1st Source Bank eMortgage API integration (loan data & OpenBanking)

SimpleNexus-based protocol analysis, loan status webhooks and Section 1033-aligned mortgage data export for U.S. lenders and fintechs

From $300 · Pay-per-call available
OpenData · OpenFinance · Mortgage protocol analysis · Section 1033

Connect 1st Source Bank eMortgage to your loan stack — under borrower consent

1st Source Bank eMortgage runs on the SimpleNexus (now part of nCino) point-of-sale platform, with the package identifier com.simplenexus.loans.client.s__87640 showing the tenant binding to 1st Source. The app handles refinance calculators, scenario comparison, in-app loan applications, mobile document capture, electronic signing and real-time milestone updates. All of that produces structured data your downstream systems can use — if you have an integration layer that can speak to it. We build that layer.

Loan application API — Mirror the borrower-facing 1003 / URLA workflow: applicant identity, income, assets, properties, employment history, and declarations. Outputs MISMO 3.4-compatible JSON for downstream LOS systems.
Loan status & milestone webhooks — Push updates such as Application Started, Conditions Issued, Appraisal Ordered, Cleared to Close, and Funded into your CRM the instant the eMortgage app surfaces them to the borrower.
Document & e-sign mirror — Pull the checklist of borrower-uploaded documents (W-2, paystubs, bank statements, ID) and disclosure e-sign events so compliance and audit trails stay current outside the lender portal.
Refinance & scenario calculator export — Capture the same payment, savings and break-even math the app shows the borrower, then store it as a reusable scenario object for marketing automation, recapture analytics, and rate-watch triggers.

Data available for integration

The table below is built from the eMortgage app's visible screens and from public information about the underlying SimpleNexus platform. Each row maps a borrower-facing surface to the structured data it produces, the granularity you can expect, and a typical downstream use. This is the "OpenData inventory" we work from when scoping a build.

Data typeSource (app screen / feature)GranularityTypical use
Borrower profileAccount / sign-up / profile screenPer applicant; name, contact, SSN-hashed reference, marital statusCRM enrichment, KYC reconciliation, lead-to-loan attribution
Loan application (URLA / 1003)"Apply for a loan" wizardFull 1003 sections: income, assets, REO, employment, declarationsLOS handoff, pre-qualification scoring, decisioning input
Loan status & milestones"Real time status updates"Event stream with timestamp, milestone code, and human labelBorrower notifications, pipeline dashboards, SLA tracking
Document checklist"Scan and submit documents"Per-loan task list; file metadata, status (requested / received / accepted)Audit trail, compliance evidence, vendor doc routing
E-sign events"View and sign documents electronically"Per-document signature events with timestamp and IPTRID / RESPA evidence, retention store, fraud signals
Refinance / scenario calculator"Calculate possible savings of refinancing"Inputs (rate, term, balance) and outputs (payment, savings, break-even)Recapture campaigns, rate-watch alerts, advisor talking points
Loan officer messagingIn-app chat / contact MLOThread metadata and timestamps (content under consent)Response-time SLAs, escalation routing, NPS triggers
Pricing snapshotsScenario comparison viewsRate, APR, points, lock period at time of quotePricing analytics, hit-rate analysis, secondary marketing

Typical integration scenarios

1. Loan officer CRM sync

A regional brokerage runs HubSpot for its loan officers but the eMortgage app is the borrower's entry point. We expose a normalized /loans endpoint and a webhook for milestone changes; HubSpot deals advance from "Application Started" to "Cleared to Close" automatically. Mapped fields include loan_id, milestone_code, last_event_at, and borrower_email_hash. This is the OpenFinance pattern of treating the lender's own POS as the system of record and projecting the relevant subset into the broker's CRM.

2. Refinance recapture and rate-watch

The eMortgage refinance calculator already produces a personalized savings number. We persist each calculation as a scenario object (scenario_id, current_rate, target_rate, monthly_savings, break_even_months) and pair it with a daily rate feed. When the spread crosses a threshold, a rate-watch service emails the borrower with the same math they already saw — the OpenData angle is reusing borrower-consented numbers instead of cold-marketing them.

