@rewall/sdk

The core library. Every other part of Rewall is built on it.

It does three things. It turns a wallet signature into an encryption key. It encrypts a secret and seals the key to each reader's ENS name. It reads and writes the ENS records that hold all of that.

npm install @rewall/sdk

Full documentation is at docs.rewall.me.

The key

A name's private key is never stored. To get it, the wallet signs one fixed EIP-712 message. The signature is reduced to 64 bytes, hashed with SHA-256, and the result is the X25519 secret key. The same wallet always gives the same key, so nothing has to be saved.

The public half is published under the name as rewall.pubkey. Anyone can read it, and that is what lets them share a secret with you.

Two things follow from this and both matter. The signature is the key, so anyone who gets that signature can read every secret ever shared with you, forever. And a wallet that does not sign the same way twice cannot be used. MetaMask is the supported wallet.

A secret on chain

A secret is a set of ENS text records on <secret>.rewall.<name>.eth. The value is encrypted with AES-256-GCM under a random key. That key is sealed once per reader with a libsodium sealed box, and each sealed copy is its own record, rewall.key.<fingerprint>. The names of everyone with access are written too, signed by the owner, because a rotation has to know who to re-seal for.

Sharing adds one sealed copy. Revoking encrypts again with a new key and re-seals for everyone who stays. The old copies then open nothing.

Using it

const rewall = new Rewall({ publicClient, walletClient, account, name: "alice.eth", universalResolver });

await rewall.publishIdentity();
await rewall.create("openai.rewall.alice.eth", plaintext, {
    type: "apikey",
    grantees: ["bob.eth"],
    recovery: ["vault.alice.eth"],
    allow: ["api.openai.com"],
});

const value = await rewall.get("openai.rewall.alice.eth");
await rewall.grant("openai.rewall.alice.eth", "carol.eth");
await rewall.revoke("openai.rewall.alice.eth", "bob.eth");
await rewall.list();

A client built with an identity and no walletClient can read but not write. That is how the MCP server and the extension run, holding only the derived key.

rewall.subtree shares one key with every subname under a name. rewall.guardians splits a recovery key across several names so a lost wallet can be recovered by a threshold of them.

@rewall/sdk/2fa is a separate import that reads TOTP setup keys and computes codes. It does not pull in viem or libsodium, so a browser background script can use it on its own.

Building and testing

pnpm install
pnpm run build     # writes dist/, which every other folder imports
pnpm test          # unit tests, no network

The tests prove things the docs cannot. They recover a signer from N - s to show the curve order is right. They show that crypto_box_seed_keypair gives a different key from the same seed, which is why the SDK never uses it. They show that moving a blob to another name makes it refuse to open.

What it never does

It never writes a secret to disk. It never logs one. It never uses a crypto primitive that is not libsodium or WebCrypto. And it never reads anything from a Rewall server, because there is none.