What is MCP and why should we care?
Model Context Protocol (MCP) is a standard introduced by Anthropic in late 2024 for exposing tools, data, and prompts to LLM clients. Think 'REST for AI tools.' Write the server once, and every MCP-compatible client (Claude Desktop, Cursor, Windsurf, ChatGPT Desktop, Zed, OpenAI Responses API, Gemini experimental) can call it. For teams where 'which AI client our people use' is a moving target, MCP is the bet that stops you locking into one vendor.
Which MCP clients support OAuth today?
Claude Desktop, Cursor, and ChatGPT Desktop support OAuth 2.0 + PKCE for MCP servers as of Q1 2026. Windsurf and smaller editor clients typically use API-key bearer tokens. We default to API keys (compatible everywhere) and deploy OAuth when tools expose sensitive per-user data (mailbox access, per-user billing). Enterprise OAuth with SSO is a Q2 2026 roadmap item most clients are tracking.
How does this compare to Claude's native tool use?
Claude's native tool use is locked to Claude. OpenAI Assistants tools are locked to OpenAI. MCP is portable — one server, every client. If you're sure you'll only ever use one AI client, the vendor-specific path is simpler and sometimes faster. If your team expects to switch clients or use multiple, MCP is the right bet. We map that trade-off explicitly on the Day-1 scoping call.
Transport choice — stdio, HTTP, or SSE?
stdio: best for desktop-local tools the user already has installed (file system access, local git, local commands). HTTP: best for server-hosted production tools (query your Postgres, write to your CRM, call your internal API). SSE: best when a tool streams partial results (long-running searches, batch operations with progress). We pick on the scoping call based on client mix and tool latency profile.
Do we need one MCP server per domain or one big server?
One MCP server per tool domain is the clean pattern. E.g., one server for 'customer data' (query, update, export), one for 'deploy / ops' (deploy, rollback, status), one for 'billing' (invoice, refund). Each owns its auth scope, deploys independently, and can be versioned separately. MCP clients connect to multiple servers at once, so there's no drawback to splitting. A monster server with 50 tools is harder to reason about and harder to secure.
What does the typical engagement look like?
MCP Server Build ($5,999 / 2 weeks) is the most common — one MCP server exposing 3–8 tools from your stack, with auth, rate limits, audit logging, and a runbook. For multi-server or enterprise OAuth work, we scope a custom engagement on Day 1. For teams migrating existing Claude tool-use code to MCP, the build is often closer to 10 days.