bitspire/CLAUDE.md

CLAUDE.md

Guidance for Claude Code when working in this repo. Read this before touching code.

Project Overview

bitSpire is a Nostr-native Lightning ATM. Production ATMs (batm3, douro) currently run from main against Lightning.Pub; the dev branch — which is what this file describes — has been migrated to LNbits over the nostr-native-transport.

Core principles:

• KYC-free — no identity collection, no compliance theater
• No HTTP to the Lightning backend — every ATM↔LNbits RPC goes over kind-21000 NIP-44 v2 events on a relay
• The ATM's nostr private key IS the credential — LNbits auto-creates the wallet on first contact (issue aiolabs/lnbits#9 alignment, prvkey=NULL)
• Open source first — every component auditable and forkable

Provenance + legal status

The HAL drivers (validators / dispensers / printers) and the cash-flow state machine derive from Lamassu Industries AG's lamassu-machine repository, only up to commit c0b69d1ed196d396c5f057478c2ea290babd58ab ("chore: v8.6.0-beta.9", 2023-09-19) — the last commit published into the public domain (UNLICENSE in tree). The very next commit, a9234d124d ("chore: add LICENSE (#1019)", 2023-09-19), removed UNLICENSE and added Lamassu's proprietary "Appendix A SLA". The v8.1.5 tag (2023-09-21) already ships the Appendix A license — the previously documented "8.1.5 is the open boundary" was wrong (verified against GitHub history 2026-07-04). Note the public-domain boundary sits on the 8.6-beta line, which is further along than 8.1.5 feature-wise.

Hard rule when working in this repo: do not pull, port, or copy lamassu-machine code from a9234d124d or later (which includes every 8.1.5+ tag). Reference only c0b69d1 or earlier. If a HAL bug fix or feature exists upstream past that commit, either (a) reimplement from protocol docs / hardware specs without looking at the licensed source, or (b) raise the question with the maintainer first. To fetch the open tree safely: git fetch --depth 1 origin c0b69d1ed196d396c5f057478c2ea290babd58ab — never check out a tag.

The lamassu-server boundary has not been re-verified against its own history and may differ — check its license-change commit before referencing it.

bitSpire is an independent project under AGPL-3.0 and is not affiliated with Lamassu Industries AG.

Branch model

• main — production. Lightning.Pub backend. The two production ATMs auto-pull from here daily at 04:00 (flake.nix:152-160). DO NOT push to main casually — a wrong commit gets baked into prod ATMs the next morning.
• dev — staging. LNbits backend. The Sintra dev unit auto-pulls from here (?ref=dev pin on this branch's flake.nix). Push freely; tag pre-bitspire-cutover is the rollback target if the migration ever needs to be reverted on prod.

Architecture

bitSpire/
├── apps/
│   └── machine/          # Electron + Vue 3 ATM kiosk
├── packages/
│   ├── nostr-client/     # NIP-01 client, NIP-44 v2 (encryptContentV2/decryptContentV2)
│   ├── lnbits/           # LnbitsClient — kind-21000 RPC over nostr-transport
│   ├── clink/            # CLINK protocol (kinds 21001-21003) — IN TREE BUT UNUSED ON DEV
│   ├── state-machine/    # XState v5 ATM state machine
│   ├── hal/              # Hardware abstraction (JCM iVIZION, Fujitsu F56, etc.)
│   ├── cashu/            # placeholder
│   └── ui-shared/        # placeholder
└── deploy/nixos/         # NixOS module + provisioning for Sintra/tejo/douro/batm3

packages/lightning/ (the Lightning.Pub RPC client) was deleted on dev in commit a51d7af. If a piece of code on dev needs LP semantics, look at the equivalent in packages/lnbits/ or in apps/machine/src/services/lightning.ts (which has a LightningBackend interface implemented by an LNbits-backed adapter).

Package status

Package	Scope	Notes
@bitSpire/nostr-client	active	NIP-01 + NIP-44 v2 helpers. Used by every other package.
@bitSpire/lnbits	active	Wraps the nostr-native-transport API (10 core RPCs + lnurlw/lnurlp + subscribe_payments). Mirror peer of the old @bitSpire/lightning.
@bitSpire/state-machine	active	XState v5. Tests pass. generateNdebit / generateClinkOffer / generateNoffer services are stubs returning placeholder strings (state machine contract preserved; outputs unused by views).
@bitSpire/hal	active	TypeScript HAL. JCM iVIZION + Fujitsu F56 drivers.
@bitSpire/clink	dormant	Code kept for future re-wire if direct nostr-to-nostr cash-in returns. Don't import on dev — services/lightning.ts no longer wires it.
@bitSpire/cashu	placeholder	empty
@bitSpire/ui-shared	placeholder	empty

Backend wiring

apps/machine/src/services/lightning.ts is the central file. After the 3d cutover it:

