Cowrie Research

seaport-signedzone

2 min read

Seaport SignedZone

  • Name: Seaport SignedZone
  • URL: https://github.com/ProjectOpenSea/SIPs/blob/main/SIPS/sip-7.md
  • Category: Seaport order-authorizer zone / server-signed order middleware / marketplace-side transfer-authorization layer
  • Summary: Seaport SignedZone is OpenSea’s server-signed order gate for restricted Seaport flows. The mechanism is simple: if an approved signer vends the right signature and context, the order goes through. That makes the note useful because it shows how transfer power can sit in marketplace-side signer operations even when token-side policy also exists.
  • What it does:
    • Implements SIP-7 server-signed-order validation for Seaport restricted orders
    • Requires extraData to include an expected fulfiller, expiration, compact signature, and optional context payload
    • Maintains an owner-controlled signer set and rejects removed signers from being reauthorized later
    • Exposes metadata and an API endpoint so fulfillers know where to request server-produced signatures
    • Operates as a Seaport zone hook, so it can participate in order validation around token transfers
    • Serves as OpenSea’s supported authorizer zone for creator-fee-enforced ERC721-C / ERC1155-C flows
  • Key claims:
    • SIP-7 makes the core idea plain: a third party can vend just-in-time signatures for order fulfillment, which also means the order can effectively die when that signer service stops cooperating.
    • The reference SignedZone.sol contract shows where practical power sits. The owner controls the active signer set and advertised API endpoint, and removed signers cannot be restored later.
    • Seaport Hooks documentation matters because it shows zones sit in the execution path, not in some decorative metadata layer. Restricted orders call the zone before and after transfers.
    • In OpenSea’s creator-fee-enforcement flow, SignedZone is also an authorizer on the transfer validator. So this is not just marketplace safety plumbing; it is part of the transfer-admission stack.
    • The note earns its keep because it cleanly separates marketplace-side signed-order control from token-side transfer validators. Those layers can cooperate, but they are not the same thing.
  • Whitepaper: No canonical whitepaper surfaced in this pass. The strongest primary materials were the SIP-7 spec, the reference SignedZone.sol implementation, the Seaport Hooks docs, and OpenSea’s creator-fee-enforcement docs collected in ../../whitepapers/seaport-signedzone-primary-sources-2026-05-11.md.
  • Sources:

Internal linkages

Graph View

Backlinks