Glossary#

Terms are defined in the context of Hightop. For deeper explanations, follow the links to the relevant pages.

A#

Account-wide rules — Rules that apply to every agent on the account. These set the outer ceiling. Agent-specific rules can narrow them but never widen them. See Agent Permissions and Limits.

Action-count limit — A cap on how many actions an agent can take in a given period. Controls frequency, not just dollar value. See Agent Permissions and Limits.

Active — The state where an agent, vendor relationship, or trusted destination is live and can be used. Reached after any required activation delay or timelock has passed. See also: pending.

Active lifetime — The defined duration of an agent's or vendor relationship's active access before automatic expiry. Can be made shorter than the account-wide default but not longer. See also: activation delay, expiry window. See Agent Permissions and Limits.

Activation delay — A waiting period before a new agent or vendor relationship becomes active. Distinct from a review delay (which holds a specific payment), a cooldown (which spaces out repeated actions), and a timelock (which guards high-impact management changes like adding a trusted destination). During this delay, a pending recurring vendor relationship can still be cancelled before it becomes active. Enforced by the control layer. See also: active lifetime, cooldown, review delay, timelock.

Adapter — A standardized interface that connects the smart contract wallet to an external protocol (like a lending market or trading venue). New adapters can be added without changing your wallet. See Wallet Model.

Agent — The Hightop object that gives an external agent or workflow a scoped financial lane. It is not the AI itself — it is the lane the AI operates inside. Each agent has a control profile that defines its permissions, limits, approved destinations, and timing rules. See AI Agents.

Agent lifecycle — The stages an agent moves through: Created → Waiting → Active → Expired or Removed. An agent cannot act before its activation delay ends or after its expiry. See AI Agents.

Agent rules — Rules that apply to one individual agent, narrowing the ceiling set by account-wide rules. Each agent can have its own permissions, limits, asset restrictions, and timing controls. Also called agent-specific rules. See Agent Permissions and Limits.

Approved vendor — A vendor that has been added to the recurring payments list and confirmed through any required activation delay. Once active, agents with recurring payment permission can pay this vendor within the configured limits. Also called a recurring vendor. See Recurring Payments.

Amplified Vault — A Hightop Earn vault that uses managed leverage to target higher yield. It borrows against Core Vault shares through Ripe Protocol and deploys borrowed stablecoins back into Core Vaults for additional yield. See Earn Under the Hood.

API key — A credential that an external agent uses to authenticate with the Hightop API. If compromised, the attacker can only use whatever permissions and limits were configured for that agent — they cannot widen them.

Atomic transaction — A transaction where all steps either succeed together or fail together. There is no partial execution. If any rule check fails, the entire transaction reverts and no funds move.

B#

Base — A Layer 2 blockchain built on Ethereum. This is where Hightop's smart contracts are deployed, where transactions settle, and where the public record of every action is stored. Hightop users do not interact with Base directly.

Batch operation — The ability for the smart contract wallet to execute multiple actions in a single atomic transaction. Used for complex operations like withdrawing from one protocol and depositing into another in one step. See Wallet Model.

Blockchain — A network of computers that maintains a shared, tamper-resistant record of transactions. No single party controls it, and anyone can verify what happened. Hightop runs on blockchain infrastructure because it is the natural fit for AI agent finance: global, 24/7, no downtime, transaction costs low enough to make micropayments viable, and programmable rules enforced by code rather than by a company's servers. Combined with stablecoins, it gives agents a money layer that settles in seconds, works across borders, and costs fractions of a cent per transaction. See Wallet Model.

C#

Cancellation window — The period during which a one-off payment can be cancelled before the recipient claims it or it is executed. This term is specific to one-off payments, not to pending recurring vendors or pending trusted destinations. Only the account controller can cancel. See One-Off Payments.

Claimable — The state where a one-off payment's review delay has passed and the recipient can claim the funds (if recipient claim is enabled). Reached after the Waiting stage in the one-off payment lifecycle. See also: review delay, recipient claim. See One-Off Payments.

