boxmaker/docs/specs/2026-09-24-m5a-local-memory.md

# M5a design: local memory

Status: draft for the owner's review, 2026-09-24, revised the same day: memory writes need no
approval (P21, proposed). It rests on the brief as changed by P17 to P20 (applied 2026-09-24,
`docs/decisions.md`) and P21: memory is three files read into the baseline, edited by the agent
through a `memory` tool without questions, as Hermes does; a new role, `memoryd`, owns the files and a full-text index; and
M5 is split into M5a (this), M5b (Honcho) and M5c (the scheduler). Owner's decisions of
2026-09-24, beyond those: `soul.md` starts from a generic file shipped in the repository, and
`memory.md` and `user.md` start empty; and compaction (new epochs) comes with the scheduler in
M5c. Until then every session has one epoch, so this spec says "the next session" where the
brief says "the next epoch". Over Mattermost every thread is a session, so a new thread is a new
session.

Facts this rests on, checked on 2026-09-24:

- `rusqlite` 0.40.2 (MIT, 2026-08-08; crates.io) with the `bundled` feature compiles SQLite from
  source, and its build script always defines `SQLITE_ENABLE_FTS5` in that mode (the
  `libsqlite3-sys` `build.rs`). No system SQLite is needed.
- `loopd` has no epochs yet: `Session::create` writes `0.baseline.json` and `0.jsonl`, and a full
  context ends in `TurnError::SessionFull`. The baseline is saved once per session and replayed
  from that file, so whatever goes into it is frozen for the session's life.
- Every tool result in a session log records its `class` and `untrusted` label
  (`LogRecord::ToolResult`), so a session's taint at any record can be worked out from the log.

## 1. What M5a proves

1. A fact from one session is recalled in another.
2. An entry moved out of `memory.md` by `consolidate` is found by `recall`.
3. A memory write reaches the prompt only in the next session; a session already running keeps
   the bytes it started with. No write asks the owner anything.
4. A write from a session that has seen untrusted content lands in the archive, labelled
   untrusted, and never in the prompt.
5. The baseline with the starter `soul.md` stays at 3,000 tokens or less, measured on the device.
6. A hit from a session that had seen untrusted content comes back marked untrusted.
7. The owner can list every write (`bxctl memory log`), and undo the latest one of a file.

## 2. Components

| Piece | Change |
|---|---|
| `memoryd` (new crate) | Owns `memory/` and `index/`. Serves the memory block to `loopd`, runs `recall` and `memory` calls for `brokerd`, indexes session logs, rebuilds the index for `bxctl`. No network. |
| `proto` | Eight new message kinds (section 7); the `memory` tool's argument structs. |
| `loopd` | The baseline takes the memory block from `memoryd` instead of reading `memory/core.md`. `recall` and `memory` are core tools. After each finished turn it tells `memoryd` the session has new records. |
| `brokerd` | `recall` and `memory` are decided under built-in grants (both `auto`); a decided call goes to `memoryd` with the session's state, instead of a container. A result's label can only be made stricter by the runtime. |
| `bxctl` | `bxctl reindex`; `bxctl memory log`, `undo`, and, when review is on, `pending`, `accept`, `reject`. |
| `config/soul.md` (new) | The generic starter persona. |

`memoryd` depends only on `proto` (and `rusqlite`), like every role.

## 3. The files

All under `{home}/memory/`, directory 0700, files 0600, owned by `memoryd`. The owner may edit
any of them with an editor; `soul.md` only ever that way.

| File | Written by | Limit | Starts as |
|---|---|---|---|
| `soul.md` | the owner | 4,000 characters | a copy of the starter (`[memory] soul_starter`, default `soul.md` next to the config file) |
| `memory.md` | `memoryd`, applying the agent's writes | 2,200 characters | empty |
| `user.md` | `memoryd`, applying the agent's writes | 1,375 characters | empty |
| `archive.md` | `memoryd`, appending moved and dropped entries, and writes from untrusted sessions | none | empty |
| `edits/YYYY-MM.jsonl` | `memoryd`, appending one line per applied edit | none | absent |
| `pending.jsonl` | `memoryd`, when review is on (section 5) | none | absent |
| `recalls/YYYY-MM.jsonl` | `memoryd`, appending one line per `recall` | none | absent |

At startup `memoryd` creates what is missing and never overwrites anything. Characters are
counted with `chars()`. Limits are on the file's text.

