Claude Desktop: Enable Developer Mode for Local Tools
Developer mode in Claude Desktop unlocks the ability to connect local MCP servers. Here is when you need it, how to enable it and how to record the team-approved tool-use rules so every session starts from the same policy.
Updated 5 min read
Claude Desktop requires developer mode to be enabled before you can add local MCP servers. Without it, the MCP config file is not read and tool connections are unavailable. Enabling it is a one-time setting, not something you toggle per session.
Once local tools are connected, fenbs can store the team's tool-use rules and approved connection procedures, so every assistant session starts from the same agreed policy rather than from a blank prompt.
What developer mode does in Claude Desktop
Developer mode enables the MCP (Model Context Protocol) integration layer. With it on, Claude Desktop reads the config file at startup, connects to the listed MCP servers and makes their tools available in the conversation. With it off, the config file is ignored even if it exists and is correctly formatted.
The term "developer mode" does not change how Claude reasons or what it will say. It is a feature-access gate, not a safety switch. Enabling it on a personal machine carries no risk beyond those introduced by the specific MCP servers you connect.
When you need developer mode
You need developer mode any time you want to connect a local tool to Claude Desktop: a file-system server, a database client, a local API server or a custom integration you built. Remote connectors that Claude Desktop supports natively do not require developer mode.
If you are following a tutorial for an MCP integration and the connection does not appear in the app, check developer mode before assuming the config file has an error. Many connection issues trace back to this setting being off rather than a misconfigured server.
How to enable developer mode
Open Claude Desktop and go to Settings. Developer mode is a toggle in the settings panel; its exact label may shift between app versions, so check for anything related to "developer" or "MCP" if it is not immediately visible.
After enabling it, restart Claude Desktop. Then add your first MCP server entry to the config file and restart again. The server should appear in the connected tools list after the second restart. The MCP config guide explains the config file structure in detail.
If you see an error about a server failing to start, the issue is usually the server command path or a missing dependency, not developer mode itself. The MCP not working guide covers those startup errors.
Check the logs if the server silently fails. Claude Desktop logs its startup messages in a platform-specific location. On Windows, look in %APPDATA%\Claude\logs\. On macOS, check ~/Library/Logs/Claude/. The log will usually name the server and the first error it encountered on startup.
A common startup error is a missing runtime. If the server is a Node.js script and Node.js is not in the path that Claude Desktop uses when spawning processes, the server command will fail immediately. Test by running the server command in a terminal first; if it runs there, the same command should work in the config.
What happens if you disable it later
If you turn developer mode off after adding MCP servers, the servers become unavailable in new sessions. The config file is not deleted; it is simply not read. Re-enabling developer mode and restarting the app restores the connections.
This means you can temporarily disable tool access without losing your configuration, which is useful if you share a machine and want to run a session without the local tools active.
Team considerations
On a shared machine or in a team environment, decide which MCP servers are approved before anyone enables developer mode. An MCP server with write access to a shared file store or database should go through a review before you connect it. Developer mode plus a permissive MCP server gives the AI session write access to anything that server can reach.
Write down the approved servers, their permission scope and any servers that are not approved. Keeping that list in a shared project record means a new team member or a future session does not have to ask what is permitted. It also creates an audit trail: if a connection causes a problem, you can trace which session added it and who approved it.
The review process does not need to be elaborate. A simple rule works well: any new MCP server goes into a shared decision as pending, is reviewed by whoever is responsible for tool access, and moves to approved before anyone connects it. That one-step gate prevents ad hoc connections that are forgotten and never audited.
Record the approved connection procedure
In fenbs, write the team's MCP connection policy as a standing decision: which servers are approved, which permissions each needs, and what review is required before adding a new one. Every connected assistant reads those decisions at the start of a session, so the policy does not depend on who is in the room when a new tool is proposed.
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How to do this with fenbs
- Create a free account and set up your project in fenbs.
- Enable developer mode in Claude Desktop settings and restart the app.
- Add your first MCP server to the config file following the MCP config guide. Connect fenbs from Integrations.
- In fenbs, record each approved MCP server as a decision: the server name, what it can access and who approved it.
- Before adding a new MCP server in future, check the Decisions list. If it is not already approved, add an open decision for the team to review before connecting it.
fenbs does not manage Claude Desktop settings. It keeps the policy decisions that govern which tools the team connects.