Enterprise LLM Gateway Comparison: How to Evaluate One
Reviewed October 2026
An enterprise LLM gateway sits between your applications, agents and the models they call. It checks who is calling, applies policy and spend limits, routes the request, and keeps a record of what happened. Gateways differ less in what they claim than in who runs them, where they run, who holds the provider keys, and where the record ends up. This page sets out the criteria that separate them, grouped by the four common approaches, so you can compare any option on the same terms.
What an Enterprise LLM Gateway Does
A gateway gives every model call one path to cross. On that path it does four things: it establishes identity (which person, team or agent is calling, with which rights), it applies policy (which models and tools are allowed, with which limits and guardrails), it controls spend (request, token and dollar limits), and it keeps a record (caller, model, tokens, cost and the policy decision). Most gateways also route between providers and retry on failure.
- Identity: who is calling, with which rights
- Policy: approved models and tools, limits and guardrails
- Spend: request, token and dollar limits by team, project or agent
- Record: caller, model, tokens, cost and the policy decision for each call
- Routing: one endpoint in front of several model providers
Key Evaluation Criteria
Compare options on the questions a risk or audit team will ask, not only on features. Start with the constraint you cannot relax, whether that is where the gateway may run, who may hold the keys, or where the record must live, and rule out options that fail it before you compare anything else.
- Who runs it: install, patching, upgrades and incidents, 24×7
- Where it runs: shared service, dedicated single-tenant instance, your own cloud account, or air-gapped
- Who holds the keys: your provider accounts and keys, or the vendor's
- Model choice: any model on your accounts, or the vendor's supported list
- Tools: whether MCP tool calls and business APIs pass through the same policy
- The record: what is captured, whether content capture is optional, and whether it lands in storage you own
- Developer impact: OpenAI-compatible, Anthropic-compatible or MCP endpoints so SDKs keep working
Four Common Approaches
Most options fall into one of four categories. This is a comparison of approaches, not a claim about any named product, and any given product may span more than one.
- Hosted AI gateways: a vendor-run shared service. Fast to start; your traffic and logs pass through the vendor's service.
- Cloud AI gateways: services from a cloud provider. Close to that cloud's models; tied to its supported list and console.
- Open source, self-run: full control of deployment; your team installs, runs, upgrades and secures it, and assembles the record.
- Managed, dedicated: a single-tenant gateway run for you, on your keys, with the record written to your storage.
How to Choose
Regulated institutions usually find the deciding questions are about control rather than features: whether the gateway can run inside the boundary they require, whether they keep their own provider keys, and whether the record of every call lands in storage they own. Write those requirements down first, test each option against them on one real traffic path, and keep the comparison dated, because gateway products change quickly.
- Name the boundary the gateway must run inside, including air-gapped if required
- Require your own provider accounts and keys; agents should never hold them
- Require the record in your storage and telemetry to your collector
- Test one real traffic path before you commit
- Date your comparison and re-check it each quarter
Where Reign Gateway Fits
Reign Gateway is one governed path to the models your teams use. It checks identity on every request, applies your policy and spend limits, and records each model call and each MCP tool call sent through it, in storage you own. Agents never hold the provider keys. It runs single-tenant, on Reign Dedicated or in your own AWS or Azure account. Air-gapped and sovereign deployment are supported. Reign runs, patches and upgrades it 24×7.
See Reign Gateway on one traffic path
Reign Gateway applies identity, policy and spend limits to the AI traffic sent through it and records each call in storage you own.