--- [EXPLICIT] name: mcp-creator description: [EXPLICIT] This skill should be used when the user asks to "configure an MCP server", "connect Claude to [EXPLICIT] an external tool", "set up a database MCP", "add an API integration via MCP", or "list MCP [EXPLICIT] servers". Also triggers on mentions of Model Context Protocol, stdio transport, MCP JSON config, [EXPLICIT] or remote tool connections. Use this skill even if the user only wants to check existing MCP [EXPLICIT] configuration — the full setup and validation workflow applies. [EXPLICIT] argument-hint: server-name [transport: stdio|http] [EXPLICIT] model: opus [EXPLICIT] context: fork [EXPLICIT] allowed-tools: Read, Write, Edit, Bash, Glob, Grep [EXPLICIT] --- [EXPLICIT] [EXPLICIT]

MCP Creator [EXPLICIT]

[EXPLICIT] Configure Model Context Protocol servers — the bridge between Claude Code and external tools, databases, APIs. [EXPLICIT] [EXPLICIT]

Assumptions & Limits [EXPLICIT]

[EXPLICIT]

• Assumes the target service exists and is accessible (this skill configures the connection, not the server) [EXPLICIT]
• Limit: stdio servers run as child processes — they consume resources for the session duration [EXPLICIT]
• Limit: SSE transport is deprecated — use HTTP for all new remote connections [EXPLICIT]
• Limit: OAuth flows require browser access; headless environments need pre-configured tokens [EXPLICIT]
• Trade-off: Local scope (default) = private but not shared; project scope = shared but exposes config to git [EXPLICIT] [EXPLICIT]

When NOT to use MCP [EXPLICIT]

[EXPLICIT] | Situation | Better alternative | [EXPLICIT] |---|---| [EXPLICIT] | One-off API call | Bash with curl | [EXPLICIT] | File system operations | Built-in Read/Write/Glob tools | [EXPLICIT] | Git operations | Built-in Bash with git | [EXPLICIT] | Static data reference | CLAUDE.md or skill reference files | [EXPLICIT] [EXPLICIT]

Usage [EXPLICIT]

[EXPLICIT]

