memware
Memory for AI agents that only remembers the latest truth.
memware is one SQLite file with two stores:
- turns — immutable evidence. Every prompt and answer from past sessions, split into ~400-token passages and indexed with FTS5. Recall ranks passages and quotes only the matching ones; reading a session back returns whole turns. BM25 × recency × use, no model in the loop.
- beliefs — a bi-temporal ledger of facts. A new value for the same
(subject, relation)supersedes the old one. Recall only ever returns the currently valid belief; history is kept for audit and never reaches a prompt.
No daemon, no vector database, and no model call at capture or read time unless you switch on the optional relevance filter. A 30-day corpus of a busy coding agent — 18k turns, 40k passages — indexes in about fourteen seconds into ~120 MB.
$ memware sync ~/.claude/projects --harness claude-code
{"added": 14348, "files": 1475}
$ memware assert "api" "listens on port" "8443" --source "session 3f2a, turn 41"
{"outcome": "superseded", "belief_id": 2, "incumbent_id": 1}
$ memware recall "which port does the api use" --what beliefs
api listens on port 8443 # 8080 is in the ledger, retired, and never surfaces
Why
Agent memory systems that rewrite what they remember degrade: continuous LLM consolidation can push utility below having no memory at all (Useful Memories Become Faulty When Continuously Updated by LLMs). And embeddings cannot tell a contradicted fact from a rephrased one — AUROC 0.59 — so vector stores serve stale facts 15–40% of the time on evolving knowledge (Temporal Validity in Retrieval Memory).
memware borrows four mechanisms from human memory research and keeps them deliberately small:
| mechanism | in the brain | in memware |
|---|---|---|
| evidence ≠ belief | hippocampus vs neocortex (complementary learning systems) | turn table is append-only; belief table is separate |
| update on surprise | reconsolidation driven by prediction error | memware assert at the moment an agent notices a conflict |
| only the latest understanding | reconsolidated traces overwrite in place | deterministic supersession keyed on (subject, relation), ordered by event time |
| need-probability recall | Anderson & Schooler 1991 / ACT-R activation | bm25 × (1+age)^-d × (1 + w·ln(1+uses)) |
Full rationale and citations: docs/design.md.
Install
The Claude Code plugin's hooks call memware as a bare command, so the CLI must be on
the PATH your shell uses — install it as a tool, not into a project virtualenv:
uv tool install "memware[mcp]" # recommended
# or
pipx install "memware[mcp]"
Then confirm the shim resolves (if this prints nothing, the hooks will silently do nothing):
memware --version
which memware
Plain pip install
pip install "memware[mcp]" works for library and CLI use, but a plain pip install into a
project or conda environment usually leaves memware off the PATH that Claude Code's hooks
run under — use uv tool or pipx (above) for the plugin, or install into an environment
that is always active. memware (core) omits the MCP server; drop [mcp] only if you do
not want the MCP tools.
Use it from Claude Code
claude plugin marketplace add ericwalisko/memware
claude plugin install memware@memware
claude mcp add -s user memware -- memware-mcp # optional tools; -s user = every project, not just this dir
Backfill your existing sessions (optional, once). The plugin only captures new sessions; index the transcripts already on disk so recall works over past work from day one:
memware backfill # indexes ~/.claude/projects (idempotent; ~5 s for a month)
Prefer a guided first run? memware setup walks through the backfill and backups together, asks
whether derive may run automatically, and prints the operating guidance. Run it on a fresh install
or after an upgrade. memware setup --yes accepts the defaults non-interactively and never
switches derive on.
The belief ledger starts empty and is not backfilled — beliefs are derived, not stored in
transcripts. It fills as you work (via the remember tool) and through memware derive,
which mines the indexed transcripts for durable facts — see Deriving beliefs.
Transcript recall is what backfill gives you immediately, and it is where most of the value is.
