Overview - Corsair

Use OpenSea through Corsair: one client, typed API calls. OpenSea uses an x-api-key header. Create a key at docs.opensea.io from a signed-in account, then save it for the opensea integration. Every marketplace route requires it: a request with no key answers 401 and {"errors":["Missing an API Key, ..."]}. Every chain argument takes a slug from chains.list, such as ethereum or base. OpenSea adds chains over time, so the slug is sent as given and the API refuses one it does not index. collections.list also accepts a chain filter. Order lookups come in two shapes. orders.get wraps the result under order; offers.best returns the order bare. Both carry the Seaport protocol_data and the order_hash that identifies the order. Most paged routes take a next cursor and return it back; pass the previous response’s next as this call’s next, which is null on the last page. Three routes differ: collections.top, collections.trending and collections.holders take cursor instead of next. traits.list answers the trait names on a collection, the type of each, and under counts every value with how many NFTs carry it. To select NFTs by trait, pass collection.nfts a traits filter: a JSON array sent as a string, such as [{"traitType":"Background","value":"Red"}]. Several filters are AND-combined. Prices arrive as base-unit strings. An 18-decimal wei amount such as "5900000000000000000" does not fit a JavaScript number, so the value stays a string and decimals tells you where to put the point. What you get:

24 typed API operations

Setup

Install

npm install corsair @corsair-dev/opensea better-sqlite3
npm install --save-dev @types/better-sqlite3

yarn add corsair @corsair-dev/opensea better-sqlite3
yarn add --dev @types/better-sqlite3

pnpm install corsair @corsair-dev/opensea better-sqlite3
pnpm install --save-dev @types/better-sqlite3

bun add corsair @corsair-dev/opensea better-sqlite3
bun add --dev @types/better-sqlite3

Add the plugin

corsair.ts

import Database from 'better-sqlite3';
import { createCorsair } from 'corsair';
import { opensea } from '@corsair-dev/opensea';

export const corsair = createCorsair({
	plugins: [
		opensea(),
	],
	database: new Database('corsair.db'),
	kek: process.env.CORSAIR_KEK!,
	multiTenancy: true,
	hub: {
		projectApiKey: process.env.CORSAIR_API_KEY!,
		signingSecret: process.env.CORSAIR_SIGNING_SECRET!,
	},
});

With multiTenancy: true, scope calls with corsair.withTenant(id). See Quick start for KEK + Hub keys, and Multi-tenancy for account isolation.

Choose authentication

API Key (Recommended)

No setup required yet. When you make your first request as a tenant, Corsair prompts for the API key.

opensea()

More: API Key

Connect a tenant

Mint a connect link and send the tenant to it. Hub hosts the page and delivers the result to your app — see Connect / OAuth.

const { connectUrl } = await corsair.manage.connect.createLink({
	plugin: 'opensea',
	tenantId: 'acme',
});
// redirect the user's browser to connectUrl

Example API calls

Read one collection

const tenant = corsair.withTenant('acme');
await tenant.opensea.api.collections.get({ slug: 'boredapeyachtclub' });

List collections, ten at a time

const tenant = corsair.withTenant('acme');
await tenant.opensea.api.collections.list({ limit: 10 });

See the full list on the API page.

What’s next

API reference

Every opensea.api.* operation with input and output types.

Connect / OAuth

createLink, Hub delivery, and tenant connect flows.

Use with agents

Expose this plugin’s operations as MCP tools.

​Setup

​Example API calls

​What’s next