**Entries.** `memory.md` and `user.md` are lists of entries separated by a line holding only `§`
(as Hermes does). An entry is trimmed, is not empty, and may span lines, but may not contain a
line holding only `§`. Two identical entries in one file are refused.

**`archive.md`.** Append-only. Each entry starts with one header line saying how it got there:

```text
§ moved 2026-09-24T20:14Z from memory.md in session mm-y73sxj3popgwumyccptb56p1ah
<the entry>
§ dropped 2026-09-24T20:14Z from memory.md in session mm-y73sxj3popgwumyccptb56p1ah
<the entry>
§ written 2026-09-24T21:02Z for user.md in session mm-dh45qg… · untrusted
<the entry>
```

Nothing a write removes is lost: moved and dropped entries are archived, and the journal keeps
every before and after.

**The edit journal** (`edits/`) records every applied edit: its id (`YYYY-MM-DD-NNNN`), time,
session, call, action, file, where it went (`memory.md`, `user.md` or the archive), the entries
before and after, and whether the session had seen untrusted content. It is the history `archive.md` alone cannot give (when
an entry first appeared), and the record an owner reads when a memory looks wrong. **The recall
log** (`recalls/`) records time, session, query, and the source of every hit, and the queries that
found nothing: hit counts for M5c's tiering job are worked out from it, so they survive a reindex.

## 4. The memory block

At the start of each session `loopd` asks `memoryd` for the block and appends it to the system
prompt, after `system.md` and a blank line. `memoryd` renders it:

```text
# soul.md
<soul.md, trimmed>

# memory.md (1,474 of 2,200 characters)
<entries, separated by a line holding only §>

# user.md (0 of 1,375 characters)
(empty)
```

The block goes into the session's saved baseline, so it is frozen for the session: a restarted
`loopd` replays the saved bytes whatever the files say by then (inference contract 2, "strict
extension"). Each entry of `memory.md` and `user.md` is checked again as the block is built
(section 5, "The check"); an entry that fails is left out of the block, and `memoryd` logs its
file and the reason. `soul.md` is the owner's and is not checked. `memoryd` refuses to serve the
block when a file is over its limit (the owner edited it) or unreadable; `loopd` then refuses to start the session, with the error and a pointer to the
runbook entry `memory-unavailable`. Existing sessions are unaffected. A starting session with no
memory, and no sign of it, is what this prevents; the M2b rule for `core.md` stays, moved.

`loopd` keeps no memory code: `memory/core.md` and the `core-memory-unreadable` entry go.

## 5. The tools

Both are core tools: declared in the `tools` array of every session, so the model never needs
`find_tool` for them. Their schemas count toward the baseline.

### `recall`

Arguments: `{"query": string, "k": integer}`; `query` 1 to 500 characters, `k` 1 to 10, default 5.

`memoryd` searches the index (section 6) and answers with at most `k` hits, best first, each with
its source and label, and each snippet at most 600 characters:

```text
[1] session mm-8ass9m…, 2026-09-20 14:02 UTC, the owner said · private
…the launch window moved to Thursday…
[2] archive.md, moved 2026-09-24 from memory.md · private
Owner prefers answers in UTC.
[3] session chat-1789…, 2026-09-21 09:15 UTC, the assistant said · private · untrusted
…
[4] session mm-dh45qg…, 2026-09-22 18:17 UTC, the assistant called · private
http_fetch {"url":"https://example.org/notes"}
```

`(no matches for "…")` when nothing is found. The query goes into FTS5 only as quoted terms: it
is split on anything that is not a letter or digit, each term is wrapped in double quotes, and the
terms are joined with `OR`, so no FTS5 operator from the model ever reaches SQLite. Ranking is
FTS5's `bm25`.

