Western Alliance Bank

Western Alliance Bancorporation (NYSE: WAL) is a Phoenix, Arizona based super-regional bank holding company with roughly $80 billion in assets, operating through its principal subsidiary Western Alliance Bank, an Arizona state-chartered commercial bank and member FDIC that runs regional divisions including Alliance Bank of Arizona, Bank of Nevada, Bridge Bank, and Torrey Pines Bank. It is a commercial- and business-banking focused institution rather than a consumer neobank. Western Alliance runs a real first-party developer portal, the WAB API Developer Portal ("Developer Hub") at developer.westernalliancebank.com, exposing commercial Treasury Management open-banking APIs for balance and transaction information, check images, funds transfers, and stop payments. Access is partner/customer-gated: API specifications are downloaded from the Developer Hub only with WAB-issued credentials, and authentication uses OAuth2 client-credentials (Client ID, Client Secret), a Client Certificate (mTLS), and access tokens across UAT and Production environments. Its APIs are also reachable through payment-platform partners such as Modern Treasury. No public consumer FDX or CFPB Section 1033 data-access API is documented, and no OpenAPI/Swagger is publicly downloadable.

Western Alliance Bank publishes 1 API on the APIs.io network. Tagged areas include Financial Services, Banking, United States, Treasury Management, and Open Banking.

Western Alliance Bank’s developer surface includes engineering blog, authentication, documentation, API reference, getting-started guide, signup flow, and 10 more developer resources.

🌐 Visit website 📡 Source on GitHub
26.2/100 emerging ▬ flat Agent 9/100 agent aware saas Full breakdown ↓
scored 2026-08-17 · rubric v0.11.0
1 APIs
Financial ServicesBankingUnited StatesTreasury ManagementOpen BankingPaymentsCommercial Banking

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-17 · rubric v0.11.0
Composite quality — 26.2/100 · emerging
Contract Quality 0.0 / 21
Developer Ergonomics 8.1 / 17
Commercial Clarity 5.8 / 17
Operational Transparency 0.6 / 11
Governance 1.3 / 10
Discoverability 5.7 / 9
Regulatory Posture 4.7 / 15
Agent readiness — 9/100 · agent aware
Machine-Readable Contract 0 / 18
Agentic Access Contract 0 / 10
MCP Server 0 / 12
Machine-Readable Auth 10 / 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
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.
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/.
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/western-alliance: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 1

Individual APIs this provider publishes, each with its own machine-readable definition.

Western Alliance Bank API (Treasury Management)

Western Alliance Bank's commercial open-banking API lets approved business clients interact directly with WAB systems to access balance and transaction information, retrieve che...

Security Posture 2

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

Western Alliance Authentication

oauth2/mutualTLS · 3 schemes

SECURITY

Western Alliance Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Resources

Get Started 3

Portal, sign-up, and the first successful call

DeveloperPortal
DeveloperPortal
 GettingStarted
GettingStarted
 Signup
Signup

Documentation 2

Reference material describing how the API behaves

Documentation
Documentation
 APIReference
APIReference

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

WellKnown
WellKnown
 LLMsTxt
LLMsTxt

Design & Contract 1

Pagination, idempotency, versioning, errors, and events

Conformance
Conformance

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity
 Authentication
Authentication

Commercial 2

Pricing, plans, and the legal terms of use

PrivacyPolicy
PrivacyPolicy
 TermsOfService
TermsOfService

Company 3

The organization behind the API

Blog
Blog
 Website
Website
 LinkedIn
LinkedIn

Source (apis.yml)

apis.yml Raw ↑ 
aid: western-alliance
url: https://raw.githubusercontent.com/api-evangelist/western-alliance/refs/heads/main/apis.yml
name: Western Alliance Bank
kind: company
description: 'Western Alliance Bancorporation (NYSE: WAL) is a Phoenix, Arizona based super-regional bank holding company
  with roughly $80 billion in assets, operating through its principal subsidiary Western Alliance Bank, an Arizona state-chartered
  commercial bank and member FDIC that runs regional divisions including Alliance Bank of Arizona, Bank of Nevada, Bridge
  Bank, and Torrey Pines Bank. It is a commercial- and business-banking focused institution rather than a consumer neobank.
  Western Alliance runs a real first-party developer portal, the WAB API Developer Portal ("Developer Hub") at developer.westernalliancebank.com,
  exposing commercial Treasury Management open-banking APIs for balance and transaction information, check images, funds transfers,
  and stop payments. Access is partner/customer-gated: API specifications are downloaded from the Developer Hub only with
  WAB-issued credentials, and authentication uses OAuth2 client-credentials (Client ID, Client Secret), a Client Certificate
  (mTLS), and access tokens across UAT and Production environments. Its APIs are also reachable through payment-platform partners
  such as Modern Treasury. No public consumer FDX or CFPB Section 1033 data-access API is documented, and no OpenAPI/Swagger
  is publicly downloadable.'
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: false
  label: Hosted service · you call their endpoint
  confidence: medium
  source:
  - pricing
  generated: '2026-08-11'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
tags:
- Financial Services
- Banking
- United States
- Treasury Management
- Open Banking
- Payments
- Commercial Banking
created: '2026-07-23'
modified: '2026-07-23'
specificationVersion: '0.19'
apis:
- aid: western-alliance:wab-treasury-management-api
  name: Western Alliance Bank API (Treasury Management)
  description: Western Alliance Bank's commercial open-banking API lets approved business clients interact directly with WAB
    systems to access balance and transaction information, retrieve check images, initiate funds transfers, and place stop
    payments. Documented publicly as an open-banking capability; API specifications and endpoints are gated behind the WAB
    Developer Hub and issued credentials.
  humanURL: https://developer.westernalliancebank.com/s/
  tags:
  - Treasury Management
  - Open Banking
  - Payments
  properties:
  - type: Documentation
    url: https://developer.westernalliancebank.com/s/
  - type: Documentation
    url: https://www.westernalliancebancorporation.com/commercial/treasury-management
  - type: TermsOfService
    url: https://www.westernalliancebancorporation.com/sites/default/files/2025-05/api-services-terms-conditions.pdf
common:
- type: Blog
  url: https://www.westernalliancebancorporation.com/insights
- type: DomainSecurity
  url: security/western-alliance-domain-security.yml
- type: Authentication
  url: authentication/western-alliance-authentication.yml
- type: Conformance
  url: conformance/western-alliance-conformance.yml
- type: WellKnown
  url: well-known/western-alliance-well-known.yml
- type: LLMsTxt
  url: llms/western-alliance-llms.txt
- type: Website
  url: https://www.westernalliancebancorporation.com/
- type: DeveloperPortal
  url: https://developer.westernalliancebank.com/s/
- type: Documentation
  url: https://developer.westernalliancebank.com/s/
- type: APIReference
  url: https://developer.westernalliancebank.com/s/apis
- type: GettingStarted
  url: https://developer.westernalliancebank.com/s/getting-started
- type: Signup
  url: https://developer.westernalliancebank.com/s/login
- type: GitHubOrganization
  url: https://github.com/westernalliancebank
- type: LinkedIn
  url: https://www.linkedin.com/company/western-alliance-bank
- type: PrivacyPolicy
  url: https://www.westernalliancebancorporation.com/privacy-legal-home/privacy-policy
- type: TermsOfService
  url: https://www.westernalliancebancorporation.com/sites/default/files/2025-05/api-services-terms-conditions.pdf
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com