What is mcp-registry CLAUDE.md?

A reference guide for mcp-registry, a system that stores MCP server settings and connects multiple servers so their tools can be used together. It explains the registry, connection handling, tool aggregation, and command-line interface.

Use it when changing server registration, persistent connections, aggregated tool calls, filtering, or the registry’s command-line commands.

It helps a coding agent understand how servers are configured, connected, filtered, and exposed through one combined interface.

How changjonathanc/mcp-registry configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to changjonathanc/mcp-registry. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/changjonathanc/mcp-registry/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/changjonathanc/mcp-registry

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/changjonathanc/mcp-registry/claude-md.svg)](https://agentmods.dev/instructions/changjonathanc/mcp-registry/claude-md)

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<a href="https://agentmods.dev/instructions/changjonathanc/mcp-registry/claude-md"><img src="https://agentmods.dev/badge/instructions/changjonathanc/mcp-registry/claude-md.svg" alt="Measured on agentmods" height="20"></a>

Per session 1,298 This file is loaded in full into every session.

When invoked 1,298 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.01298	$0.01298
Opus 5	$0.00649	$0.00649
Sonnet 5	$0.00260	$0.00260
Haiku 4.5	$0.00130	$0.00130

Measured 8d ago against content hash 99cf93286756, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

mcp-registry CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

CLAUDE.md · 157 lines

How it starts

The opening of the file, as written. The whole thing — 157 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Claude's Reference Guide for MCP Registry

Core Architecture

MCP Registry: Manages MCP servers, provides CLI tools, and aggregates server tools
Server configuration: Stored in ~/.config/mcp_registry/mcp_registry_config.json (configurable via MCP_REGISTRY_CONFIG)

Key Components

ServerRegistry (compound.py)
- Loads/saves server configurations from JSON
- Maps server names to MCPServerSettings objects
- Creates client sessions for connecting to servers
- Supports filtering to create subsets with filter_servers()
MCPAggregator (compound.py)
- Namespaces tools as server_name__tool_name
- Supports temporary and persistent connections
- Handles tool listing and calling across servers
- Implements the list_tools() and call_tool() methods
- Key entrypoint for programmatic tool calls
- Supports tool-level filtering with tool_filter parameter
MCPConnectionManager (connection.py)
- Handles concurrent persistent connections
- Uses async context managers for proper lifecycle
- More efficient for multiple tool calls
CLI Commands (cli.py, commands/*.py)
- init: Create config file and import Claude Desktop settings
- add/remove/list: Manage server configurations
- serve: Run compound server with all/selected servers
- list-tools: Display tools from servers with 3 verbosity levels
- test-tool: Test tools interactively or programmatically

Core Files

src/mcp_registry/compound.py: Server registry, settings, and aggregator
src/mcp_registry/connection.py: Persistent connection management
src/mcp_registry/cli.py: Main CLI entrypoint
src/mcp_registry/commands/tools.py: Tool-related commands (list-tools, test-tool)
src/mcp_registry/commands/serve.py: Server command
src/mcp_registry/utils/config.py: Configuration utilities
src/mcp_registry/utils/cli.py: CLI decorators and helpers

Important Code Patterns

Read the full file on GitHub · 157 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

8d ago First seen · 157 lines · 1,298 tokens per session scan A 99cf93286756

Subscribe to this mod's changes

mcp-registry CLAUDE.md is an instructions file published in the GitHub repository changjonathanc/mcp-registry (5 stars, last pushed 1y ago), licensed Apache-2.0. It adds 1,298 tokens to every session, about $0.0065 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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mcp-registry: Instructions file for Claude Code