polymerdao/polymer-pay-nansen

Nansen Smart Money Analytics

Nansen provides premium onchain analytics — smart money tracking, whale movements, and token flows — as a pay-per-use API through the Polymer Pay proxy. Each request is paid individually with no Nansen account or API key required. Only the three smart money endpoints below are available via x402; other Nansen API endpoints require a direct Nansen subscription.

Authentication

All requests route through the Polymer Pay proxy. Include your Polymer Pay API key in every request:

{
  "headers": {
    "Content-Type": "application/json",
    "x-polymer-pay-api-key": "{{POLYMER_PAY_API_KEY}}"
  }
}

Base URL: https://pay.polymerlabs.org/proxy/https/api.nansen.ai

To get an Polymer Pay API key, sign up at https://my.pay.polymerlabs.org/dashboard/api-keys.

Common Operations

Smart Money Net Flows

Retrieve token net flow data aggregated across labeled smart money wallets. Shows which tokens smart money is accumulating or dumping over 1h, 24h, 7d, and 30d timeframes.

Pricing: $0.05

{
  "method": "POST",
  "url": "https://pay.polymerlabs.org/proxy/https/api.nansen.ai/api/v1/smart-money/netflow",
  "headers": {
    "Content-Type": "application/json",
    "x-polymer-pay-api-key": "{{POLYMER_PAY_API_KEY}}"
  },
  "body": {
    "chains": ["ethereum"],
    "filters": {
      "include_native_tokens": true,
      "include_stablecoins": false
    },
    "pagination": {
      "page": 1,
      "items_per_page": 10
    },
    "order_by": [
      {
        "field": "net_flow_24h_usd",
        "direction": "DESC"
      }
    ]
  }
}

Response: JSON array of tokens with net flow amounts in USD across timeframes (1h, 24h, 7d, 30d), number of smart money wallets involved, and token metadata.

Smart Money DEX Trades

Get real-time DEX trades executed by Nansen-labeled smart money wallets. Useful for spotting what whales are trading right now.

Pricing: $0.05

{
  "method": "POST",
  "url": "https://pay.polymerlabs.org/proxy/https/api.nansen.ai/api/v1/smart-money/dex-trades",
  "headers": {
    "Content-Type": "application/json",
    "x-polymer-pay-api-key": "{{POLYMER_PAY_API_KEY}}"
  },
  "body": {
    "chains": ["ethereum"],
    "filters": {
      "include_smart_money_labels": ["Smart Money"]
    },
    "pagination": {
      "page": 1,
      "items_per_page": 10
    }
  }
}

Response: JSON array of recent DEX trades with wallet label, token pair, trade size in USD, DEX used, transaction hash, and timestamp.

Smart Money Holdings

View aggregate token holdings across all Nansen-labeled smart money wallets. Shows what the smart money is currently holding.

Pricing: $0.05

{
  "method": "POST",
  "url": "https://pay.polymerlabs.org/proxy/https/api.nansen.ai/api/v1/smart-money/holdings",
  "headers": {
    "Content-Type": "application/json",
    "x-polymer-pay-api-key": "{{POLYMER_PAY_API_KEY}}"
  },
  "body": {
    "chains": ["ethereum"],
    "filters": {
      "include_stablecoins": false
    },
    "pagination": {
      "page": 1,
      "items_per_page": 10
    }
  }
}

Response: JSON array of tokens held by smart money wallets with aggregate USD value, number of holders, percentage change over time, and token metadata.

When to Use

• Smart money tracking -- User wants to know what tokens smart money is buying or selling.
• Whale watching -- User wants to see large DEX trades by labeled wallets in real time.
• Alpha hunting -- User wants to find tokens with significant smart money inflows before they pump.
• Portfolio intel -- User wants to see what tokens smart money currently holds.
• Chain comparison -- User wants to compare smart money activity between Ethereum and Solana.

Best Practices

• Filter out stablecoins for signal -- Set include_stablecoins: false to focus on tokens with alpha potential rather than stable parking.
• Use order_by for ranking -- Sort by net_flow_24h_usd descending to surface the highest-conviction moves first.
• Combine endpoints for context -- Cross-reference net flows with holdings to distinguish new accumulation from existing positions being increased.
• Paginate large results -- Default to 10 items per page and paginate forward to avoid oversized responses.
• Respect rate limits -- The API allows 5 requests per second and 60 per minute. Add short delays in batch workflows.
• Chain selection matters -- Pass ["ethereum"], ["solana"], or both in the chains array depending on which ecosystem you need.
• For errors — See @skills/polymer-pay-api-errors/SKILL.md for complete error code reference and troubleshooting