Getting started

fold sits between MCP clients and any number of upstream MCP servers. This walkthrough federates two servers behind one endpoint.

1. Build the gateway

   git clone https://github.com/fold-run/fold.git && cd fold
   pnpm install && pnpm build

2. Describe your upstreams

   fold.config.json

   {
     "upstreams": [
       {
         "id": "github-tools",
         "url": "https://mcp.platform.acme.com/mcp",
         "namespace": "gh",
         "owner": { "org": "acme-platform", "team": "devex" }
       },
       {
         "id": "ml-search",
         "url": "https://mcp.ml.acquired-co.com/mcp",
         "namespace": "search",
         "owner": { "org": "acquired-co", "team": "ml" }
       }
     ]
   }

   A single upstream without a namespace runs in zero-copy passthrough mode. Multiple upstreams require namespaces; tools surface as {namespace}__{name}.

3. Run it

   Node.js

   8080/mcp

   node apps/gateway-node/dist/index.mjs --config fold.config.json --port 8080

   Docker

   docker build -f apps/gateway-node/Dockerfile -t fold-gateway .
   docker run -p 8080:8080 \
     -v $PWD/fold.config.json:/app/fold.config.json fold-gateway

   Cloudflare Workers

   cd apps/gateway-workers
   # put the config JSON in the FOLD_CONFIG var (wrangler.jsonc or a secret)
   npx wrangler deploy

4. Point a client at it

   Any MCP client — 2026-07-28 stateless or 2025-era stateful — connects to /mcp and sees one virtual server named fold with every team’s tools:

   gh__create_pr        (acme-platform / devex)
   gh__get_issue
   search__query        (acquired-co / ml)

5. Turn on governance

   Add auth, policy, and audit blocks when you’re ready to require tokens, scope tools per team, and stream audit events — then walk the production checklist.