If you set up Claude MCP six months ago and have not touched the config since, three things have changed underneath you: the recommended transport, how tools are loaded into context, and how teams share server configs. None of these are cosmetic. If you ignore them, you are leaving tokens, money, and stability on the table.
This is the working Claude MCP setup I use in May 2026 — what the claude mcp add command actually does, which scope to pick, what the deprecation of SSE means in practice, and where Claude Code still falls short.
The three-scope mental model
Every MCP server you wire into Claude Code lives at exactly one of three scopes. Get this wrong and you will either leak credentials into git or wonder why your teammate cannot use the same database the AI just queried.
- Local (default): the server is available only to you, only inside the current project. Config is written into your project’s entry inside
~/.claude.json. Good for project-specific servers like a dev database or a Sentry project key you do not want other repos to inherit. - User: the server is available to you across every project on your machine. Also stored in
~/.claude.json. This is where GitHub, search providers, and personal productivity servers belong. - Project: the server is written to a
.mcp.jsonfile at the repo root and shared with the whole team via git. Claude Code prompts for approval the first time a teammate opens the project — by design, because anyone who can push to the repo can wire a new server into your environment.
When the same server is defined in more than one scope, Claude Code resolves it in this order: local beats project beats user beats plugin-provided. This is the part that bites people the most. If you have a “github” entry at user scope and someone adds a different “github” entry at project scope in .mcp.json, the project definition wins for that repo. Run claude mcp list when something behaves strangely.
The commands you actually need
The CLI is more useful than the docs make it look. Three commands cover ~90% of real setup work:
# Add a remote HTTP MCP server at user scope (available everywhere)
claude mcp add --transport http hubspot --scope user https://mcp.hubspot.com/anthropic
# Add a local stdio server scoped only to this project
claude mcp add my-db -s local -- node ./scripts/db-mcp.js
# Share a server with your team via the repo's .mcp.json
claude mcp add my-server -s project -- node server.js
The short flag is -s, the long is --scope. The -- separator is required for stdio servers because everything after it is treated as the literal command to spawn. Forget it and Claude Code will try to interpret your Node arguments as its own flags.
SSE is dead. Use Streamable HTTP.
If your MCP server documentation still tells you to use the sse transport, the documentation is stale. The MCP spec dated 2025-03-26 introduced Streamable HTTP and simultaneously deprecated HTTP+SSE. Through 2026, vendor after vendor has set hard cutoff dates — Atlassian’s Rovo MCP server keeps SSE around until June 30, 2026 and then drops it; Keboola pulled SSE on April 1; Cumulocity’s AI Agent Manager flipped to Streamable HTTP on May 8.
Why this matters beyond a name change: SSE required Claude Code to hold a persistent connection to a single server replica, which broke horizontal scaling and made every transient network blip a reconnection drama. Streamable HTTP is stateless. Multiple replicas behind a load balancer just work. If you have flaky MCP connections in production, the first thing to check is whether the server is still on SSE.
For new setups, use --transport http. The older --transport sse still functions but is on the deprecation path.
Tool Search is the feature you should actually care about
The single biggest change in how Claude Code uses MCP in 2026 is lazy tool loading via Tool Search. Older MCP clients dumped every tool schema from every connected server into the model’s context window at the start of every conversation. With ten servers wired up that could easily be 20,000+ tokens of overhead before you typed a single character.
Tool Search inverts this. Claude Code keeps only the server names and short descriptions resident. When a tool is actually needed, it fetches that tool’s full schema on demand. Anthropic’s own documentation says this reduces tool-definition context usage by roughly 95% versus eager-loading clients. In practice that means you can run a serious MCP fleet — GitHub, Sentry, a database, a search provider, your internal API — without quietly burning through your context budget. The Sonnet 4.6 and Opus 4.7 1M-token context window does not save you here, because anything you let crowd the prompt is also being re-read on every turn.
Companion feature: list_changed notifications. An MCP server can now tell Claude Code “my tool list changed” and Claude Code refreshes capabilities without a disconnect-reconnect dance. If you build your own server, emit this when you swap tool definitions and you save users a restart.
What it still gets wrong
Honest take: claude mcp list still does not surface scope information for every entry in a useful way — there is an open issue on the anthropics/claude-code repo asking for it (#8288 if you want to track). Project-scoped servers from .mcp.json have a separate history of not appearing in the list output (#5963) depending on how you opened the project. If you cannot find a server, check both ~/.claude.json and ./.mcp.json directly.
The other rough edge is the project-approval prompt. The first time you open a repo with a new .mcp.json, Claude Code asks you to approve each project-scoped server. That is the right security default. It is also infuriating in CI or any non-interactive shell, where the prompt blocks the session. The current workaround is to bake the servers in at user scope on build agents so the project-scope approval never fires in CI. A cleaner non-interactive approval flow is the single most-requested fix I see in real teams.
The setup I would run on a new machine today
User-scope: GitHub, a code search server, and a single notes/Notion server. Project-scope in each repo’s .mcp.json: whatever database the project owns and whatever observability backend it reports to. Local-scope: anything experimental I am evaluating but do not want my team or my other repos to inherit.
Pin --transport http on everything remote. Skip Desktop Extensions (.dxt) for anything you want versioned with the codebase — they are a Claude Desktop convenience, not a Claude Code primitive, and they hide the config from your team. Run claude mcp list when something is off and read .mcp.json directly when list is unhelpful.
That is the whole working model. The pieces that matter — three scopes, Streamable HTTP, Tool Search — fit on a single screen. The pieces that have not caught up yet — list output, non-interactive approvals — are visible in the issue tracker and will move.
