How to connect OpenSea to Hermes Agent
Connect OpenSea to Hermes with ClawLink: paste your OpenSea key once and 24 tools work from chat. No MCP server to run, nothing stored on your machine.
OpenSeaAPI KEYMCPOpenSea is the world's first and largest NFT marketplace for NFTs and crypto collectibles.. Once connected, Hermes Agent can read and act on OpenSea from chat — pairing, token refresh, and tool wiring handled for you.
Most guides for giving Hermes Agent OpenSea access start with registering your own OAuth app or pasting API keys into env files, then leave the token refresh and tool wiring to you. ClawLink gives Hermes a more practical OpenSea setup: pair once in the browser and your always-on Hermes agent can act on OpenSea for you, reading and doing real work on your behalf with no auth, token refresh, or tool wiring to build yourself.
Setup
It takes three steps to connect Hermes to OpenSea.
1Install and pair
Install the ClawLink plugin, then pair Hermes with a one-time browser approval:
hermes plugins install ClawLink-HQ/hermes-plugin --enable- 2
Connect OpenSea
Paste your API key in the dashboard.
- 3
Use it from chat
Ask Hermes Agent: "What can you do with OpenSea?"
Install by command
The prompt above walks Hermes through this. By hand, it is four commands and a browser approval:
hermes plugins install ClawLink-HQ/hermes-plugin --enable
hermes clawlink begin # prints an approval link — open it and approve
hermes clawlink finish # after approving in the browser
hermes clawlink testThen connect OpenSea in the ClawLink dashboard — paste your OpenSea API key once.
Verify the connection by asking Hermes:
Use OpenSea to build criteria offer and walk me through the result in plain English.
Using a different agent?
The Hermes plugin is one client of ClawLink's MCP server. Claude Code, Cursor, Codex, or any agent that can run a shell command pairs with the same ClawLink account through the CLI:
npx -y @useclawlink/cli loginlogin opens the same browser approval and stores a credential locally. Once OpenSea is connected in the dashboard, that agent calls the same 24 OpenSea tools over MCP. Full setup for MCP clients and shell agents: connect apps to any AI agent.
OpenSea MCP for Hermes
Looking for a OpenSea MCP server for Hermes Agent? ClawLink connects OpenSea to Hermes Agent and exposes 24 OpenSea tools your agent can call over MCP, with hosted auth and nothing to run or maintain yourself. Using OpenClaw instead? The OpenClaw OpenSea integration works the same way.
What the Hermes Agent OpenSea integration can do
24 OpenSea tools are ready for Hermes Agent once the account is connected.
All 24 OpenSea tools for Hermes
| Tool | What it does |
|---|---|
Build criteria offer open_sea_build_criteria_offer | Build a portion of a criteria offer including the merkle tree needed to post an offer |
Fulfill listing open_sea_fulfill_listing | Retrieve all the information, including signatures, needed to fulfill a listing directly onchain |
Fulfill offer open_sea_fulfill_offer | Retrieve all the information, including signatures, needed to fulfill an offer directly onchain |
Get account open_sea_get_account | Get an OpenSea Account Profile including details such as bio, social media usernames, and |
Get all listings by collection open_sea_get_all_listings_by_collection | Get all active, valid listings for a single collection |
Get all offers by collection open_sea_get_all_offers_by_collection | Get all active, valid offers for the specified collection |
Get best listing by nft open_sea_get_best_listing_by_nft | Get the best listing for an NFT |
Get best listings by collection open_sea_get_best_listings_by_collection | Get the cheapest priced active, valid listings on a single collection |
Get best offer by nft open_sea_get_best_offer_by_nft | Get the best offers for an NFT |
Get collection open_sea_get_collection | Get a single collection including details such as fees, traits, and links |
Get collection stats open_sea_get_collection_stats | Get stats for a single collection on OpenSea |
Get collections open_sea_get_collections | Get a list of OpenSea collections with optional filtering and pagination |
Get contract open_sea_get_contract | Get a smart contract for a given chain and address |
Get events open_sea_get_events | Get a list of events from OpenSea based on various filters like timestamps and event types |
Get listings open_sea_get_listings | Get the complete set of active, valid listings |
Get nft open_sea_get_nft | Get metadata, traits, ownership information, and rarity for a single NFT |
Get order open_sea_get_order | Get a single order, offer or listing, by its order hash |
Get payment token open_sea_get_payment_token | Get a smart contract for a given chain and address |
Get traits open_sea_get_traits | Get the traits in a collection |
Create criteria offer open_sea_create_criteria_offer | Create a criteria offer to purchase any NFT in a collection or which matches the specified trait |
Create item offer open_sea_create_item_offer | Create an offer to purchase a single NFT (ERC721 or ERC1155) |
Create listing open_sea_create_listing | List a single NFT (ERC721 or ERC1155) for sale on the OpenSea marketplace |
Refresh nft metadata open_sea_refresh_nft_metadata | Refresh metadata for a single NFT |
Cancel order open_sea_cancel_order | Offchain cancel a single order, offer or listing, by its order hash when protected by the |
Try it: find the OpenSea tool you need
Browse the 24 OpenSea tools
Click any tool to see exactly what Hermes can do and copy a ready-to-use prompt.
