III. How It Works

This integration connects Streamer.bot to Stream Deck using Elgato’s MCP (Multi Control Protocol).

It allows Streamer.bot triggers to execute Stream Deck actions, including plugin actions, by resolving a provided input (actionInput) into a valid MCP action and executing it through Stream Deck’s local server.

Flow Overview

Streamer.bot Trigger
→ actionInput argument
→ Execute C# Method (ExecuteMcpAction)
→ MCP lookup
→ Stream Deck
→ Action executes

What’s Happening

1. Streamer.bot fires a trigger
   This can be any trigger (chat, redeems, voice commands, etc.)

2. actionInput is passed
   You define this in your Streamer.bot action using a Set Argument sub-action.

   This value can be:

   • A button Title
   • A button ID

3. C# method is executed
   The ExecuteMcpAction method receives the actionInput value.

4. Action is resolved
   The integration searches the available MCP actions (from Stream Deck) and tries to match:

   • Title first (if provided)
   • ID as a direct reference

5. MCP request is sent
   Once resolved, a request is sent to Stream Deck via MCP.

6. Stream Deck executes the action
   The corresponding button is triggered — including supported plugin actions.

Action Resolution Logic

The system determines which button to execute using the actionInput.

Resolution Flow

actionInput
↓
Match by Title OR ID
↓
Find MCP Action
↓
Execute via MCP

Where Actions Come From

All executable actions come from Stream Deck’s MCP Actions page.

These are:

• Synced into Streamer.bot as Global Variables (prefixed with [SD])
• Refreshed using the RefreshExecutableActions method

Plugin Support

Because MCP exposes executable actions:

• Plugin actions are treated the same as regular buttons
• This allows Streamer.bot to trigger functionality it does not natively support

Note

Behavior depends on how each plugin supports MCP.

Action List Sync

When you modify your Stream Deck buttons:

• The MCP action list changes
• Streamer.bot must refresh its cached list

This is done via:

RefreshExecutableActions

Without refreshing:

• New buttons may not be available
• Old mappings may become outdated

MCP Action Payload Example

When actions are retrieved from Stream Deck (via RefreshExecutableActions), they follow a structure like this:

{
  "id": "...",
  "title": "...",
  "action": {
    "name": "Play Audio",
    "pluginId": "com.elgato.streamdeck.soundboard"
  }
}

What This Represents

• id → Unique identifier of the button (used for execution)
• title → Display name of the button (used for matching)
• action.name → The action type (e.g., Play Audio)
• action.pluginId → Source plugin of the action

This is the data used to:

• Populate Global Variables ([SD] entries)
• Resolve actionInput into an executable action

Important Notes

• Only actions visible in the MCP Actions page are executable
• actionInput must match a valid Title or ID
• Stream Deck must be running
• MCP must be enabled
• Some actions may depend on plugin or system state

Summary

This integration works by:

• Using Streamer.bot for triggers and logic
• Using Stream Deck (via MCP) as the execution layer
• Resolving a simple input (actionInput) into a real button action

This creates a flexible bridge between both systems, including support for plugin-based workflows.

Need Help?

If something isn’t working as expected:

👉 Troubleshooting