LLM gateways and routers
Nobody sets out to build one of these. What happens is that four teams ship four applications over eighteen months, each with its own API key pasted into its own secret store, two of them on one vendor and two on another. Then a finance director asks what the AI spend was last quarter and which team it belonged to. The answer is four invoices from three vendors, none of which knows anything about teams.
MCP gateways
Start with a team that has done everything right. Twelve MCP servers, all useful: the issue tracker, the wiki, two databases, the deployment tool, a log search, a few more. Every developer has them configured locally. Which means every developer holds a token for the issue tracker, a token for the wiki, a read credential for each database, and a deploy credential, on a laptop, in a JSON file, rotated whenever somebody remembers.