3. Document compliance vault

Mortgage compliance teams need every borrower-submitted document and every e-sign event captured in an immutable store, often outside the LOS. We stream the document checklist and e-sign timestamps to an S3 / GCS bucket with an append-only audit log. Maps directly to TRID, RESPA, and HMDA evidence requirements and gives auditors a single read endpoint that does not depend on lender portal access.

4. Section 1033 borrower data portal

Under the CFPB's Personal Financial Data Rights framework (Section 1033 of Dodd-Frank), covered institutions must let consumers export their data to authorized third parties. We can wrap eMortgage data in a Section 1033-style consumer-facing endpoint that returns a 24-month transaction-style view of loan events, conditions, and balances for a single borrower.

5. Realtor and builder partner feed

Builders and real estate teams care about a small slice: which buyers are pre-approved, which are conditionally approved, and which are clear-to-close. We expose a narrow partner-feed endpoint that returns only status milestones and approved loan amount (no PII), authorized by the borrower at the eMortgage onboarding step.

Technical implementation

We deliver the integration as production-grade source you can read, modify, and host yourself, plus an OpenAPI spec. Below are three representative shapes from a typical build. The endpoint names follow our gateway convention; the underlying calls go through the SimpleNexus-style POS protocol or via authorized partner endpoints under borrower consent.

1. Borrower login / token exchange

POST /api/v1/emortgage/auth
Content-Type: application/json

{
  "username": "borrower@example.com",
  "password": "<app-credential>",
  "device_id": "ios-7F8A...",
  "tenant": "1st-source-bank"
}

Response 200:
{
  "access_token": "eyJhbGciOi...",
  "refresh_token": "rt_...",
  "expires_in": 1800,
  "scope": "loans:read documents:read status:subscribe"
}

2. Loan list and status snapshot

GET /api/v1/emortgage/loans?include=status,conditions
Authorization: Bearer <ACCESS_TOKEN>

Response 200:
{
  "loans": [
    {
      "loan_id": "LN-87640-220031",
      "type": "Refinance",
      "milestone": "ConditionsIssued",
      "last_event_at": "2026-05-08T14:21:09Z",
      "open_conditions": 3,
      "lo_assigned": "mlo-1109",
      "loan_amount": 312000,
      "rate": 6.125
    }
  ],
  "pagination": {"next_cursor": null}
}

3. Milestone webhook payload

POST https://your-app.example/webhooks/emortgage
X-Signature: sha256=...

{
  "event": "loan.milestone.changed",
  "tenant": "1st-source-bank",
  "loan_id": "LN-87640-220031",
  "from": "AppraisalOrdered",
  "to": "ClearedToClose",
  "occurred_at": "2026-05-09T17:02:44Z",
  "actor": "lo-system"
}

// On 4xx the gateway retries with exponential backoff
// up to 24h, then routes the event to a dead-letter topic.

For deeper depth we also ship: HMAC signature verification helpers, a replay-protection nonce store, a MISMO 3.4 mapper, a sandbox harness with fixture loans, and Postman / Insomnia collections. Source ships with unit and integration tests and a docker-compose stack for local runs.

Compliance & privacy

Regulatory anchors

1st Source Corporation is a U.S. bank holding company supervised by the Federal Reserve and the FDIC, with consumer protection under the CFPB. Mortgage-specific rules that shape what we do include the Truth in Lending Act (TILA) / Regulation Z, RESPA / Regulation X, TRID disclosure timing, and the recent CFPB final rule on Personal Financial Data Rights (Section 1033, published October 2024 and currently in reconsideration as of 2025). For data-handling we follow SOC 2-aligned controls, NIST SP 800-63 for authentication patterns, and state privacy laws (CCPA / CPRA where the borrower is in California).

