Fees

HISS is free to use. This page is the single, honest answer to “what does HISS cost?” There is no subscription, no HISS Credits to buy, no plan tiers, and nothing on the website is gated behind a paywall. The only things you ever pay are ordinary blockchain costs and the onchain vault fees that a vault discloses before you deposit.

The website and app are free

Browsing HISS, authoring and validating Coils, running readiness checks, generating receipts, connecting a wallet, reading every risk disclosure, and using the workbench are all free — forever. HISS does not sell a subscription, does not meter access behind a paid plan, and does not run a checkout. Safety information and validation are never paywalled.

The SDK, CLI, MCP server, and skills are open and free

The agent surfaces are free too. The HISS CoilOps MCP server, the agent kit, the tools API, and the agent skill file are open-source and route agents to deterministic, local computations. Skills carry no charge; they simply point agents at the tools.

What you actually pay

• Blockchain gas. Any onchain action — a deposit, a stake, a withdrawal — costs network gas on Robinhood Chain. That is a network cost paid to validators, not a fee to HISS.
• Vault creation fee (disclosed, contract-enforced). Publishing a public vault onchain may carry a disclosed creation fee. Saving and validating a vault candidate is free. The full schedule lives in vault fees and is enforced by the deployed contracts, shown on every vault page and in every receipt.
• Vault performance fees (per vault config). A vault may charge a creator performance fee on new net profit above its high-water mark — never on losses, never until prior losses are recovered. The rate is set per vault and always displayed. HISS’s protocol share is carved from the creator fee, never from depositor principal.
• Swap slippage and liquidity costs. When a vault trades, market slippage and liquidity conditions are real costs of execution. They are market costs, not a HISS fee, and there is no hidden spread taken by HISS.

No hidden costs

To be explicit: there is no hidden subscription, no HISS Credits checkout, and no website plan gating anywhere on HISS. An onchain vault fee is an onchain vault fee — never described as a website subscription. Every fee that can ever apply is disclosed onchain and on the surface where it applies before you act.