VSTN Technologies
Engineered for professional firms

The App
that lives where
your firm already works.

Native to Microsoft 365 — Outlook, Teams, SharePoint and OneDrive. Augmented by AI. Built on Azure to scale on demand.

Talk to us See what it does
VSTN 4ONE Product Specifications
app.vstn4one.com
VSTN CbCR Solution
17+
Countries served by VSTN Group
150+
Years of domain expertise
500+
Client engagements
ITR
Award-recognized practice

Why VSTN 4ONE

Designed for the way modern firms actually work.

One platform. One login. Built for the tools your team already opens every morning.

01

Native to Microsoft 365.

Lives in Outlook, Teams, SharePoint and OneDrive. No second password, no context switch, no extension headaches.

02

Augmented by AI.

Ask questions of your application in plain English. Inbox triage, business-card capture and draft assistance — all grounded on your tenant.

03

Cloud-native scale.

Serverless delivery engine, edge-cached workspace, managed PostgreSQL. Pay for what you use. Scale when you need to.

Designed for clarity

The interface gets out of the way.

Calm typography. Generous spacing. Keyboard-first where it counts. The workspace fades into the background so your team's work stays in front.

Calm by default

Restrained color, focused layouts. Your attention stays on the engagement, not the chrome.

Responsive everywhere

The same workspace on desktop, tablet and phone — sized for the screen, not crammed onto it.

Accessible by default

Sufficient contrast, focus rings, semantic markup and keyboard navigation — built in, not bolted on.

Fast where it matters

Virtualised tables, optimistic UI, edge-cached assets. Pages just feel quick — because they are.

It just feels different from our last CRM.
— Designed in collaboration with VSTN Consultancy practice leads

A complete practice OS

Everything a firm runs on — in one place.

AI READY DISCOVERY PROPOSAL DELIVERY INVOICE
Pipeline

From lead to invoice, on one board.

Track every engagement through clear, structured stages. Drag a deal, log a task, send a follow-up — all without leaving the workspace.

Outlook Inbox · 23 From: Priya Ramesh · Acme Mfg Re: Q3 transfer-pricing review VSTN 4ONE SUGGESTED Create Task
Outlook Add-in

Log a client email without leaving Outlook.

The 4ONE pane opens in Outlook for Desktop, Web and Mobile. Reads the email, pre-fills a task, syncs silently via Entra ID SSO.

4ONE Intelligence - VaSTiN Grounded on your app. Private to your tenant. Which clients haven't submitted Q3 docs yet? 7 clients are pending Q3 documentation: • Acme Mfg — TP study, due 30 May • Helix Pharma — benchmarking • Nordic Foods — CbCR XML • Lumen Capital — annual TP • Brightline, Cobalt, Equinox Open list Draft reminder
4ONE Intelligence - VaSTiN

Ask questions. Get a real answer.

Natural-language queries against your live app data — bounded by the user's existing permissions, grounded by your tenant's records.

Draft TEMPLATE Send Preview 2,148 recipients 62% opened
Campaign Studio

Compose, send, measure — at scale.

Author templated campaigns with live preview. The Delivery Engine handles the send. Opens and clicks stream back to your app dashboard.

VSTN 4ONE
My day
DUE TODAY
Q3 OTP proposal — Acme Mfg
10:30 AM
Discovery call · Helix Pharma
02:00 PM
Nordic Foods — CbCR review
On the go

Your firm. In your pocket.

The same workspace, optimised for mobile. Tasks, schedule and approvals — wherever you are, on any device.

Firm performance · May 2026 REVENUE $1.4M +18% MoM UTILIZATION 82% +4 pts OPEN DEALS 42 12 closing W1W2W3W4W5W6
Reports

Insight, not just data.

Revenue, utilisation, profitability — surfaced in a single dashboard. Drill in, slice by team, export to Excel.

This week · 5 engagements MONTUEWEDTHUFRI 10:00 Acme Mfg Discovery 09:30 Helix Pharma Proposal 14:00 Nordic Foods 10:30 Brightline Review 11:00 Cobalt Sign-off UPCOMING DEADLINES Q3 OTP proposal — Fri 30 May CbCR XML filing — Mon 2 Jun
Schedule

The week, at a glance.

Discovery calls, deadlines and engagements — synced with your Microsoft 365 calendar, surfaced where you work.