Requires the memware CLI on your PATH (see Install). Hooks:
a SessionStart hook catches up any session whose SessionEnd was skipped (some environments force-kill Claude Code — a worktree manager may SIGKILL it — and a kill cannot run SessionEnd); a second one injects memware digest, a short block with this project's recent sessions and beliefs and a line pointing at recall; SessionEnd/PreCompact sync the transcript into the index; an optional UserPromptSubmit
hook injects the handful of beliefs whose subject the prompt names, each with the date it was
recorded (beliefs only — transcript search is on demand through the MCP tools). Neither block
injects a derived measurement, moving version or status, or a version the project's manifest
overrules; memware beliefs --stale lists what they leave out. Set MEMWARE_DB to move the
store. Start a session with MEMWARE_NO_CAPTURE=1 to keep it out of the index and the backup
mirror: the hooks list its transcript, and every sync and backup skips what is listed. A session
that runs no memware hook cannot be recognised that way. See
docs/integrations.md and docs/keeping-memory-clean.md.
Deriving beliefs
memware derive --plan # no network: every excerpt a run would send, and where
memware derive # dry run: sends the excerpts to the model, prints the facts, files nothing
memware derive --apply # files them; runs again later from where it stopped
derive reads every turn from an interactive session indexed since its last run, has a model
turn the sentences that look like facts into (subject, relation, value) triples, and files only
the triples that pass a deterministic check: every word of the value must appear in the
excerpt, so a model cannot introduce a fact the evidence does not contain. Derived beliefs
carry reliability 0.5, below anything you stated yourself, so a contradiction lands in
memware review rather than on top of your belief.
The default provider is the Claude Code CLI on your own subscription (claude -p, Haiku),
so there is nothing to configure. --provider openai sends the extraction to any
OpenAI-compatible endpoint instead (OPENAI_BASE_URL / OPENAI_MODEL / OPENAI_API_KEY).
Interactive sessions only, by default. Claude Code records what started each session
(entrypoint: cli interactive, sdk-cli for claude -p), and derive skips the turns of
claude -p and Agent SDK runs. On a machine that runs agent lanes those are most of the
transcripts, and the eval scaffolding among them reads like fact. They stay indexed and
recallable; they just never become beliefs. If your headless runs hold decisions you want in
the ledger, opt them back in with memware config derive.sources all. A turn with no recorded
entrypoint (a transcript from before Claude Code wrote the field, or another harness) is read as
interactive, so nothing the filter cannot label is dropped. memware derive --plan prints the
setting and how many new turns each setting would read, and memware stats counts sessions,
turns and beliefs by entrypoint and names the project directories holding the most sessions.
A dry run is not offline: it sends the excerpts to that provider and skips only the write.
--plan is the view that sends nothing. It lists every excerpt a run would send with its
source pointer, then the session, excerpt, character and model-call counts and the
destination, and it works before claude or OPENAI_* is set up. Read it before you turn
derive on for transcripts that must not leave the machine.
You do not need an always-on machine. The plugin can run it for you on session start, at
most once a day. memware setup is where you switch that on: it shows where the excerpts go
before it asks. memware config derive.auto true sets the same switch directly. Other
options — a macOS LaunchAgent that catches up after sleep, a systemd timer with
Persistent=true, plain cron — are in docs/scheduling.md.
Use it from Hermes Agent
integrations/hermes/memware/ is a memory-provider plugin built on Hermes's
MemoryProvider ABC — prompt-time belief prefetch, non-blocking turn capture, and
memware_recall / memware_remember tools — sharing one store with Claude Code.
The supersession rule
same key, same value → reinforce (reliability rises, use is counted)
same key, newer value → supersede: incumbent gets valid_to = new.valid_from
same key, older value → filed as history; the timeline stays consistent
weaker challenger → parked as a candidate and sent to review
Ordering is decided by valid_from (when the evidence says it became true), never by
insertion order — so a backfill converges to the same state in any order, twice, or in
batches. Three policies: auto (last writer by event time), gate_conflicts
(default: a less reliable challenger goes to review), await_confirmation.
Recall is keyword search; the agent supplies the meaning
The index is FTS5/BM25 — fast, model-free, and literal. The recall tool therefore takes
several phrasings and fuses them by reciprocal rank, so a tool-calling agent puts its
own reasoning into retrieval at call time (synonyms, related concepts, the literal value it
expects), the same way it would issue a few grep or web-search queries:
recall(queries=["which port does the api listen on", "api port", "8443", "gateway listen port"])
Byte-identical hits collapse to a single slot, so a prompt captured on many days — a scheduled job's own preamble, say — never crowds out distinct evidence; the turns stay in the store and a session still reads back whole.
Prompt-time injection (the hooks) stays deterministic and only injects beliefs whose subject the prompt names. The optional filter below can drop some of those; it never adds one.
