MCP Center

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Connect any MCP server to your DeepSeek Harness — point, click, done. MCP Center is a settings-driven MCP server manager. Register servers (Streamable HTTP or local stdio processes) on the dedicated Settings → MCP Center page; save and they connect immediately, their tools becoming first-class, model-callable tools in every session.

Why use it

• No code, no config files — everything happens in the Settings UI.
• Both MCP server types supported:
  • Streamable HTTP — remote MCP endpoints, with optional auth (none / static Bearer token / custom headers).
  • stdio — local processes (npx, uvx, python, …).
• Tools are instantly usable — each connected server's tools appear as mcp__<name>__<tool> and can be called by the model in all sessions.
• Zero-dependency install — the client transport is implemented in the plugin itself (no external MCP SDK), so the plugin adds no peer-dependency chain to your profile.
• Per-server on/off — disable a server to unregister its tools and drop the connection; the config is kept.

Requirements

• DeepSeek Harness with the web profile
• Node.js ^22.19 or >=24

Quick start

1. Install the plugin

The package is published on npm as dsh-mcp-center:

# install from the npm registry
dsh plugin --profile web add dsh-mcp-center

Prefer installing from source? See Development.

2. Restart and open the settings page

Restart dsh web, open Settings → MCP Center, and click ＋ Add MCP server:

• Streamable HTTP: name (the mcp__<name>__* prefix), URL, and auth mode (none / Bearer token / custom headers).
• stdio: name, command (e.g. npx), args (space-separated; quote args containing spaces), optional env (JSON object) and working directory.

3. Save — and it's connected

The server connects as soon as you save. Status badges show Connected (N tools) / Connecting / Error / Disabled. Per server you can enable/disable, delete, and (for Bearer servers) re-token.

The model can use it right away

Tools from connected servers are first-class to the model. For a server named web:

mcp__web__ping    mcp__web__shout

Tool results are rendered as native text; isError results surface through the registry's error path.

The plugin depends only on @deepseek-ai/cordis (peer) and React (client half). No MCP SDK, no settings-service coupling, no fallback-tree resolution of MCP peer packages.

Configuration storage

Server configs live in ~/.dsh/mcp-center.json:

{
  "servers": [
    { "id": "…", "name": "web", "type": "http", "url": "http://localhost:3000/mcp", "authMode": "none" },
    { "id": "…", "name": "fs", "type": "stdio", "command": "npx", "args": ["-y", "@modelcontextprotocol/server-filesystem", "/tmp"] }
  ]
}

⚠️ Bearer tokens are stored here in plain text — treat this file as a secret.

How it works

Piece	Mechanism
Settings page	settings.section slot entry (MCP Center tab)
API	Same-origin JSON under /mcp-center/api/* (ping, servers CRUD, connect, enabled)
HTTP transport	Streamable HTTP: JSON-RPC over POST, Mcp-Session-Id, JSON or SSE responses (each SSE frame is parsed separately, so one stream may carry several messages)
stdio transport	child_process.spawn a local command, JSON-RPC over stdin/stdout (newline-delimited); reconnect reaps the old process first
Tool schema	Server JSON Schemas sanitized to the registry's supported raw subset (unsupported vocabulary degrades to unconstrained)
State	~/.dsh/mcp-center.json, written atomically with owner-only permissions

Current limitations

• Only tools are bridged; resources and prompts MCP capabilities are not.
• Bearer tokens and custom auth headers live in the state file under ~/.dsh, in plain text under owner-only permissions — treat it as a secret.
• A config that exists but cannot be parsed fails the plugin load instead of starting with no servers, because the next save would otherwise overwrite that file and lose every stored server.
• Request bodies are capped at 1 MiB (answered as 413) and one stdio server's undecoded stdout at 4 MiB; exceeding the latter fails that server's pending calls and stops its process.
• stdio servers run as long-lived child processes tied to the plugin lifecycle; args are whitespace-tokenized (quotes protect args with spaces) with no shell expansion — write absolute paths or env vars yourself for ~, $VAR, pipes, etc.
• No automatic reconnect after a crash in this version; re-enable or restart the server to reconnect.

Development

pnpm install
pnpm build      # tsdown: lib/index.js (node) + lib/client.js (browser)
pnpm typecheck