Collateral — Assets deposited to back a borrowing position. In Hightop, your entire portfolio — including Earn positions — can serve as collateral. See Borrowing Under the Hood.

Control layer — The rules engine in Hightop's architecture. Agent permissions, spending limits, payment paths, timing rules, and asset restrictions all live here. Key controls are enforced onchain by smart contracts. See Architecture.

Control profile — The permissions, limits, approved destinations, asset restrictions, and timing rules attached to a Hightop agent. The agent is the object; the control profile is the rules that define its lane. See AI Agents.

Control wallet — The wallet address that controls your Hightop account. It is the only address that can change the rules — add agents, update limits, approve recipients, or remove agents. It is not where your funds live; your funds live in the smart contract wallet. By default, the control wallet is created through Turnkey and can later be moved to a hardware wallet or Safe. See Your Hightop Wallet.

Cooldown — A required waiting period between actions. Cooldowns are tracked at different layers — an agent-level cooldown is separate from recurring-payment cooldowns and one-off-payment cooldowns, so one path hitting its cooldown does not freeze every other path. Slows rapid-fire behavior and limits the damage from a bad loop or compromised key. See also: activation delay, review delay. See Agent Permissions and Limits.

Core Vault — A Hightop Earn vault that provides passive, AI-managed yield. Deposits go into a shared pool where an AI agent optimizes across approved lending protocols. See Earn Under the Hood.

Custody — Direct control over funds or private keys. In Hightop, agents do not have custody — they have execution rights within configured rules. Hightop's servers also do not hold your control wallet's private keys or have unilateral authority to move funds. That separation is a core part of the control model.

D#

DeFi — Decentralized finance: financial services built on public blockchains using smart contracts rather than traditional intermediaries. Hightop connects to DeFi protocols for yield, borrowing, and trading through its wallet's adapters. DeFi is not risk-free and Hightop is not FDIC insured.

Deleveraging — Automatically reducing a leveraged position when debt ratios approach configured limits. Amplified Vaults deleverage by repaying debt, not by selling volatile assets. See Earn Under the Hood.

E#

Embedded wallet — A wallet created through Turnkey and tied to your email-based login. This is the default control wallet for new Hightop accounts. Keys are stored within Turnkey's infrastructure, not on Hightop's servers. See Your Hightop Wallet.

Entry layer — The top layer of Hightop's architecture: the app and the API. Humans use the app. Agents use the API. Both connect to the same control layer and wallet layer underneath. See Architecture.

Execution rights — The authority to execute actions within configured boundaries, without holding private keys or having custody of funds. This is what Hightop agents receive — not control of the wallet itself.

Expiry window — The configured duration or end time for an agent, vendor relationship, or payment. Once the window closes, the entity can no longer act. Prevents permanent, unlimited delegation. See also: active lifetime. Also called expiry.

F#

Fail on missing price — A safety setting that blocks an action when Hightop cannot establish a reliable price for the assets involved. Protects against manipulation when price data is unavailable. See Agent Permissions and Limits.

G#

Guardrails — Informal term for the rules and limits that constrain agent behavior. Account-wide guardrails set the ceiling; agent rules narrow it further. Used interchangeably with "rules" in the docs.

Gas — Transaction fees that blockchains charge to process transactions. Hightop covers gas fees for normal product usage — you do not need to manage gas yourself.

GREEN — A stablecoin minted by Ripe Protocol, designed to track the US dollar. Created when you borrow against your collateral. See Borrowing Under the Hood.

H#

Hightop account — Your unified account in Hightop, backed by one smart contract wallet and controlled by one control wallet. All your agents, balances, Earn positions, and borrowing state live in this single account — there is no separate wallet per agent or per purpose. See Your Hightop Wallet.

Hightop Borrow — Hightop's borrowing feature, powered by Ripe Protocol. Lets you borrow against your assets — including Earn positions as productive collateral — through a single unified loan. See Borrowing Under the Hood.