**The label.** The result's class is the highest class among the hits (at least `private`), and
it is untrusted if any hit is. `brokerd` combines that with the grant's label and keeps the
stricter of each (section 8).

### `memory`

Arguments, one of (`file` is `"memory"` or `"user"`):

```json
{"action": "add", "file": "memory", "text": "…"}
{"action": "replace", "file": "memory", "old": "<an entry, exactly>", "text": "…"}
{"action": "remove", "file": "user", "old": "<an entry, exactly>"}
{"action": "consolidate", "file": "memory", "entries": [
  {"old": "<an entry>", "keep": true},
  {"old": "<an entry>", "text": "<its rewrite>"},
  {"old": "<an entry>", "move": true},
  {"old": "<an entry>", "drop": true},
  {"text": "<a new entry>"}
]}
```

No write asks the owner anything (P21). Entries are named by their **full text**, never by number,
so the journal reads on its own, and an edit made against an old view of
the file fails safely: every `old` must match an entry of the file as it is now, exactly.

**Where a write goes.** `brokerd` sends each call with the session's state (section 7):

- In a session that has **not** seen untrusted content, the write applies to `memory.md` or
  `user.md`.
- In a session that **has**, only `add` is possible, and the entry is appended to `archive.md`
  with the header `§ written … · untrusted`, never to the file named. `recall` finds it, labelled
  untrusted; it never reaches the prompt on its own. The answer says so: `saved to the archive,
  not memory.md: this session has read untrusted content`. `replace`, `remove` and `consolidate`
  are refused with `this session has read untrusted content; it can add to the archive but not
  change memory.md`. The owner can move an archived entry into a file by editing it.

**Rules**, checked by `brokerd` when parsing (shape) and by `memoryd` when applying (content):

- `add`: the new file must fit its limit; a duplicate is refused.
- `replace`, `remove`: `old` must match exactly one entry. A removed entry is archived as dropped.
- `consolidate`: every current entry of the file must appear exactly once as an `old`, each with
  exactly one of `keep`, `text`, `move`, `drop`; entries with only `text` are new. The resulting
  file must fit its limit. Moved and dropped entries are appended to `archive.md` in the order
  given, with their headers.
- An edit that would go over the limit is refused with: `memory.md would be 2,350 of 2,200
  characters; use consolidate to move entries to the archive`. That sentence is fixed apart from
  the numbers and the file.

**The check.** Every new or rewritten entry is refused, with a fixed sentence naming which rule,
if it contains:

1. a control character other than newline and tab (C0, DEL, C1);
2. an invisible or direction-changing character (Unicode general category `Cf`: zero-width
   spaces and joiners, bidirectional controls, and the like);
3. chat-template markup: `<|` or `|>`, or `<think`, `</think`, `<tool_call`, `</tool_call`;
4. one of these phrases, ignoring case and runs of spaces: `ignore previous instructions`,
   `ignore all previous`, `disregard previous instructions`, `disregard all previous`,
   `new instructions:`, `system prompt:`.

The list is short and fixed on purpose: it is defence in depth, as Hermes' scan is. The archive
routing above is the real defence, because a pattern cannot tell a plausible planted fact from a
true one.

**Applying.** The file is written to a temporary file and renamed, then the journal line is
appended. The answer to the model: `memory.md updated (1,510 of 2,200 characters); it takes
effect in the next session`, or the archive sentence above.

**Seeing writes.** Writes are not posted anywhere (owner, 2026-09-24): the journal is the
record, and `bxctl memory log` shows it.

**Undo.** `bxctl memory log [N]` prints the last N edits (default 10) from the journal: id, time,
session, action, file. `bxctl memory undo <id>` reverts an edit if it is the **latest** edit of
its file and the file still holds exactly what that edit left: the file gets its entries back from
the journal, entries the edit archived stay in the archive (append-only), and the undo is itself
journalled. Anything else is refused with the reason, so an undo never overwrites a later change.

