Glossary
These pages use one vocabulary, and the terms below have exact meanings. Capitalisation is part of a term: a capitalised noun here names a concept with an exact definition, and the same word in lower case is ordinary English.
The chain
| Term | What it names |
|---|---|
| Monad | the chain Tab's contracts run on |
| Monad Testnet | chain id 10143, where the Assets are Circle's Testnet USDC and mUSDC, and trying Tab costs nothing |
| Monad Mainnet | chain id 143, where the Assets are the canonical USDC and AUSD |
| MON | the gas token. Tab charges no fee in it and holds none |
| chain id | the number a deployment is scoped to |
| base units | the integer denomination every amount is written in. A price, a Bond, a tab and a Settlement are all counts of base units of one Asset, and nothing anywhere takes a decimal |
| mUSDC | the mintable mock token deployed to Testnet. Its own symbol() says USDC; Tab shows it as mUSDC so it is never confused with Circle's |
| Permit2 | Uniswap's Permit2 at its canonical address, which a gasless Settlement is signed against |
| x402 | the prepaid pay-per-request protocol. An x402 payment is never a Settlement |
| the Hub | the Monad API Hub, whose paid endpoints a Service can front on credit |
| ERC-8004 | the agent identity standard. An identity is the registered agent, never a credential |
| reputation entry | one ERC-8004 feedback entry a Service's gateway writes about the paying Agent after a Settlement, value 100 under the tags tab and settled. Derived, and never read by the Credit Limit |
| funding step | what the intents-funded strategy does before a Settlement when the Agent's Monad balance is short: bring USDC from another chain to the Agent's own Monad address through NEAR Intents. It is not a Settlement |
The product
| Term | What it names |
|---|---|
| Tab | the product: contracts, settlement surface, services and client tooling together |
| tab | one accounting record, per Agent, per Service, per Asset |
| Open Tab | the unsettled balance of a tab, in a single Asset |
| prepaid credit | the part of a tab settled ahead of any delivery, spent before the Open Tab is raised again |
| Agent | an autonomous client holding its own Monad key |
| Service | a metered provider registered with Collection addresses, prices, a Settlement Window and a Bond |
| Asset | an ERC-20 token on the deployment's chain used for Settlement |
| Collection address | the address, one per Service and Asset, that TabSettlement transfers Settlements to |
| delivery | a TabBook record attributing a priced unit of work to an Agent |
| Settlement | one payment through TabSettlement, by settle, settleBatch or settleWithPermit2, that moved an Asset to a Collection address and was applied to a tab in the same transaction |
settlementId | the identifier TabBook assigns to one Settlement |
| Settlement Window | the time a tab may stay open, from its oldest unsettled delivery, before anyone may mark it delinquent |
| Credit Limit | the maximum aggregate Open Tab, per Asset, that an Agent may hold |
| headroom | the Credit Limit less the Open Tab, which is what the next delivery may raise the tab by |
| Bond | Asset-denominated stake a Service escrows in the Bond contract |
| free Bond | staked minus withdrawn, which is the figure the Credit Limit reads |
| witness | the ordered Settlement history and the counterparty Bond entries a caller supplies so the limit can be computed without a storage read |
| authorisation | the ceiling an Agent sets on what one Service may meter to one tab, and until when |
| delinquent tab | an Open Tab that passed its Settlement Window unsettled and was marked |
markDelinquent | the permissionless call that marks one |
| Curated tier | the Services whose Settlement history contributes to Credit Limit computation |
| Permissionless tier | Services that may meter usage but contribute zero weight to credit |
The components
| Term | What it names |
|---|---|
ServiceRegistry | who may meter, prices, Collection addresses, Settlement Windows and tiers, every change behind a 48-hour timelock |
Bond | the escrow Services stake into and withdraw from |
TabBook | the ledger of tabs, authorisations, Settlements and the history commitment |
TabSettlement | the one way a tab is paid. Holds nothing |
LimitLib | the pure credit arithmetic |
CurationMultisig | the m-of-n contract that holds the curation role, 2-of-3 on Mainnet |
MeteringDelegates | where an Agent names a metering delegate until an expiry, and revokes one; read by gateways, wired to no other contract |
| registry read API | the indexer that serves Services, Agents, Settlements and deliveries, and a Credit Limit only where its cross-check agrees |
| metering gateway | the Service-side process that meters through the SDK's plugin, offers x402 on a refusal, fronts upstreams and relays gasless Settlements |
| relay | POST /relay/settle on the gateway, which submits a Permit2 Settlement the Agent signed and pays its gas |
| keeper | the process that marks overdue tabs delinquent; the CRE workflow is its schedule |
| passkey account | one passkey and the owner and session keys derived from it on the Dashboard's /keys |
| Agent Wallet plugin | mm tab, the MetaMask Agent Wallet commands |
| Metering delegate | a session key an Agent registered in MeteringDelegates, until an expiry, to sign its metering claims; it cannot move funds and stays within the Agent's authorisation ceilings |
| Dashboard | the web application presenting credit, registry, settlement and analytics views |
| SDK | the published TypeScript package, @tabai/sdk |
| CLI | the SDK's command-line entry point, tab |
| MCP Server | the Model Context Protocol server exposing Tab to MCP clients |