Optional: a relevance filter for prompt-time injection
Off by default. Nothing in this section happens until you switch it on, and with it off memware makes no network call and injects exactly what it did before the filter existed.
The prompt hook picks beliefs by keyword, and a shared word is not relevance. A prompt about an incident report also gets a weekly report's file path, and a prompt that says "draft a short note" gets a short story's title. memware can ask the System One model ("Jev") from TypeSafe whether each candidate bears on the prompt, and inject only the ones that clear a threshold. This is the only model call memware can make at read time, so you have to opt in to it.
What leaves your machine when it is on: for each prompt the Claude Code hook sees, and each
turn the Hermes provider prefetches for, memware sends the prompt text (cut to 2,000 characters)
and up to 20 candidate beliefs, each as subject relation: value. They go over HTTPS to
api.typesafe.ai with your API key. It sends no session id, path, transcript or date. What
TypeSafe does with the data is set by its terms.
Two kinds of turn are never sent:
- A turn nobody typed: a background task's notification, or a hook that fires inside a subagent.
- A session memware keeps out of its store:
MEMWARE_NO_CAPTURE=1, the no-capture list, acapture.excludeglob, or an ignore marker in the prompt.
So memware exclude --add '*-Users-me-work*' --apply keeps every prompt from the project in
/Users/me/work on the machine, its subdirectories' and worktrees' too: Claude Code names each
one's transcript directory after its path with every character but a letter or digit a dash, and
a worktree's name starts with the project's (-Users-me-work--claude-worktrees-feat). It also
matches a sibling whose name starts the same way, such as /Users/me/workshop. It keeps those
projects out of memware's index as well, since that is what the glob is for. If
some of your work must not leave the machine, exclude it that way before you turn the filter on,
or leave the filter off.
echo 'TYPESAFE_API_KEY=<your key>' >> ~/.memware/.env # or export it where the hooks run
memware config relevance.mode shadow # make the call and log it; injection unchanged
memware config relevance.mode filter # once the log says the threshold is right
memware config relevance.mode off # no calls at all (the default)
| mode | request per prompt | what is injected | log |
|---|---|---|---|
off |
none | memware's own top k | none |
shadow |
one | unchanged | one line per candidate |
filter |
one | the candidates at or above the threshold, most probable first, at most k | one line per candidate |
Any other value reads as off, so a typo never switches it on. The other settings, each set with
memware config relevance.<name> VALUE:
threshold(0.5)pool(20 candidates, taken from memware's own ranking, so a relevant fact ranked seventh can replace a lexical hit)timeout_s(1.5, at most 5)model(jev-1.13.0, pinned rather thanjev-latestbecause a threshold is tuned against one version)
The Hermes provider reads the same switch.
It fails open. memware makes one request with no retry, under a hard deadline. If it has no key, the request times out, the server returns an HTTP error or redirect, or the reply is not one probability per candidate, the hook injects exactly what it would with the filter off. Measured end to end on a synthetic ledger with a full pool of 20 candidates, over 100 prompts:
| hook | p50 | p95 |
|---|---|---|
| off | 84 ms | 99 ms |
| filter | 553 ms | 753 ms |
One of the 100 calls hit the 1.5 s deadline and fell back to the unfiltered output.
Cost: a full pool is about 3,200 input tokens per prompt. At jev-1.13's list price of $0.042
per million input tokens (output is free), that is about $0.00014 per prompt.
~/.memware/relevance-usage.jsonl records each answered request: its tokens, cost and latency,
and no text.
Calibrating: the default threshold of 0.5 has not been calibrated against your ledger. Shadow
mode writes ~/.memware/relevance-log.jsonl, with one line per prompt and candidate. Each line
carries:
pair_id: the prompt's hash and the belief id, so the same pair is labelled once- memware's
rankfor the candidate, andtoday: whether memware injected it p: the probability the model returnedchosen: whether filter mode would have injected itpromptandfact: the texts that were sent
Label a few dozen pairs as relevant or not, and pick the threshold that keeps what you need.
The log holds the text of your prompts, so delete it when you are done. memware nuke removes
both files; memware scan and prune do not read them.
The model answers with probabilities and never with text. The injected block therefore holds only beliefs from your own ledger that passed memware's subject and staleness gates. A prompt or a stored fact written to steer the model can do no more than move a candidate that was already in the pool.