**Review (off by default).** With `[memory] review = true`, a write that would change `memory.md`
or `user.md` is appended to `pending.jsonl` instead, and the answer says it is waiting for the
owner. `bxctl memory pending` lists them; `bxctl memory accept <id>` applies one (with the same
checks, against the file as it is then); `bxctl memory reject <id>` discards it (journalled).
Writes to the archive are never staged.

## 6. The index

`{home}/index/memory.sqlite3`, directory 0700, file 0600, owned by `memoryd`. Disposable: deleting
it and restarting `memoryd`, or `bxctl reindex`, rebuilds it from `sessions/` and `archive.md`.

**What is indexed.** From session logs: the `content` of `User` records, of `Assistant` records
that have content, and each tool call the assistant made, as its tool name and arguments
(`read_file {"path":"/srv/notes/q3.txt"}`), so `recall` can answer "did we read that, and when".
Not tool results (the bulk of every log, and the way injected text arrives) and not
`reasoning_content`. A summary of a tool's output is M5c's (owner, 2026-09-24): it needs a model
to write it. From `archive.md`: every entry.
`memory.md` and `user.md` are not indexed: they are already in every prompt.

**Labels.** Walking a session log in order, `memoryd` keeps the session's label so far: the
highest `class` of any `ToolResult` before this record (at least `private`), and whether any was
untrusted. Each indexed record gets the label in force when it was written. A record whose class
is above `[index] max_class` (default `private`) is not indexed at all. Archive entries are
labelled `private`, and untrusted when their header says so; moved and dropped entries came from
`memory.md` or `user.md`, which only clean sessions write, so they are trusted.

**Keeping up.** The index stores, per session log, how many records it has read. After each
finished turn `loopd` sends `memoryd` `session_updated` with the session id (section 7), and
`memoryd` reads the records past that count. At startup it does the same for every log under
`sessions/`, so a turn missed while it was down is caught up. `memoryd` only ever reads
`sessions/`. A log it cannot parse is skipped with a log line naming it; it is `loopd`'s file, and
`loopd` reports damage itself.

Schema (one FTS5 table with the text, and a plain table for its metadata):

```sql
CREATE VIRTUAL TABLE hits USING fts5(text, tokenize = 'unicode61');
CREATE TABLE sources (rowid INTEGER PRIMARY KEY, kind TEXT, session TEXT, epoch INTEGER,
  record INTEGER, time TEXT, role TEXT, class TEXT, untrusted INTEGER);
CREATE TABLE progress (log TEXT PRIMARY KEY, records INTEGER);
```

## 7. Sockets and messages

| Socket | Default path | Peer | Messages |
|---|---|---|---|
| `loopd` | `{home}/run/loop-memory/memory.sock` | `loopd` | `memory_block` → `memory_block_reply`; `session_updated` → `ok` |
| `brokerd` | `{home}/run/broker-memory/memory.sock` | `brokerd` | `memory_call` → `tool_response` (the existing kind) |
| owner | `{home}/run/owner-memory/admin.sock` | `bxctl` | `reindex` → `reindexed`; `memory_admin` → `memory_admin_reply` |

Directories 0700, sockets 0600, stale sockets removed, as `brokerd`'s. One request per
connection, the existing frames (`proto::frame`, `MAX_FRAME`). New message kinds in `proto`:

| Kind | Body |
|---|---|
| `memory_block` | `{}` |
| `memory_block_reply` | `{"text": string}` |
| `session_updated` | `{"session": SessionId}` |
| `memory_call` | `{"request": ToolRequest, "taint": DataClass, "untrusted": bool}`: the decided call, with the session's state when `brokerd` decided it |
| `reindex` | `{}` |
| `reindexed` | `{"logs": u64, "records": u64, "archive": u64}` |
| `memory_admin` | `{"command": "log" \| "undo" \| "pending" \| "accept" \| "reject", "arg": string}` |
| `memory_admin_reply` | `{"text": string}` |

`brokerd`'s list of kinds grows from eighteen to twenty-six.

