teams-app-developer

Builds, tests, and deploys Microsoft 365 apps and agents for Teams and Copilot. Includes sub-skills for project creation, local testing, cloud deployment,…

Microsoft 365 Agents Toolkit Skill

Build Microsoft 365 agents and Teams apps using the ATK CLI.

AI Behavior Guidelines

Testing Strategy: Recommend Agents Playground first (faster, no M365 needed). Use Teams workflow only if user explicitly requests it.
Environment Variables: NEVER hardcode secrets or make up placeholder values. Always ask users for real values.
Error Handling: Read error messages carefully. Check env/.env.local, .localConfigs, and atk auth list. Common pitfalls:
- AADSTS7000229 → aadApp/create missing generateServicePrincipal: true in YAML — add it and re-provision
- Missing TENANT_ID in .localConfigs → SDK uses wrong token authority → 401 from Bot Connector
- 401 persists after auth fix → devtunnel URL may be blacklisted — create a fresh tunnel
- See troubleshoot/troubleshoot.md for full diagnostic steps
Long-Running Commands — WAIT for completion:
- atk new, atk provision, atk deploy can take several minutes
- Always wait for completion before running the next step (timeout 120000ms+)
Local Service Startup — Hangs terminal (expected):
- npm run dev, npm start, python app.py, devtunnel host, etc. will hang — the process keeps running indefinitely
- ALWAYS run as a background process (isBackground=true) — NEVER use isBackground=false for these commands
- Do NOT wait for it to "finish" — verify startup by checking output for "listening on port" or tunnel URL
- If errors appear, read logs, diagnose, fix, restart
- Use a NEW terminal to launch Agents Playground or open Teams sideloading URL
Monitor App Logs: Periodically check background terminal output for runtime errors. If the app crashes, read the error, fix the root cause, and restart.
Telemetry Tagging: Before running any atk CLI commands, set the session environment variable so all CLI invocations are tagged as skill-initiated:
```
export ATK_CLI_SKILL=true
```
Run this once at the start of the session. All subsequent atk commands in the same terminal will inherit it.

ATK CLI Setup

atk --version  # Must be > 1.1.5-beta

If ATK is not found or version is too old:

npm i -g @microsoft/m365agentstoolkit-cli@beta

CLI Global Options

Option	Meaning	Recommendation
`-i`	Interactive mode	Always use `-i false` in automation to avoid hanging
`-f`	Project folder	Default to be current directory, used when specifying a custom folder. When scaffolding a new project, this is the parent folder where the project folder will be created under.
`-h`	Command help	Use `atk <command> -h` for quick syntax checks

Sub-Skills

Sub-Skill	When to Use	Reference
create-project	Scaffold new project from template, choose template, `atk new`	create-project/create-project.md
test-playground	Test locally with Agents Playground, `agentsplayground`, quick testing	test-playground/test-playground.md
test-teams	Run on Teams, devtunnel, sideload, Teams testing, test in Copilot	test-teams/test-teams.md
provision-deploy	Provision Azure resources, deploy to cloud, `atk provision`, `atk deploy`	provision-deploy/provision-deploy.md
troubleshoot	Fix errors, 401, port conflicts, YAML errors, stale bots	troubleshoot/troubleshoot.md
slack-to-teams	Migrate Slack bot to Teams, cross-platform bridging, Block Kit to Adaptive Cards	slack-to-teams/SKILL.md

MANDATORY: Before executing any workflow, read the corresponding sub-skill document.

Shared References

manifest-and-yaml.md — Project files, YAML config, env vars, .localConfigs flow
commands.md — ATK CLI commands: package, validate, share, collaborate
templates.md — Complete template catalog with language support
experts/ — 100+ micro-expert files: Teams SDK, Slack SDK, cross-platform bridging, deploy, AI models, security, language conversion
docs/ — Platform comparison guides: UI, messaging, identity, infrastructure, feature gaps

Workflow Chains

Match user intent to the smallest valid workflow.

User Intent	Workflow (read in order)
Build new app from scratch	create-project → test-playground
Test existing project locally	test-playground (recommended) or test-teams
Deploy to Azure	provision-deploy
Fix broken bot	troubleshoot → re-test
Migrate Slack bot to Teams	slack-to-teams

MANDATORY: Before executing any slack-to-teams workflow, read slack-to-teams/SKILL.md first. The sub-skill contains a routed expert system with 100+ micro-expert files for cross-platform bot development.

ATK Project Context Resolution

Resolve config values only when missing. If a value is already known in the session, reuse it.

Step 1: Detect ATK Project

If m365agentstoolkit*.yml exists in the current folder, treat it as an ATK project and parse configuration.

Step 2: Resolve Common Configuration

Resolve variables referenced in m365agentstoolkit*.yml. Common variables: AZURE_OPENAI_API_KEY AZURE_OPENAI_ENDPOINT AZURE_OPENAI_DEPLOYMENT_NAME

Step 3: Collect Missing Values

If required values are missing, ask the user for only the missing ones.

Refer to manifest-and-yaml.md for full config-file details.