Use Claude Code to Scaffold a Small MCP Server Before You Connect It

Advanced builder lesson. MCP servers can connect an assistant to tools and data, but the first useful milestone is not automation. It is a small server you can inspect.

This guide uses Claude Code’s official MCP documentation to outline a fictional read-only server for a team asset catalog. The setup is documentation-based. The server was not scaffolded or executed here, and the example does not claim a working connection.

What you will make

You will make a local project plan and a scaffold for a server with one narrow job: look up a fictional asset by ID and return its title and review status. You will not connect a production system, add credentials, or create a write-capable tool.

Prerequisites

You need:

Claude Code available in a terminal, IDE, desktop app, or browser surface. The official overview says access requirements vary by surface and account.
A disposable project directory with no production credentials.
Permission to install the official mcp-server-dev plugin in your Claude Code environment.
A technical reviewer who can inspect the generated code.

Anthropic’s MCP reference says Claude Code can connect to external tools and data sources. It also says to verify that you trust a server because external content can carry prompt injection risk.

Fictional task map

Create asset-catalog-task.txt with this content:

Server name: asset-catalog-read
Purpose: look up one approved asset record for an internal review
Input: asset ID such as DEMO-ASSET-17
Output: asset ID, title, review status
Data source: fictional local JSON file for the prototype
Allowed action: read one record
Forbidden actions: create, edit, delete, list all records, call the network, read environment secrets
Acceptance check: a known asset ID returns the matching title and review status; an unknown ID returns a clear not-found message
Reviewer: Priya Shah

This map is the boundary. If the generated server does more than it says, stop and review it.

1. Install the official build plugin

Open Claude Code in the disposable project and use the documented plugin command:

/plugin install mcp-server-dev@claude-plugins-official

If Claude Code reports that the marketplace is missing, follow the official marketplace instruction rather than installing a similarly named package from an arbitrary source. If the install reports a reload requirement, complete that reload before continuing.

2. Ask for a bounded scaffold

Run the documented build skill:

/mcp-server-dev:build-mcp-server

When Claude Code asks about the use case, paste this request:

Scaffold a local MCP server called asset-catalog-read for the attached fictional task map.

Requirements:
- Expose one read-only tool named get_asset.
- Accept one asset_id string.
- Read only the fictional local JSON fixture.
- Return asset_id, title, and review_status.
- Return a clear not-found response for an unknown ID.
- Do not add network calls, credentials, environment-secret access, create tools, update tools, delete tools, or list-all tools.
- Include a small fixture and tests for one known ID and one unknown ID.
- Explain every generated file before asking to run anything.
- Do not install dependencies or execute commands until I approve the file list.

The expected artifact is a proposed file list, interface description, fixture, and tests. It is illustrative, not a recorded scaffold output.

3. Review the files before running them

Ask Claude Code to show:

Review the proposed scaffold against asset-catalog-task.txt.

Return a table with:
- file path
- purpose
- reads or writes performed
- external calls
- secrets or environment variables used
- test that covers the file

Stop if any file can write data, call the network, read secrets, or expose a broader tool than get_asset.
Do not run the server.

The acceptance table should show no external calls, no secrets, and no write actions. If any value is unknown, mark it unknown and send it to Priya Shah for review.

4. Test the boundary on fixture data

After the reviewer approves the file list, ask Claude Code to run only the local tests:

Run the tests against the fictional fixture only.

Confirm:
1. DEMO-ASSET-17 returns the exact fixture title and review status.
2. UNKNOWN-999 returns a not-found response.
3. No test writes to the fixture.
4. No network request is made.
5. The server exposes no create, update, delete, or list-all tool.

Show the test commands and output. Do not connect an external account or start a production service.

A real test result would need to be recorded before calling this a reproduced demo. This article makes no such claim.

No-code alternative

If you only need to inspect the catalog once, keep asset-catalog-task.txt and the fixture in a folder, then ask a normal chat tool to explain one approved record. You will give up the reusable tool, but you also avoid installing a server while the task is still being evaluated.

Troubleshooting

The plugin is not found: use the official marketplace path and verify the exact plugin name before retrying.
The scaffold includes write tools: stop, remove the write requirement from the task map, and ask for a fresh review. Do not rely on a prompt to constrain a tool that is already write-capable.
The server wants credentials: the fictional prototype does not need them. Stop and review the dependency and data flow.
The tests touch the network: treat that as a failed boundary check. Replace the dependency with the local fixture or stop the exercise.
The server starts but the tool is unclear: classify the tool as unknown and ask the reviewer to inspect its handler and inputs.

Limits and safe use

A scaffold is not a trusted integration. Review generated code, dependencies, permissions, data retention, and every tool exposed by the server. Keep the first task local and read-only. Only a technical owner should approve a move from fixture data to an external system.

TRY this with a disposable folder and fictional data. SKIP production credentials and write actions during the first pass. USE the server only after the file review, tests, and scope checks pass.

Evidence label

Documentation-based guide with a fictional task map and illustrative artifacts. The plugin, scaffold, tests, and server connection were not executed here.

Sources

For a no-code starting point, use ChatGPT Work to keep a multi-step task from drifting.