Documents · Acme Manufacturing All Proposals Engagements PDF Q3 OTP Proposal — Acme Mfg v2.docx SharePoint · updated 2 hours ago by Priya R. XL Benchmarking workbook — FY25.xlsx OneDrive · shared with engagement team DOC Engagement letter — signed.pdf SharePoint · v3 · approved TEAM Acme Mfg — TP project channel Microsoft Teams · 12 members
Documents

Every file. Right where you'd expect it.

Engagement docs live in SharePoint. Personal drafts in OneDrive. Conversations in Teams. The app record stitches them together.

Outlook — Inbox
From: Priya Ramesh · Acme Manufacturing
Re: Q3 transfer-pricing review
Thanks for yesterday's call. We'd like a scoped proposal by Friday — the CFO will join next week's session.
VSTN 4ONE
Acme Manufacturing
Q3 OTP proposal
Due Fri, 30 May
Create a Task in app

Outlook Add-in

The CRM, right inside the inbox.

Read a client email. Click the pane. The 4ONE add-in already knows who they are, what stage you're at, and what to do next.

  • Every Outlook, everywhere.Outlook for Windows, Mac, the web, iOS and Android — same code, same experience.
  • Silent SSO.Nested App Authentication exchanges your Office identity for an Entra ID token — no second login.
  • AI prefilled.Contact details, summary, suggested deal stage and due date — drafted before you click.
4ONE Intelligence - VaSTiN
✦
Ask VaSTiN
Grounded on your app data · private to your tenant
Show me partner-referred customers with overdue proposals.
5 partner-referred clients have overdue proposals:
• Brightline Energy — 4 days overdue · referred by Mehta & Co.
• Cobalt Logistics — 2 days · referred by KPMG India
• Lumen Capital — 1 day · referred by Singh & Assoc.
+ 2 more
Open list
Draft follow-ups

4ONE Intelligence - VaSTiN

AI that answers questions about your data. Not the internet.

Powered by Azure OpenAI, running in your Azure tenant. Bounded by the same permissions your users already have. Your data stays your data.

  • Natural-language queries.Ask in plain English. The assistant translates intent into safe, schema-aware queries.
  • Inbox triage.Microsoft Graph emails are classified and routed to the right deal automatically.
  • Drafted content.Proposal summaries, follow-up emails and campaign subject lines — written from app context.

How VaSTiN is built

Frontier models. Grounded in your firm's data.

Powered by Azure AI Foundry — Microsoft's enterprise platform for production AI. We use the latest GPT-5 family models, with retrieval grounded on your app records, your documents and your firm's playbooks. Every answer cites the source.

YOUR DATA App records Practice Cloud · PostgreSQL Documents SharePoint · OneDrive Playbooks & templates Firm methodology Live email & calendar Microsoft Graph YOUR PERMISSIONS, ENFORCED Foundry IQ — retrieval layer Vector search · embeddings · ranking Embedding Index your tenant data in your subscription RBAC pre-filter Only rows the user can already see Compose grounded context Cite every source · audit every prompt Customer data never trains foundation models Azure AI Foundry · Foundry IQ FRONTIER MODELS GPT-5 family Latest OpenAI models Streaming responses Function calling Tool use · agents Safe schema-aware queries Content safety Foundry policies · evals Audit log of every call DELIVERED IN-APP 4ONE Agents in your workspace Ask 4ONE chat Inbox triage Drafted content Business-card OCR
F

Azure AI Foundry

Microsoft's enterprise AI platform — model catalogue, evaluations, content safety and observability, all in your subscription.

G

Latest GPT-5 models

The current GPT-5 family — swappable as new versions ship. No code changes when a better model arrives.

R

Grounded in your data

Retrieval over your app records, documents and playbooks. Pre-filtered by the user's existing permissions before the model sees anything.

⚿

Your data, your tenant

Inference runs in your Azure subscription. Customer data is never used to train foundation models. Every prompt is audit-logged.

Microsoft 365 native

Eight surfaces. One login. Zero context switch.

VSTN 4ONE meets users in the tools they already open every morning. Nothing new to install. Nothing new to learn.

O

Outlook Add-in

Desktop, Web and Mobile. Reads the email, creates a task. Silent SSO via NAA.

T

Microsoft Teams

Deep links into app records from chat. Graph-powered notifications in your channels.

SP

SharePoint

Team libraries for proposals, agreements and templates — linked from each app record.

