> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tentaclepay.com/llms.txt
> Use this file to discover all available pages before exploring further.

# FAQ

> Common questions about Tentacle Pay, x402 on Sui, the wallet, and cross-chain payments.

<AccordionGroup>
  <Accordion title="What is Tentacle Pay?">
    Tentacle Pay is payment infrastructure for autonomous agents on Sui. It ships a wallet agents control (`tpay`), an [x402](https://x402.org) facilitator so any API, MCP server, or agent can accept onchain payments on Sui, and a cross-chain layer so an agent holding funds on Sui can pay services on other chains — all without a human in the loop.
  </Accordion>

  <Accordion title="What is x402?">
    [x402](https://x402.org) is an open payment standard built around the HTTP `402 Payment Required` status code. A server returns payment requirements; a client signs a payment; a facilitator verifies and settles it onchain. See the [x402 docs](https://x402.org) for the full protocol.
  </Accordion>

  <Accordion title="Why Sui?">
    Sui covers gas for [stablecoin transfers](https://blog.sui.io/sui-launches-gasless-stablecoin-transfers/) at the network level: agents can move USDC and other supported stablecoins without holding a gas token, with sub-second finality and parallel execution. The Tentacle Pay facilitator sponsors gas for everything Sui's native path leaves out — sub-cent stablecoin payments and any non-stablecoin coin — so agents only ever need a stablecoin balance and no payment fails for lack of SUI.
  </Accordion>

  <Accordion title="Do I need to run my own facilitator?">
    No. Point your server at `https://facilitator.tentaclepay.com` and you're done. The facilitator is free to use and implements the standard x402 `/verify`, `/settle`, and `/supported` endpoints, so any x402-compatible server library works.
  </Accordion>

  <Accordion title="Does the facilitator hold funds?">
    No. The facilitator verifies signed payment payloads and submits them to Sui. It never custodies funds — settlement goes directly from the buyer to the seller's `payTo` address onchain. It does sponsor gas, so the buyer never needs SUI.
  </Accordion>

  <Accordion title="Which networks are supported?">
    Sui Mainnet (`sui:mainnet`) and Sui Testnet (`sui:testnet`) for native x402 payments. Cross-chain settlement to EVM destinations is live on testnet. See [Supported networks](/x402/supported-networks).
  </Accordion>

  <Accordion title="Which tokens can agents pay with?">
    USDC is the default stablecoin on both mainnet and testnet. On mainnet, USDSUI, sUSDe, USDY, FDUSD, AUSD, and USDB are also supported — all 6-decimal stablecoins that Sui transfers gasless natively, with the facilitator covering sub-cent payments. See [Supported networks](/x402/supported-networks) for the coin types.
  </Accordion>

  <Accordion title="How small can a payment be?">
    Payments are denominated in stablecoin atomic units (USDC has 6 decimals), so an endpoint can charge a fraction of a cent per call, and a payment of any size settles gasless. Price routes in USD (for example `"$0.001"`) and the SDK resolves the exact token amount. On mainnet, Sui's native gasless transfers cover stablecoin payments of `0.01` or more, and the facilitator sponsors gas for anything below that.
  </Accordion>

  <Accordion title="What is the Tentacle Pay wallet (tpay)?">
    `tpay` is a command-line wallet built for agents. It holds a Sui keypair in your OS keychain, enforces spending rules, and turns `tpay curl` into a drop-in for `curl` that clears x402 paywalls automatically. It also runs as an [MCP server](/wallet/agents) so agents like Claude can pay for APIs directly. See the [Wallet overview](/wallet/overview).
  </Accordion>

  <Accordion title="Can I use any x402 SDK?">
    Yes. The facilitator speaks the standard x402 v2 protocol, so any x402 client or server library works. On Sui, `@tentaclepay/sui-x402` provides the `exact` scheme for the client, server, and facilitator roles, with USD price parsing for Sui's default stablecoin.
  </Accordion>

  <Accordion title="How does cross-chain payment work?">
    The agent keeps one Sui wallet. To pay a service on another chain, it pays USDC into the Tentacle Pay Move package and asks a [dWallet](https://ika.xyz) — a key split across Ika's 2PC-MPC network — to sign the destination-chain payment. A verifier attestation authorizes the call. The signed authorization settles on the destination chain. See [Cross-Chain architecture](/cross-chain/architecture).
  </Accordion>

  <Accordion title="Is Tentacle Pay open source?">
    Yes. The wallet, the `@tentaclepay/sui-x402` SDK, the facilitator, and the Move smart contracts are on [GitHub](https://github.com/tentaclepay).
  </Accordion>
</AccordionGroup>