teams-app-developer

The saved excerpt is a snapshot from when this skill was listed. The external source remains the complete and most current version.

---
name: teams-app-developer
description: "Builds, tests, and deploys Microsoft 365 apps and agents for Teams and Copilot. Includes sub-skills for project creation, local testing, cloud deployment, troubleshooting, and Slack-to-Teams migration. USE FOR: Teams agent, bot, tab, message extension, Declarative Agents, Custom Engine Agents, local testing, Agents Playground, Azure resource provision, remote deployment, Slack to Teams migration, cross-platform bot development, Block Kit to Adaptive Cards conversion. DO NOT USE FOR: general web development, non-bot/non-Teams projects."
---

# Microsoft 365 Agents Toolkit Skill

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

## AI Behavior Guidelines

1. **Testing Strategy:** Recommend Agents Playground first (faster, no M365 needed). Use Teams workflow only if user explicitly requests it.

2. **Environment Variables:** NEVER hardcode secrets or make up placeholder values. Always ask users for real values.

3. **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](troubleshoot/troubleshoot.md) for full diagnostic steps

4. **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+)

5. **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

6. **Monitor App Logs:** Periodically check background terminal output for runtime errors. If the app crashes, read the error, fix the root cause, and restart.

7. **Telemetry Tagging:** Before running any `atk` CLI commands, set the session environment variable so all CLI invocations are tagged as skill-initiated:
   ```bash
   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

```bash
atk --version  # Must be > 1.1.5-beta
```

If ATK is not found or version is too old:

```bash
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