psffpp-payments

CashScript payout contracts for PSFFPP (Permissionless Software Foundation File Pinning Protocol) deposits on Bitcoin Cash.

Users send BCH to a single PoolContract address. Once per payout epoch (blockheight-gated), the pool splits 20% to treasury and 80% into three ShareContract UTXOs (one per node). A K-of-M (2-of-3) operator quorum must sign before any share pays out.

Project docs live in docs/. Start with Why CashScript for the high-level motivation (replacing PSF-token proof-of-burn with pure BCH payouts). External references: CashScript · Design: circular-economy trust-minimized federation (M=3, K=2).

Scope (v1)

In scope	Out of scope
ShareContract.cash, PoolContract.cash	Cron (consolidate/split/broadcast)
Compile + mock tests	Timecard web GUI / sig collection
Address + deploy record scripts	Treasury multisig, withdrawal caps

Epoch model

Each Pool deploy bakes a single splitBlockheight. After that height, split() may run once the pool is consolidated. Later months are not gated by the same contract: deploy a new Pool+Shares with the next height, then K-of-M migrate() any remaining pool value into the new Pool.

Contracts

ShareContract

Constructor: node0, node1, node2 pubkeys + this node's nodePkh.

• claim(s0, s1, s2) — requires ≥2 valid ECDSA sigs against registered pubs; pays exactly to nodePkh; terminating (no self-replication). Unused sigs must be empty (0x).

PoolContract

Constructor: three pubs, treasuryPkh, three share locking bytecodes, minConsolidation (100_000), splitBlockheight.

• consolidate() — permissionless; outputs must self-replicate (same P2SH locking bytecode), pure BCH, ≥ minConsolidation.
• split() — permissionless after tx.time >= splitBlockheight; 4 outputs: treasury (20% + rounding remainder) + three equal shares locked in the baked ShareContracts. Prefer a companion fee-paying input so the full pool value is apportioned.
• migrate(s0, s1, s2) — 2-of-3; destinations are authorized by the signatures (no baked next-pool bytecode).

Setup

npm install
npm run compile
npm test

Requires Node.js ≥ 22. Matches cashc / cashscript ^0.13.

Config

cp config/deploy.mainnet.example.json config/deploy.mainnet.json

Fill in:

• Three compressed operator pubkeys (66 hex chars)
• Three node payout pkh values (40 hex chars) — usually hash160(pubkey) for each operator’s payout key
• Treasury pkh
• splitBlockheight (absolute BCH block height for this epoch)
• minConsolidation (default 100000)

config/deploy.mainnet.json is gitignored. Never put private keys in config.

Deploy order (mainnet)

Contracts are immutable. Order matters:

1. Freeze operator pubs / PKHs / treasury PKH / splitBlockheight.
2. npm run compile
3. npm run addresses -- config/deploy.mainnet.json — prints three Share addresses + Pool address.
4. npm run deploy -- config/deploy.mainnet.json — writes deployments/<timestamp>.json (addresses, locking bytecodes, artifact fingerprints). Does not move funds.
5. Publish Pool P2SH32 address as the deposit address.
6. Smoke checklist (small intentional funding only):
   • Deposit a small amount to the Pool
   • Run consolidate if multiple UTXOs
   • Confirm split fails before the gate
   • After height: split with a fee-paying companion input
   • claim a share with 2-of-3 ECDSA signatures
   • Optionally test migrate to a next-epoch Pool
7. Only then accept production deposits

Signing (ECDSA)

import { SignatureTemplate, HashType, SignatureAlgorithm } from 'cashscript'

const tmpl = new SignatureTemplate(
  privateKey,
  HashType.SIGHASH_ALL | HashType.SIGHASH_UTXOS,
  SignatureAlgorithm.ECDSA
)

Pass Uint8Array.of() for unused signature slots.

Next epoch

1. Deploy new Shares + Pool with the next splitBlockheight.
2. K-of-M migrate remaining old-pool value to the new Pool address.
3. Claim any unclaimed old Share UTXOs separately (still valid under the old Share contracts).

Security notes

• Limit outputs first in every function.
• Consolidate compares against tx.inputs[this.activeInputIndex].lockingBytecode (P2SH wrapper), not redeem script.
• Empty tokenCategory on covenant outputs (pure BCH).
• Use tx.time >= (never >).
• Fee stalls on claim/migrate require rebuilding the tx and re-collecting all K signatures.
• If ≥K operators collude they can approve any signed migrate destination — trust-minimized federation, not permissionless.

License

MIT