Custom Microsoft Teams App Development
Custom Microsoft Teams App Development designs, builds, and deploys a Teams app tailored to your daily workflows — personal and channel tabs, bots, message extensions, and approval flows — built with the Microsoft 365 Agents Toolkit, secured with Microsoft Entra ID single sign-on, and integrated with your data through Microsoft Graph. We publish to your organization's app catalog or prepare an AppSource-ready package. Work is time and materials at $175/hour; a typical first app runs from $7,500 over about 4 weeks.
What this engagement is
Your team already lives in Microsoft Teams — but the work often doesn't. Approvals sit in email, status lives in spreadsheets, and line-of-business systems make people swivel-chair between browser tabs all day. A custom Teams app puts the workflow where people already are: a tab that shows the data that matters, a bot that answers and escalates, a message extension that turns a chat message into a tracked request, an Adaptive Card that gets the approval done without leaving the conversation. We build these apps the way Microsoft builds them now: with the Microsoft 365 Agents Toolkit (the successor to Teams Toolkit), Microsoft Entra ID single sign-on, least-privilege Microsoft Graph permissions, and hosting in your own Azure subscription — your data never lands on our infrastructure. Because modern Teams apps share one manifest across Microsoft 365, many of them also surface in Outlook and the Microsoft 365 app, and message extensions can be exposed to Microsoft 365 Copilot as agent plugins — so the app you build for Teams today is a building block for your AI roadmap tomorrow. This isn't theory for us: our own ITP Assistant Teams app is Microsoft 365 App Certified, with the attestation published on Microsoft's site, and our Tenant Optimizer application is listed on Microsoft Marketplace under our own publisher account. We have been through Teams app validation, permissions review, and real-world operations with our own products — and we bring that experience to yours.
Success criteria
What you receive
How the work unfolds
Discovery and scoping — confirm the use case, users, app surfaces, integrations, and success measures; deliver a written estimate against the $175/hour rate before any build hours.
Solution design — tab and card UX, bot conversation design, data flows, Graph permission set, hosting architecture, and the app manifest plan.
Environment setup — Entra ID app registrations, Azure resources in your subscription, a dev/test setup, and deployment scripts.
Build — iterative development with the Microsoft 365 Agents Toolkit, with demo checkpoints against the approved scope so you see progress weekly.
Integration and security review — validate least-privilege scopes, admin consent, secret handling, and data flows before anything reaches production users.
Pilot — deploy to a pilot team through the org catalog, collect feedback, fix and tune.
Rollout and handoff — publish per your Teams app policies (or hand off the AppSource-ready package), deliver documentation and source code, and run the knowledge-transfer session.
Prerequisites
Who does what
IT Partner
- Use-case scoping, written estimate, and solution design.
- App development across the agreed surfaces with the Microsoft 365 Agents Toolkit.
- Entra ID app registrations, single sign-on, and least-privilege Graph permission design.
- Azure hosting configuration in your subscription and deployment automation.
- Functional testing, pilot support, and fixes within the approved scope.
- Publication to your org catalog (or AppSource-ready packaging), documentation, and knowledge transfer.
Your team
- Name a business owner empowered to make scope and design decisions at weekly checkpoints.
- Approve the written estimate, and any re-estimates, before hours are worked.
- Provide tenant and Azure access, and approve admin-consent requests for app registrations.
- Provide access, documentation, and test credentials for systems the app integrates with.
- Run user-acceptance testing with the pilot team and give timely feedback.
- Purchase any required Microsoft licensing (for example Microsoft 365 Copilot for plugin scenarios) and own Azure consumption costs.
- Own internal communication and adoption after rollout unless separately contracted.
What's not included
Limitations & technical notes
Frequently asked questions
What can a custom Microsoft Teams app actually do?