/mcp-creator my-database stdio        # local database server [EXPLICIT]
/mcp-creator analytics-api http       # remote API [EXPLICIT]
/mcp-creator project-tools            # interview mode [EXPLICIT]
``` [EXPLICIT]
 [EXPLICIT]
Parse `$1` as server name (kebab-case), `$2` as transport. If missing, ask: [EXPLICIT]
1. What external system? (database, API, file service, custom tool) [EXPLICIT]
2. Local process or remote endpoint? [EXPLICIT]
3. Auth required? (API key, OAuth, none) [EXPLICIT]
 [EXPLICIT]
## Before Creating [EXPLICIT]
 [EXPLICIT]
1. **Check existing**: Run `claude mcp list` to see configured servers [EXPLICIT]
2. **Read project MCP**: `Read .mcp.json` if it exists [EXPLICIT]
3. **Verify no name collision**: Server names must be unique across all scopes [EXPLICIT]
 [EXPLICIT]
## Transport Types [EXPLICIT]
 [EXPLICIT]
### stdio (local processes — most common) [EXPLICIT]
 [EXPLICIT]
```json [EXPLICIT]
{ [EXPLICIT]
  "mcpServers": { [EXPLICIT]
    "{name}": { [EXPLICIT]
      "type": "stdio", [EXPLICIT]
      "command": "node", [EXPLICIT]
      "args": ["./mcp-server/index.js"], [EXPLICIT]
      "env": { [EXPLICIT]
        "DATABASE_URL": "${DATABASE_URL}" [EXPLICIT]
      } [EXPLICIT]
    } [EXPLICIT]
  } [EXPLICIT]
} [EXPLICIT]
``` [EXPLICIT]
 [EXPLICIT]
**When**: Server runs on the same machine. Typical for databases, local tools, custom scripts. [EXPLICIT]
**Lifecycle**: Spawned on first tool use, killed on session end. [EXPLICIT]
 [EXPLICIT]
### HTTP (remote — recommended for cloud) [EXPLICIT]
 [EXPLICIT]
```json [EXPLICIT]
{ [EXPLICIT]
  "mcpServers": { [EXPLICIT]
    "{name}": { [EXPLICIT]
      "type": "http", [EXPLICIT]
      "url": "https://api.example.com/mcp", [EXPLICIT]
      "headers": { [EXPLICIT]
        "Authorization": "Bearer ${API_TOKEN}" [EXPLICIT]
      } [EXPLICIT]
    } [EXPLICIT]
  } [EXPLICIT]
} [EXPLICIT]
``` [EXPLICIT]
 [EXPLICIT]
**When**: Server is a remote endpoint. Stateless, no process management. [EXPLICIT]
 [EXPLICIT]
## Configuration Scopes [EXPLICIT]
 [EXPLICIT]
| Scope | Storage | Precedence | Use When | [EXPLICIT]
|---|---|---|---| [EXPLICIT]
| Local | `~/.claude.json` | Highest | Personal, current project | [EXPLICIT]
| Project | `.mcp.json` (git tracked) | Medium | Team-shared servers | [EXPLICIT]
| User | `~/.claude.json` | Lowest | Personal, all projects | [EXPLICIT]
| Plugin | Plugin's `.mcp.json` | Plugin scope | Bundled with plugin | [EXPLICIT]
 [EXPLICIT]
**Decision logic**: If the whole team needs it → project scope. If only you → local. If across all your projects → user. [EXPLICIT]
 [EXPLICIT]
## Environment Variables [EXPLICIT]
 [EXPLICIT]
Use `${VAR}` in command, args, env, url, headers: [EXPLICIT]
 [EXPLICIT]
```json [EXPLICIT]
{ [EXPLICIT]
  "env": { [EXPLICIT]
    "API_KEY": "${MY_API_KEY}", [EXPLICIT]
    "DB_URL": "${DATABASE_URL:-sqlite:///fallback.db}", [EXPLICIT]
    "HOME_DIR": "${HOME}" [EXPLICIT]
  } [EXPLICIT]
} [EXPLICIT]
``` [EXPLICIT]
 [EXPLICIT]
- `${VAR}` — required, fails if missing [EXPLICIT]
- `${VAR:-default}` — optional with fallback [EXPLICIT]
 [EXPLICIT]
**Security rule**: NEVER hardcode secrets. Always use env vars. [EXPLICIT]
 [EXPLICIT]
## Common Server Patterns [EXPLICIT]
 [EXPLICIT]
### PostgreSQL [EXPLICIT]
```json [EXPLICIT]
{ [EXPLICIT]
  "mcpServers": { [EXPLICIT]
    "postgres": { [EXPLICIT]
      "type": "stdio", [EXPLICIT]
      "command": "npx", [EXPLICIT]
      "args": ["-y", "@modelcontextprotocol/server-postgres", "${DATABASE_URL}"] [EXPLICIT]
    } [EXPLICIT]
  } [EXPLICIT]
} [EXPLICIT]
``` [EXPLICIT]
 [EXPLICIT]
### Filesystem (sandboxed) [EXPLICIT]
```json [EXPLICIT]
{ [EXPLICIT]
  "mcpServers": { [EXPLICIT]
    "files": { [EXPLICIT]
      "type": "stdio", [EXPLICIT]
      "command": "npx", [EXPLICIT]
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "${PROJECT_DATA_DIR}"] [EXPLICIT]
    } [EXPLICIT]
  } [EXPLICIT]
} [EXPLICIT]
``` [EXPLICIT]
 [EXPLICIT]
### Custom API with OAuth [EXPLICIT]
```bash [EXPLICIT]
claude mcp add --transport http my-api https://api.example.com/mcp \ [EXPLICIT]
  --client-id "${CLIENT_ID}" \ [EXPLICIT]
  --client-secret "${CLIENT_SECRET}" \ [EXPLICIT]
  --callback-port 3000 [EXPLICIT]
``` [EXPLICIT]
Then authenticate via `/mcp` in session. [EXPLICIT]
 [EXPLICIT]
### Plugin-bundled server [EXPLICIT]
```json [EXPLICIT]
{ [EXPLICIT]
  "mcpServers": { [EXPLICIT]
    "my-tool": { [EXPLICIT]
      "type": "stdio", [EXPLICIT]
      "command": "node", [EXPLICIT]
      "args": ["${CLAUDE_PLUGIN_ROOT}/servers/tool.js"] [EXPLICIT]
    } [EXPLICIT]
  } [EXPLICIT]
} [EXPLICIT]
``` [EXPLICIT]
 [EXPLICIT]
## CLI Quick Reference [EXPLICIT]
 [EXPLICIT]
```bash [EXPLICIT]
claude mcp add --transport stdio my-db -- node server.js   # Add stdio [EXPLICIT]
claude mcp add --transport http my-api https://url.com      # Add HTTP [EXPLICIT]
claude mcp list                                             # List all
claude mcp remove my-db                                     # Remove

Flag order matters: --transport, --env, --scope BEFORE server name. -- separates name from command/args.

Output Token Limits

Threshold	Behavior
10,000 tokens	Warning logged
25,000 tokens	Default max (truncated)
Custom	MAX_MCP_OUTPUT_TOKENS=50000 env var

MCP Tool Search (auto-discovery)

When MCP tools exceed 10% of context window, Claude auto-enables tool search — loading tool definitions on demand instead of all at once. Control with ENABLE_TOOL_SEARCH: auto (default), true, false. [EXPLICIT]

Edge Cases

• Server crashes mid-session: Claude retries once, then reports error. Add health check in server.
• Port conflict on stdio: Each server gets its own process; ports only conflict if servers bind the same port.
• Large tool output: Exceeding MAX_MCP_OUTPUT_TOKENS silently truncates. Paginate in server if possible.
• Multiple servers, same API: Valid — use for different auth contexts or rate limit isolation.

Validation Gate

• Server name is kebab-case and unique across all scopes
• Transport type is stdio or http (not deprecated sse)
• For stdio: command exists (which {command}) and is executable
• For http: URL is valid format (https preferred)
• All secrets use ${ENV_VAR} syntax, none hardcoded
• Config saved to correct scope (local/project/user)
• Server responds after config: claude mcp list shows it
• Env vars referenced in config are actually set in environment

---

Author: Javier Montaño | Last updated: 2026-03-12