nSealr

Quickstart (no hardware)

You do not need any hardware to see the signing flow end-to-end. The Raspberry/Pi flow has a desktop simulator that signs fixture events, and the companion verifies them. This page walks through it.

What you’ll have at the end

  • The nsealr CLI installed locally.
  • A signed-fixture event you produced yourself.
  • The companion verifying it against the same shared contracts that govern the real hardware path.

1. Install the companion CLI

git clone https://github.com/nSealr/companion
cd companion
make setup

Verify:

nsealr --version
# → nsealr <semver>

2. Install the Raspberry/Pi desktop simulator

The Pi software runs on desktop too — it’s the same Python package with hardware adapters stubbed out.

git clone https://github.com/nSealr/raspberry
cd raspberry
make setup

3. Build a signing request

A v0 signing request is just JSON — see Signing request v0 for the shape. A canned fixture lives in nSealr/specs/vectors/.

cp ../specs/vectors/requests/request-v0.json req.json
cat req.json
# { "spec": "nsealr/signing-request/v0", "id": "01HXY...", ... }

4. Sign it with the simulator

nsealr-rasp sign-fixture --request req.json --output resp.json

Behind the scenes the simulator:

  1. Validates the request against signing-request-v0 and the v0 implementation limits.
  2. Renders the canonical material on a virtual review screen.
  3. Computes approval_digest.
  4. Signs BIP-340 / secp256k1 over the NIP-01 event id.
  5. Emits a qr-response-v0 JSON in resp.json.

5. Verify with the companion

nsealr verify-response --request req.json --response resp.json

Expected:

✓ event id matches BIP-340 signature
✓ approval_digest matches reviewed material
✓ public key matches signer descriptor

That’s the same verifier the production path uses. If any line fails, the response is rejected — even if the signature is mathematically valid.

What just happened

  • You did not type a private key anywhere.
  • The simulator generated a deterministic fixture key from the fixture seed (seed-id 0 in shared specs).
  • The companion verified four contracts: signing-request-v0, nostr-sign-event-bip340-v0, approval-digest-v0, signed-response-verification-v0.

Next

Last updated 2026-05-20