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title: Lesson 1 weight: 10 draft: true

TO BE REVIEWED!

📘 Lesson 1 – Integrated Services & First Exercise

Welcome! After launching and configuring your environment, ensure you're logged in to begin.

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📥 Downloading the Lesson

1. In the extension, select Lesson 1 from the sidebar.
2. This will automatically download all lesson files.
3. You can preview the new lesson by selecting the markdown file under lessons/.

✅ Lesson 0 was the environment setup. Lesson 1 is the first real lesson of the course.

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🧰 Included “Hello” Examples

The hello package includes small examples demonstrating system services:

Service	Description
Redis	Cache operations (info, keys, etc.)
Milvus	Vector DB search using embedding
Streamer	ASCII-based output streaming
LLM (Alma)	Query small language model
S3 Storage	Store, list, upload & delete files
Tests	2 failing tests to practice debugging

These examples are useful for testing, debugging, and learning the system APIs.

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✅ Running and Fixing Tests

1. Run the tests (🧪 Tests tab).
2. Two tests intentionally fail.
3. Locate the TODO in the broken test.
4. Example fix: change "Hi" to "Hello" and save.

Why Tests Still Fail After Fix?

• ✅ Unit test will pass immediately.
• ❌ Integration test will still fail — it requires deployment!

Fix Integration Tests

# Deploy the fixed code
obs deploy

# Or just redeploy the specific action
obs ide deploy hello-llm

Enable Dev Mode (Devil) for automatic deploy on save.

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🌐 Using the Deployed Examples

After deployment, you’ll get a custom URL. Login with your user credentials.

Example Services Overview

1. 🤖 Alma (LLM)

• Powered by a 3.18B parameter model
• Works in Italian and English
• Example:
  • Ask: What is the capital of Italy?
  • Response: Rome

2. 🔄 Streamer

• Demonstrates streaming via slow ASCII output
• Example: Hi, how are you? → streamed char-by-char

3. ⚡ Redis

• Supports CLI-like interaction
• Examples:

  info
  keys *
  

4. 🗂️ Object Storage (MinIO)

• S3-compatible local storage
• Commands: list, insert (+ key = value), search, delete
• Supports file upload via UI

5. 📚 Vector DB (Milvus)

• Supports semantic search
• Example:

  This is a test
  Another test
  

  Then search: *test → shows ranked results by similarity

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🔧 Command-Line Tools (OBS CLI)

Use obs or oops for CLI actions. Common subcommands:

obs ai lesson            # download lessons
obs ai user              # manage users
obs ai chat <svc>        # chat with an LLM from CLI
obs ide deploy <action>  # deploy a single action
obs action delete <svc>  # delete an action
obs clean                # cleanup temp files

obs ai chat is a terminal version of the web chat.

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✨ Creating a New Service: Reverse Text

Step-by-step: “Reverse Text” Chat App

1. Ask Alma: “How do I reverse a string in Python?”
2. Create the service:

obs ai new reverse -p messiah

This creates:

packages/
  messiah/
    reverse/      # your new action
    __tests__/
      reverse.unit.test.py
      reverse.int.test.py

3. Run the tests → Integration test should fail initially
4. Deploy:

obs deploy

5. Add to UI:
   • Edit packages/mastrogpt/index/index.py
   • Add:

     reverse("messiah/reverse")
     

6. Redeploy the index:

obs ide deploy mastrogpt-index

7. Try it in the web UI:
   Log in → Select Reverse → Input: hello → Output: olleh

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🧠 Edit Logic in Code

File: packages/messiah/reverse/main.py

def main(args):
    inp = args.get("input", "")
    if inp == "":
        return {"output": "Please provide an input"}
    else:
        out = inp[::-1]
        return {"output": f"**{out}**"}  # bold markdown

Use Dev Mode to auto-deploy as you edit.

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✅ Summary

You now:

• Downloaded your first real lesson
• Ran & fixed tests (unit + integration)
• Explored system services: Redis, Alma, MinIO, Milvus, Streamer
• Built and deployed a custom chat service
• Learned how to modify and extend the UI

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🧑‍🏫 Up Next

Next lessons will:

• Dive deeper into LLM usage
• Cover vision models and embeddings
• Show full-stack app development using Open Serverless

Happy hacking! 🧪🤖