What is MCP?
Model Context Protocol (MCP) is a framework that allows external systems to pass structured, real-time information to large language models (LLMs) like GPT during each interaction. It bridges the gap between stateless systems such as REST APIs or command-line tools and the varying contextual needs of modern applications. By supplying this additional context, MCP enables the model to produce more accurate, relevant, and consistent responses. At a technical level, MCP works by attaching a structured JSON payload to the user’s prompt at runtime. This payload carries background details such as the user’s identity, recent actions, task-specific instructions, or relevant domain knowledge. This is referred to as runtime context — data that helps the model understand the situation in which it is being used, without needing to ask for that information in the prompt itself. While invisible in the model’s final response, this context directly influences how the model interprets the prompt and generates output.What is the Siren MCP server?
When it comes to Siren, the Model Context Protocol (MCP) Server serves as the integration layer that enables LLM-powered environments to interact with the Siren platform using standardized function calls. It acts as a communication bridge, allowing language models to trigger messaging workflows and retrieve delivery insights in real time.
Rather than manually composing HTTP requests or managing channel-specific logic, AI agents can call predefined functions like messaging.send
, users.add
, or workflows.schedule
. These are optimized for channels including Email, Slack, SMS, WhatsApp, and others, making it easy to embed messaging actions into intelligent, event-driven workflows.
By abstracting the messaging infrastructure behind clean, callable interfaces, the Siren MCP Server allows developers to build smarter, more responsive AI agents that can operate autonomously across user-facing communication channels.
Available Tools in the Siren MCP Server
The Siren MCP server provides a suite of standardized tools that LLM agents can call during runtime. These tools enable seamless integration with Siren’s messaging, template, user, workflow, and webhook infrastructure.Messaging Tools
Tool | Description |
---|---|
messaging.send | Send a message to a recipient via a chosen channel |
messaging.getStatus | Get the status of a sent message |
messaging.getReplies | Get replies to a sent message |
Template Management Tools
Tool | Description |
---|---|
templates.list | List available message templates |
templates.create | Create a new message template |
templates.update | Update an existing message template |
templates.delete | Delete a message template |
templates.publish | Publish a template for use |
User Management Tools
Tool | Description |
---|---|
users.add | Add a new user to the system |
users.update | Update an existing user |
users.delete | Delete a user |
Workflow Tools
Tool | Description |
---|---|
workflows.trigger | Trigger a workflow execution |
workflows.triggerBulk | Trigger multiple workflow executions |
workflows.schedule | Schedule a workflow for future execution |
Webhook Configuration Tools
Tool | Description |
---|---|
webhooks.configureNotification | Configure notification webhooks |
webhooks.configureInbound | Configure inbound webhooks |
Tool Categories
To simplify configuration, Siren MCP supports tool categories — predefined groups of related tools that can be referenced using a single flag.Category Mappings
Category | Included Tools | Usage Example |
---|---|---|
communication | messaging.send , messaging.getStatus , messaging.getReplies | --tools=communication |
content | templates.list , templates.create , templates.update , templates.delete , templates.publish | --tools=content |
identity | users.add , users.update , users.delete | --tools=identity |
automation | workflows.trigger , workflows.triggerBulk , workflows.schedule | --tools=automation |
integration | webhooks.configureNotification , webhooks.configureInbound | --tools=integration |
You can also combine multiple categories or individual tools in a single command: |
Getting Started with Siren MCP Server Integrations
To get started with the Siren MCP server, you’ll need an API key to authenticate your access. If you’ve already signed up, you may have received this key during onboarding. Otherwise, you can generate one from the Siren Dashboard underSettings > Configuration > API Keys
.
Once you have the API key, you can configure the Siren MCP server within any AI application that supports the Model Context Protocol (MCP). While we’ve included integration examples for tools like Clause, VS Code, and CLI-based agents, the same approach applies to any MCP-compatible environment.
Learn more about generating and managing API keys →
Add the following to your Or if you are using Docker:
claude_desktop_config.json
. See Claude MCP documentation for more details.Configuration Options
Command Line Arguments
Argument | Description | Default | Example |
---|---|---|---|
--tools | Comma-separated list of tools to enable | none | --tools=messaging.send,templates.list |
--api-key | Your Siren API key | none | --api-key=sk_siren_... |
--workspace | Siren workspace ID | Default workspace | --workspace=ws_abc123 |
--port | Port for HTTP server mode | 3000 | --port=8080 |
--debug | Enable debug logging | false | --debug |
API Key Format
Siren supports multiple API key formats:Format | Description | Use Case |
---|---|---|
sk_siren_... | Standard Siren API key | General purpose |
sk_test_... | Test environment key | Development and testing |
sk_live_... | Production environment key | Production systems |
Workspace Configuration
If you are working with multiple Siren workspaces, specify the workspace ID:Environment Variables
You can set environment variables instead of passing API keys as arguments:Debugging
Debug Mode
Enable verbose logging with the--debug
flag:
Using MCP Inspector
The MCP Inspector provides a visual interface for debugging your MCP server.1
First, build the server:
2
Run with the MCP Inspector:
3
Open the inspector in your browser at `http://localhost:6274`
Open the URL in your web browser to access the debugging interface.
Docker Debugging
For Docker-based debugging:1
Build the Docker image:
2
Run with MCP Inspector:
Health Check
- Verify your configuration with a simple health check:
- If the server starts successfully, you will see:
- You can also check the version:
Troubleshooting
Some of the common issues and solutions are stated below.Invalid API Key
Invalid API Key
Possible Causes
- Incorrect format
- Expired key
- Key not set properly Solutions
- Ensure key starts with
sk_siren_
,sk_test_
, orsk_live_
- Check your environment variables or CLI argument
- Generate a new API key from the Siren dashboard if needed
Tool Not Found
Tool Not Found
Possible Causes
- Typo in tool name
- Tool not enabled
- Outdated MCP package Solutions
- Verify tool name (case-sensitive)
- Add the tool to the
--tools
list in the command - Update to the latest MCP version
Connection Issues
Connection Issues
Possible Causes
- Network problems
- Firewall blocking
- API endpoint down Solutions
- Check your internet connection
- Configure firewall exceptions for outbound calls
- Verify Siren API availability at status.trysiren.io
Permission Denied
Permission Denied
Possible Causes
- Insufficient API key permissions
- Workspace-specific access restrictions Solutions
- Ensure your API key has required scopes
- Check your workspace access level
- Contact Siren Support if the issue persists
Rate Limiting
Rate Limiting
Possible Causes
- Too many requests in a short time
- Plan quota exceeded Solutions
- Implement retry logic or request throttling
- Upgrade your Siren plan if you are consistently hitting limits