OD

OneDrive

Personal documents live in the user's OneDrive — versioning, sharing and search included.

X

Excel

Native XLSX exports — reports open in Excel Online or desktop, formulas intact.

ID

Entra ID + MFA

SSO via your existing tenant. MFA and Conditional Access are inherited automatically.

G

Microsoft Graph

Delegated and app-only flows surface mail, calendars, files and people in the app.

A

Azure-native

Hosted entirely on Azure. Static Web Apps, App Service, Functions, Service Bus, PostgreSQL.

Engineered for scale

Built for the largest practices. Right-sized for yours.

VSTN 4ONE is the same product whether it runs on a single Azure VM for a small firm or a multi-region Kubernetes cluster for a global group. The architecture is built for enterprise load; the deployment is sized to the operations you actually run — so a small firm pays for a small footprint, and a large one gets the headroom it needs without re-platforming later.

Smaller VMs · lower compute · lower cost AKS clusters · multi-region · enterprise capacity Small footprint Small firms · shared App Service ~2 instances Mid footprint Growing firms · auto-scale plan 4 - 12 instances · auto-scale Enterprise footprint Large groups · dedicated AKS N pods · multi-region · failover

SAME CODE · SAME DATA MODEL · SAME WORKSPACE · DIFFERENT FOOTPRINT

Container-native

The platform ships as containers. The same image runs in development, on small VMs and on production AKS clusters — no behavioural drift between environments.

Elastic by design

APIs scale out on CPU and request queues; serverless workers scale to zero when idle. Quiet evenings cost nothing. Quarter-ends absorb the spike.

Cost-efficient at small scale

Small firms run on small Azure VMs and shared App Service plans — a fraction of the operating cost of running an enterprise stack, with none of the architectural compromises.

Proven at enterprise scale

For the largest practices — dedicated Azure Kubernetes Service, geo-redundant data, multi-region failover, vNet isolation and private endpoints. The headroom is there when you need it.

Automation, end to end

From a commit to production — no human in the console.

Every change is reviewed, tested and deployed by automation. Our engineers ship features; the pipeline ships the rest. Faster releases, fewer regressions, no late-night cutovers — and no compromise on quality.

01 REVIEW · AUTOMATED

AI inspects every change.

GitHub Copilot reviews each pull request — flags issues, suggests fixes and summarises the diff. A human approves; automation handles the boilerplate.

Copilot · 3 suggestions
Security & lint scans
Human approval
02 TEST · AUTOMATED

Every push, every layer.

Unit and integration suites run on every push. Browser journeys are driven end-to-end before any release candidate ships. Coverage is tracked per change.

Unit · 1,284 passed
Integration · 312 passed
Playwright · 42 journeys
03 DEPLOY · AUTOMATED

Pushed to Azure, hands-off.

GitHub Actions deploys via federated OIDC — short-lived tokens, no stored secrets. Slot + swap means production never blinks. Releases are routine, not events.

Build · 1m 42s
Slot swap · production
Live · 0 downtime
04 OBSERVE · AUTOMATED

Caught by alerts, not by users.

Every request, every layer is captured by Application Insights. Distributed traces follow a request from browser through API to background workers — issues surface before they reach a user.

Live metrics & tracing
Health probes · auto-heal
Alerts on anomalies

Faster, without compromising on quality. Time saved on manual checks goes back into building the features your team asked for.

Built for adoption

If your team can use Outlook, they can use VSTN 4ONE.

The fastest way to make an app stick isn't training. It's familiarity. VSTN 4ONE uses the same visual language your team already lives in — Microsoft 365 patterns, calm typography, predictable layouts. There's nothing exotic to learn. They open it and it just makes sense.

  • Microsoft 365 visual language.Toolbars, panes, lists, ribbons, calendars — the patterns your team already uses every morning, applied consistently across every screen.
  • Inline help, not manuals.Tooltips, empty-states and contextual hints explain things at the point of use. The product teaches itself; nobody needs to read a 60-page guide.
  • Keyboard-first where it counts.Power users move at their own pace — command palette, inline edit, jump-to-record, bulk-action shortcuts. The mouse becomes optional.
  • Responsive, accessible, alive on every device.Desktop, laptop, tablet and phone — same workspace, sized for the screen. WCAG-aware from day one.
VSTN 4ONE — Workspace
WORKSPACE
Pipeline
Clients
Engagements
Schedule
Acme Manufacturing
Quick find
Contact
Priya Ramesh, CFO Office
Stage
Proposal — inline edit
Due
Fri, 30 May 2026
Documents
Proposal v2.docxBenchmarks.xlsx
Press E to edit, to save
command palette
Inline edit, no modals
Contextual shortcuts
~1 day
Median time to a user's first independent task — no formal training required
0 manuals
Help lives in-product — tooltips, empty states, contextual hints — not in a PDF that nobody reads
WCAG 2.1 AA
Accessible to every user from day one — keyboard navigation, focus rings, sufficient contrast, semantic markup

Architecture

Three clean layers. Built to evolve.