Hightop Earn — Hightop's yield feature, powered by Underscore Protocol vaults. AI-managed vaults continuously optimize yield across approved protocols. See Earn Under the Hood.

I#

Instant threshold — The value below which a one-off payment can clear immediately without a review delay. Payments above this threshold wait behind a configurable delay. See One-Off Payments.

L#

Lane — The bounded operational space defined by an agent's permissions, limits, approved assets, approved recipients, and timing controls. An agent operates inside its lane and cannot redraw it.

Layer 2 — A blockchain built on top of Ethereum that inherits its security while offering lower transaction costs and faster settlement. Hightop runs on Base, a Layer 2 network.

Lifetime limit — A cap on total activity over an agent's full lifespan. Once reached, the agent cannot take further actions of that type regardless of period resets. See Agent Permissions and Limits.

Liquidation — Forced sale of collateral when a borrowing position becomes unhealthy enough that the protocol needs to restore it to safety. In Hightop's borrowing model, the protocol aims to liquidate only what is needed rather than the entire position. See Borrowing Under the Hood.

M#

MPP — Short for Machine Payments Protocol: an emerging protocol from Stripe and Tempo for machine-native payments, including agent-to-agent and agent-to-service flows. See Emerging Payment Protocols.

O#

Onchain — Enforced by code running on a public blockchain, not just by application servers. When Hightop says a rule is "enforced onchain," it means the smart contracts check and enforce that rule independently of Hightop's own infrastructure. See Why Onchain Enforcement Matters.

One-off payment — A controlled ad hoc payout to a recipient that is not pre-approved as a recurring vendor. Small amounts can clear instantly; larger amounts wait behind a review delay and can be cancelled before they execute. See One-Off Payments.

Overcollateralized — A borrowing position where the value of the collateral exceeds the value of the debt. Hightop borrowing requires overcollateralization. See Borrowing Under the Hood.

P#

Path-specific rules — The narrowest layer in the rule stack: rules attached to the specific recurring vendor relationship, one-off payment, or trusted destination an action is using. These narrow the ceiling set by agent rules, which in turn narrow account-wide rules. Includes per-vendor rules, per-payment rules, and per-destination rules. See Agent Permissions and Limits.

Payment commitment — The core mental model for a one-off payment: a controlled promise to pay rather than an instant irreversible transfer. The recipient, amount, and expiry are fixed when the one-off payment is created and enforced onchain. Larger one-off payments can wait behind a review delay before they clear, while smaller ones below the instant threshold can clear immediately. See One-Off Payments.

Payment path — One of three mechanisms for outbound money in Hightop: recurring payments, one-off payments, or trusted transfers. Each path has different trust assumptions and safety properties. See Security and Control.

Per-transaction limit — A cap on the size of any single action. No individual payment, deposit, or trade can exceed this value. See Agent Permissions and Limits.

Per-payment rules — Rules that apply to a specific one-off payment, such as a custom review delay, expiry, or whether recipient claim is allowed. These narrow the account-wide one-off payment rules. See One-Off Payments.

Per-vendor rules — Rules that apply to a specific recurring vendor relationship, such as the period window, transaction count limit, cooldown, unit limits, USD limits, and asset mode. These narrow the account-wide recurring payment rules. See Recurring Payments.

Performance fee — A fee charged only on Earn vault profits, never on principal. Currently 20% on profits. See Earn Under the Hood.

Period limit — A cap on how much an agent can do within a recurring time window (day, week, or month). Applies to spending, action counts, and swap or rebalance frequency. Unused capacity does not roll over. See also: period window. See Agent Permissions and Limits.

Period window — The recurring time basis for period-based limits (day, week, or month). The agent-wide period window is an account-wide setting, so all agents reset on the same cycle. Recurring payment paths and one-off payment paths can also define their own period windows at the account-wide or per-vendor level. See also: period limit. See Agent Permissions and Limits.

Pending — The state where a new agent, vendor relationship, or trusted destination has been added but is waiting behind an activation delay or timelock before it becomes active. Pending entities cannot be used until the delay passes and they are confirmed. See also: active.

