Armory

The Protocol Gateway that aggregates multiple tool sources and exposes them through a unified MCP interface, with built-in protocol translation and token optimization.

Why "Armory"?

Just as a forge creates tools and an armory stores them, the Armory is where you go to access all your tools. It aggregates tools from various sources and provides them through a single, consistent interface.

The OpenRouter Analogy

Armory is to MCP servers what OpenRouter is to LLMs — one unified interface to many backends.

Aspect	OpenRouter	Armory
Aggregates	LLM providers	MCP servers & tool sources
Protocol	OpenAI-compatible API	MCP (Streamable HTTP)
Client sees	One API, many models	One endpoint, many tools

Architecture

Hybrid Gateway Pattern

Armory exposes multiple MCP endpoints, giving clients flexibility:

Endpoints:

• /mcp → Aggregated (all tools with prefixes)
• /mcp/weather → Direct access to weather server
• /mcp/search → Direct access to search server
• /.well-known/mcp.json → Discovery metadata

Why hybrid? Clients wanting simplicity connect to /mcp (one connection, all tools). Clients wanting isolation connect to /mcp/{server} (specific server only).

Key Features

Unified MCP Interface

Orchestrators connect to the Armory as a single MCP server. They don't need to know about the various backends - they just see a collection of tools.

Protocol Translation

The Armory translates between different protocol formats automatically:

Result Transformation (JSON → TOON)

Tool results are automatically converted to TOON format for token efficiency. Send Accept: text/toon header to enable.

Before (JSON):

[{"name": "John", "email": "john@x.com", "status": "active"},
 {"name": "Jane", "email": "jane@x.com", "status": "pending"}]

After (TOON):

@users [2] {name|email|status}
John | john@x.com | active
Jane | jane@x.com | pending

~40% fewer tokens, and LLMs actually understand TOON better than JSON (73.9% accuracy vs 69.7% in benchmarks).

Transport: Streamable HTTP

The Armory uses MCP's Streamable HTTP transport (not the deprecated SSE transport):

Transport	Status	Use Case
stdio	Active	Local subprocess
HTTP+SSE	Deprecated	Legacy remote
Streamable HTTP	Current	Remote (single endpoint)

Benefits of Streamable HTTP:

• Single endpoint - /mcp handles everything
• Resumable streams - Last-Event-ID header
• Session management - Mcp-Session-Id header
• Infrastructure friendly - Works with proxies, load balancers

Protocol Adapters

Adapter	Backend Type	Translation
MCPAdapter	MCP Servers	Mostly passthrough
RESTAdapter	REST APIs	HTTP methods, auth headers
OpenAIFCAdapter	OpenAI FC services	OpenAI function format
LocalAdapter	Python functions	Direct invocation

MCP Server Strategy

Don't reinvent the wheel. Use existing MCP servers where available, build custom only when needed.

Category	Servers	Notes
Use Existing	Brave Search, GitHub (remote), fetch, filesystem, time	Well-tested, maintained by others
Build Custom	weather (Open-Meteo), uptime checker, notes	FastMCP + Python, learn the patterns

Free APIs for Custom Servers

• Open-Meteo — Weather data, no API key required (open-meteo.com)
• Brave Search — 2,000 queries/month free (brave.com/search/api)

Configuration

# armory.yaml
server:
  host: "0.0.0.0"
  port: 8000
  transport: "streamable_http"

tool_rag:
  enabled: true
  embedding_model: "text-embedding-3-small"
  similarity_threshold: 0.5

result_transformer:
  toon_enabled: true

sources:
  # Existing MCP servers (npm packages)
  - type: mcp
    name: "brave-search"
    command: "npx"
    args: ["-y", "@modelcontextprotocol/server-brave-search"]
    env:
      BRAVE_API_KEY: "${BRAVE_API_KEY}"

  - type: mcp
    name: "filesystem"
    command: "npx"
    args: ["-y", "@modelcontextprotocol/server-filesystem", "/allowed/path"]

  # Remote MCP servers (hosted by provider)
  - type: mcp
    name: "github"
    url: "https://api.github.com/mcp"
    auth: oauth

  # Custom MCP servers (FastMCP)
  - type: mcp
    name: "weather"
    command: "python"
    args: ["-m", "forge_mcp_servers.weather"]

  - type: mcp
    name: "notes"
    command: "python"
    args: ["-m", "forge_mcp_servers.notes"]

Benefits

Problem	Solution
Multiple tool sources	Single MCP interface
Different protocols	Protocol adapters translate
JSON wastes tokens	TOON transformation
Too many tools in context	Tool RAG filters dynamically
Managing MCP servers	Centralized configuration