Data API

A public REST API for large on-chain transfers, wallet balances, token checks, decoded transactions, curated labels and market context on Ethereum, Base, BNB Chain, Arbitrum, OP Mainnet, Polygon and Solana. Reading needs no sign-up. A free key, created after a wallet sign-in, raises the limit.

Base URL: https://farbeamlabs.com/api/v1. The API reference covers every parameter, and the OpenAPI file is machine-readable. You can send requests from the playground.

#Endpoint groups

#Example request

This call asks for the newest USDT transfer on Ethereum of at least $1,000,000.

curl -s "https://farbeamlabs.com/api/v1/transfers?chain=ethereum&token=USDT&min_usd=1000000&limit=1"

const url = new URL("https://farbeamlabs.com/api/v1/transfers");
url.search = new URLSearchParams({ chain: "ethereum", token: "USDT", min_usd: "1000000", limit: "1" });

const res = await fetch(url);
const { data, meta, error } = await res.json();
if (error) throw new Error(`${error.code}: ${error.message}`);
console.log(data[0].uid, data[0].usd, "next:", meta.next_cursor);

import requests

res = requests.get(
    "https://farbeamlabs.com/api/v1/transfers",
    params={"chain": "ethereum", "token": "USDT", "min_usd": 1000000, "limit": 1},
    timeout=30,
)
body = res.json()
if "error" in body:
    raise RuntimeError(body["error"]["code"])
print(body["data"][0]["uid"], body["data"][0]["usd"], body["meta"]["next_cursor"])

#Real response

This response was captured from the running API at 2026-11-04T19:24:11Z. It is complete and unedited. The call also returned the headers x-ratelimit-limit: 120, x-ratelimit-remaining: 119 and x-request-id: req_9e666357141a.

{
  "data": [
    {
      "id": 1217,
      "uid": "ethereum:0x5fe8bf27f732de57e963cb92a0f17173c1e2cdadfdabb241e7d3dc25a346c342:335",
      "ts": "2026-11-04T19:12:59.000Z",
      "chain": "ethereum",
      "block": 26343466,
      "tx": "0x5fe8bf27f732de57e963cb92a0f17173c1e2cdadfdabb241e7d3dc25a346c342",
      "kind": "token",
      "token": "USDT",
      "token_address": "0xdAC17F958D2ee523a2206206994597C13D831ec7",
      "amount": 2500000,
      "usd": 2498505,
      "from": "0x8c5d0c5339c282b3e7f22a207e47d73d0227cba9",
      "to": "0x8b820fe67e8367d322d0c1bfc809cd9fe478df52",
      "sampled": false,
      "from_label": null,
      "from_type": null,
      "to_label": null,
      "to_type": null
    }
  ],
  "meta": {
    "request_id": "req_9e666357141a",
    "as_of": "2026-11-04T19:24:11.890Z",
    "next_cursor": 1217,
    "min_stored_usd": 100000,
    "retention_days": 7
  }
}

The fields worth reading first:

• uid is stable. Use it to remove duplicates between the stream, the REST API and webhooks.
• usd is the amount times the price at indexing. Here the price of USDT was $0.999402.
• from_label and to_label are null because neither address is in the label set. Null means unlabeled, not unknown to the chain.
• next_cursor goes into before on the next call.

#Limits

Cost per call: wallet and token endpoints cost 3 units, transaction lookup costs 2, health, status, key endpoints and /me cost 0, and most other endpoints cost 1. The cost is charged before the handler runs, so a request with a bad parameter still spends units. See rate limits.

#Error format

Every error has one shape. This one is real, from GET /chains/fantom at 2026-11-04T19:23:10Z, with HTTP status 400.

{
  "error": {
    "code": "invalid_chain",
    "message": "Unknown chain. Use one of: ethereum, base, bnb, arbitrum, optimism, polygon, solana.",
    "request_id": "req_fddb4d074326"
  }
}

Details are on the errors page.

#What makes it different

This API is small, and these are the choices that shape it.

• Every token check names its source and the exact field it read, in checks[].source and checks[].field.
• A missing field is unknown. It never counts as a pass. There is no composite score to hide that in.
• Coverage is part of the data: sampled on every event, large_transfer_index on every chain, coverage_note on wallets, blocks_scanned on activity, stale on a saved copy.
• Accounts need no email and no password, only a Solana wallet signature. The server stores only a SHA-256 hash of each key.
• Status reports measured poller and source state, including failure counts since the last restart.

#What it lacks

Check this list before you build on it.

• History ends at 7 days. There is no archive and no export. Planned
• The index covers curated tokens on four EVM chains, plus a Solana sample. You cannot ask for all transfers of an arbitrary token.
• Transfers below $100,000 are not stored. There is no time-range filter, only the before cursor.
• There is no raw RPC, no trace data, no internal transfers, no decoded events beyond ERC-20 Transfer.
• Time fields are not uniform. /transfers returns ISO 8601 strings. /tx and indexed_transfers inside /wallets return Unix milliseconds.
• There is no SLA, no paid tier, no official SDK, no GraphQL and no WebSocket. Planned
• Sign-in works with Solana wallets only, so an EVM-only user cannot create a key today. EVM sign-in is Planned.

If you need any of these today, see the RPC provider comparison and the explorer comparison.

#Start

1. Send a request without a key to confirm the shape.
2. Sign in to the console with a Solana wallet, and create a free key. Save it, because it is shown once.
3. Send it as Authorization: Bearer <key>.
4. Read the quickstart.

Farbeam data is for information only. It is not financial advice.