Primary asset — The main token tracked for unit-based limits in a recurring vendor relationship. For example, USDC might be the primary asset for unit caps while other stablecoins could still be accepted under USD-denominated caps. See also: unit limits. See Recurring Payments.

Private key — A cryptographic secret that controls a key-based wallet. In Hightop, your funds live in a smart contract wallet, which is enforced by smart contract logic rather than controlled by a single private key. The relevant private keys belong to the control wallet — not to the Hightop smart contract wallet itself. Agents do not hold those keys, and Hightop's servers do not hold them either; by default they live within Turnkey's infrastructure, and control can later be moved to a wallet you fully control.

Productive collateral — Earn vault shares used as collateral for borrowing. They continue to earn yield while backing your debt, so your collateral is not sitting idle. See Borrowing Under the Hood.

Protocol layer — The layer in Hightop's architecture that connects to external financial protocols — yield markets, trading venues, and borrowing infrastructure — through the wallet's adapters. In Hightop, the two most important protocols in this layer are Underscore Protocol for wallet and earn infrastructure and Ripe Protocol for borrowing. See Architecture.

R#

Rebalance — Moving funds between protocols, assets, or positions to optimize allocation. Vault agents rebalance Earn positions; user agents can rebalance portfolio holdings within policy-aware boundaries.

Recipient claim — The ability for the recipient of a one-off payment to claim the funds directly once the payment becomes claimable. Must be enabled at both the account-wide level and the individual payment level. See also: claimable. See One-Off Payments.

Recurring payment — A payment to a pre-approved vendor that repeats within configured limits. The vendor, limits, and relationship rules are fixed when the vendor is approved. See Recurring Payments.

Recurring vendor — See: approved vendor.

Review delay — A waiting period before a one-off payment can be claimed or executed. Applied to payments above the instant threshold. Gives you time to review and cancel. Distinct from an activation delay (which holds a new agent or vendor) and a cooldown (which spaces out repeated actions). See also: activation delay, cooldown, instant threshold. See One-Off Payments.

Revert — When a blockchain transaction fails, it reverts — all changes are undone and no funds move. In Hightop, any action that violates a rule reverts entirely.

Ripe Protocol — The open-source borrowing and lending protocol that powers Hightop Borrow, built by the Hightop team. Supports unified multi-collateral lending with productive collateral. Learn more at ripe.finance and see the source code on GitHub.

Rule stacking — The way Hightop evaluates controls in layers: account-wide rules → agent rules → path-specific rules (per-vendor rules, per-payment rules, or per-destination rules depending on the payment path). The most restrictive rule always wins. See Agent Permissions and Limits.

S#

Safe — A multi-signature wallet (by Safe) that requires multiple approvals to act. You can move your control wallet to a Safe so no single key can change your account's rules. See Your Hightop Wallet.

Seed phrase — A recovery phrase for a crypto wallet, typically 12 or 24 words. Hightop users do not need to manage a seed phrase — the control wallet is created and secured through Turnkey.

Settlement layer — The bottom layer of Hightop's architecture: the Base blockchain where transactions settle and the public record lives. See Architecture.

Slippage — The difference between the expected price and the actual execution price of a trade. Hightop lets you set a maximum slippage limit per agent to protect against poor execution. See Agent Permissions and Limits.

Smart contract — A program deployed on a public blockchain with built-in logic for who can do what, under what conditions, and within what limits. Hightop's control model is enforced by smart contracts — not just by app settings or backend policy. See Why Onchain Enforcement Matters.

Smart contract wallet — The onchain wallet that holds your assets, Earn positions, and borrowing state, and enforces the rules your control wallet configured. This is where your funds actually live. It is not the same thing as the control wallet, and it is not a simple wallet address controlled by a single private key. Every Hightop account is backed by one smart contract wallet deployed on Base. See Your Hightop Wallet.

