Tab

Demo

About

Tab is a credit rail for autonomous agents on Hedera. Agents today need a funded wallet before they can transact at all — that's a cold-start problem no amount of deployment tooling fixes. Tab removes the wallet entirely. A gateway sits on both sides of an agent's economic life: when the agent spends, the gateway pays the seller from a house float and debits the agent's tab; when the agent earns, the gateway collects payment on its behalf and credits the tab. Once per settlement window, the net position clears in a single on-chain transfer. The agent never holds funds and never signs a payment — it just spends and earns against a ceiling that's underwritten by its own attested revenue, not collateral it doesn't have.

How it's made

Tab runs entirely on native Hedera services — no smart contracts. Every debit, credit, and ceiling change is a message on an HCS topic, giving us a consensus-ordered, publicly replayable ledger instead of a contract we'd have to audit ourselves. HTS handles every USDC transfer, both to sellers and in the netted settlement. The settlement tick itself is a Scheduled Transaction (HIP-423) — created at window open and executed by consensus at window close, so there's no keeper bot to run or trust. Mirror Node feeds our background scoring engine, which builds a counterparty graph to detect control clusters (an agent transacting with a seller it secretly owns) and computes each agent's credit ceiling from trailing attested revenue. The gateway itself speaks x402 on both legs, so any unmodified x402 seller or buyer can transact with a Tab-backed agent without knowing Tab exists. On top of that, Tab ships as a Hedera Agent Kit v4 plugin with policy hooks, an MCP server, a TypeScript SDK, and a CLI — so any agent can get a tab with no wallet provisioning step. Backend is Node.js/TypeScript on Fastify. HCS remains the source of truth throughout. Frontend is Next.js 15 with a live SSE feed of the HCS receipt stream.