Backups and the wipe trap
Transcripts are deleted by the OS after ~30 days, so an aged session lives only in the store —
back it up, and never wipe-and-re-backfill (backfill only re-indexes transcripts still on
disk). memware guards this: migrations snapshot first, and backfill warns if a backup is
larger than the store. Once a destination is set, backups happen automatically at session boundaries — the
SessionStart hook takes a throttled snapshot (at most once every ~20h), and a clean
SessionEnd does too. No cron; immune to a laptop sleeping through a scheduled time, and — because
the start hook always runs — also to a session being force-killed (a worktree/pane manager that
SIGKILLs Claude Code never runs SessionEnd).
memware setup # guided: index sessions, pick a folder, take a first backup
memware backup # tiered snapshot (1/3/7/14-day) + transcript mirror
memware restore --latest # after a wipe, restore — do not re-backfill
memware nuke # delete everything, typed-confirmation guarded
Full guide: docs/backup.md.
Keeping evaluations out of the evidence
Full guide: docs/keeping-memory-clean.md.
Headless runs write transcripts too, unless you pass --no-session-persistence to claude -p.
Set MEMWARE_NO_CAPTURE=1 in any run you do not want indexed: the plugin's hooks list its
transcript so no sync indexes it and no backup mirrors it, and the Hermes provider captures
nothing. That needs a memware hook to run in the session, so also put [memware-eval] in
evaluation prompts, and use memware-eval --corpus ROOT --db scratch.db --beliefs-from ~/.memware/memware.db to judge retrieval against a store that excludes them.
memware prune --containing TEXT shows the runs that already slipped in and the beliefs derived from them, and --apply un-indexes the runs and retracts those beliefs; copies already
mirrored to a backup folder have to be deleted there by hand. For a pasted secret, run memware prune --turns-containing --apply from a plain terminal: it asks for the value without echoing it and removes it from the store file too, and memware scan --backups counts every place it is left, the transcripts memware does not index included (removal runbook). For a durable filter that every sync and backup honours — including runs that predate a marker — list content signatures in ~/.memware/ignore-markers.txt (or MEMWARE_IGNORE_MARKERS); any transcript whose head contains one is never indexed or mirrored.
A generator that runs from its own working directory can be excluded by path, whatever its environment: memware exclude --add '*/<project-dir>/*' previews a capture.exclude glob and --apply writes it (docs/keeping-memory-clean.md).
Reviewing contested supersessions
memware does not ship a UI. It ships a contract — ReviewBackend with publish() and
collect() — plus two implementations: JSONL outbox/inbox files and a plain HTTP
endpoint. Wire it to whatever you already use to make decisions.
memware review sync # outbox ~/.memware/review-outbox.jsonl
echo '{"review_id": 7, "decision": "approve"}' >> ~/.memware/review-inbox.jsonl
memware review sync # applied
Evaluation
memware-eval scores retrieval against a question set: does the right evidence
surface, and does the stale value stay hidden? It needs no model, so results are
reproducible. The protocol for end-to-end comparisons — agent alone vs agent + memware —
is in docs/eval.md.
Editor and shell integration
memware ships no editor plugins — --plain (tab-separated, id-first) and --json are the
integration surface, and everything is a copy-paste recipe on top of them. Shell completions
come from memware completions zsh|bash|fish (needs the [shell] extra:
uv tool install "memware[mcp,shell]"). --plain pipes cleanly to fzf/awk/cut:
memware recall "which port does the api use" --plain | fzf --delimiter='\t' --with-nth=10
Emacs, Vim, Neovim, an $EDITOR bulk-edit round-trip, and completion install steps are in
docs/editor-integration.md.
Accessibility
memware emits no colour at all (so NO_COLOR is honoured by construction), and no information
is ever carried by colour. Default output is screen-reader-friendly — labeled, one field per
line, blank line between records; --plain and --json are the stable machine formats; and
--ascii (auto-on in a non-UTF-8 locale) avoids glyphs a screen reader or terminal might
mangle. Full statement: docs/accessibility.md.
Status
Alpha. The schema may change before 1.0; the ledger semantics will not.
License
MIT. See LICENSE.
Release files for memware 0.9.0
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|---|---|---|---|---|
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Total release size: 491.6 kB
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