Stablecoin — A digital currency designed to track the value of a traditional currency, typically the US dollar. USDC is the primary stablecoin used in Hightop — one USDC represents one dollar. Stablecoins settle in seconds, move across borders without intermediaries, and cost fractions of a cent to send.

T#

Timelock — A mandatory waiting period before certain high-impact changes take effect. Adding a trusted destination, for example, is timelocked for days. During this timelock, the pending trusted destination can still be cancelled before it becomes active. Timelocks exist so that even a compromised control wallet cannot cause instant damage. See Why Onchain Enforcement Matters.

Trusted destination — A pre-approved address inside the Trusted Transfers path — typically your own wallet, cold storage, reserve destination, or a connected bank account. Hightop may refer to the full set as your trusted destinations or trusted destination list. See Trusted Transfers.

Trusted Transfers — The highest-trust payment path in Hightop, for fast transfers to your own pre-approved destinations. This is the main product term. Once a trusted destination is active, transfers to it bypass the recipient-level friction of recurring and one-off payments. If an agent initiates the transfer, that agent's delegated limits still apply. If the control wallet initiates it, those agent caps do not apply. Adding new destinations is delayed for security; removing them is immediate. See Trusted Transfers.

Turnkey — A secure key-management platform (turnkey.com) that creates and secures the default control wallet for Hightop accounts. By default, access to that control wallet is tied to your email-based login. The keys are stored within Turnkey's infrastructure, not on Hightop's servers. See Your Hightop Wallet.

Two-phase validation — The way Hightop checks agent actions: once before execution (is the agent active? does it have permission? is the asset allowed?) and once after (did the financial outcome stay within limits?). Both phases happen within the same atomic transaction. See Wallet Model.

U#

Underscore Protocol — The open-source wallet and vault infrastructure that powers Hightop's smart contract wallets and Earn vaults, built by the Hightop team. Learn more at underscore.finance and see the source code on GitHub.

Unified loan — Hightop's borrowing model where your entire portfolio backs a single loan rather than requiring separate loans per asset. One position, one interest rate, one set of thresholds to monitor. Powered by Ripe Protocol. See Borrowing Under the Hood.

Unit limits — Token-denominated caps (per-payment, per-period, and lifetime) on a recurring vendor relationship, tracked in the primary asset. Distinct from USD limits, which are dollar-denominated. The most restrictive of the two always applies. See also: primary asset. See Recurring Payments.

USD limits — Dollar-denominated caps (per-payment, per-period, and lifetime) on a recurring vendor relationship. Distinct from unit limits, which are token-denominated. The most restrictive of the two always applies. See also: unit limits. See Recurring Payments.

USDC — A stablecoin pegged to the US dollar — one USDC equals one dollar. The primary asset for payments and yield in Hightop. USDC settles in seconds on the blockchain and costs fractions of a cent to send.

V#

Vault shares — Tokens that represent your proportional ownership of a Hightop Earn vault. When you deposit into a vault, you receive shares. When you withdraw, you redeem shares. Vault shares can also serve as productive collateral for borrowing. See Earn Under the Hood.

Vendor-initiated billing — A mode where an approved recurring vendor can claim payment directly, within configured limits, without the agent or account controller pushing each payment. Requires both an account-wide master switch and a per-relationship opt-in — neither alone is sufficient. Also called pull payments. See Recurring Payments.

Venue — A supported market, protocol, or exchange that an agent can interact with. Agents can be restricted to a specific set of approved venues. See Agent Permissions and Limits.

W#

Working capital — Liquid funds available for operations. In Hightop, agents can access working capital by borrowing against existing assets rather than selling them — useful when agents need to spend before revenue settles. See Borrowing Under the Hood.

Wallet layer — The layer in Hightop's architecture where the smart contract wallet lives. It holds assets, enforces policies onchain, and connects to external protocols through adapters. See Architecture.

X#

x402 — An open payment protocol developed by Coinbase that builds on HTTP 402 Payment Required so apps, APIs, and AI agents can charge and pay for digital services directly over standard web requests. See Emerging Payment Protocols. See also: MPP.