1. Loads config from Electron IPC (get-config + one-shot get-atm-secrets) or from import.meta.env (browser dev)
2. Creates an LnbitsClient, calls list_wallets, picks the first wallet — fails-fast if either step doesn't return data
3. Exposes a tiny LightningBackend adapter on services.lightningPub that satisfies apps/machine/src/stores/atm.ts's expectations:
   • getBalance() → wraps lnbits.getBalance(walletId)
   • watchBalance(cb) → wraps lnbits.watchWallet and refetches balance per push
   • createInvoice({amountSats, description}) → wraps lnbits.createInvoice(walletId, {amount, memo, unit:'sat'})
   • payInvoice(bolt11, amountSats) → wraps lnbits.payInvoice(walletId, {bolt11, max_sat})
4. Implements the four flow-critical ATMServices methods on top of LNbits:
   • generateInvoice(msat) → cash-out BOLT11
   • watchInvoice(bolt11, cb) → subscribe_payments({payment_hash, max_seconds:600}) push
   • generateLnurlWithdraw(ctx) → lnurlw_create_link({uses:1, ...}), use link.lnurl directly (LNbits populates it from settings.lnbits_baseurl per aiolabs/withdraw#1 / e9d911e), subscribe for tag:"withdraw", link_id settlement push
   • getAvailableBalance() → wraps lnbits.getBalance(walletId).balanceSats

CashInView.vue calls atmStore.generateLnurlWithdraw() directly when entering displayingQR; the state machine still invokes generateNdebit as an actor but its output is discarded (kept only to avoid an invasive state-machine rewrite).

Environment variables

Renderer reads (Electron IPC or Vite import.meta.env):

Var	Required	Notes
VITE_RELAY_URL	no (seed-provided)	Relay both ATM and LNbits subscribe to. Comes from the pairing seed (aiolabs/bitspire#70); set this only as an override — it WINS over the seed via env-first precedence. Dev override: ws://localhost:5001/nostrrelay/test (LNbits's bundled nostrrelay extension — no separate strfry container)
VITE_LNBITS_SERVER_PUBKEY	no (seed-provided)	64-char hex transport pubkey. Comes from the seed's lnbits_npub (#70); env override only. LNbits prints it on startup (docker logs lnbits | grep 'Public key (share this)')
VITE_SPIRE_SEED	yes (prod)	Spire pairing seed (spire-seed:v1:<base64url>) from spirekeeper. Carries the relay(s), the LNbits transport pubkey (lnbits_npub), the spire signing pubkey (spire_npub), and a one-shot NIP-46 connect token (#70 slimmed the shape). First boot redeems it and persists the binding to state.db; later boots resume by fingerprint. A changed seed re-pairs. Provisioning it up front is optional — an unpaired machine renders an on-screen QR-pairing wizard that scans the seed off the camera (see below). See aiolabs/bitspire#52.
VITE_ATM_PRIVATE_KEY	dev only	64-char hex raw nsec fallback for running without a bunker. Ignored when VITE_SPIRE_SEED or a stored binding exists.
VITE_OPERATOR_PUBKEYS	optional	Comma-separated hex pubkeys allowed to send kind-21003 management commands

The LP-era vars (VITE_LIGHTNING_PUB_PUBKEY, VITE_LIGHTNING_PUB_API_URL, VITE_EXTENSION_API_URL, VITE_ADMIN_TOKEN) are gone from the dev branch's .env.example and LightningConfig interface.

Pairing (on-machine QR wizard)

A machine with no seed and no stored binding boots unpaired and, under Electron, renders an interactive wizard (src/components/PairingWizard.vue) instead of a dead-end fault screen. The operator displays the spire-seed QR (minted by spirekeeper's /pair) to the machine's camera; the wizard:

1. captures + decodes via a PairingSource (src/services/pairing/) — camera today (decode through qr, paulmillr's zero-dep lib), NFC scaffolded;
2. validates the scan parses as a spire-seed (ingestScannedSeed), rejecting a stray QR;
3. persists it as VITE_SPIRE_SEED via the state:save-spire-seed IPC and relaunches (app:relaunch).

Pairing itself is not done in the wizard — relaunch lets the normal boot path (signer-resolver → connectNewSeed) redeem the one-shot token, so there's one tested pairing path. A revoked/expired binding lands on the same wizard (re-pair = scan a fresh seed). Provisioning VITE_SPIRE_SEED up front still works and skips the wizard.

Commands

# Inside devenv shell
pnpm install                 # install all workspace deps
pnpm dev                     # start the machine app (Vite + Electron with hot reload)
pnpm typecheck               # vue-tsc --noEmit
pnpm test                    # vitest across all packages

# In apps/machine specifically
cd apps/machine && pnpm build  # full prod build: vue-tsc + vite build + electron tsc + fund-atm esbuild bundle

Disk image build (for Sintra/douro/etc.):

nix build .#disk-image-sintra   # → result/nixos.img

Nostr event kinds

Kind	Role	Status on dev
21000	LNbits nostr-native-transport (request + ack + push)	active — all backend traffic
21001	CLINK Offer (invoice request/response)	dormant
21002	CLINK Debit (payment authorization)	dormant
21003	CLINK Manage (operator commands)	partially wired — clink.onManagement still listens for operator dispense, decoupled from LP
30078	Service Beacon (replaceable, ATM availability)	active — startAvailabilityBroadcast() heartbeats every 5 min
30079	Transaction Record (replaceable)	planned

