Sending Data to Minecraft (Phase 3)

Now comes the action: the event is processed, and now Minecraft has to execute it. How does this communication work?

The Problem: How Do We Tell Minecraft What to Do?

Minecraft is a game on a server. We are a Python program. How do we communicate?

Options:

• ✗ Write directly into the game code? (Too complicated, thousands of lines of code required)
• ✗ Chat messages? (Doesn't work technically)
• ✓ Commands! (This is the solution)

Minecraft has a console where you can enter commands:

/say "Hallo Welt!"
/give @s diamond 5
/function my_namespace:special_event
/tp @a 100 64 200

We just need to run these commands remotely (from outside). That's what RCON is for.

Solution: RCON (Remote Console)

What Is RCON?

RCON = Remote Console – a kind of "remote control" for Minecraft servers.

┌─────────────────────────────┐
│  Our Python program         │
│  "Run /say Thank you!"      │
└──────────────┬──────────────┘
               │ RCON command via network
               ↓
┌──────────────────────────────┐
│  Minecraft server            │
│  Console receives command    │
│  Executes /say               │
│  Result: Chat shows "Thanks!"│
└──────────────────────────────┘

How RCON Works

1. Establish connection

   Program → "I am admin, here is the password"
   Server → Authentication OK, connection open
   

2. Send command

   Program → "/say User XY followed!"
   Server → Command is executed (visible in game)
   

3. Confirmation (optional)

   Server → Short response (usually empty or "ok")
   Program → Command processed
   

[!NOTE] Simplified representation!

The above explanation is simplified for illustration. In reality:

• RCON does not send meaningful replies like "5 players received a message"
• The response is usually empty
• We don't know if anything was actually executed
• We don't know what error occurred if the command fails

This is a limitation of RCON. In practice: we send the command and hope it works.

RCON Uses TCP/IP

RCON uses the TCP/IP protocol – the same Internet protocol used by email, websites, etc.

Our program       Network          Minecraft server
(Port XYZ)  ←------TCP/IP----→  (usually port 25575)

Important details:

• Default behavior: RCON normally connects for each command individually – open connection, send command, close connection.
• The streaming tool: Uses a persistent connection – the connection remains open. But this has to be set up specifically and is not the standard.
• Reliability: RCON is not guaranteed to be reliable. Commands can be lost and connections can drop. This is a known limitation.

[!WARNING] RCON has limitations:

• Not guaranteed reliable (commands may be lost)
• Persistent connections must be implemented manually
• No meaningful error responses
• When a command fails, we often don't know it

The streaming tool handles this through:

• Its own persistent connection management
• Logging and retry mechanisms
• Hoping it works

From Event to Minecraft Command

Example: User sends 5 gifts

1. PHASE 1: Event arrives
   TikTok: "User 'Streamer_Fan_123' sent 5x gifts"
   
   ↓
   
2. PHASE 2: Event is processed
   System: "This is a gift event, 5x"
   Data extracted: User = "Streamer_Fan_123", Quantity = 5
   Placed in queue → Waits for its turn
   
   ↓
   
3. PHASE 3: Command is sent to Minecraft
   System: "Which command should be triggered for 5x gifts?"
   (look up in `actions.mca`)
   
   Command: /say "Thanks to Streamer_Fan_123 for 5x gifts!"
   
   RCON: Send command to Minecraft
   
   ↓
   
4. RESULT: Minecraft executes
   Server: Chat shows "Thanks to Streamer_Fan_123 for 5x gifts!"
   All players see it

The Internal Process: How Commands Are Processed

1. TAKE EVENT FROM QUEUE
   Gift event from Streamer_Fan_123
   
   ↓
   
2. LOOK UP ACTION
   "What should happen when a gift is received?"
   → Check actions.mca file
   → Command: /say "Thanks for the gift!"
   
   ↓
   
3. CHECK RCON CONNECTION
   Password: OK
   Port 25575: Reachable
   Server: Reachable
   
   ↓
   
4. SEND COMMAND
   Command: /say "Thanks for the gift!"
   
   ↓
   
5. HOPE THE COMMAND ARRIVES
   Server: ...
   
   ↓
   
6. LOGGING & COMPLETION
   Log: "Gift event processed, command successful"
   Event is done

Error Scenarios: What Can Go Wrong?

Summary of Phase 3

What happens here:

• Event is taken from the queue
• The matching Minecraft command is determined
• Command is sent to Minecraft via RCON
• Minecraft executes the command
• Commands are processed one after the other (not in parallel)

What does not happen here:

• We do not change the game code (that wouldn't work)
• We do not store events (that is a separate component)
• We do not show anything in the TikTok app (that is not possible)

[!NOTE] RCON is synchronous and blocking. Bottlenecks can occur with many commands per second. That's why some tools use Minecraft functions (.mcfunction) for batch operations. (The streaming tool also does this – we'll talk about it later.)

The Whole System Together

The 3 phases only work together:

Phase 1           Phase 2              Phase 3
RECEIVE      →   PROCESS         →    EXECUTE
  ↓                 ↓                    ↓
TikTokLive       Queue system         RCON commands
  ↓                 ↓                    ↓
Events in        Sort events          Minecraft reacts

If a phase fails:

• No Phase 1 → No events
• No Phase 2 → Commands are incorrect
• No Phase 3 → Minecraft does not respond

[!TIP] If you understand how these 3 phases are connected, you understand the whole system. You will learn the details (exactly how RCON works, how to write commands, etc.) in the next chapters.

Next chapter: Python in this project – Now let's look at how the code implements these 3 phases.