shiro-neko/docs/memory.md

Memory and state

Four kinds of state, each with a different lifetime.

State	Lives in	Survives
transcript	the message array	until /compact or /clear
task list	the system prompt, rebuilt each step	pruning and /compact
project memory	~/.shiro-neko/memory/<hash>.json	across sessions, forever
session record	~/.shiro-neko/sessions/<uuid>.json	until you delete it

The split exists because compaction is destructive. pruneMessages deletes tool results and /compact deletes the whole transcript, so anything recorded only in messages is lost exactly when a long task needs it most.

The practical rule: if it should survive this turn, todo_write it. If it should survive this session, remember it. The transcript is for the conversation, not for storage.

Project memory

Durable notes about the codebase, injected at the start of every session.

remember

kind  fact | decision | gotcha | command
text  one self-contained line

• fact — how something is. "The API is versioned under /v2."
• decision — what was chosen and why. "We use snake_case for DB columns; the ORM expects it."
• gotcha — a trap. "The migration must run before the seed or the FK fails."
• command — an invocation that works. "Tests run with bun test, not npm test."

Duplicates are refused. Text is capped at 400 characters, the store at 300 entries.

The kinds are not decoration: they are what the model reads back at boot, and they set how much to trust a note. A command is verifiable in one run. A decision explains why the obvious alternative was not taken, which is the thing a newcomer most often gets wrong.

"One self-contained line" is the part that matters most. A note reading "use the new approach" is worthless next session — there is no conversation left to say which approach.

recall

Every term must appear. A match increments that entry's hit count, which protects it from compaction later — an entry the agent actually uses is worth keeping verbatim.

AND rather than OR, on purpose: "migration seed order" should find the one note about that, not every note mentioning any of the three words. Returns the 15 most recent matches.

forget

Removes by substring, for a note that turned out wrong.

What the agent sees

What you learned about this project in earlier sessions. Trust it, but verify anything
that contradicts what you can see in the code now:
- (command) tests run with bun test, not npm test
- (gotcha) the migration must run before the seed
- (decision) snake_case for DB columns, the ORM expects it

Top 20 by hit count, then recency. The "verify anything that contradicts" line matters: memory goes stale and a confidently wrong note is worse than none.

Compacting

/memory has the model merge entries. Two rules make it safe:

• Entries with at least one recall are kept verbatim and never merged.
• A model returning nothing parseable leaves the store untouched.

Without the second rule a bad response wipes everything the agent has learned. The store also has to be past 60 entries with at least two unused ones before anything happens, so /memory on a small store is a deliberate no-op rather than a rewrite.

/notes lists the store with hit counts. --no-memory disables loading and writing.

Task list

todo_write replaces the whole list each call. Four states:

tasks ##########.............. 1/4  1 blocked
[x] read the pagination code
[~] fix the boundary
[ ] add a test
[!] update the docs  (no write access to the wiki)

blocked requires a note saying what is blocking it. The tool warns when more than one task is in_progress, when nothing is in_progress while work remains, or when a blocked task has no note.

The list is re-rendered into the system prompt on every step, not once per turn — a todo_write on step one has to be visible to step two. It is saved with the session and restored by -c or /resume.

/todos shows it. The panel above the input shows it live.

Sessions

Every turn autosaves, debounced 400 ms so a long tool loop does not hit the disk each step.

{
  "id": "0193ab2c-…",
  "createdAt": "…", "updatedAt": "…",
  "cwd": "/home/you/project",
  "provider": "openai", "model": "gpt-5",
  "title": "why does the pagination test fail?",
  "inputTokens": 48210, "outputTokens": 3105,
  "costUsd": 0.0913,
  "notebook": { "todos": [ … ] },
  "messages": [ … ]
}

shiro -c                  # newest session for this directory
shiro -r 0193ab2c         # by id or unique prefix

/sessions   list the last 15
/resume <id>
/save       write now instead of waiting for the debounce

A corrupt session file is skipped rather than crashing the list.

Ids are UUIDv7, so they sort by creation time and a prefix is usually enough to identify one. -c matches on cwd, so it picks up the newest session for this directory rather than the newest overall — two projects side by side do not steal each other's -c.

Resuming restores the messages and the task list, but not the model or agent variant: those come from the current config and flags. A session started with --agent deep resumes as default unless you pass it again.

Compaction

Two mechanisms.

Automatic, at roughly 120k estimated tokens: reasoning is stripped first, then older tool content is removed in a bounded ladder until the request fits. The SDK keeps that pruned view for later steps in the turn; local session history remains complete. One compacted event is reported per turn:

context compacted: 192 messages pruned to 15 on the wire

The status bar warns before that happens: context is shown as a percentage of the threshold, amber from two thirds, red at 90.

What gets discarded, in order: reasoning items first, then the oldest tool calls and results as needed. Recent exchanges are kept by the ladder, which lets a turn continue rather than restart.

Manual, /compact: the model writes a summary — goal, files touched, decisions, commands and outcomes, what remains — and it replaces the transcript entirely.

The difference is which history is destroyed. Automatic pruning touches the wire only, so scrolling back still shows everything and /save records everything. /compact replaces the real message array, so it is irreversible for that session.

Use /compact when a session has drifted across several unrelated tasks and the early part is noise. Let automatic pruning handle a single long task, since it keeps the recent work intact.

The pruning repair

Pruning breaks two provider invariants. src/prune.ts repairs both, and both were real 400s before it did.

A message without its reasoning item. pruneMessages({ reasoning: 'all' }) strips a reasoning item and keeps the message item from the same response. That message carries a provider itemId, and the OpenAI responses provider serialises anything with one as { type: 'item_reference', id } — a pointer to an item stored on their side, which depends on the reasoning item that is now gone:

400 Item 'msg_…' of type 'message' was provided without its required 'reasoning' item: 'rs_…'

The two carry different ids, so they cannot be matched by id. What links them is the assistant message they arrived in — one message is one response. detachOrphanedItems strips the itemId from those parts. Without one the same content is serialised inline, which carries no dependency on anything stored, so the turn survives intact.

Dropping the parts instead was the first attempt, and it was wrong in a way that only showed up over a long turn: on a reasoning model every tool call carries an itemId, so after the first compaction the model could no longer see what it had already run. It re-ran the same tools until the step limit ended the turn. The history is the model's memory; compaction may shorten it but must not blank it.

A tool result without its tool call. Tool pruning counts messages, not call/result pairs, so the cut can land between the assistant message holding a tool-call and the tool message answering it:

400 No tool call found for function call output with call_id call_…

dropOrphanedResults drops any result whose call id no longer survives. The reverse is left alone deliberately: a tool call still waiting for its result is what a suspended approval looks like, and dropping it would break /resume.

What compaction still does not do

It tells the model the history was pruned but not what was in it. A decision from forty messages ago can be contradicted with confidence, because from the model's side that span never existed. Summarising the discarded part is next on the list.

The threshold is also measured with JSON.stringify(messages).length / 4, which is an estimate. It is fine for deciding when to prune and wrong enough that it should not be read as a token count — the real numbers in /cost come from the provider.

Prompt history

Per-directory, capped at 200, deduplicated against the previous entry. Up and down in the input walk it; down past the newest restores what you were typing. While an @ token is open those keys move in the file picker instead.

Stored at ~/.shiro-neko/history/<hash>.json, where the hash is a SHA-256 prefix of the project path.

The prompt queue

Not persisted, and deliberately so. A prompt typed during a turn lives in memory until the turn ends, then runs. esc clears it along with aborting the turn, and quitting discards it — a queued thought that fires on next launch, against a workspace that has since changed, is worse than a lost one.