nanomem MCP server

<!-- mcp-name: io.github.OmBansod2/nanomem -->

nanomem

An embedded store for facts that change.

A fact your application remembers is not a document. It gets corrected — people move, change jobs, switch phone numbers. A vector store keeps both statements and returns whichever one is worded closer to the question, which is how an assistant ends up confidently repeating an address you left two years ago. nanomem keeps the chain and knows which end of it is current.

Evidence — how it compares to FAISS, sqlite-vec and Chroma (including where it loses), what happens when the process is killed mid-write, and the pytest command that re-runs most of those claims on the copy you just installed.

Quickstart — give your assistant a memory that knows what changed

pip install nanomem

Add this to your MCP client's config. On macOS claudedesktopconfig.json lives in ~/Library/Application Support/Claude/:

{
  "mcpServers": {
    "nanomem": {
      "command": "nanomem-mcp"
    }
  }
}

That is the whole configuration. The vault defaults to ~/.nanomem/memory.dat; set NANOMEM_VAULT, or pass --vault /some/path.dat, to put it elsewhere.

Restart the client and tell it something that will change later:

"Remember that I work at Acme Corp."

(a week later) "Actually I moved — I'm at Globex now."

"Where do I work? And where did I work before?"

It answers Globex, and can tell you it used to be Acme — not because the second sentence was worded closer to the question, but because nanomem kept the chain and knows which end of it is current. Ask it "what did I believe about this in March?" and it can answer that too.

Seven tools: nanomemadd, nanomemsearch, nanomemhistory, nanomemasof, nanomemchanges, nanomemvolatility, nanomemstats — so the assistant can ask what a fact USED to be, what the memory believed at a past moment, what changed last week, and which of its own beliefs have gone stale.

The vault is an ordinary file. Point the CLI or a Python script at the same path to read what the assistant wrote — a write is on disk before its reply is sent, so another process sees it immediately and stopping the server cannot lose it.

Through 0.7.17 that was not true: the server flushed only on a clean exit, and an MCP client stops its servers with SIGTERM. Twenty nanomemadd calls, each answered "Stored …", then SIGTERM, left zero rows** in the vault. If you ran an earlier version, anything the assistant "remembered" in a session that was not closed cleanly was never written.

Or use it from Python

pip install nanomem

import time
from nanomem import Vault

DAY, now = 86400, time.time()
job = {"entity": "employer"}

v = Vault("memory.dat")
v.add("I work at Acme Corp.",                    metadata=job, timestamp=now - 300*DAY)
v.add("I moved jobs, I now work at Initech.",    metadata=job, timestamp=now - 155*DAY)
v.add("I switched again, I work at Globex now.", metadata=job, timestamp=now - 10*DAY)

print(v.search("where do I work")[0]["text"])
# I switched again, I work at Globex now.

for r in v.history("where do I work"):
    print(r["revision"], r["superseded"], r["text"])
# 1 True I work at Acme Corp.
# 2 True I moved jobs, I now work at Initech.
# 3 False I switched again, I work at Globex now.

print(v.search("where do I work", as_of=now - 200*DAY)[0]["text"])
# I work at Acme Corp.

f = v.volatility()[0]
print(f["entity"], f["n_revisions"], round(f["median_interval"]/DAY))
# employer 3 145

Shortened. The full README is on GitHub.