How we keep integrations lawful

  • Only borrower-authorized access — credentials, OAuth, or partner sandbox
  • Field-level data minimization; PII tokenized at the gateway by default
  • Audit log of every borrower-consented call with retention policy
  • NDA and DPA available on request; we sign vendor security questionnaires
  • Documentation explicitly excludes any technique that breaks app integrity

Data flow / architecture

A typical 1st Source eMortgage integration is built as a four-stage pipeline:

  1. eMortgage Client — borrower interacts with the app on iOS or Android; tokens issued under consent.
  2. Integration Gateway — our hosted (or self-hosted) gateway terminates the POS protocol, normalizes payloads, signs webhooks, and enforces rate limits.
  3. Normalized Store — Postgres or a warehouse such as Snowflake / BigQuery holds loans, milestones, conditions, documents, scenarios.
  4. Downstream Consumers — CRM (HubSpot / Salesforce), LOS (Encompass, Finastra MortgagebotLOS, LendingQB), analytics, and Section 1033 borrower portal.

Market positioning & user profile

1st Source Bank is the largest locally controlled financial institution headquartered in northern Indiana and southwest Michigan, with 81 branches across the region and a Forbes "Best In-State Bank" recognition for 2022 through 2025. The eMortgage app serves retail mortgage and refinance borrowers in those markets plus customers of the bank's wider footprint, and runs on the SimpleNexus (now nCino) point-of-sale platform that hundreds of U.S. lenders share. Primary users are first-time home buyers, refinance shoppers, and existing 1st Source customers consolidating banking and home-loan relationships. Platform coverage is Android and iOS; there is no public consumer-facing developer API, which is why a protocol-analysis integration layer is the realistic route for partners and aggregators.

What we deliver

Deliverables checklist

  • OpenAPI 3.1 specification covering auth, loans, conditions, documents, webhooks
  • Protocol and auth-flow report (token lifecycle, refresh, signing)
  • Runnable source for login, loan list, status, and webhook receiver (Python / Node.js / Go)
  • MISMO 3.4 mapper plus golden-file tests
  • Sandbox docker-compose with fixture loans and replayable events
  • Postman / Insomnia collection and a CLI for ops
  • Compliance notes (TILA, RESPA / TRID, Section 1033 alignment) and a retention policy template

Engagement workflow

  1. Scope confirmation: which loan flows and which downstream system
  2. Protocol analysis and API design (2–5 business days)
  3. Build and internal validation (3–8 business days)
  4. Docs, samples, MISMO mapping, test cases (1–2 business days)
  5. Acceptance run on your environment; pay-after-delivery for source code engagements

App screenshots

Click any thumbnail to view a larger version. These are the borrower-facing surfaces our integration layer reads from and writes to.

1st Source Bank eMortgage screenshot 1
1st Source Bank eMortgage screenshot 2
1st Source Bank eMortgage screenshot 3
1st Source Bank eMortgage screenshot 4
1st Source Bank eMortgage screenshot 5

Similar apps & integration landscape

Teams that integrate one mortgage point-of-sale usually have data sitting in several others. Below is the wider ecosystem we see most often during scoping calls. Each holds a different cut of borrower, loan, or rate data, and unified exports across them are a common request.

  • Rocket Mortgage — Direct-to-consumer giant from Rocket Companies; holds application, milestone, and pricing data for millions of borrowers and is a frequent counterpart in unified-export projects.
  • Better.com (Better Mortgage) — Online-first lender known for fast pre-approval; integration requests typically focus on application and pricing data for cross-platform analytics.
  • Chase Home Lending — Big-bank lender bundled inside the Chase mobile app; users with relationship pricing often need loan status pulled into household finance dashboards.
  • SoFi Home Loans — Part of SoFi's broader fintech app; teams ask for unified balance and loan event feeds alongside SoFi's banking and investing data.
  • LoanDepot mello — One of the largest non-bank lenders in the U.S.; loan and status feeds appear in cross-lender analytics work.
  • PennyMac — Servicing-heavy mortgage platform; users frequently want servicing milestone and payment data flowing alongside origination data.
  • Guild Mortgage — Retail and correspondent lender with a strong mobile presence; appears in CRM-sync projects similar to the eMortgage use case.
  • New American Funding (NAF) — Large independent lender; common in pipelines that unify multiple non-bank lender feeds.
  • Fairway Independent Mortgage — Retail lender with strong loan-officer-driven workflows; cross-feed with CRM is a common ask.
  • Freedom Mortgage — Major VA and FHA originator; servicing-side data is a frequent integration target.
  • Roostify / Blend — White-label digital mortgage platforms that many regional banks deploy; similar protocol-analysis shape to the SimpleNexus tenant used by eMortgage.