Four main things, in any combination: tabs that embed your data and tools directly in a channel or as a personal app; bots that answer questions, collect input, and escalate to humans; message extensions that turn chat messages into structured, tracked items in your systems; and workflow apps that run approvals and notifications through Adaptive Cards inside the conversation. Typical builds include approval workflows, request intake, dashboards, onboarding assistants, and line-of-business front ends.
Where does the app run besides Teams?
Modern Teams apps are built on a single Microsoft 365 manifest, so many app surfaces — personal tabs and message extensions in particular — can also run in Outlook and the Microsoft 365 app without a separate codebase. We tell you during design which of your app's surfaces can be extended this way at no extra build effort.
Can our Teams app extend Microsoft 365 Copilot?
Yes. Message extensions can be exposed to Microsoft 365 Copilot as plugins, which lets Copilot search and act on your line-of-business data through the app you already built. This requires Microsoft 365 Copilot licensing and tenant enablement, and we scope it explicitly — it is a design decision, not an automatic side effect.
Do our users need extra licenses to use a custom Teams app?
No per-user license is required to use a custom app published to your organization's catalog — any Teams user your admins allow can run it. The costs that do exist are Azure consumption for the app's back end (billed to your subscription) and, only if you want Copilot plugin scenarios, Microsoft 365 Copilot licenses for those users.
Have you built certified Teams apps yourselves?
Yes. Our own ITP Assistant Teams app is Microsoft 365 App Certified, and the attestation — including our security answers — is published on Microsoft's site, not ours. Our Tenant Optimizer application is also listed on Microsoft Marketplace under IT Partner's publisher account. We have been through Microsoft's app validation and operate our own apps in production.
How is the service priced?
Time and materials at $175/hour. You get a written estimate after discovery and before any build hours, and no out-of-scope hours are worked without your written approval. A typical first app — one or two surfaces, one integration — runs from $7,500; the estimate for your specific scope is what governs.
How long does it take?
About 4 weeks for a typical first app, from discovery through pilot and rollout. Apps with several surfaces, multiple integrations, or heavy compliance review take longer — the written estimate states the expected duration for your scope.
Who owns the source code?
You do. We hand off the full source repository, deployment scripts, and documentation at the end of the engagement, and everything runs in your tenant and your Azure subscription. There is nothing of ours you depend on afterward.
How does authentication and security work?
The app signs users in with Microsoft Entra ID single sign-on, so there are no separate accounts or passwords. Data access goes through Microsoft Graph or your APIs using least-privilege, admin-consented permissions that we document for your review. For our own access during the project, we request granular, time-bound admin access that you approve — never standing global admin.
Where does our data live?
In your Microsoft 365 tenant and your Azure subscription. We build and deploy into infrastructure you own; we do not host your app or route your data through our systems.
Should we publish to our org catalog or to AppSource?
For internal workflow apps, the org catalog is almost always right: your admins control who sees the app, and there is no external review cycle. AppSource is for apps you want to distribute outside your organization — we can prepare a store-ready package, but managing the Partner Center listing and Microsoft's certification cycle is a separate engagement, and we will say so up front.
Can the app connect to systems outside Microsoft 365?
Yes — that is one of the most common reasons to build one. The app's back end can call any API your systems expose, so a tab or bot can read and write CRM records, tickets, ERP data, or anything else with an accessible API. We need documentation and test credentials for each system during the project.
Couldn't we build this with Power Apps instead of custom code?
Sometimes, yes — and when a Power Apps or Power Automate solution genuinely fits, we will tell you in discovery, because it is usually cheaper. Custom Teams apps win when you need a polished multi-surface experience, message extensions, deep Graph integration, marketplace distribution, or behavior the low-code platform cannot express. See our custom business apps service for the low-code route.
What happens after launch?
You own the app, the code, and the infrastructure, with documentation to run it. If you want ongoing help, we can arrange support separately — from ad-hoc changes billed at the same hourly rate to our Microsoft Teams Administrator on Demand service — but no ongoing contract is required or assumed.