Example prompts
Use OpenSea to build criteria offer and walk me through the result in plain English.
Use OpenSea to fulfill listing and walk me through the result in plain English.
Use OpenSea to fulfill offer and walk me through the result in plain English.
Pull the relevant data from OpenSea, summarize it in plain English, and point out anything that needs attention.
ClawLink vs. building it yourself
The alternative to ClawLink is usually manual API key setup plus your own token handling, permission troubleshooting, and tool plumbing for Hermes Agent. That is fine if you want to build and maintain the integration yourself. Most teams just want OpenSea working from chat.
| Manual | ClawLink | |
|---|---|---|
| Credential handling | Collect, validate, store, and rotate the OpenSea API key yourself, then make sure every tool call uses the right account. | Users complete the hosted ClawLink setup once and the connected OpenSea account becomes available to the agent without you building credential management. |
| Ongoing maintenance | You own refresh logic, permission debugging, environment config, and every provider-specific edge case for OpenSea. | ClawLink handles the repetitive integration plumbing so your team can focus on the workflow instead of the infrastructure. |
| Agent usability | You still need to expose the right OpenSea actions to the runtime in a format your agent can reliably use. | 24 tools for OpenSea are already exposed through ClawLink, so the agent can read and act from chat immediately. |
ClawLink vs. Composio
Composio also exposes OpenSea to AI agents. It is developer infrastructure: Python and TypeScript SDKs, an MCP server, and a catalog past 1,000 apps, aimed at teams shipping agent products. ClawLink is built for Hermes Agent users instead. You install the plugin once, connect OpenSea in the browser, and the 24 tools above work from chat. There is no SDK and no config file, and the OpenSea key you paste at setup is stored server-side rather than kept in your environment. Choosing between them? Read the full Composio alternatives comparison.
Troubleshooting
Hermes paired but still can't use OpenSea
Pairing is a two-step handshake: run hermes clawlink begin, approve the link in your browser, then run hermes clawlink finish. If you ran finish before approving, or the approval link expired, run hermes clawlink begin again to get a fresh link. Confirm the plugin was installed with --enable, then verify with hermes clawlink test.
Connection succeeds but no tools appear
Reconnect OpenSea from the dashboard, then start a fresh chat if the runtime still has the old tool catalog loaded.
"Tool schema not loaded yet" error when calling OpenSea tools
OpenSea tool schemas load on demand the first time a tool runs and are cached after that, so this error usually clears on its own: wait a few seconds and retry the same request. If every OpenSea call keeps failing with it in a fresh chat, reconnect from the dashboard, and contact support if it still persists — that pattern points to a configuration problem on our side, not something you can fix by reconnecting again.
OpenSea returns 403 or "permission denied" on one action while others work
Two usual causes. The connected account may not have access to the specific workspace, inbox, store, or project in the request — check that first. If access looks right, the agent may have sent a placeholder value (like "YOUR_ID" or an example id from documentation) instead of a real one: ask it to run a list or search tool first, then retry the action with a real id from those results. Most failures at this stage are one of these two, not ClawLink bugs.
API key setup works but results look incomplete
Double-check that the API key for OpenSea has the right scopes or account access. A valid key can still be too limited for some reads or writes.
FAQ
Is there a Hermes Agent OpenSea integration?
Yes. ClawLink is the fastest way to connect Hermes to OpenSea: link your OpenSea account once in the browser and Hermes Agent can call the OpenSea API through 24 ready-made tools — no custom code or token handling.
How do I connect OpenSea to Hermes with ClawLink?
Install the plugin with hermes plugins install ClawLink-HQ/hermes-plugin --enable, then pair once: run hermes clawlink begin, approve the link in your browser, and run hermes clawlink finish. Connect OpenSea in the dashboard and Hermes can use it from the next message — no config files, and the OpenSea key you paste is stored server-side instead of in your environment.
How long does it take to connect OpenSea to Hermes Agent?
About two minutes. Sign in, click Connect next to OpenSea in the dashboard, authenticate, and Hermes Agent can use it from the next chat message.
Why use ClawLink instead of wiring OpenSea up myself?
The alternative to ClawLink is usually manual API key setup plus your own token handling, permission troubleshooting, and tool plumbing for Hermes Agent. That is fine if you want to build and maintain the integration yourself. Most teams just want OpenSea working from chat.
Hermes paired but still can't use OpenSea
Pairing is a two-step handshake: run hermes clawlink begin, approve the link in your browser, then run hermes clawlink finish. If you ran finish before approving, or the approval link expired, run hermes clawlink begin again to get a fresh link. Confirm the plugin was installed with --enable, then verify with hermes clawlink test.
