Marketplace MCP Server

Prepare the on-chain Seaport cancel transaction for an active order. Only the order's offerer can execute it (Seaport enforces msg.sender == offerer), so the calldata is safe to return. After it confirms, POST { txHash } to the confirm endpoint to update the book.

Prepare a SELL listing or Dutch auction. Verifies the seller OWNS the position and it's transferable (not voted/attached), builds the Seaport order with the Interface fee injected by the server, and returns the one-time NFT approval + EIP-712 typed data to sign. Never signs or holds keys.

Prepare a BID/offer on a position: returns the Seaport order to sign (EIP-712), the currency approval needed, and how to submit it. The agent reads its Seaport counter, signs, and POSTs the signed order — settlement stays on Seaport.

Prepare the non-custodial transaction package to BUY a listing (or accept an offer): ordered approvals + Seaport fulfillOrder calldata + a fresh contents snapshot. prepared.summary quotes the CURRENT price (Dutch auctions interpolate, asOf says when); the approval grants approveBaseUnits — slightly above the quote on a decaying order, never above maxTotalBaseUnits — and Seaport charges the exact interpolated amount at fill. On auctions, prepared.cleanup is an optional post-settlement tx that zeroes the residual allowance. The agent's own wallet signs and submits — this never signs or holds keys.

Full detail for one order including a FRESH live-contents snapshot (principal, claimable rewards, voting/earning power, as_of_block).

Active listings/auctions for a market. Each row carries the ask and the position's underlying contents priced at current market (published formula: /docs#data-sources), plus discountPct (the difference between them). Sorted by discount percentage, descending.

List the markets this marketplace facilitates (asset, chain, currencies, fee).

List orders created by an address (its listings, auctions, offers). Status is reconciled by the background worker — treat as advisory until checked at fill.

List the positions an address owns in a market, with listability (voted/attached positions can't transfer).

Recently settled sales for a market. `amount` is the EXACT settled total (incl. fee) from the on-chain fill where the indexer recorded it, with `settledAt` the block time and `exact: true`; otherwise it falls back to the listed ask with `exact: false` (a decayed Dutch auction settles BELOW its listed amount, so treat inexact rows as an upper bound).

Subscribe a wallet to push notifications (order_filled / offer_received / saved_search) via an HMAC-signed webhook — the agent-native alternative to polling. Two-step: call WITHOUT `signature` to get the exact message to sign (EIP-191 personal_sign), then call again WITH the signature. `chainId` is signed over and the signature is verified on THAT chain, so pass the chain the wallet actually signs on (smart-wallet signatures do not validate cross-chain). Each signed message is SINGLE-USE: resending the same body returns 409 replayed_signature — retry with a fresh timestamp and a new signature. The response includes the webhook HMAC secret ONCE (verify x-market0x-signature = hex(HMAC-SHA256(rawBody, secret))).

List a wallet's notification subscriptions (webhook URLs redacted to origin).

Delete a notification subscription. Two-step like subscribe_notifications: call without `signature` to get the message to sign. `chainId` is signed over and verified on that chain. Signed messages are single-use.