About OpenFinance Lab

We are an independent studio focused on fintech, OpenBanking, and mortgage-tech API integration. The team mixes engineers from U.S. and European banks, payment gateways, protocol analysis labs, and cloud platforms. We have shipped integrations against loan origination systems (Encompass, MortgagebotLOS, LendingQB, nCino), CRM platforms (HubSpot, Salesforce Financial Services Cloud), and Section 1033-style consumer data portals. Engagements are scoped tightly and shipped under NDA when needed.

  • Mortgage POS / LOS integrations and milestone webhooks
  • Open banking and Section 1033 data-rights endpoints
  • Document and e-sign capture pipelines for compliance vaults
  • Two engagement models: Source code from $300 (pay after delivery upon satisfaction) or Pay-per-call hosted API with no upfront fee

Contact

To request a quote or share your target app and scope, open our contact page. We typically reply within one business day, U.S. Eastern.

Contact page

FAQ

Do I need authorization from 1st Source Bank to integrate eMortgage data?

Yes. We only work with the consumer's own credentials or with bank-issued sandbox or partner access. The CFPB Section 1033 framework gives borrowers the right to authorize a third party to retrieve their loan and account data from covered institutions, so integrations stay within that consented scope.

Which loan data can be exposed through the API layer?

Borrower profile, loan application status, conditions and tasks, document checklist and e-sign events, rate and pricing scenarios, refinance calculator outputs, and loan officer messages. All fields can be normalized to MISMO 3.4 where the downstream LOS expects it.

How long does a first delivery usually take?

Five to twelve business days for the first API drop covering login, loan list, and status webhooks. Deeper flows such as document upload and e-sign mirroring typically add another one to two weeks depending on scope.

What programming languages do you deliver source code in?

Python (FastAPI), Node.js (Express or NestJS), and Go are the defaults. Java and .NET are available on request when the buyer's loan origination stack requires native libraries.

Why a SimpleNexus-tenant app fits OpenData

The eMortgage app is a tenant of a multi-lender point-of-sale platform. The data model is consistent across hundreds of lenders, which means an integration we build for 1st Source Bank generalizes to peer banks running the same platform. That is exactly the shape OpenFinance is meant for: standardize the borrower-consented data, then federate consumers — CRMs, dashboards, compliance vaults, recapture engines — on top of a stable schema instead of bespoke scrapers per lender.

📱 Original app overview (1st Source Bank eMortgage)

1st Source Bank eMortgage is the mobile front door to 1st Source Bank's home-loan process. Built on the SimpleNexus (now part of nCino) digital mortgage platform, it lets borrowers calculate refinance savings, compare scenarios, apply for a loan from a phone, scan and upload required documents, electronically sign disclosures, and follow real-time status updates as the file moves through the lender's pipeline.

Key features as described by the publisher:

  • Calculate possible savings (or cost) of refinancing a mortgage
  • Compare scenarios that guide the borrower to a suitable loan
  • Apply for a loan from the phone, when and where convenient
  • Scan and submit required documents to speed up approval and processing
  • View and sign documents electronically to expedite the loan process
  • Receive real-time status updates showing the progress of the loan

About the lender: 1st Source Corporation is a Forbes "Best In-State Bank" (2022–2025) headquartered in South Bend, Indiana, operating roughly 81 branches across northern Indiana and southwest Michigan. It is the largest locally controlled financial institution headquartered in that region. The eMortgage app sits alongside the bank's broader mobile banking app for everyday checking, savings, Zelle, and card-control features.

The calculations the app provides are educational — for a personalized loan recommendation, the publisher directs borrowers to speak with their Mortgage Loan Originator. App is available on the Google Play Store and the Apple App Store.

Last updated: 2026-05-10