Your decisions, handed to your agents' sessions and held at the edits they govern — append-only and signed in the repository, and checkable by anyone.
mnema keeps the calls behind your agents' work as signed, append-only facts in the repository. A
session opens with the ones in force, a rule can refuse or pause the write it governs, and
mnema verify checks the record with no key and no network.
| Remember | Enforce | Prove |
|---|---|---|
| With the plugin, each agent session opens with the decisions in force, by name and id. | A rule addressed at a path can refuse an agent's write there, or hold it for a person where the host allows. | Every write is signed and hash-chained; anyone can verify it, even in a browser. |
Claude Code · VS Code · Cursor CLI · GitHub Action · SDK · mnema site. The Action, the SDK and the VS Code extension run from a checkout; nothing is on npm yet.
Tamper-evident, not tamper-proof: what is still in the record has not changed since it was signed, and a stranger can check that without your keys and without installing this.
Quick start · How it works · Features · Watch it · What it proves · Docs
# install: npm i -g the four release tarballs; the exact line is in docs/install.md
claude plugin marketplace add felipesauer/mnema # the plugin hands each session the record
claude plugin install mnema@mnema
cd your-repository && mnema init
mnema decision record "Keep money as integer cents" "Float sums drift; cents are exact."
mnema verifyThe whole install, the other hosts and the first record, line by line, are in
docs/install.md and docs/first-record.md.
- Record. An agent over MCP, or you at the command line, writes a decision with its reasoning and the options turned down.
- Rule. A person accepts it, and
mnema linkaddresses it at a path. The rule can govern that path, ask for a person there, or refuse a write. - Hand over. With the plugin, each session opens with what is in force, and each edit meets the rules for its file.
- Verify. Every fact is signed and hash-chained.
mnema verify, a second reader in Python, or the pagemnema sitewrites checks it.
More in docs/how-it-works.md; what each host does and does not reach is in
docs/agent-hosts.md.
| Feature | What it does |
|---|---|
| Opens every session | With the plugin, the decisions in force, the adopted patterns and the notes near the work. Agent hosts |
| Rules at each edit | In Claude Code, the rules for a file land beside the write. Agent hosts |
| Refuses a write | refuses-a-write stops an agent's write there, in Claude Code, VS Code and Cursor CLI. Features |
| Asks for a person | asks-for-a-person holds the write until someone decides, in Claude Code and VS Code. Features |
| Supersede, never edit | A change of mind is a new decision. The old one leaves the opening and stays in the record. How it works |
| Take a note back | mnema retract appends a signed retraction, and nothing is erased. Features |
| Every write signed | The command line and the MCP server sign each write before they return. How it works |
mnema verify |
No key, no network. It names the level it reached, not yes or no. What it proves |
| A second reader | A dependency-free Python verifier, written from the format's spec alone. Verify without installing |
| A page that verifies itself | mnema site writes one HTML file, and the reader's browser checks it. The page |
| A pull-request check | The Action comments what a PR does to the record and fails when it is not signed. Packages |
| The git log, read against it | trailer, commits, why and aging tie commits to decisions. Features |
 The first record: the command line in an empty repository, from init to verify. Recorded from the built binary by recordings/first-record.sh. |
 At a terminal, mnema alone asks what you want to do here, and its first door opens the console: a session that reads the record and refuses to write. It needs a window at least 80 columns wide and 42 rows tall. Driven through a pseudo-terminal by recordings/console.json. |
 A write refused: the rule addressed at the path stops an agent's edit there. Recorded from the built binary by recordings/a-write-refused.sh. |
 A decision superseded: a later call takes its place, the old one leaves what the next session is handed and stays in the record. Recorded from the built binary by recordings/a-decision-superseded.sh. |
A case in the suite runs the scripts again against the built binary and fails when a recording no longer
shows what the binary draws, so none of them can go on showing an older product in silence
(the-recordings-are-what-the-binary-draws.test.ts).
mnema verify reads the events and the committed public keys of a project's trees — no private
key, no network — and prints each verdict verbatim, naming the level it reached.
- What holds. A changed or reordered event breaks the hash chain, and an edit made without the signing key fails the signed checkpoints.
- What does not hold. Nothing proves that nothing was removed: a hash chain shows what changed, never what is gone, and the history a git remote keeps is what covers omission. A record forged whole under a fresh key verifies clean, and a key is not proven to be the person a name says. A refusal of a write covers the editing tools of Claude Code, the VS Code agent (Copilot) and Cursor, and not their shell:
sed -ion a protected file goes round it. - What a green
verifymeans. That nothing verifiable is broken, not that the record is honest, and the gate protects the shape of a change, not who may make it.
The whole table, claim by claim, is in docs/what-it-proves.md; what was
measured, and what it does not show, is in docs/measured.md.
Install · Your first record · How it works · Agent hosts · Features · What it proves · Verify without installing · The page that verifies itself · What was measured · Where it fits · Packages · Build from source · Contributing