finity

Demo

About

AI agents need to buy APIs, data, compute, and other services—but giving a model unrestricted payment access is unsafe, while approving every purchase destroys autonomy. Finity lets an owner delegate procurement authority, not control of a wallet. The owner clear-signs a human-readable spending mandate once on a Ledger device. It defines which providers, services, methods and assets the agent may use, together with per-request limits, total budgets, data-sensitivity rules, expiration and escalation requirements. The agent can then make many purchases inside those boundaries without further wallet prompts, but it never receives payment keys or provider credentials. For each request, Finity’s deterministic broker discovers services registered on Hedera, obtains signed quotes and evaluates every term against the mandate. If authorized, it reserves the amount in the on-chain MandateRegistry, issues a single-use capability and settles through x402 using native HBAR. An isolated Connector Vault supplies credentials only for that approved request. The demo sends two otherwise identical requests to the same paid service. One satisfies the mandate, completes a real HBAR payment and returns the service result. The other changes one policy-controlled field and is refused before reservation, credential access or settlement—producing zero payment. Both outcomes create signed, hash-chained decision receipts committed to Hedera Consensus Service. Anyone can independently verify what the agent requested, which rules were evaluated and why money did or did not move. Ledger grants authority, deterministic code enforces it, the vault isolates secrets, and the AI only expresses intent. Finity turns a hardware wallet into a programmable root of trust for autonomous commerce.

How it's made

Finity lets a Pi-based AI purchase paid services autonomously without ever receiving a payment key or blanket spending authority. A Ledger owner clear-signs one bounded mandate; every later purchase is deterministically authorized, settled through x402 in native HBAR, and independently auditable on Hedera. Finity is a pnpm monorepo centered on strict TypeScript, with a Solidity registry deployed to Hedera EVM. Its architecture follows three trust boundaries: the Pi-based AI produces structured purchase intent, finityd makes deterministic authorization decisions, and an isolated Connector Vault holds payment keys and provider credentials . Every purchase follows one explicit state machine: INTENT → DISCOVERY → SIGNED QUOTE → POLICY EVALUATION → RESERVATION → CAPABILITY → x402 PAYMENT → DELIVERY → RECONCILIATION The agent never receives a payment key or plaintext credential. The vault accepts only single-use capabilities, restricts outbound hosts, injects secrets inside the approved request and redacts sensitive output. Human policy starts in the mandate compiler, which converts provider, service, method, asset, budget, expiry and data-sensitivity rules into EIP-712 typed data plus a human-readable Ledger display model. The owner clear-signs this mandate once. Ledger signs authority changes—mandates, amendments and revocations—but never individual purchases. The pure policy engine evaluates signed quotes and current policy state in a fixed order. Unknown or malformed inputs fail closed. MandateRegistry.sol verifies the Ledger authority on Hedera EVM, tracks mandate status and consumption, reserves budget before payment, finalizes or releases reservations and binds each mandate to an HCS audit topic. Hardhat tests cross-check its EIP-712 digest against ethers. Services are published through a provider SDK built on @x402/core, @x402/express and @x402/hedera. It generates signed manifests, quotes and usage receipts. finityd discovers these records through HCS, selects a quote deterministically, reserves the amount, mints a capability and asks the vault to settle native HBAR through Blocky402. SQLite makes the workflow resumable across failures. Each authorization, refusal, payment and reconciliation event becomes a signed, hash-chained receipt committed to HCS. The independent verifier reconstructs the chain, checks signatures and policy state, confirms HCS inclusion and correlates the x402 settlement. The hackiest integration problem was Pi’s jiti loader crashing on a static Ledger signer import with Cannot redefine property: module.exports. I reproduced it by bisecting the Ledger imports and moved SDK loading into the signing path. The complete EIP-712 mandate hash also exceeded Solidity’s normal stack limit, so the registry is compiled with viaIR.