Portkey MCP gateway: per-user tool allowlists for Sume write tools

An MCP gateway sits between your agents and the servers they call. Portkey's version proxies authentication, access control and logging, per the Portkey MCP gateway page, read 2026-10-03. Clients connect at https://mcp.portkey.ai/{server-slug}/mcp. For a team using Sume's hosted MCP server, the useful part is the page's statement that tools can be enabled or disabled per user.

Two layers of control

Sume enforces its own gates: idempotency_key is required on paid and write tools, and under OAuth the mcp:read scope gives read-only tools while mcp:write is opt-in. The Sume OAuth page says a write or paid tool under mcp:read returns insufficient_scope. A gateway adds a second layer that applies before the request reaches Sume.

A sensible split

Give most users the read tools: listing assets, checking jobs_result, reading balance_get. Enable the create tools for a small group that owns generation. The gateway page also lists guardrails and approval workflows; it does not detail them, so check Portkey's docs for how an approval would interrupt a paid call before you rely on it.

Remember that logs contain parameters and responses. A Sume create call carries prompts and an idempotency key, and results can contain asset URLs. Decide who may read the gateway logs the same way you decide who may call the tool.

What the gateway cannot do for you

Treat the gateway as access control and audit, and keep spend control where the job is created. A user allowed to call generate_video should still send a preview first and a cap with the real call.

• It cannot make a retried create safe; only the idempotency_key does that.
• It cannot cancel a job that has started generating; Sume returns 409 job_generation_already_started on late cancels.
• It does not replace max_spend_usd or a cost preview.