search)

Built: `huginn chat search [TEXT]... [--room R]... [--after T] [--before T] [--top-k N] [--json]`
over request `SearchChat` (`sources::search_chat`), listing oldest first without
texts and ranking by meaning with them. The chat point's shape is `ChatPayload`
(`sources/mod.rs`); every point carries `corpus` (`forge` or `chat`) and
`SourcesMeta.corpus` is `forge:GameCult+chat:rooms`. Not built: the ingest job
that writes chat points through `upsert_chat`, and the event-id window. Until the
ingest lands the collection holds no chat points and a chat search answers empty.
In a listing across rooms, the last hit's `ts_end_ms + 1` can repeat messages of
an earlier-starting longer chunk of another room; within one room it continues
exactly.

Known limits (owner of the fix: cut chat-window). Hits are ordered by their
trimmed start, not by the stored chunk start, and a long chunk trimmed to a span
that crosses rooms can be listed again by the continuation `--after`. Behaviour
is deliberately unchanged here; the event-id window in cut chat-window replaces
the time cursor.

`huginn chat window <EVENT_ID> [--before N] [--after N]` (cut chat-window) reads
the cited message and its neighbours in the same room from this index, no
embedder and no Synapse; an id the index lacks is refused naming `event_id`.
The listing limit above is not changed by it: the cut spec does not assign that
fix, so it stays open.

## Status: ingest core (cut chat-ingest-core)

`sources::chat::refresh_chat` writes chat points; scope is `sources/room_scope.rs`
and the credential scrub is `huginn_mind::redact`. Rules the code holds, which a
reader of the index must know:

- A text edit changes the stored body in place, only when its sender is the
  original's sender. Edits are never stored as events, so no payload field
  records which edit changed a body.
- **Rebuild on an unknown redaction.** A redaction whose target is neither a
  message in the room's stored chunks nor an event of the same page may be of an
  edit whose own id Huginn never stored, so the body that edit set cannot be
  taken back from the chunk. The room is then rebuilt: its points and cursor are
  purged and the next read re-ingests its history from the port. Synapse serves a
  redacted edit without its content (verified against Synapse 1.164.1), so the
  original body returns and the edited text does not. Within one page, a redacted
  edit is reverted in the fold without a rebuild. Redactions the rebuild itself
  replays do not trigger another rebuild. A redaction of a media or state event
  also lands here (the cost is one rebuild of that room).
- **Edits of a redacted original are dropped.** Synapse keeps serving the
  edits of a redacted original, with their replacement text, so Huginn drops any
  edit whose target is not a message it holds or has just read (a redacted,
  purged, never-stored or unknown original), live or late, in the fold and in a
  rebuild alike.
- How the Matrix port maps a pruned event (`content: {}`) to `EventKind::Other`
  is the ingest-job cut's to pin; this core only assumes it does.
- An error reading a joined room's facts is not a reclassification: the room
  keeps its points and cursor, and the run's report for the room says why.