The mesh-mongodb container goes with its Dockerfile, build bases and bus credential. Its client shelled out to mongosh, which no machine's system carries, so it now speaks to the server through the official mongodb driver its package.json names, inlined into the bundle by the builder (ADR 0198 §4); the tools answer exactly as before (relaxed Extended JSON). The server is reached on loopback at the port the machine published (${port:27017}). The root secret was owned by the mongo image's user (secrets-owner 999:999), which the runtime's account cannot read; the module's own copy is now the runtime's, and the server is given its own 999-owned copy rendered from the same secret.