Opus finding
Workflow: Selling an NFT documents a non-existent two-POST flow
mediumdocs-gaphigh
- opensea/opensea-marketplace/references/marketplace-api.md:327-332
Step 1 says 'POST to build', step 3 says 'POST again with signature'. The endpoint does not support a build/preview round-trip — listings are constructed client-side (counter, salt, zone, EIP-712 hash) and POSTed once. The Making an Offer workflow has the same defect. Agents executing this workflow would either double-post (creating a duplicate listing or a 400) or wait for a build response that doesn't exist.
Recommendation
Replace the workflow with: (1) Construct OrderComponents client-side (fetch counter from Seaport, pick salt/zone), (2) Sign EIP-712, (3) POST { protocol_address, parameters, signature } once, (4) Monitor.