A modular platform — independently deployable services, all running on managed Azure infrastructure.

Workspace What users touch App Workspace Web app · React Edge-cached, globally available Campaign Studio Web app · React Compose · send · measure Outlook Add-in Desktop · Web · Mobile Nested App Authentication Teams & Mobile Deep links Responsive surfaces Platform services What runs the business logic Practice Cloud App core service Clients · engagements workflows · invoicing Managed on App Service Campaign Cloud Campaign authoring audience & scheduling analytics ingestion Managed on App Service 4ONE Intelligence(VaSTiN) NL chat · classifiers OCR · drafting RBAC pre-filter Azure OpenAI Delivery Engine Serverless workers Scale to zero Burst-tolerant sends Azure Functions Foundation Microsoft cloud the platform runs on Microsoft Entra ID SSO · MFA · NAA Microsoft Graph Mail · files · calendar Azure PostgreSQL Flexible Server · HA Azure Service Bus Queues · DLQ Blob Storage Attachments Communication Services Managed email delivery Azure Key Vault Secrets · Managed Identity Application Insights Distributed tracing Static Web Apps Edge CDN · TLS

A request, end to end

From a click in Outlook to an app record — in five hops.

STEP 1

Click in Outlook

The 4ONE pane loads from a global CDN, close to the user.

STEP 2

Silent SSO

Nested App Auth exchanges the Office token for an Entra ID token.

STEP 3

Practice Cloud

The request is validated, RBAC-checked, persisted to managed PostgreSQL.

STEP 4

Sync to M365

Graph adds a calendar reminder and saves attachments to OneDrive.

STEP 5

Trace & return

Every hop is captured in Application Insights. The pane updates in under a second.

Built on

Current-generation tooling, end to end.

Every layer uses an actively maintained, widely adopted stack — easy to hire for, easy to support, easy to evolve.

Workspace

The two web surfaces — App Workspace and Campaign Studio.

ReactTypeScriptViteMantineTanStack QueryStorybook

Platform services

Practice Cloud and Campaign Cloud — typed, documented APIs.

NestJSTypeScriptFastifyPrismaJWTOpenAPI

4ONE Intelligence - VaSTiN

AI runs in your Azure tenant. Bounded by user permissions.

Azure OpenAISchema-aware promptsRBAC pre-filterAudit log

Delivery Engine

Serverless workers — scale to zero when idle, surge under load.

.NETAzure FunctionsService BusLiquid templatesManaged Identity

Foundation

Managed Azure services — geo-replication, backup, patching included.

Azure PostgreSQLService BusBlob StorageKey VaultApp ServiceStatic Web Apps

Identity & security

SSO and MFA inherited from your existing Microsoft Entra ID tenant.

Microsoft Entra IDOAuth 2.0 / OIDCMFAConditional AccessRBAC

Quality & CI/CD

Test-driven, component-driven, browser-tested on every release.

GitHub ActionsOIDC deploysJestVitestPlaywrightStorybook

Observability

Every request, every layer — one pane of glass.

Application InsightsDistributed tracingLive metricsStructured logsHealth probes

Trust

Microsoft-grade security, inherited from your tenant.

No new identity provider. No new password store. VSTN 4ONE runs inside your Microsoft Entra ID tenant and benefits from every policy already in place.

Microsoft Entra ID SSO MFA & Conditional Access TLS 1.2+ · AES-256 Azure Key Vault Managed Identity Distributed tracing Role-based access Hosted on Microsoft Azure
Detailed security posture, data residency and sub-processor list available under NDA — get in touch.

Ready when you are

Bring your firm to the workspace your team
already loves.

Talk to us about a guided demo, a sandbox tenant, or a proof of value tailored to your practice.

Talk to us Visit vstntech.com