Flagstar

Flagstar Bank, N.A. is the OCC-chartered national bank subsidiary of Flagstar Financial, Inc. (NYSE: FLG), the Hicksville, New York holding company formerly known as New York Community Bancorp (NYCB). It is one of the largest regional (super-regional) banks in the United States, formed when NYCB acquired Flagstar Bancorp in December 2022, converted Flagstar Bank, FSB into a national bank (Flagstar Bank, N.A.), and subsequently acquired certain assets and liabilities of Signature Bridge Bank from the FDIC in March 2023; the holding company rebranded to Flagstar Financial in October 2024. Flagstar operates in retail and commercial banking, mortgage origination and servicing, and warehouse lending. On the API front, Flagstar runs a first-party developer portal at developer.flagstar.com (a Broadcom/Layer7 "LivePortal" API Developer Portal), but as of this review it publishes no public, self-serve API products, API documentation, or downloadable OpenAPI/Swagger to anonymous visitors — all products are sign-in gated behind partner/consumer-team access. Flagstar has no publicly documented FDX (Financial Data Exchange) participation or CFPB Section 1033 data-access posture; consumer-permissioned data sharing appears to be available only through third-party aggregators (e.g. Plaid, Tink, TrueLayer) rather than a first-party public API.

Flagstar is profiled on the APIs.io network. Tagged areas include Financial Services, Banking, United States, National Bank, and Super-Regional Bank.

🌐 Visit website 📡 Profile data on GitHub

6.4/100 minimal ▬ flat Agent 0/100 human only saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

0 APIs

Financial Services Banking United States National Bank Super-Regional Bank Mortgage Open Finance

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 6.4/100 · minimal

Contract Quality 0.0 / 21

Developer Ergonomics 0.0 / 17

Access Clarity 2.9 / 17

Operational Transparency 0.0 / 11

Contract Governance 0.0 / 10

Discoverability 4.1 / 9

Regulatory Posture 1.2 / 15

Agent readiness — 0/100 · human only

Machine-Readable Contract 0 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Banking & Open Finance regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

Show this score on your site.

It updates itself when the score changes. Paste this where you link to your API docs:

<a href="https://apis.io/providers/flagstar/"><img src="https://apis.io/badge/flagstar/card.svg" alt="Flagstar on APIs.io — Kin Score by API Evangelist"></a>

Other styles, a README pill and a shields.io endpoint are on the badge page.

Raise your score.

Agent readiness — checks not met, largest first (exact, from this profile):

Machine-Readable Contract +18 pts — api_specs includes an OpenAPI document
MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
Machine-Readable Auth +10 pts — a served openid-configuration/oauth-authorization-server carrying `issuer` (served), else the securitySchemes class in the provider OpenAPIs — bound (mutualTLS, DPoP, Signature) > negotiable (oauth2 authorizationCode/clientCredentials, openIdConnect) > bearer (http bearer, apiKey)
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes

13 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 0.0 — up to +25.0 composite points
Developer Ergonomics scores 0.0 — up to +20.0 composite points
Access Clarity scores 17.1 — up to +16.6 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/flagstar/apis.yml: open an issue on github.com/api-evangelist/flagstar to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
Consumer Lending Licensing (UK, US, Canada credit licence registers)	regulated	57.5	-	-
US Banks and Credit Unions (FDIC BankFind + NCUA insured credit unions)	regulated	57.5	-	-

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Flagstar Domain Security

TLSv1.2 · HSTS · DNSSEC · DMARC

SECURITY

Resources

Get Started 2

Portal, sign-up, and the first successful call

Login

DeveloperPortal

DeveloperPortal

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Commercial 1

Pricing, plans, and the legal terms of use

PrivacyPolicy

PrivacyPolicy

Company 2

The organization behind the API

Website

Website

LinkedIn

Source (apis.yml)

aid: flagstar
url: https://raw.githubusercontent.com/api-evangelist/flagstar/refs/heads/main/apis.yml
name: Flagstar
kind: company
description: 'Flagstar Bank, N.A. is the OCC-chartered national bank subsidiary of Flagstar Financial, Inc. (NYSE: FLG), the
  Hicksville, New York holding company formerly known as New York Community Bancorp (NYCB). It is one of the largest regional
  (super-regional) banks in the United States, formed when NYCB acquired Flagstar Bancorp in December 2022, converted Flagstar
  Bank, FSB into a national bank (Flagstar Bank, N.A.), and subsequently acquired certain assets and liabilities of Signature
  Bridge Bank from the FDIC in March 2023; the holding company rebranded to Flagstar Financial in October 2024. Flagstar operates
  in retail and commercial banking, mortgage origination and servicing, and warehouse lending. On the API front, Flagstar
  runs a first-party developer portal at developer.flagstar.com (a Broadcom/Layer7 "LivePortal" API Developer Portal), but
  as of this review it publishes no public, self-serve API products, API documentation, or downloadable OpenAPI/Swagger to
  anonymous visitors — all products are sign-in gated behind partner/consumer-team access. Flagstar has no publicly documented
  FDX (Financial Data Exchange) participation or CFPB Section 1033 data-access posture; consumer-permissioned data sharing
  appears to be available only through third-party aggregators (e.g. Plaid, Tink, TrueLayer) rather than a first-party public
  API.'
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: false
  label: Hosted service · you call their endpoint
  confidence: medium
  source:
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - security
  generated: '2026-11-06'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
tags:
- Financial Services
- Banking
- United States
- National Bank
- Super-Regional Bank
- Mortgage
- Open Finance
tags_raw:
- Financial Services
- Banking
- United States
- National Bank
- Super-Regional Bank
- Mortgage
- Open Finance
- Financial-Services
created: '2026-07-23'
modified: '2026-07-23'
specificationVersion: '0.23'
apis: []
common:
- type: Login
  url: https://roc.flagstar.com/comp/login.jsp
- type: DomainSecurity
  url: security/flagstar-domain-security.yml
- type: Website
  url: https://www.flagstar.com
- type: DeveloperPortal
  url: https://developer.flagstar.com
- type: LinkedIn
  url: https://www.linkedin.com/company/flagstar-bank
- type: PrivacyPolicy
  url: https://www.flagstar.com/legal-disclaimers/privacy.html
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
x-tags-removed:
- Data Aggregation

Work with this as data

Every provider here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for providers

9 MCP tools reach this

find_providersBrowse and filter every provider in the catalog.
get_provider_artifactsEvery artifact this provider publishes, grouped by type.
get_provider_operationsEvery operation across all of their OpenAPIs — one call instead of parsing every spec.
get_provider_toolsEvery MCP tool they ship, with the operation each wraps.
get_provider_evidenceHow each part of their score was established. Free — the basis for a claim should not sit behind it.
get_provider_ratingPRO — composite, band, trend and facet scores.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

All 92 tools →

Call it yourself

curl for this page

This provider

curl "https://apis.io/api/v1/providers/flagstar"

All providers

curl "https://apis.io/api/v1/providers?limit=25"

Every operation they expose

curl "https://apis.io/api/v1/providers/flagstar/operations?limit=25"

How their score was established

curl "https://apis.io/api/v1/providers/flagstar/evidence"

Calls without X-API-Key need no key. Calls with it need a paid plan — get a key.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.