A bank routing search API returns ABA numbers from a partial bank name — not a single routing validate. On BankDataStack that is POST https://www.bankdatastack.com/api/v1/routing/database/bank with header X-API-Key and JSON. Official success sample: bank=CITIZENS → CITIZENS NATIONAL BANK, Crockett TX, 113110984.
Starter is $49.99/mo (1,000 calls, then $0.002) with a 7-day trial. Docs: bankdatastack.com/docs. MCP worker host mcp.bankdatastack.com did not resolve on 17 September 2026 — do not assume MCP is live.
Request: official CITIZENS query
curl -X POST "https://www.bankdatastack.com/api/v1/routing/database/bank" \
-H "X-API-Key: YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"bank":"CITIZENS","limit":25}'
Response: official sample (first row)
{
"status": "success",
"message": "Found 25 routing number(s) for bank: CITIZENS",
"count": 25,
"limit": 25,
"data": [
{
"routingNumber": "113110984",
"bank": "CITIZENS NATIONAL BANK",
"address": "1320 LOOP 304 EAST",
"city": "CROCKETT",
"state": "TX",
"zip": "75835",
"phone": "(936) 544-9661",
"dateOfRevision": "042104",
"newRoutingNumber": null,
"active": true
}
]
}
Partial match is supported (CHASE, CITIZENS). Limit is 1–10 on the public docs table; the LLM/example body uses 25 — send what your live docs accept.
Go live
1. Register — 7-day trial.
2. Copy X-API-Key.
3. POST /api/v1/routing/database/bank.
4. Store routingNumber + city/state.
