Hosted platform apps

Explainer for hosted-gateway-mcp, registry-mcp-server, hosted-loops, and registry-loop — roles, stacks, and how they connect.

Hosted platform apps

These four apps/ services are proprietary, monorepo-hosted surfaces in the Better Data stack. They sit next to — but are not the same as — the OSS packages published from Commerce Gateway and Loop Engine.

For gateway-console and a focused comparison of Registry MCP vs hosted commerce MCP, see MCP surfaces first. This page adds the Loop Engine pair (hosted-loops, registry-loop) and places all four on one map.

At a glance

	hosted-gateway-mcp	registry-mcp-server	hosted-loops	registry-loop
Role	Multi-tenant MCP HTTP endpoint for commerce tool execution (gated by capability set)	Deployed Registry MCP — discovery tools (@shop, merchants, GTIN) over streamable HTTP	Hosted Loop Engine — owns the loops database; loop instances, transitions, events, JWT API	Loop Registry — catalogs published loop definitions and versioned manifests (integrity, stability)
Protocol plane	Commerce execution (MCP)	Registry discovery (MCP)	Loop runtime (HTTP + DB)	Loop catalog (HTTP + DB)
Typical caller	Hosted tenants / agents with org-scoped keys	Remote MCP clients (IDEs, hosted AI) calling the public registry MCP URL	SCM, admin, and internal services emitting or advancing loops	Runtimes and tooling resolving which definition version to run
Local dev stack	Node http server; default PORT 8081	Next.js; pnpm dev → port 3015, POST /mcp	Next.js; port 3012 (apps/hosted-loops/package.json)	Next.js; port 3011 (apps/registry-loop/package.json)
Core packages	@commercegateway/commerce-gateway (/mcp, /capabilities)	@commercegateway/registry-mcp + MCP SDK	@loop-engine/*, @betterdata/database-loops, @loop-engine/events, @loop-engine/definitions	@loop-engine/core, Prisma (MySQL catalog)

One line each

• hosted-gateway-mcp — Serves tenant-scoped commerce MCP tools built from @commercegateway/commerce-gateway; org resolution and tooling are still evolving (e.g. demo-key stub paths in source). Not registry discovery.

• registry-mcp-server — The hosted Registry MCP app: same discovery story as the OSS @commercegateway/registry-mcp package, delivered as a deployable Next.js route. Operators wire REGISTRY_URL / keys per deploy notes (e.g. apps/registry-mcp-server/DEPLOY.md in the monorepo).

• hosted-loops — The service boundary for governed workflows: starts, transitions, cancellations, and audit-loop events for tenant workloads; external callers use signed JWTs and must not write the loops DB except through this API. Aligns with Hosted Loop Engine and Loops product narrative.

• registry-loop — Catalog only: stores loop IDs, semver-style versions, JSON definitions, manifests, and integrity metadata (see registry_loops / registry_loop_versions in Prisma). Consumed when a runtime needs a pinned, published definition — distinct from executing an instance in hosted-loops.

How the four fit together

registry-mcp-server          hosted-gateway-mcp
   (discover @shop)    →        (execute commerce tools)
         │                              │
         └──────── Commerce Agent / SCM / agents ────────┘
                                │
                    registry-loop          hosted-loops
              (published definitions)   (running instances + audit)

• Discovery vs execution (MCP): registry-mcp-server answers “which gateway / merchant?”; hosted-gateway-mcp answers “run the tool session for this tenant.” Same split as in MCP surfaces.

• Catalog vs runtime (loops): registry-loop is the definition store (what shipped, which version, integrity). hosted-loops is the runtime plane (state, guards, evidence, events). Product-level context: Loops.

HTTP surface (hosted-gateway-mcp)

From apps/hosted-gateway-mcp/src/index.ts (monorepo truth):

Method / path	Purpose
GET /	Minimal HTML landing (links /health, documents /tools/list)
GET /health	JSON { "status": "ok" }
GET /tools/list?org=	Tool list filtered by getMCPToolDefinitions; auth via Bearer demo-key / x-api-key: demo-key or org slug branch (see source)

Implementation detail pending verification: mapping from demo-key to production org resolution / non-demo keys.

Monorepo paths

App	Path (bd-forge-main)
hosted-gateway-mcp	apps/hosted-gateway-mcp/
registry-mcp-server	apps/registry-mcp-server/
hosted-loops	apps/hosted-loops/
registry-loop	apps/registry-loop/

Related

• SCM workspace (apps/scm) — tenant CCO app; SCM vs DCM split and billing
• MCP surfaces — gateway-console, Registry MCP, hosted gateway MCP (canonical MCP comparison)
• Commerce Agent pattern (C9) — discover → execute → govern
• Loops — governed workflows and hosted runtime overview
• MCP Tool Reference