## 8. `brokerd`

- **Tools.** `ToolName` gains `Recall` and `Memory`; `ToolArgs` gains their parsed arguments
  (`proto` holds the serde structs, as for the other tools). Parsing enforces the shapes and
  limits in section 5. Neither tool has constraints (`paths`, `hosts`, `patterns` must be empty).
- **Grants: built in** (owner, 2026-09-24: reading and writing memory is what an agent is).
  `brokerd` holds two fixed grants, always present whatever is in `grants/`:

  ```toml
  # built in: recall
  tool = "recall"
  mode = "auto"
  max_taint = "secret"
  result_class = "private"
  untrusted = false
  ```

  ```toml
  # built in: memory
  tool = "memory"
  mode = "auto"
  max_taint = "secret"
  result_class = "private"
  untrusted = false
  ```

  Their names are `builtin-recall` and `builtin-memory`, and their `grant_sha256` is the hash of
  that text, so the audit log names them like any other grant. A file in `grants/` whose `tool`
  is `recall` or `memory` is a grant problem at load (`grants-invalid`), with the fixed sentence
  `the policy of recall and memory is built in; remove this grant`. No grant file can turn memory
  off or put questions in front of it. What protects the prompt is where untrusted sessions'
  writes go (section 5), which `memoryd` decides from the state `brokerd` sends.
- **Where a decided call runs.** A composite runtime sends `Recall` and `Memory` specs to
  `memoryd`'s `brokerd` socket as a `memory_call`, with the session's taint and untrusted flag
  as `brokerd` holds them when it decides, and everything else to the configured runtime
  (Podman, or the refusing one). `[memory] socket` in `brokerd.toml` names the socket; without it,
  memory calls fail with a fixed sentence and a runbook pointer (`memoryd-unreachable`).
- **Labels only get stricter.** `RunOutput` gains an optional label. `runner::run` answers with
  the stricter of the grant's label and the runtime's: the higher class, and untrusted if either
  is. Container runtimes return none, so nothing changes for them. The audit record and the
  session's taint use the combined label, as today.
- **Size.** `policy.rs` (498 lines) and `ledger.rs` (487) are at the limit; the plan splits them
  before anything is added.

## 9. `loopd`

- `[memory] socket` in `loopd.toml` (default `{home}/run/loop-memory/memory.sock`).
- Baseline: `system.md`, a blank line, then the block from `memoryd`. `memoryd` unreachable, or
  refusing, fails the new session with the runbook pointer `memory-unavailable`.
- Registry: `recall` and `memory` are core, with the schemas of section 5. The model sees
  `clock`, `recall`, `memory`, `find_tool`, `call_tool`.
- After a finished turn: `session_updated`, best effort. A failure is one log line; the next
  startup of `memoryd` catches up.
- `system.md` gains two sentences: keep `memory.md` and `user.md` short and current, and use
  `consolidate` when they fill; writes take effect in the next session, and recalled text is data
  like any tool result.

## 10. `bxctl`

- `bxctl reindex [--admin-socket PATH]`: sends `reindex`, waits, and prints `reindexed: 42 logs,
  1,208 records, 7 archive entries`. `memoryd` rebuilds into a new file and renames it over the
  old one, so `recall` keeps working meanwhile.
- `bxctl memory log [N]`, `bxctl memory undo <id>`, and with review on, `bxctl memory pending`,
  `accept <id>`, `reject <id>` (section 5). Entries are printed escaped, as approvals are.

