Claude

Connect Nansen to Claude with your Nansen account. Sign in through OAuth, no API key. Tool calls spend your Nansen API credits.

Explore tokens, Smart Money activity, and public wallets from inside Claude. Sign in with your Nansen account; no API key to create or paste.

Install

1. Open Nansen in the Claude connector directory and select it. You can also open Customize → Connectors and search for Nansen.

2. Select Connect, then sign in to Nansen. Choose the account whose API credits you want to use. Claude identifies itself to Nansen automatically; there is no client ID or secret to enter.

Nansen then works in Claude on the web, in the desktop app, and on mobile. In a conversation, open the + menu, choose Connectors, and make sure Nansen is turned on.

Connectors submenu in a Claude conversation with the Nansen toggle turned on

Tool calls spend your Nansen API credits, not your Claude subscription, and are subject to rate limits. One prompt can trigger several calls, and some tools cost far more per call than others. Nansen is read-only: it cannot trade or move assets.

Plan and workspace eligibility

Connectors are available on Claude Free, Pro, Max, Team, and Enterprise. On Team and Enterprise plans an organization Owner may need to enable Nansen in Organization settings → Connectors before members can connect. Nansen itself imposes no Claude plan requirement; it requires a Nansen account with sufficient API credits.

Claude Code

Claude Code signs in through the same Nansen account and needs no API key in its configuration.

claude mcp add --transport http nansen https://mcp.nansen.ai/ra/connector-curated/mcp

Then run /mcp inside Claude Code, select nansen, and choose Authenticate. Your browser opens the Nansen sign-in page. Approve access and return to the terminal; Claude Code stores the session and refreshes it for you.

This signs in with your Nansen account and uses the 12 curated tools. For the full tool catalog, use the API-key command on Manually connecting to Nansen MCP instead, or alongside it under a different server name.

If you previously added Nansen with an API key, remove that entry first:

claude mcp remove nansen

Claude in Slack (Claude Tag)

Follow the Claude Tag OAuth setup to connect Nansen in Slack. For shared channels, connect a dedicated Nansen account and limit the access bundle to the intended channels. Requests through the bundle consume that account's Nansen API credits.

Verify your connection

With Nansen turned on, send:

Use Nansen to get token information for USDC on Ethereum, contract 0xA0b86991c6218b36c1d19d4a2e9eb0ce3606eb48. Show the returned data and report any tool error.

Check that Claude actually calls Nansen and returns token data. A visible tool list or a general answer about USDC does not verify account access. This check consumes API credits. Market figures change, so compare the answer with the tool result rather than expecting a fixed price.

Try a research prompt

• "Show Solana tokens with Smart Money inflows over the last 24 hours."

• "Show the current token balances held by Smart Traders and funds on Ethereum."

• "Find Wintermute in Nansen, then show its current token holdings. Tell me which entity or address you used."

• "Look up PEPE on Ethereum and summarize its recent price and token flows."

Claude, ChatGPT, and Grok use the same 12 curated tools. See credits per call. Availability depends on supported chains, markets, and account access. If you need the full tool catalog, connect with an API key as described in Manually connecting to Nansen MCP.

Troubleshooting

Problem	What to do
Nansen is missing from the connector list	On Team and Enterprise, ask an Owner to enable Nansen in Organization settings → Connectors. If it is still unavailable, use the manual setup.
Sign-in is requested again, or access is denied	Reconnect with the intended Nansen account.
Insufficient credits	Check API credits for the account used during sign-in at Nansen API. The requested operation may cost more than the remaining balance.
Rate limit reached	Wait before retrying and follow any retry guidance in the error. Avoid repeatedly submitting the same prompt.
Tool call fails with a request ID	Save the request ID, prompt, error text, and time of the request, then send them to Nansen support. Do not share credentials.
Claude answers without calling Nansen	Turn Nansen on in the conversation's tools menu and explicitly ask it to use Nansen.
Claude Code says the server needs authentication	Run /mcp, select nansen, and choose Authenticate again.

To stop using Nansen, open Customize → Connectors → Yours, select Nansen, and disconnect or remove it. In Claude Code, run /mcp, select nansen, and choose Clear authentication.

Manual setup (custom connector)

You do not need this once Nansen is installed from the directory. Use it if your organization cannot install directory connectors, or to test against the server directly.

1. In Claude, open Customize → Connectors, select Add, then Add custom connector. On Team or Enterprise, an Owner does this under Organization settings → Connectors.

   

   Customize page with the Connectors tab selected and the Add button

   

   Add menu showing Add custom connector
2. Enter these values, then select Continue. Leave the OAuth client fields on the next screen empty; Claude identifies itself to Nansen automatically.

   Field	Value
   Name	Nansen
   MCP server URL	https://mcp.nansen.ai/ra/connector-curated/mcp

   

   Add custom connector dialog with the name Nansen and the Nansen MCP server URL
3. Select Add, then Connect. Sign in to Nansen on the consent page and select Allow. The page shows the access being requested (read-only) and where you will be sent back to (claude.ai).

   

   Nansen consent page asking to connect Nansen to Claude with read-only access
4. Nansen now shows as connected, with its 12 read-only tools listed under Tool permissions.

   

   Nansen connector page in Claude showing Disconnect and the list of read-only tools

Use the server URL above for Claude. The /ra/mcp endpoint in Manually connecting to Nansen MCP is for API-key clients.