Wire envelope (kind 21000 RPC)

Plaintext JSON, encrypted as NIP-44 v2 inside the event content:

// Request (client → server)
{
  "rpc_name": "create_invoice",
  "request_id": "create_invoice-7-ab12cd",
  "wallet_id": "<uuid>",
  "body": { "amount": 1000, "memo": "...", "unit": "sat" }
}

// Reply (server → client, one-shot)
{
  "status": "OK",
  "request_id": "create_invoice-7-ab12cd",
  "data": { /* Payment object */ }
}

// Subscription push (server → client, repeated)
{
  "status": "OK",
  "request_id": "sub-9-ef34gh",
  "subscription_id": "<server-issued>",
  "data": { "payment": { /* Payment */ } }
}

// Subscription close (server → client, terminal)
{
  "status": "OK",
  "request_id": "sub-9-ef34gh",
  "subscription_id": "<server-issued>",
  "data": { "closed": true, "reason": "ttl" | "unsubscribed" }
}

See packages/lnbits/src/types.ts for the TypeScript surface and ~/dev/lnbits/nostr-transport/docs/devs/nostr-transport.md for the authoritative wire spec.

Hardware drivers

TypeScript drivers in packages/hal/. Coverage by device class:

Category	Drivers
Validators	id003, ccnet, cashflow_sc, bnr_advance, genmega, hcm2, gsr50
Dispensers	puloon, f56, genmega, hcm2, gsr50
Recyclers	MEI SCR (planned — hardware in BATM3, no driver yet)
Printers	nippon, zebra, genmega

Sintra hardware specifics (Aaeon UP Board)

• Validator (JCM iVIZION, ID003): FTDI USB-serial bridge → /dev/ttyUSB1 → udev symlink /dev/ttyJ5
• Dispenser (Fujitsu F56): SoC MMIO UART (the only on-carrier RS-232) → /dev/ttyS4 → udev symlink /dev/ttyJ7. ttyS4 must NOT be the kernel console — upboard.nix keeps console=tty0 only
• The kernel-enumerated ttyS1/ttyS2/ttyS3 are placeholder nodes that error on any I/O — the legacy 16550A is ttyS0, the SoC MMIO is ttyS4. Confirm with dmesg \| grep ttyS

Initrd modules for eMMC boot

UP Board enumerates its eMMC controller via ACPI, not PCI. upboard.nix force-loads sdhci-acpi and mmc_block in initrd.kernelModules so root-by-label resolves in stage 1. If you ever rebuild the disk image for a different SoC, double-check this list.

Code style

• TypeScript: ESM only, strict mode + strictNullChecks + noUncheckedIndexedAccess. No any. Zod for runtime validation at boundaries.
• Vue 3: Composition API, <script setup lang="ts">. Pinia for state.
• Formatting: Prettier (2 spaces, no semicolons, single quotes). Pre-commit hooks enforce.
• Tests: Vitest. Cash-out is the critical-path flow — keep packages/state-machine coverage tight.

Security priorities

1. Private keys — Never log nsec. In production the ATM holds no signing nsec: VITE_SPIRE_SEED (in /var/lib/bitspire/.env, mode 0600) carries a one-shot connect token, and the ATM's own NIP-46 transport key (client_secret_hex) lives in state.db (bunker_binding). The operator's signing key stays in the bunker. The legacy VITE_ATM_PRIVATE_KEY is a dev-only fallback.
2. Payments — Validate the bolt11 amount on cash-out before exposing the QR. Decode payment_hash from the bolt11 (cheap, avoids a roundtrip) and use it as the subscribe_payments filter.
3. Replay — LNURL-withdraw links use uses:1 and are deleted on session abort.
4. Encryption — All RPC content is NIP-44 v2. NIP-04 is forbidden.

Useful invariants when debugging

• The renderer logs prefix every line with a tag: [Lightning], [ATM], [ATM Service], [LNURL Session], [CLINK], [StateStore]. journalctl -u bitspire | grep '\[' is your friend.
• Never pass an object as a console argument in the renderer. Electron's console bridge stringifies each argument, so console.log('msg:', { a, b }) reaches the journal as msg: [object Object] and every field is lost. Interpolate instead. Cost a debugging session on 2026-09-23, when a cassette publish that had worked looked like it had done nothing.
• bitspire.service runs as the lamassu user; /var/lib/bitspire is its dataDir (ReadWritePaths). DB lives at /var/lib/bitspire/state.db (we previously had /var/lib/lamassu-atm — that path is gone on dev, see commit 9c455d6).
• The lightning.lightningPub field on LightningServices is a LightningBackend adapter, not a LightningPubClient. Don't try to call LP-only methods on it.

Related documentation

• docs/machine-installation.md — Sintra deployment walkthrough (build, flash, provision)
• deploy/nixos/README.md — NixOS module options, runtime config layout
• docs/architecture-comparison.md — Nostr-native vs traditional lamassu-server
• .claude/skills/*.md — Custom skills (/security, /nostr-check, /test, etc.)

External:

• LNbits nostr-transport docs — wire spec
• NIP-44 encryption
• CLINK Protocol Spec (historical reference)