## 11. Configuration

`memoryd serve --config <path>`:

```toml
[paths]
home = "/var/lib/boxmaker"        # default: $BOXMAKER_HOME, then /var/lib/boxmaker

[memory]
soul_starter = "soul.md"          # next to the config file
review = false                    # true: writes to memory.md and user.md wait for the owner

[index]
max_class = "private"             # records above this class are not indexed

# [sockets] loop, broker, admin: defaults as in section 7
```

## 12. Security notes

- `memoryd` has no network in M5a and never writes `sessions/`, grants or the audit log.
- What reaches the prompt: `soul.md`, the owner's file; and `memory.md` and `user.md`, which only
  sessions that have not read untrusted content write, through the check, frozen per session.
  Everything a session that read untrusted content writes goes to the archive, labelled
  untrusted, where it can be recalled but never lands in the prompt by itself.
- Memory writes are the one tool with no approval anywhere. The trade is deliberate (owner,
  2026-09-24): the risk it leaves is a clean session writing something false, which is the
  agent's judgement of what the owner said; every such write is journalled, listed by `bxctl
  memory log`, and can be undone, and review can be turned on.
- Recalled text is a tool result: appended, labelled, and it taints the session like any other.
  Tool results are not indexed, so a fetched page cannot come back through `recall`; what the
  assistant said after reading one can, marked untrusted.
- The FTS5 query is built only from quoted terms; the model's text is never SQL.
- Entries shown by `bxctl` are escaped (`proto::escape`), so an entry
  cannot render as markup or mention anyone.

## 13. Runbook

New entries: `memoryd-start-failed` (configuration, `memory/` or `index/` unusable),
`memory-unavailable` (a new session refused: `memoryd` down, a file unreadable or over its limit),
`memoryd-unreachable` (`brokerd` cannot reach it: memory calls fail), `memory-index-damaged`
(rebuild with `bxctl reindex`). `core-memory-unreadable` is removed.

## 14. Testing

Offline, in `make gate`:

- `memoryd`: entries parsing and rendering; each edit's rules, including a stale `old`, a
  duplicate, the limit sentence, and `consolidate` missing an entry or naming one twice; every
  rule of the check, on write and on building the block; routing by the session's state (an
  untrusted `add` to the archive, the other actions refused); the archive headers and journal
  lines; undo of the latest edit, and its refusal when the file changed; review on and off; the block; the quoted-terms query builder against FTS5 operators
  (`NEAR`, `*`, `^`, quotes, column filters); labels walked from a log; `max_class`; catching up
  from `progress`; a reindex equal to the incremental index; the recall log.
- `brokerd`: parsing both tools; the built-in grants present with an empty `grants/`; a grant
  file naming either tool refused at load; the session's state carried in `memory_call`; the composite runtime; the
  stricter label, with a runtime that returns a stricter and a laxer one.
- `loopd`: the baseline with a fake `memoryd`; the refusal and its pointer; `session_updated`
  sent after a finished turn and not after a turn ending in tool calls.
- `bxctl`: `reindex` and each `memory` command against a fake socket.

On the device (the owner's Mattermost, as for M4b): the baseline token count with the starter
soul; a fact told in one thread and recalled in another; an `add`, made with no question and listed by
`bxctl memory log`, that appears in a new thread and not in the thread that wrote it; a `consolidate` that
moves an entry, which `recall` then finds; a write after a fetched page that lands in the archive,
untrusted; `bxctl memory undo` of the latest edit.

## 15. For the owner's review

1. Decided: tool results are not indexed; tool calls are, by name and arguments (section 6).
   Summaries of a tool's output, where the tool opts in (a web fetch, say), come with M5c's
   summariser, labelled like the output they summarise.
2. Decided: memory writes need no approval (P21); the policy of `recall` and `memory` is built in
   and no grant file can change it (section 8). A session that read untrusted content writes only
   to the archive (section 5).
3. Decided: entries are named by their full text, not by number (section 5).
4. Decided: the starter `soul.md` is generic (section 3).
5. Open: the phrase list of the check (section 5) is short on purpose. Add phrases you have seen
   in the wild, or drop the list and keep only rules 1 to 3.
6. Decided: writes are not announced; `bxctl memory log` lists them (section 5).