Gateway MCP Pattern
Tool-access architecture where the agent sees one small MCP router while backend service schemas are loaded or invoked lazily. It preserves structured MCP-style outputs without injecting every service’s full tool catalog into every prompt.
Key points
- In [src-041], the Nexus-Dev gateway exposes a single routing tool with about 20 tokens of fixed schema overhead.
- The gateway has slightly higher per-operation cost than Native MCP because each call includes a routing envelope, but the fixed cost remains tiny even as backend services grow [src-041].
- For a 20-prompt session with two GitHub operations, the article estimates the gateway at 892 tokens versus 61,654 for Native GitHub MCP [src-041].
- Gateway MCP is recommended for services used regularly but not constantly, roughly the 15-40 percent G/N band, and can also compete with on-demand skills in the 5-15 percent band [src-041].
- The pattern is especially useful for general-purpose coding agents that may need many external services, but only a few in any single session [src-041].
Related entities
Related concepts
- Model Context Protocol (MCP)
- Tool Schema Tax
- G/N Ratio Tool Selection
- MCP vs CLI Token Trade-off
- Agent Orchestration
Source references
- [src-041] Marco Mornati — “The Future of Agentic Tooling: MCP Servers vs. CLI A Data-Driven Comparison” (2026-04-27)