Fairview Savings and Loan API integration (OpenBanking)

Deliverables checklist

• OpenAPI 3.1 specification covering login, accounts, transactions, transfers and RDC
• Protocol analysis report (TLS pinning, endpoint map, header signing, retry semantics)
• Reference client in Python (httpx + pydantic) and Node.js (undici + zod)
• Postman / Bruno collection plus replayable HAR captures
• Unit tests, contract tests and a synthetic-data fixture set
• Compliance brief: §1033 readiness, GLBA Safeguards mapping, consent-record schema

Why a custom integration is needed

Roughly 4,500 US community banks and savings & loans share the structural reality of Fairview: small enough to fall under the SBA size standard that exempts them from the mandatory phases of the CFPB §1033 rule, large enough to operate a real mobile app with member transaction data. As of Q1 2025 there were 546 federally insured savings banks in the United States according to the FDIC. Most of these institutions will never publish a first-party developer API — but their members still want their data inside personal-finance, accounting and tax tools. That is exactly the gap we close.

1. Bookkeeping & accounting sync

Pull GET /accounts and GET /accounts/{id}/transactions nightly, normalize to OFX-equivalent fields (FITID, TRNAMT, MEMO), and push into QuickBooks Online or Xero. Solves the "small-business member with a thrift account" problem that aggregators like Plaid sometimes mis-categorize.

2. Member-facing PFM dashboard

A credit-union-adjacent fintech embeds a Fairview connector to ingest balances and transactions via OAuth-style consent. The OpenFinance pattern: consumer authorizes data sharing under §1033, the connector hits POST /oauth/token with an access ID, and the dashboard renders the same balance the member sees in the bank app.

3. Loan underwriting & mortgage refi

Mortgage originators request 24 months of statements through GET /statements?from=YYYY-MM&to=YYYY-MM to verify income and reserves. The pipeline produces redacted PDFs plus structured JSON, signed for tamper-evidence. Useful for community lenders that integrate with Fannie Mae's Day 1 Certainty.

4. Treasury automation for SMB members

A small-business member using a Fairview operating account triggers internal sweeps to a Money Market account when balances exceed a threshold. The flow: webhook on transaction posting → server-side rule → idempotent POST /transfers with a client-generated UUID. End-to-end test fixtures included.

5. Fraud & compliance monitoring

Stream transactions to a SIEM or AML platform (e.g. Unit21, Hawk AI). Each event carries device-binding metadata from the biometric session bridge, so risk teams can score "new device + large transfer" patterns without weakening the original Face ID or fingerprint authentication.

Login + token exchange (Python, httpx)

# Authenticate against the analyzed online-banking endpoint
import httpx, hashlib, time

def login(access_id: str, passcode: str, device_id: str) -> dict:
    nonce = hashlib.sha256(f"{device_id}:{time.time()}".encode()).hexdigest()
    r = httpx.post(
        "https://api.openfinance-lab.com/v1/fsl/session",
        json={
            "access_id": access_id,
            "passcode": passcode,
            "device_id": device_id,
            "nonce": nonce,
            "biometric_bound": True
        },
        timeout=15.0,
    )
    r.raise_for_status()
    # Returns: { access_token, refresh_token, expires_in, member_id }
    return r.json()

Transaction query with filters

POST /v1/fsl/accounts/{account_id}/transactions
Authorization: Bearer <ACCESS_TOKEN>
Content-Type: application/json

{
  "from_date": "2026-04-01",
  "to_date":   "2026-04-30",
  "min_amount": 25.00,
  "check_number": null,
  "page_size": 100,
  "cursor": null
}

200 OK
{
  "items": [
    {"id":"t_8a2…","posted_at":"2026-04-29","amount":-128.44,
     "type":"DEBIT","memo":"ACH XFER OUT","check_no":null}
  ],
  "next_cursor": "eyJvIjoxMDB9",
  "has_more": true
}

Transfer webhook (Node.js, Express)

// Verify and ingest a transfer status webhook
import express from "express";
import crypto from "node:crypto";

const app = express();
app.post("/hooks/fsl/transfer", express.raw({type:"*/*"}), (req, res) => {
  const sig = req.header("X-OFL-Signature") ?? "";
  const expected = crypto.createHmac("sha256", process.env.OFL_SECRET)
                         .update(req.body).digest("hex");
  if (!crypto.timingSafeEqual(Buffer.from(sig), Buffer.from(expected)))
    return res.status(401).end();
  const evt = JSON.parse(req.body.toString("utf8"));
  // evt: { transfer_id, status, posted_at, idempotency_key, account_id }
  enqueue(evt);
  res.status(204).end();
});

Regulatory frame

US member data sits inside a layered framework. The most directly relevant rule is the CFPB Personal Financial Data Rights rule under Section 1033 of the Dodd-Frank Act, finalized October 22, 2024 and currently under reconsideration as of August 2025. Larger data providers must comply on a phased schedule starting April 1, 2026; depository institutions below the SBA size standard — which includes most savings & loans of Fairview's size — are exempt from the mandatory phases but may still opt in. Alongside §1033, integrations honor the GLBA Safeguards Rule, FFIEC guidance, and FDIC supervisory expectations.

Privacy & consent design

Every integration ships with a consent-record schema (member ID, scopes, granted-at, expires-at, revocation channel) and a data-minimization toggle that lets you opt in or out of optional fields per scope. Logs separate authentication telemetry from transactional content so an audit reviewer can see "who consented to what" without seeing individual transactions. We never persist passcodes; refresh tokens are encrypted with a per-tenant KMS key.

About OpenFinance Lab

We are an independent technical studio focused on App interface integration and authorized API integration. Our team comes from banks, payment networks, mobile-protocol research and cloud platforms, and we ship end-to-end financial APIs under security and compliance constraints.

• Community banks, savings & loans, credit unions, and digital banks
• Enterprise API gateways, security reviews, and §1033 readiness
• Custom Python, Node.js and Go SDKs with full test harnesses
• Full pipeline: protocol analysis → build → validation → compliance
• Source code delivery from $300 — receive runnable API source code and full documentation; pay after delivery upon satisfaction
• Pay-per-call API billing — access our hosted API and pay only per call, no upfront cost; ideal for teams that prefer usage-based pricing

Contact

For quotes or to submit your target app and requirements, open our contact page:

Contact page

For account-level questions about the original app, members should contact Fairview Savings and Loan Association directly through its official contact page.

Engagement workflow

1. Scope confirmation: target endpoints (login, balances, transactions, transfers, RDC) and data fields.
2. Protocol analysis and API design (2–5 business days, complexity-dependent).
3. Build and internal validation against synthetic and authorized live accounts (3–8 business days).
4. Documentation, samples and §1033-aware consent record schema (1–2 business days).
5. Typical first delivery: 5–15 business days; institutional or core-provider approvals may extend the timeline.

FAQ

What do you need from me to start a Fairview Savings and Loan integration?

How long does delivery take for a savings and loan mobile API?

How do you handle US privacy and Section 1033 open banking compliance?

Can you integrate without official API credentials from the bank?