Watchtower API

Deterministic sanctions & watchlist screening, built for AI agents.

OFACUNEUUK OFSIBIS Entity ListDenied PersonsCanada SEMAITAR~44k partiesdaily

Why it's built for agents: same query + same list snapshot ⇒ byte-identical response, every time. Every reply carries the list snapshot hash and matcher version, so your compliance decisions are reproducible and auditable. Typo- and alias-tolerant. Three ways to pay, one with no signup at all.

Jump to: Quickstart Payment options Endpoints Matching Watches Discovery

Quickstart — first paid call in 60 seconds

1 · Get a key (free trial credit included)

curl -X POST https://watchtower-api.com/v1/keys \
  -H 'Content-Type: application/json' -d '{"note":"my-agent"}'
# → {"api_key":"ak_...","trial_credit_usd":0.05}

2 · Screen a name ($0.02)

curl -X POST https://watchtower-api.com/v1/screen \
  -H 'Authorization: Bearer ak_YOUR_KEY' -H 'Content-Type: application/json' \
  -d '{"name":"Vladmir Putin"}'
# → {"match":true,"matches":[{"name":"PUTIN, Vladimir Vladimirovich",
#      "score":0.97,"source":"OFAC-SDN","programs":["RUSSIA-EO14024"],
#      "dob":["07 Oct 1952"],"nationality":["Russia"]}],
#     "snapshot_version":"...","algorithm":"wt-match-2"}

3 · Check a crypto address ($0.01)

curl -X POST https://watchtower-api.com/v1/screen/address \
  -H 'Authorization: Bearer ak_YOUR_KEY' -H 'Content-Type: application/json' \
  -d '{"address":"0x0330070FD38Ec3bB94F58FA55D40368271E9e54A"}'

Payment options

Option A — x402 (USDC on Base, no signup)

Both screening endpoints speak the x402 protocol (v1 and v2). Call with no credentials, read the 402 challenge (PAYMENT-REQUIRED header for v2, JSON body for v1), and retry with a signed payment. Any standard x402 client handles this automatically:

import { wrapFetchWithPayment, x402Client } from '@x402/fetch';
import { ExactEvmScheme } from '@x402/evm';

const client = new x402Client().register('eip155:8453', new ExactEvmScheme(signer));
const pay = wrapFetchWithPayment(fetch, client);
const res = await pay('https://watchtower-api.com/v1/screen', {
  method:'POST', headers:{'Content-Type':'application/json'},
  body: JSON.stringify({ name:'Wagner Group' })
});   // settlement receipt returned in the PAYMENT-RESPONSE header

Option B — API-key credit

Prepaid balance per key. New keys include free trial credit; top up with a Stripe credit pack via POST /v1/topup (card top-ups activate once the operator's Stripe account is live).

Option C — MCP (native agent tools)

Point any MCP client at https://watchtower-api.com/mcp (streamable HTTP). Tools: create_api_key, screen_name, screen_names_batch, screen_crypto_address, create_watch, list_watches, get_screening_info. Keys are passed as tool arguments — no auth handshake.

Endpoint reference

Method & path	Does	Price
`POST /v1/keys`	Create API key + trial credit	free
`POST /v1/screen`	Screen a name (sanctions + export-control)	$0.02
`POST /v1/screen/batch`	Up to 500 names in one call	$0.015/name
`POST /v1/screen/address`	OFAC sanctioned-address check	$0.01
`POST /v1/watch`	Monitor a name; webhook on change	$0.01/day
`GET /v1/entity/:uid`	Full record for a matched uid	free
`GET /v1/balance`	Remaining credit	free
`GET /v1/lists`	List versions, source hashes, freshness	free
`GET /openapi.json`	Machine-readable spec	free

Matching semantics — `wt-match-2`

Case-, punctuation-, and diacritic-insensitive; token-order-insensitive.
Typo-tolerant (Jaro–Winkler + trigram blend) and subset-aware: "Vladmir Putin" finds "PUTIN, Vladimir Vladimirovich".
Generic tokens (Inc, Company, Ltd…) are discounted, so "Apple Inc" does not false-match unrelated companies.
threshold (default 0.82) trades recall for precision; types filters person / entity / vessel / aircraft.
Deterministic ordering: score desc, then uid asc. Same snapshot + query ⇒ identical bytes.

Watches — monitoring as a subscription

Prepay to watch a counterparty. When the daily list refresh changes that name's match set, we POST your webhook a watch_changed event with added[] (full new records) and removed[] (uids). Failed deliveries retry — you never silently miss a change.

curl -X POST https://watchtower-api.com/v1/watch \
  -H 'Authorization: Bearer ak_YOUR_KEY' -H 'Content-Type: application/json' \
  -d '{"name":"Acme Trading Co","webhook_url":"https://you.example/hook","days":30}'

Discovery & machine docs

/llms.txt · /openapi.json · /.well-known/x402.json · /.well-known/agent-card.json · /v1/lists · MCP at /mcp