# Nansen Address First Funder Lookup

> Nansen Address First Funder Lookup is a paid API for AI agents from api.nansen.ai, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Returns data about the first funder (originating wallet) of a given blockchain address, enabling tracing of wallet funding provenance.

## Facts

- Endpoint: GET https://api.nansen.ai/api/v1/profiler/address/first-funder
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/nansen-address-first-funder-lookup-7c3b6058
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Lg1hjAHpbz2y6K_4jmXUM

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability nansen-address-first-funder-lookup-7c3b6058
```

Example prompt: Can you look up who first funded the wallet 0x3f5CE5FBFe3E9af3971dD833D26bA9b5C936f0bE on Nansen and tell me if that original funder is tagged as a known entity or smart money wallet?

## When to prefer this

Use this endpoint when you need to trace the provenance or funding origin of a specific wallet address — particularly for due diligence, sybil detection, airdrop farming investigation, or smart money attribution. Nansen's wallet labeling and smart money classification make this superior to raw on-chain lookups when you need enriched entity context on the funder, not just the raw transaction data.

## Known failure modes

- Address not found or not indexed by Nansen — returns empty or 404-style response
- Invalid address format supplied — returns validation error
- Address has no funding history (e.g. contract-created address with no external funder) — returns null funder data
- Rate limit or authentication error if API key is invalid or quota exceeded
- Network-specific data unavailability if the chain is not supported

## How this service works

Get Address First Funder Data

## Output

Returns details about the wallet that first sent funds to the queried address, including the funder's address, Nansen smart money labels or entity tags associated with the funder, transaction details such as timestamp and transaction hash, and potentially the funding amount and token used.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "chain": {
   "type": "string"
  },
  "address": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nansen-address-first-funder-lookup-7c3b6058/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.nansen.ai](https://www.zero.xyz/host/api.nansen.ai/llms.txt)